International Conference TOWARDS the BEST PRACTICE of RIVER

International Conference

TOWARDS THE BEST PRACTICE OF RIVER RESTORATION AND MAINTENANCE

20th - 23 rd September 2016 Kraków, Poland

BOOK OF ABSTRACTS FIELD TRIP GUIDE International Conference

TOWARDS THE BEST PRACTICE OF RIVER RESTORATION AND MAINTENANCE

20th - 23rd September 2016 Kraków, Poland

BOOK OF ABSTRACTS

FIELD TRIP GUIDE

Edited by Joanna Zawiejska and Bartłomiej Wyżga

KRAKÓW 2016 Conference supported by a grant from Switzerland through The Swiss Contribution to the enlarged European Union

ISBN 978-83-945968-1-1 CONFERENCE ORGANIZERS

Ab Ovo Association

Institute of Water Engineering and Water Management, Cracow University of Technology

Institute of Nature Conservation, Polish Academy of Sciences

Institute of Geography, Pedagogical University of Cracow

University of Agriculture in Kraków

Regional Water Management Board in Kraków SCIENTIFIC COMMITTEE David Gilvear, University of Plymouth, UNITED KINGDOM Jan Hradecký, University of Ostrava, CZECH REPUBLIC Józef Jeleński, Ab Ovo Association, POLAND Jukka Jormola, Finnish Environment Institute, FINLAND Anna Lenar-Matyas, Cracow University of Technology, POLAND Grażyna Mazurkiewicz-Boroń, Polish Academy of Sciences, POLAND Elżbieta Nachlik, Cracow University of Technology, POLAND Tomasz Okruszko, Warsaw University of Life Sciences, POLAND Hervé Piégay, CNRS & University of Lyon, FRANCE Artur Radecki-Pawlik, University of Agriculture in Kraków, POLAND Massimo Rinaldi, Università di Firenze, ITALY Virginia Ruiz-Villanueva, University of Bern, SWITZERLAND Bartłomiej Wyżga, Polish Academy of Sciences, POLAND Joanna Zawiejska, Pedagogical University of Cracow, POLAND Jan Żelazo, Warsaw University of Life Sciences, POLAND

CONFERENCE CHAIRS Józef Jeleński, Ab Ovo Association, Poland

Elżbieta Nachlik, Institute of Engineering and Water Management, Cracow University of Technology

Artur Radecki-Pawlik, Department of Hydraulics Engineering and Geotechnique, University of Agriculture in Kraków

Bartłomiej Wyżga, Institute of Nature Conservation, Polish Academy of Sciences

Joanna Zawiejska, Institute of Geography, Pedagogical University of Cracow TUESDAY 20 SEPTEMBER 12.00-19.00 REGISTRATION Pre-conference trip: Wieliczka Salt Mine WORKSHOP (1) 9.30-12.30 National strategies for monitoring and success evaluation in river rehabilitation ROOM D WORKSHOP (2) 14.15-17.15 National strategies for monitoring and success evaluation in river rehabilitation ROOM D ICEBREAKER, Interfaculty Centre of Education and Research ‘Działownia’, 17.30-20.00 Cracow University of Technology, ul. Warszawska 24 WEDNESDAY 21 SEPTEMBER 8.00-9.00 REGISTRATION 9.00-9.30 OPENING SESSION – WELCOME ADDRESS ROOM A 9.30-10.30 PLENARY SESSION 1 ROOM A 10.30-11.00 COFFEE BREAK MAIN HALL THEMATIC SESSIONS 1, 5 & 9 ROOM A ROOM B ROOM C River status evaluation: 11.00-12.30 Flood hazard and risk management European and regional hydromorphology, water quality, in the context of environmental perspectives on river ecological status (I) needs restoration and management PL/EN 12.30- 14.00 LUNCH MAIN HALL 14.00 -14.30 POSTER SESSION 1 14.30 -15.30 PLENARY SESSION 2 ROOM A THEMATIC SESSIONS 1, 3 & 4 ROOM A ROOM B ROOM C River status evaluation: 15.30 -17.00 Technical interventions in river hydromorphology, water quality, Modelling fluvial processes restoration and environmentally- ecological status (II) and practical solutions oriented maintenance PL/EN 17.00-17.45 POSTER SESSIONS 4 & 8 MAIN HALL 19.45 –23.00 CONFERENCE DINNER – STARA ZAJEZDNIA KRAKÓW by DeSilva, ul. Św. Wawrzyńca 12 THURSDAY 22 SEPTEMBER 9.00-10.00 PLENARY SESSION 3 10.00-10.30 COFFEE BREAK THEMATIC SESSIONS 2, 6 & 7 ROOM A ROOM B ROOM C 10.30 -12.20 Legal and social factors in river Restoration or preservation of Functioning of mountain restoration and river management valuable nature areas and elements gravel-bed rivers PL/EN in river corridors 12.20-12.45 POSTER SESSION 6 MAIN HALL 12.45-14.00 LUNCH 14.00-15.00 PLENARY SESSION 4 THEMATIC SESSIONS 1, 3 & 6 ROOM A ROOM B ROOM C River status evaluation: Technical interventions 15.00-16.50 Restoration or preservation of hydromorphology, water quality, in river restoration and valuable nature areas and ecological status (III) environmentally-oriented elements in river corridors PL/EN maintenance 16.50-17.30 POSTER SESSIONS 2, 3 & 7; REFRESHMENTS MAIN HALL 17.30-18.15 CLOSING SESSION ROOM A FRIDAY 23 SEPTEMBER 8.00-18.00 TECHNICAL FIELD TRIP 8.00-20.00 FIELD TRIP TO THE TATRA MOUNTAINS REGION A B S T R A C T S 7

P L E N A R Y L E C T U R E S

Heavily modified river ecosystems: what is at stake and how can we repair Tom Buijse Deltares, Department of Freshwater Ecology and Water Quality, Utrecht, The Netherlands

The assessment of the 1st River Basin Management Plans indicated that 40% of European rivers are affected by hydromorphological (HYMO) pressures caused predominantly by hydropower, navigation, agriculture, flood protection and urban development. It is insufficiently known what the ecological side effects of these modifications in hydrology and morphology are and to which extend the side effects can be effectively reversed or mitigated. Against this background, the international project REFORM (REstoring rivers FOR effective catchment Manage- ment, http://reformrivers.eu/; EC FP7 Grant 282656) addressed the challenges to reach the hydromorphological and ecological objectives for rivers as required by the European Water Framework Directive (www.reformrivers.eu). The presentation will present the following key outputs to support a better link between water policy, restoration practice and river science and will conclude with further challenges. l Hydromorphological assessment should consider physical processes and appropriate temporal and spatial aspects beyond river restoration project boundaries and project life span. l Vegetation and plants can play a cost-effective and significant role as physical ecosystem engineers for river restoration. Riparian and floodplain ecosystems are not subject to extensive monitoring but are crucial to river morphodynamics and ecology. l Current biological sampling methods are not appropriate to capture HYMO impacts and they underestimate the influence of HYMO on biota. There is a need to develop new biota sampling methods that are more sensitive to HYMO impacts. Hydromorphological assessment covering the entire range from high to bad should be a quality element in its own right in the WFD status assessment. l Restoration projects should adopt a synergistic approach with other resource users to secure win-win scenarios and have well-defined quantitative success criteria. l Application of existing planning and management tools can substantially enhance the efficiency and effectiveness of restoration. l Restoration had positive effects even in small restoration projects. It increases ecosystem services and benefits, not only aquatic biota. Hydromorphological restoration has an overall positive effect on biota, but effects vary. It is thus essential to monitor and adjust restoration projects.

River self-restoration Angela Gurnell School of Geography, Queen Mary University of London, United Kingdom

Where direct human interventions are small, the character of river channels reflects an interaction among river flow, sediment dynamics and vegetation. Although not always feasible, river restoration approaches that accommodate and use such interactions are most likely to generate outcomes that are morphologically sustainable, ecologically effective and require relatively little maintenance. This paper considers these interactions and how they might contribute to river self-restoration in different human and hydrogeomorphological settings. In particular, it considers the importance of the colonization, growth performance, form and strength of both aquatic and riparian plants for driving the development of river channel morphology and for the construction, reinforcement and turnover of physical habitats within the river channel and margins. 8 plenary lectures

Fluvial Systems, Ecosystem Services and River Restoration David Gilvear University of Plymouth, England

Fluvial systems within Europe have undergone major modifications from the 17th century onwards. These modifications were undertaken to provide an ecosystem service such as water power, navigation, floodplain agriculture. With the advancement of river science and an understanding of the impact of these past modifications on the fluvial system there is increasingly realisation as to the ecosystem services that have been negatively impacted. This led to the development of river restoration in the 20th century. A challenge for the 21st century is to better understand how river restoration can enhance levels of ecosystem services across the full range and to better understand how trade-offs between services can be made. Although ecosystem service science is fairly well developed in terrestrial environments, application to fluvial systems is still in its infancy. In particular, fluxes through the river network from supply areas to benefits areas and the temporal dynamics of rivers present challenges. This paper will explore these broad issues and present recent work and developments in the field. Sound river ecosystem services science can provide a framework to move river restoration forward over forthcoming decades.

River restoration and environmental river engineering – how to combine the needs in management of rivers and rehabilitation of ecosystems? Jukka Jormola Finnish Environment Institute (SYKE), Helsinki, Finland

Modifications of river systems for flood control, drainage, navigation and hydropower have led to weakening of ecosystems and their traditional uses, like fishing and recreation, all over the world. Dynamics in hydrology and morphology are typical for most natural watercourses, but safety and land use along rivers has needed taming of rivers. Engineering normally has meant straightening, stabilization of banks, construction of embankments against floods and dams for reservoirs and power plants. Dams have changed many rivers more to chains of lacustrine habitats. Because of the interest for renewable energy, the future of many pristine river systems in developing countries does not seem much more promising. In Europe, where the river systems have already been heavily impacted since centuries, have ongoing procedures for restoration of rivers through the implementation of the Water Framework Directive. There are good examples of new life emerging in degraded rivers after restoration measures. In many river systems there is still interest for traditional use of rivers. According to the latest EU programs, also the viability of rivers and multiple ecosystem services should be considered in water management. Environmental river engineering is an approach to combine the interests of river maintenance for different uses and at the same time safeguard or restore natural features of rivers. In cases where big modifications have been done or are necessary, compensative measures can be done to minimize the harm for ecosystems. New approaches for traditional engineering have been developed. For the natural discharge regimes, which may extend through climate change, rivers need space to spread out during flood seasons but the channels must also fit for dry seasons. The “Room for Rivers”-idea at the Rhine, where flood embankments are removed farther from riversides, is good example of a new thinking. If space is arranged for rivers, natural erosion and sedimentation processes can be allowed instead of channel stabilization. Bank protection can be restricted for special sections and natural materials like vegetation can be used for erosion control. At the river Isar, the restored floodplain with gravel bars is highly appreciated by residents of Munich city for bathing in summertime. In small rivers and brooks the idea of flood terraces can be applied as two-stage profile. Instead of excavating a large and straight channel for big discharges, the natural narrow low-flow channel is preserved and flood terraces are excavated. The low flow channel can contain deeper pools on dry seasons with minimum flow, enabling valuable fish stocks to survive. Nature-like drainage methods are promoted in the subsidy system for agriculture in Finland. Dams are a big problem for connectivity of rivers, especially for migrative fish. A movement for removal of dams with no or little value for usage is ongoing in many countries. The demand of defining environmental flows plenary lectures 9 is one reason to re-think the profitability of water use in small rivers. An evaluation of the ecosystem services of rapids with small hydropower plants can lead to a decision of stopping power generation, taking into account the responsibilities of safety and dam maintenance costs. Cultural heritage can be considered by leaving some structures or modifying dams for fish migration. If dams are still necessary for water use like power generation, fish passes should normally be required. Nature-like bypass channels with permanent environmental flow year round can also contain habitats for reproduction. Such compensative habitats are required for permitting in the legislation of many countries. In Europe there is a good policy basis to consider ecological values of rivers. Legislation about requirements and use of methods for implementing them may vary in different countries. Networking and spreading out knowledge of good cases and approaches is needed to inspire new kind of engineering, restoring and preventing degradation of rivers.

Between hate and love – a few issues on the role of rivers in wetlands restoration Tomasz Okruszko University of Life Sciences in Warsaw, Faculty of Civil and Environmental Engineering, Warszawa, Poland

For many years wetlands have been subjected to intensive human pressures. Agriculture development, river navigation and the increasing presence of urban areas resulted in elimination of many wetlands in the world, especially in Europe. Nowadays, there is no doubt about the need of wetlands conservation. Wetlands protection is necessary not only due to biodiversity concerns but also because of their functions in the hydrological cycle. In many cases wetlands restoration is seen as an option for biodiversity protection and enhancing the ecosystem services they can provide for the society. In order to avoid use of confusing number of terms and names, for purposes of this work, wetlands were divided into four categories based on the occurrence/absence of peat accumulation and major hydrological characteristics. Wetlands where peat has been or is being accumulated are called mires. Depending on the main source of water, mires can be divided into bogs and fens. In case when the area of peat accumulation is being drained for agricultural, farming, peat extraction or any other purposes, it is called peatland. Riparian wetlands are divided into two categories: marshes and swamps. Wetlands where peat does not arise are called marshes. Swamps are the wetlands where it is not a rule that peat will be formed. They are characterized by very long inundation period during each year. The role of wetlands in the hydrological cycle depends largely on their location in the river basin and their source of water. Mires located in the headwaters of river basins tend to be fed directly by precipitation and/or groundwater outflow. Wetlands in downstream locations have an additional input of river water, whilst those on a coast will also be subject to the impact of marine water. Thus, the nature of interactions between wetlands and the water cycle is very wide and complex and varies between individual wetland types. The interactions between wetlands, rivers (or channels) and groundwater determine possible restoration measures. In the groundwater-fed systems, we tend to close or diminish the outflow of water from the mires discon- necting both systems and reducing the flows in the open waters. There is no unequivocal evidence for impact of decreasing drainage efficiency of mires on downstream water regime of the river system. The old channels which are draining wetlands or small rivers which were subjected to engineering works aimed to increase their drainage efficiency become a new habitat for surface water biota. Closing or diminishing flows may impact their ecological quality. In riparian wetlands, we are going to increase their connectivity restoring the flood pulse using hydromorphological and/or hydrological measures. There is a strong opinion that floodplain restoration will enhance the ecological quality of the river system by enlarging volume of water stored in the system as well as (re)creation of new habitats. The only concern, with limited evidence, is related to biochemical reactions in restored wetlands which may temporarily impact the water quality of the watercourses. Former swamps bring more unknowns due to their high organic carbon content. And as usual in restoration activities, the constrains come from the human impact on hydrological cycle. A number of rivers which are crucial for wetlands restoration should further serve as waterways, water recipient from drained areas or water supply ways. These functions either increase drainage or limit the provision of water to the restored wetlands. 10 plenary lectures

From geomorphic diagnosis to river restoration and management: critical steps and perspectives Hervé Piégay University of Lyon, Environnement - Ville - Société Laboratory; CNRS-UMR 5600, Lyon, France

This contribution introduces a framework within which geomorphology can be applied, and provides examples of geomorphic approaches to problems in river management and restoration. Fluvial geomorphology can be useful to practitioners notably to understand natural hazards, to regulate some activities having effects on channel forms, to implement ecological conservation or restoration programs through insights into the physical functioning of ecosystems and constraints posed by human alterations. It is essential to establish a diagnosis of the state of the river, understand the causes of the management problem and their potential consequences. Applied fluvial geomorphology is now called on to evaluate the river system’s function, sensitivity to change, and its potential for humans usually based on a set of questions such as “How does the river work?”, “Why do we have such problems?” and “Where the river is going?”, “Can we improve existing conditions?”, and “Are policies efficient?”. We can distinguish a local (bottom-up) strategy, at the scale of the local river basin or reach concerned (the management unit), and a regional (top-down) strategy that priorities actions and monitors their efficiency (such as the hydrographic districts within which the European Water Framework Directive is implemented). The approach is designed to nest in a quasi-hierarchical fashion, collapsing from the catchment (strategic) overview of physical habitat resource, down to the project level design and assessment. The geomorphological assessment must be undertaken within a clear conceptual framework designed to identify the geomorphic principles relevant to management requirements. Furthermore, it is also vital in most applications to interface and transfer knowledge with other relevant disciplines, with GIS often serving as a useful platform. A few examples are given to illustrate the approach in preventing bank erosion, or evaluating risks of restoring processes following sediment reintroduction. There are now strong needs to articulate the benefits of the geomorphological approach, to identify indicators and metrics to monitor and assess the efficiency of measures, to learn from experience in river interventions, to develop more collaboration within riverine communities to share these experiences and adapt policies and actions. The development of models is a key challenge, as there are needs to simplify them, to adapt them to large-scale context, and to retrospectively test their performance. While geomorphologists may base actions on a clear understanding of the river’s past trajectory and the understanding of the current processes and interactions, they also use a set of tools to evaluate future changes. Risk analysis, predictive modelling at increasingly large spatial and temporal scales, and field/flume experiments are becoming essential to design sustainable improvement measures, balancing immediate and long-term goals. Interdisciplinary teams and scenario elaboration (prospective approaches) can help improve the chances of success of future projects.

Geomorphic approaches and tools for evaluating river conditions Massimo Rinaldi Dipartimento di Scienze della Terra, Università di Firenze, Italy

This presentation will provide an overview of the geomorphic assessment tools and methodological frameworks most recently developed for evaluating river conditions and supporting river management, with a specific reference to the outputs of the EU REFORM (REstoring rivers FOR effective catchment Management) project. Following the introduction of the EU Water Framework Directive (WFD), numerous methodologies have been proposed to collect information and assess stream hydrology and geomorphology (termed ‘hydromorphology’), which vary widely in terms of their concepts, aims, spatial scales, collected data and therefore their applicability. During the last decade, a clear trend from site-scale, form-based procedures towards more robust reach- to catchment scale, process-based geomorphic approaches has clearly emerged. Increasing effort has been devoted to the development of conceptual frameworks aimed at supporting river management (e.g., the River Styles Framework, IDRAIM) by introducing the use of fluvial geomorphology as a key component, and integrating geomorphological tools in ecological studies and river engineering applications. plenary lectures 11

However, in most EU Member States a clear gap still exists between the development of new approaches and their use for assessment and monitoring. The implementation of these approaches has remained quite limited, and the consideration of physical processes remains the main gap. There is still a need for promoting a more comprehensive process-based hydromorphological assessment that considers the character and dynamics of river reaches and how these are affected by present and past natural and human-induced changes within the catchment as well as the reach. In response to this need, new methodologies have been proposed within REFORM. Two complementary approaches have been proposed for hydromorphological assessment: (i) an open-ended approach – the REFORM hydromorphological framework, and (ii) a set of more specific hydromorphological assessment procedures, which incorporates a set of clearly defined stages and steps – the REFORM hydromorphological assessment methods. The temporal context of the framework is linked to the key concept of evolutionary trajectory, emphasising that fluvial systems are dynamic and follow a complex trajectory of changes with time in response to a series of driving variables acting at various spatial and temporal scales. This presentation will focus on the set of new assessment methods and, based on some examples of application, will illustrate and discuss their synergic use, specific features, limitations and strengths. The assessment comprises a set of three tools, the Morphological Quality Index (MQI), the Morphological Quality Index for monitoring (MQIm), and the Geomorphic Units survey and classification System (GUS). The MQI is aimed at an assessment, classification and monitoring of the current morphological state; the MQIm aims at monitoring the tendency of morphological conditions (enhancement or deterioration); the GUS provides a characterization, classification and monitoring of geomorphic units.

Ecosystem benefits and potential hazards related to large wood in rivers: a numerical modelling perspective Virginia Ruiz-Villanueva Dendrolab.ch, Institute of Geological Sciences, University of Bern, Bern, Switzerland

Large wood (LW) is a key component of stream ecosystems and significantly influences river morphology. The presence of LW in river systems has been demonstrated to have very positive effects, enhancing the ecological and hydromorphological diversity and representing an important source of organic matter. Therefore, LW is nowadays increasingly frequently used in river restoration projects. However, during floods, large quantities of wood can be mobilized and transported downstream. At critical sections such as bridges, the transported wood might be entrapped and a quick succession of backwater effects can occur as a result of the reduction of the cross-sectional area. This, in turn, may trigger bed aggradation, channel avulsion, local scouring processes that may ultimately cause embankment and/or bridge collapse, or rivers may flood larger areas. Therefore the quantification of the large wood and associated large wood mobility is crucial for understanding and managing large wood in rivers. This talk will review the state-of-the-art in relation to the key definitions and concepts along with the challenges presented by taking an integrated approach to evaluating the role of large wood in river systems. Advances in quantifying large wood dynamics will be considered, in particular considering how field measurements and modelling can be combined to integrate our understanding of how large wood moves through and is retained within river systems. Several techniques exist in the literature to analyse wood dynamics and related hazards, such as field surveys of wood distribution, or monitoring and tracking the movement of wood pieces. Models, both conceptual and numerical, are identified as an alternative or comparable research methodology to physical modelling and field-based measurements. Numerical modelling provides an alternative approach to addressing some of the unknowns in the dynamics of large wood in rivers. The model represents a controllable virtual world which replicates the real world (with limitations and uncertainties). This virtual world can be analysed fully at any space and time, and can be used to test hypotheses and to run scenarios. In contrast to other fluvial components such as fluid flow and sediment, for which models have been developed and extensively used during the last decades, modelling of wood is still quite immature. This talk will describe the main challenges about modelling LW in rivers, with special emphasis on the application to different fluvial environments and for different purposes. 12

T H E M A T I C A N D P O S T E R S E S S I O N S

Do the spatial and seasonal patterns or temporal trends in habitat conditions shape fish communities in a Carpathian gravel-bed river? Antoni Amirowicz1, Bartłomiej Wyżga1, Artur Radecki-Pawlik2, Paweł Mikuś1, Józef Jeleński3 1Institute of Nature Conservation, Polish Academy of Sciences, Kraków, Poland 2Department of Hydraulics Engineering and Geotechnique, University of Agriculture, Kraków, Poland 3The Upper Raba River Spawning Grounds Project Coordinator, Myślenice, Poland

Fish communities and their habitats were studied at twelve channel cross-sections selected along a 9.5-km reach of the Raba River located within the ranges of geographical co-ordinates 49.72–49.80 °N and 19.92–19.99 °E. Data were collected in 2012 and 2015 twice a year (in July and September). At each sampling site the taxonomical structure of fish community was determined and hydrometric characteristics of the channel (width, depth, and flow velocity) were recorded. The ichthyofauna was composed of ten species with predominance of three of them: Phoxinus phoxinus, Barba- tula barbatula, and Barbus carpathicus, which together comprised 98% of the total number of recorded individuals in age ≥1 year. The median values of measured depths (0.23 m) and velocities (0.32 m s−1) allowed us to divide the total set of 713 measurements into four categories of the depth-flow conditions. Euclidean distances between studied sites in their (1) relative location along the river course, (2) relative composition of categories of available habitats, and (3) patterns of relative abundance of fish species were calculated. The obtained distance matrices were then compared using the Spearman coefficient of rank correlation. Positive and significant correlations between composition of fish communities (CFC) and locations of sampling sites clearly evidence that neighbouring sites have more similar CFCs. It confirms the importance of site position within the river continuum for taxonomic structure of ichthyofauna in the studied reach of the Raba. The CFCs were more similar in July and September in particular years than in the same months in 2012 and 2015. Therefore, the prevalence of a long-term change over seasonal fluctuations may be supposed. The lack of correlation between composition of habitat categories (CHC) in 2012 and 2015 seems to point to the changes in riverine habitats as the cause of temporal trend in CFC. However, the CFCs did not correlated with respective CHCs. Possible explanation is that fishes live in a spatial scale larger than the size of studied cross-sections (14–55 m) and the local populations can compensate to some extent the effects of changes progressing in a part of mosaic of their habitats.

Influence of maintenance works and macrophyte removal on ecological status of rivers – a metaanalysis and review Anna Bączyk, Maciej Wagner, Tomasz Okruszko, Mateusz Grygoruk Department of Hydraulic Engineering, Warsaw University of Life Sciences, Warsaw, Poland

River ecosystems consist of many important, integral living parts such as aquatic macrophytes, macroinvertebrates and fish, which play a relevant structuring role. These biological elements create stability and resilience of rivers. However, certain management measures (regular dredging, river channel straightening, modification of flow regime and longitudinal migration barriers) do not comply to good ecological status of aquatic ecosystems and underpin significant threat of decent lose of their ecological functions. Inappropriate management of rivers becomes especially critical to lowland watercourses. Among them there are small agricultural rivers that being subjected to regular technical maintenance, are under critical risk of loss of their refugial role for biodiversity of lowland landscapes. In our study we undertake a structured metaanalysis of literature review in order to verify the main hypothesis of the research, which states that technical measures of river management induce deterioration of ecological status of rivers. We evaluated the content of 320 scientific papers which we selected on the basis of structured query in the thematic and poster sessions 13

Web of Science. The scope of our analysis was (1) to reveal the up to date status of research in the field of influence of technical measures on ecological status of rivers, (2) to assess dominant trends in the research on aquatic ecosystem responses to management measures, (3) to analyse available knowledge base in the field of river management and ecological status, and (4) to search for best management practices in river management. We particularly focused on quantitative and qualitative assessment of ichtyofauna, macroinvertebrates structure and abundance, macrophytes and hydromorphological features of river channels. The great majority of international studies analysed in our review revealed that river maintenance results in temporal and permanent deterioration of ecological status of rivers. We observed that European studies on river ecological status have started to develop approximately 15-20 years after the main progress in this field in the U.S. Finally, we conclude that inappropriate approaches to river maintenance induce decent loss of the resilience of aquatic ecosystems, making them harder to be sustained in a desirable state.

Practical application of light hydrotechnical structures to support the formation of islands and sand bars Borys Bednarek1, Iwona Zwolińska2:, Łukasz Poławski2: 1Design Office Interflow Borys Bednarek, Wrocław, Poland 2Warsaw Property City Management, Warszawa, Poland

The purpose of the following text is to present a prototype project to be carried out within the European Union LIFE + Programme and concerning erosion control of one of natural river islands as well as building of sandbars on the Vistula River near Rajszewo (downstream of Warsaw). The project investor is the Warsaw Board of Public Prop- erty. The tasks within the LIFE + PROJECT “The protection of key bird species in the Middle Vistula Valley in the condition of intense pressure from Warsaw urban area” (WislaWarszawska.pl) serve the active protection of waterfowl including, in particular, waders such as the little tern (Sternula albifrons) and the common tern (Sterna hirundo). One of the tasks within the Life+ project concerns creating most natural looking sites appropriate for nesting of seagulls and terns and improving feeding conditions and resting places during migration of other waders (sand islands without vegetation cover and with partial vegetation cover, nesting sites and resting sites, low-lying sand point bars for spawning and fry being the main prey for seagulls and terns). Thus, the planned sand point bars must be similar in their nature to the natural depositional features present within the NATURA 2000 area. In order to achieve the aim of the project, it was decided to use light hydrotechnical structures made only of natural materials such as wood, fascine and stone. Though yet forgotten, such light hydrotechnical structures (called permeable) were widely introduced in the past to determine the width of the riverbed and to expand land area beyond regulatory zone of the river. They served as supportive structures to change the direction of the flowing material and they were built in initial stage preceding the erection of fixed hydrotechnical structures. Water flowing through such a structure did not change its direction but it lost its transporting property. The classic examples of such light structures are crosswise Wolf’s fascine bundles. A. Wolf introduced them in 1885 to control the Isar River flow in Bavaria and they were to support the fixed hydrotechnical structures. This type of structures leads to the decrease of the water level behind the fascine bundles (which can be lifted by the current and can rotate around their horizontal axis made of poles) and they make water material flow along the bottom of the river. As a result, it leads to deposition of floating and submerged materials creating underwater sand point bar. Such sedimentation phenomena (creation of the sandbars and deposits) lead to a reduction of the axis depth of fixed and heavy hydrotechnical structures which consequently reduce both the costs and the future working input on the building site. As far as the above-mentioned light hydrotechnical structures, they can constitute an alternative to heavy structures used to create and maintain the river islands and sandbars within the feeding and nesting habitat restoration for waterfowl. Finally, within the PROJECT LIFE+ (WislaWarszawska.pl), six pieces of light hydrotechnical structures were introduced in order to stabilize the river bottom. These were fascine bundles, twenty-four metres each, made of rough bundle of brushwood adjusted by the wire to the poles dug into the river bottom. Works were accomplished in November 2015. 14 thematic and poster sessions

Ground beetle communities in a mountain river subjected to restoration: the Raba River, Polish Carpathians Agnieszka J. Bednarska1 Bartłomiej Wyżga1, Paweł Mikuś1, Renata Kędzior2 1Institute of Nature Conservation, Polish Academy of Sciences, Kraków, Poland 2Department of Ecology, Climatology and Air Protection, University of Agriculture, Kraków, Poland

After a century-long period of channelization of the Raba River, in the 2000s maintenance of the channelization scheme ceased in several stretches of the mountain river course. Two large floods, one in 2010 and the second in 2014, caused up to a threefold increase in channel width, with the resultant re-establishment of a multi-thread channel pattern and a considerable increase in the area of gravel bars. The effect of self-recovery of the river in these stretches on ground beetle communities of exposed riverine sediments was investigated in 2015. This was done by comparing 6 unmanaged cross-sections and 6 cross-sections from adjacent channelized reaches. In each study cross-section, the ground beetles (Coleoptera: Carabidae) were collected from 12 sample sites of 1 m2 each on three sampling occasions (spring, summer and autumn). The sampling sites were described by surface slope, the distance from and the height above the nearest low-flow channel, sediment size class and the degree of plant cover. Additionally, bankfull channel width, the number of low-flow channels and the number of actively eroded cutbanks were determined for each cross-section. Unmanaged cross-sections had significantly larger channel width than channelized cross-sections and were characterized by greater numbers of low-flow channels and eroded cutbanks. Moreover, sample sites from the unmanaged cross-sections were typified by significantly larger average distance from low-flow channels and steeper average surface slope than sample sites from the channelized cross-sections. In total, ca. 4000 individuals were collected during the study. Taxonomic study is underway but the results for beetles collected in spring (1055 individuals from 53 taxa) indicated that the ground beetle assemblages were significantly more abundant in unmanaged cross-sections than in channelized cross-sections (p = 0.01). Unmanaged cross-sections supported more taxa (p = 0.02) and were characterized by a lower proportion of dominant species in assemblages than channelized cross-sections (p = 0.01). Moreover, assemblages found in unmanaged cross-sections exhibited a higher degree of similarity than assemblages collected in channelized cross-sections. The results for one season already confirmed that ground beetles relatively rapidly respond to the restoration of gravel-bed rivers which increases availability of exposed riverine sediments and the complexity of physical habitat conditions. This study has been prepared within the scope of the restoration project KIK/37 ‘The Upper Raba River Spawning Grounds’ supported by a grant from Switzerland through the Swiss Contribution to the enlarged European Union.

River restoration informed by an Ecosystem Services perspective? The development of an automated (semi-automated) assessment of riverine ecosystem services Claire Bithell, David Gilvear Plymouth University, Plymouth, United Kingdom

The ecosystem service (ES) concept resonates with river scientists, as it emphasises the need for understanding both ecosystem structure and function, while concentrating attention on the value of rivers to modern human society. With the accelerated interest in the ES’s concept since the United Nations Millennium Ecosystem Assessment (MA, 2005), the need to expand our understanding of the condition and level of management of various freshwater systems and their potential to deliver ES’s is widely recognized. Rivers and floodplains are recognised as highly valued ecosystems providing essential ES’s which span broad categories of human societal needs. Nevertheless methodologies for riverine ES assessment are scarce. Current methods and techniques often focus on measuring a single or a few services and are mostly derived and deployed at large spatial scales. The GREAT (Google-earth River Ecosystem service AssessmenT) methodology developed by Large and Gilvear (2014) can provide a reach-based river ES assessment from source to mouth or across river networks via Google Earth (GE). Three basic steps which identify, extract and score 18 riverscape features visible from GE are used to determine the type and level of 8 ES’s delivered by the river, from 3 of the 4 MA categories thematic and poster sessions 15

(provisioning, regulating and supporting). Theoretical linkages between the 18 riverscape features and 8 ecosystem services are provided. This study aims to refine, advance and automate this existing baseline methodology for riverine ES assessment with the anticipation it could be used as the basis for river restoration to improve ecosystem service delivery. Specifically, a critical appraisal of the GREAT tool has been undertaken by applying the methodology to three differing UK river types and assessing the strengths and limitations of the approach. The main limitations of the methodology where found to be the manual effort and time it takes to implement, imagery and data quality are not universally good (in particular restricted visibility from tree cover), the scoring system does not consider negative impacts or interactions between reaches (i.e. accumulation or depletion of services) and an element of training in landscape interpretation is a basic requirement. Thus, the first logical step in advancing this approach involved a thorough desk-based study to find out ‘what are and what the evidence base is for riverine ESs’ whereby a comprehensive matrix of ESs provided by rivers and their floodplains covering all four MA (2005) categories was delivered. Next, a data review was undertaken to find out what geospatial data is readily available and can be incorporated into the advanced semi-automated or automated methodology. For each measureable riverscape feature, theoretical methods/algorithms for the extraction of the parameters have been developed with the aim being to utilise the available databases. These methods are now being developed using geospatial data (such as DEMs, AI, DRNs, MasterMap data, flood outlines etc) to devise an automated tool for the assessment of UK rivers. A sample reach of the River Wharfe, England is being used to develop algorithms and the aim is to ground-truth the results in order to provide quantification of the methods before up-scaling the methodology to the whole catchment. This will then ultimately allow scenario testing of river restoration options.

Examining historical enhancement in Irish river fisheries: Maximising ecological return and cost effectiveness in addressing the Water Framework Directive Brian Coghlan1, Nathy Gilligan2, Karen Delanty1, Rossa Ó Briain1, James J. King1 1Inland Fisheries Ireland, Dublin, Ireland 2Environment Section, Office of Public Works, Drainage Division, Headford, Ireland

Arterial drainage, undertaken on circa 11,000 km of channels in Ireland since 1950, has substantially altered the hydromorphology and ecology of impacted channels. Ongoing routine conveyance maintenance can exacerbate these impacts. In response, fisheries agencies developed instream works techniques to offset the impacts of drainage on salmonid populations. Since the 1990’s, these “Capital Works” programmes have constructed instream structures, augmented gravels and protected the immediate riparian zone, all aimed at improving ecology and hydromorphology. Thirty-two Capital Works locations were analysed utilising the Irish Water Framework Directive (WFD) Fish Ecological Quality Ratio (EQR) tool. The fish data consisted of one-year pre works and up to 5 years post works. The capital works locations represented both varying levels of water quality and a broad spread of locations around Ire- land. Initial analysis showed a non-significant increase in EQR’s post capital Works (p = 0.79). Removing poor water quality sites, a statistically significant increase in EQR ratios (p = 0.003) was observed and maintained post works, underlining the importance of water quality screening at proposed works locations. The EQR also indicated that rivers classified as Good or High were subject to works. This may not reflect cost-effective expenditure in terms of the WFD. Analysis suggests Capital Works selection criteria should focus on “Moderate” fish EQR status sites. This will generate the most cost effective returns in capital investment, having the greatest potential to achieve WFD goals. The proposed assessment model incorporates water quality, gradient, WFD Fish EQR data and an assessment of river hydromorphology (River Hydromorphology Assessment Technique). Channels failing the selection criteria could receive ‘Enhanced Maintenance’, a suite of strategies developed to facilitate both conveyance management and physical modification of channel form to benefit hydromorphology. Channels exceeding selection criteria would receive no works or passive restoration allowing the channel to find a natural equilibrium. The approach outlined three options: capital works, enhanced maintenance and no works. The refined selection criteria facilitate an examination of needs, at the catchment scale, in terms of fisheries habitat and all elements of river hydromorphology – riparian and instream. The catchment view then permits a focus on specific requirements, allowing tailored enhancement programmes that address biological bottlenecks with specific enhancement strategies that are consistent with the expected hydromorphology. 16 thematic and poster sessions

An automated and multiscale method based on Remote Sensing analysis for regional hydromorphological characterization and monitoring Luca Demarchi1, Simone Bizzi1, Hervé Piégay2, Jarosław Chormański3 1European Commission, Joint Research Centre, Institute for Environment and Sustainability, Water Resources Unit, Ispra, Italy 2UMR 5600 CNRS EVS, ISIG platform, University of Lyon, Site ENS de Lyon, Lyon, France 3Warsaw University of Life Sciences, Department of Water Engineering and Environment Restoration, Warsaw, Poland

Remote Sensing (RS) analysis can be exploited to generate continuous and consistent data suitable to support hydromorphological characterization and monitoring of river systems at multiple scales of analysis. Key riverscape units with specific geomorphic meaning have been automatically mapped for 1700 km2 of river floodplains using simultaneous very high resolution near infrared imagery (VHR, 40 cm) and low-resolution LiDAR-derived products (Digital Terrain Model at 5 m). A multilevel object based approach has been developed to automatize the classification procedure and build a novel hydromorphological database (Hymo DB) of areal and topographical variables covering the main riverscape units characterizing the valley bottom of 18 rivers (1200 km of river courses) of the Piedmont Region (Italy). This unique regional database allows for hydromorphological characterization at the large scale as well as local scale geomorphic assessments. At regional level, the DB was used for river type classification. At local scale, the Hymo DB was integrated with historical information available at the river course level for enriching and completing current understanding of the river channel processes. Four main river types have been automatically identified within the Piedmont Region, characterized by heterogeneous fluvial forms. Exploiting the richness of the Hymo DB for each river type, the channel planforms (e.g. active channel width, floodplain height etc…) have been linked with basin features (such as catchment size, average gradient, and lithological context) in order to derive averaged relationships and map degree of river alterations per river type at regional scale. The Hymo DB generated in this study offers a unique set of tools to highlight regional trends and patterns and for assessing the amount of alterations of current river systems and therefore set rehabilitation target at the large scale. This kind of information is essential for implementing river management strategies that foster the design of large-scale cost-effective rehabilitation plans.

A hydromorphological framework for the evaluation of e-flows Martina Bussettini1, Massimo Rinaldi12, Gordon E. Grant3 1Institute for Environmental Protection and Research (ISPRA), Roma, Italy 2Department of Earth Sciences, University of Florence, Firenze, Italy 3Pacific Northwest Research Station, Forestry Sciences Laboratory 280 USDA Forest Service, Corvallis, OR, United States

Alteration of hydrological and sediment regime in rivers, due to anthropogenic activities (e.g. dams, water abstraction), is a major factor that diminishes river health and undermines environmental objectives envisaged by river protection policies. Specifying environmental flows to address those impacts can be a key strategy for maintaining functional river processes and achieve those objectives. Environmental flows are determined by various methods and approaches, based primarily on hydrological and/ or hydraulic evaluations, but holistic methodologies that consider the many interacting factors that structure aquatic ecosystems, including sediments, are increasingly used. Hydrological and geomorphological processes are highly coupled and any change in one typically affects the other. The coupling varies over different spatial and temporal scales, and changing either hydrological or geomorphological processes can result in alteration of river habitats, ultimately impacting ecological processes. In spite of these linkages, current restoration approaches typically focus only on changes in hydrological regime as a means promoting ecological enhancements. Neglecting sediment transport and its interaction with flow in shaping riverine habitats is likely to result not only in minor or no enhancements in the ecology, but may also increase the costs of water use. A more integrated view of how human activities jointly affect sediment regime, river morphology and river flows is therefore needed in order to determine the most effective actions to rehabilitate river processes to thematic and poster sessions 17 desired states. These states involve considerations of the combination of intrinsic (“natural”) conditions (e.g. river sensitivity and morphological potential, off-site conditions) and socio-economic constraints. The evaluation of such factors, the analysis of different scenarios, and the selection of appropriate actions require the contextualization of river reaches within a wider spatial-temporal hydromorphological framework. Here we present such a general multiscale, process-based hydromorphological framework, and discuss its application to the problem of how best to analyse and estimate e-flows.

Understanding the ecological consequences of dam removal utilizing trends in macroinvertebrate community data Peter Carlson1, Leonard Sandin2, Erik Degerman2 1Swedish University of Agricultural Sciences, Department of Aquatic Sciences and Assessment, Uppsala, Sweden 2Swedish University of Agricultural Sciences, Institute of Freshwater Research, Drottningholm, Sweden

Dam removals as a restoration technique have increased rapidly in the last two decades, a trend that is expected to intensify on a global scale. Unfortunately this trend has not coincided with an increase in the number of published dam removal studies. Such studies are vital to assure that best practices are utilized when dam removals are decided and what should be expected in terms of ecological responses. It is well known that the installation of dams results in a press disturbance that can strongly alter the structure and dynamics of upstream and downstream aquatic and riparian habitats and biota. The removal process results in a pulse disturbance that is suggested to have only short- term negative effects, followed by recovery to ecological conditions exceeding those prior to dam removal. In order to contribute to an improved understanding of the ecological response we conducted an investigation of macroinvertebrate responses in terms of biodiversity, indicators and traits to dam removal utilizing a world-wide dataset including pre- and post-dam removal. Spatiotemporal trends in macroinvertebrate community metrics were shown to differ downstream of the dam, within the impoundment, and upstream of the impoundment.

Applying hydromorphological assessment methods in a Greek river basin Ioannis Chronis, Konstantinos Vouvalidis, Konstantinos Albanakis, Anastasios Nikolaidis Dept. of Physical & Environmental Geography, School of Geology, Aristotle University of Thessaloniki, Greece

Different hydromorphological assessment methods were selected to present the best method for analysis in the frame of WFD. Initially, modification or alteration scores were analyzed and compared to investigate the best approach. The Greek part of Strymonas transboundary river basin was selected as it contains various types of water bodies (natural, modified and artificial). Strymonas River Basin is constantly under human pressure and intensive human management (like: flow regulations, extensive interconnected irrigation channels, agricultural activities ea.). Hydromorphological features and pressures appear along the water bodies changing the habitats. Geomorphological units such as Kerkini Dam Lake, an extremely low terrain unit, in the central part of the basin, and a narrow passage at Amphipoli Straits, just before the formation of a small estuary to the North Aegean Sea, were analyzed and related to quality assessment. Critical geomorphological features along the channel that modify the river behavior and its functions were assessed. Habitat Modification Score (HMS) from RHS and MQI-Alteration Index were calculated, analyzed and compared. The MQI-Alteration Index sensitivity was checked and showed a good coincidence to HMS and derived critical conclusions. A preliminary approach is proposed to cover different legal and management needs. 18 thematic and poster sessions

Hydraulic parameters of flood flows in a mountain river undergoing restoration Wiktoria Czech1, Artur Radecki-Pawlik1, Bartłomiej Wyżga2, Hanna Hajdukiewicz2 1Department of Hydraulics Engineering and Geotechnique, University of Agriculture, Kraków, Poland 2Institute of Nature Conservation, Polish Academy of Sciences, Kraków, Poland

The gravel-bed Biała River, Polish Carpathians, was heavily affected by channelization and channel incision in the twentieth century. Not only were these impacts detrimental to the ecological state of the river, but they also adversely modified the conditions of floodwater retention and flood wave passage. Therefore, a few years ago an erodible corridor was delimited in two sections of the Biała to enable restoration of the river. In these sections, short, channelized reaches located in the vicinity of bridges alternate with longer, unmanaged channel reaches which either avoided channelization or in which the channel has widened after the channelization scheme ceased to be maintained. Effects of these alternating channel morphologies on the conditions for flood flows were investigated in a study of 10 pairs of neighbouring river cross-sections with constrained and freely developed morphology. Dis- charges of particular recurrence intervals were determined for each cross-section using an empirical formula. The morphology of the cross-sections together with data about channel slope and roughness of particular parts of the cross-sections were used as input data to the hydraulic modelling performed with the 1D steady-flow HEC-RAS model. The results indicated that freely developed cross-sections, usually with multi-thread morphology, are typified by significantly lower water depth but larger width and cross-sectional flow area at particular discharges than single-thread, channelized cross-sections. They also exhibit significantly lower average flow velocity, unit stream power, and bed shear stress. The pattern of differences in the hydraulic parameters of flood flows apparent between the two types of river cross-sections varies with the discharges of different frequency, and the contrasts in hydraulic parameters between unmanaged and channelized cross-sections are most pronounced at low-frequency, high-magnitude floods. However, due to the deep incision of the river, both cross-section types are typified by a similar, low potential for the retention of floodwater in floodplain areas. The study indicated that even though river restoration has only begun here, it already brings beneficial effects for the flood risk management, reducing flow energy and shear forces exerted on the bed and banks of the channel in unmanaged river reaches. Only within wide, unmanaged channel reaches can the flows of low-frequency, high-magnitude floods be conveyed with relatively low shear forces exerted on the channel boundary. In contrast, in channelized reaches, flow velocity and shear forces are substantially higher, inevitably causing bank erosion and channel incision.

Ecological effects of river restoration projects in the Netherlands Prisca P. Duijn Rijkswaterstaat, the executive organization of the ministry of Infrastructure and the Environment in the Netherlands, Utrecht, The Netherlands

The Netherlands is situated in the deltas of Rhine and Meuse, and also for a little part in the deltas of Ems and Scheldt. It’s a densely populated area, and many inhabitants live on the banks of the main rivers. Due the fact that big parts are lying below sea level, we Dutch have not only embanked our rivers but also closed off parts of former estuaries and North Sea. Rijkswaterstaat, the executive organization of the ministry of Infrastructure and the Environment in the Neth- erlands, is managing the main water network which varies from providing safety against flooding, irrigation water supply, reliable waterways and a good water quality for many users (nature, drinking water, fishery etc.) We’re making progress on water quality: after forty years of improving the chemical quality, for the last twenty years we’re now working on ecological quality. In order to reach the objectives of the European Water Framework Directive, we focus on restoration of hydro morphological processes, ecological functions and habitats. The main measures which are already realized and monitored, are: l improving fish migration by solving connectivity problems; l improving the ecological functions of river banks; l creating side channels in the flood plain; thematic and poster sessions 19

l creating habitat like wood in the river and flood plain; l improving the ecological connections with streams; l improving the ecological functions of intertidal waters and; l restoring the connections between fresh and salt water. In this presentation a few examples of ecological effective measures will be shown: l facilitating fish migration by opening lock boxes part of the day at theWadden Sea at the town Den Oever; l improving river banks by removing rip-rap along the rivers Meuse and Ijssel; l different type of side channels along the river Waal; l nature friendly river banks along the river Lek. The focus will be on the technical implementation with regard to the other functions of the river. Various ecological monitoring results will be presented. Key factors to success and/or failure will be discussed based on our experiences. An outlook into the future will be given: l restoring the connections between fresh and salt water, like the ‘Fish migrating river’ at the ‘Afsluitdijk’ (barrier dam); l keeping the ecological equilibrium after realization of the measures, what kind of ecological management do we need; l upscaling successful measures to create not only a local ecological or hydromorphological effect, but also a large scale ecological improvement (for example WFD waterbodies). An example is bringing wood in erosion pits or next to every possible groin in the river Waal.

Legal framework and challenges of river restoration projects in Switzerland Katharina Edmaier Federal Office for the Environment, Water Division, River Restoration and Water Management Section, Berne, Switzerland

Since the 19th century, many Swiss rivers and streams have been straightened and channelized in order to gain land for agriculture and settlement. In addition, aquatic ecosystems suffer negative impacts of hydropower production. Consequently, today almost 50% of streams and rivers in the Swiss lowland (< 600 m a.s.l.) show a deficient morphology and numerous barriers and sills disrupt longitudinal connectivity. Hence, aquatic biodiversity has been significantly decreased. Negative impacts are pronounced in regions where the demand for land is increasing due to economic development, agriculture and population growth. In 2011, the Swiss water protection law was revised in order to rehabilitate natural aquatic ecosystems. One of the key modifications is that approximately 4,000 km of stream and river reaches have to be restored within the next 80 years. To reach this goal, federal funds (40 million Francs per year) are provided which allow a funding of restoration projects between 35 and 80% of the total costs. The 26 Swiss cantons need to implement the revised water protection law into practice. First, they were obliged to carry out strategic planning of restoration projects. Therein restoration sites are prioritized according to their potential benefits for nature. From a total of approximately 65,000 km of streams and rivers in Switzerland 37,767 were considered in the cantonal restoration planning. Strategic planifications consider 20 year periods and have to be updated every 12 years. Results from the first restoration planning were completed in 2014. Contemporaneously, first restoration projects have already been conducted. The focus of the presentation is on the challenges that can accompany river restoration projects. Land acquisition strategies, early communication, public relation and the integration of all relevant stakeholders as well as maintenance strategy proved to be key points for successful river restoration projects. Guidelines of success evaluation are being established in order to evolve restoration practice to a better outcome in the future. Restoration efforts in Switzerland are accompanied by a number of research projects in various disciplines. 20 thematic and poster sessions

Does river restoration restore ecological function? Judy England1, Martin Wilkes2 1Environment Agency, Wallingford, United Kingdom 2Coventry University, Coventry, United Kingdom

Over the past few years there has been a gradual increase in the appraisal and assessment of river restoration practices. Whilst many of these have concentrated on traditional biological assessments such as richness, diversity or equitability, some studies are starting to examine changes in ecological processes, such as nutrient dynamics, input of organic matter and productivity. We explore how river restoration work restores ecological functioning of macroinvertebrates using case study assessments. The River Rib is chalk fed watercourse with tributaries that flow over areas of boulder clay within southern En- gland. The river is 35 km long from the perennial head and characterised by riffle and pool sequences that have been interrupted by numerous weirs - especially within the lower section where a series of weirs has essentially turned the river into a series of connected ponds. A weir removal scheme from a section of channel that was historically straightened and widened. The changes in the watercourse were assessed for changes in habitat structure and biological communities. Habitat and plant mapping was accompanied by macroinvertebrate surveys. The weir removal restored connectivity and habitat composition in comparison with a target site up stream. Changes in the plant and macroinvertebrate communities were assessed and a change in community reflecting the change from lentic to lotic conditions. We demonstrate how different analytical techniques can be used to examine the changes in the macroinvertebrate communities.

An integrated approach to chalk stream restoration Judy England1, Di Hammond2 1Environment Agency, Wallingford, United Kingdom 2Affinity Water Ltd, Hatfield, United Kingdom

A combination of geology and climate means that chalk streams provide a unique environment and have characteristic features that support special wildlife habitats and species. There are approximately 200 chalk streams in the world with more than 80% of these found in England. They are fed from groundwater aquifers, meaning that the water is of high clarity and good chemical quality. This provides the ideal habitat for many invertebrates such as rare species like the fine-lined pea mussel. Chalk streams are important habitats for fish such as brown trout, brook lamprey and bullhead. They also have characteristic plant communities including river water crowfoot in the channel and diverse vegetated margins. The chalk streams of Hertfordshire have been modified and changed over many 100s of years. They are affected by groundwater abstraction, dredging, channel straightening, loss of riparian habitat and have numerous weirs inter- rupting longitudinal connectivity. Land use changes have meant an increase in the amount of fine sediment entering the channel. Working in partnership we are addressing these issues to restore the watercourses to physically and biologically functioning systems. We have extensive baseline data of the hydrology, geomorphology and biology which we have used to identify where the rivers are impacted and attribute the causes. This has included identifying a target discharge for the different rivers and where supporting morphological measures are needed. We have an integrated monitoring programme to assess the success of the programme of measures in both the short and long term. thematic and poster sessions 21

GIS environmental information analysis of the Darro River basin as the key for the management and hydrological forest restoration Paz Fernandez-Oliveras, Expectacion Delgado-Merlo, Monica Lopez-Alonso, Jose M. Poyatos Civil Engineering Department, University of Granada, Granada, Spain

In this article we present the methods and results obtained from soil and environmental information analysis of the Darro River basin (Granada-Spain), which was carried out using a geographical information system (GIS) called GvGIS. To date, the steps and workflow used for the environmental analysis are original and totally new. The article summarizes the workflow followed to compute the soil parameters selected for the environmental analysis in order to decide upon adequate basin management and an appropriate hydrological forestry restoration. The complete analysis includes morphological analysis, soil and climate characteristics, as well as vegetation and land use. It also studies soil erosion computation by applying the Universal Soil Loss Equation (USLE) and by mapping erosion fragility units. Results are presented in the form of maps and their analysis. These provide a starting point for river basin management, and the actions of hydrological and forestry restoration. Morphometric analysis reveals that the Darro River basin’s shape is not a key factor in flood risk consideration, however, the opposite occurs with relief factors that evidence a very hilly orography. Hydrographic network parameters are in accordance with the relief effect, resulting in a short time of concentration (3 hours) in the lower part. The presence of soft substrates (e.g. gravel and sand) indicates a tendency to suffer erosion processes; the areas that are dominated by human activity and that have little soil protection contribute to this distortion. Finally, land use and vegetation coverage have been revealed as key factors in the erosion phenomenon.

Geomorphological effects of a catastrophic flood in small mountain catchments: case study of the Skawica catchment, southern Poland Paweł Franczak Institute of Geography and Spatial Management, Jagiellonian University, Kraków, Poland

The channels of mountain streams are subject to continuous modelling by floods. However, they undergo greatest changes during catastrophic floods caused by sudden rainfall. The increase in the intensity of channel transformation occurs in forest areas, where accumulations of large wood deposited by streams during floods force increased accumulation of clastic material and formation of a mosaic of fluvial landforms. The study was conducted in the Skawica catchment (Western Beskidy Mountains, Poland). On 15 and 16 May 2014, Skawica Stream flooded following a heavy rainfall with a total of 216.5 mm recorded over three days, 138 mm of which fell on 15 May. With the mean rainfall intensity reaching 9.1 mm/h, the upper part of the catchment on the slopes of the Babia Mountain was most affected: the peak discharge at Zawoja was 76.6 m3 s–1, while the maximum specific discharge ranged from 1.15 to 2.15 m3 s-1 km2. The maximum flood flow had an exceedance probability of 5-10%. This resulted in a sudden flooding in several streams that significantly changed the morphology of their channels and valley floors. Stream channels and floodplains where most affected, whereas adjacent hillslopes were transformed only moderately. Following the flood, two geomorphologic surveys were carried out in the valleys of Rybny Potok, Marków Potok, Jaworzyna and Czatożanka streams; photographic documentation was made immediately after the event (19 May 2014), whereas detailed geomorphological mapping was performed between 22 and 30 May 2014. A methodology developed in the Department of Physical Geography of the Jagiellonian University in Cracow was adapted for geomorphological mapping and systematic collection of quantitative and qualitative data. This was complemented with analyses of thematic maps (topographical, geological etc.) and aerial photographs. The collected data provided information on (i) river channel (e.g. geology, morphometry, hydrotechnical infrastructure, types and dimensions of landforms; (ii) hydrological and meteorological conditions during fieldwork; (iii) catchment morphometry. Location and dimensions of channel bars (length, width, area) and cutbanks (length, height) as well as channel width (for 100-m sections) were determined in the field with a GPS receiver and a laser rangefinder. 22 thematic and poster sessions

The greatest change occurred in the catchment of Rybny Stream and the least in the Czatożanka catchment. Despite considerable transformation of the channel, the changes consisted mostly in the increase in the number and area of the channel forms. In the upper part of the catchment erosional forms were enlarged, whereas in the downstream reaches several new erosional and depositional forms developed. The largest increase in the number of bank undercuts occurred in the upper Rybny Stream where their total length doubled or even tripled. The largest bank undercuts were 9 m high. In the upstream reaches, these changes were accompanied by deepening of the channel bed by approx. 0.4 m with a maximum of 1.1 m (Rybny Stream). In the middle and lower courses of the streams the recorded increase in the area of depositional forms was by 600% (5750 m2) and the average area of an individual form reached 358 m2. Mean grain size of the material was 0.1-0.3 m and the largest transported sandstone particles reached 0.8 m in size. Accumulations of organic material deposited on bars reached 3 m in height and induced formation of 1.5 m-deep pools below and accumulation of mineral material in the upstream direction. Within terraces, avulsion channels were formed, with the largest one 8-m wide and 2.4-m deep. The flood in the catchment of the upper Skawica River was caused by one of the highest daily rainfalls on record that exceeded 100 mm with an intensity reaching 10 mm/h for a few hours. Maximum specific runoff was lower than mean maximum specific runoff recorded during flash floods in small Polish Carpthian catchments. The highest specific runoff was recorded in the catchments with streams draining the summit parts of the Babia Góra Massif (Rybny and Marków streams). The changes of channel form were surveyed in the sections with little human impact within and adjacent to the Babia Góra National Park. In the upper parts of the catchments with greater slope, the existing erosional forms were rejuvenated and their dimensions increased. In the lower stream courses, with smaller slope, several new accumulation forms developed and the area of the existing forms largely increased, especially upstream of accumulations of organic material and in the wider valley sections with floodplains overgrown with dense riparian forest. A decrease in the channel conveyance for floodwater by trees and woody debris accumulations resulted in the increase of the dimensions of fluvial landforms.

Active protection of water-crowfoots habitats and restoration of wildlife corridor in the River Drawa basin in Poland – LIFEDrawaPL Artur Furdyna, Piotr Waloch, Beata Gąsiorowska Regional Directorate for Environmental Protection in Szczecin, Szczecin, Poland

The rivers Drawa, Grabowa and Radew are among the most important sites in West Pomerania, Poland, for water-crowfoot (Ranunculus fluitans), an aquatic plant at the eastern periphery of its range. It is a defining vegetation of the Natura 2000 network habitat type ‘watercourses of plain to montane levels with the Ranunculion fluitantis and Callitricho-Batrachion vegetation’, which is listed in Annex I of the Habitats Directive. At the same time the Drava river basin is the last position of the native salmon in Poland, and 3260 site is a typical habitat for this species in the river phase of the life cycle. For this reason, the project, in addition to the purpose of improving the conservation status of habitats, is also aimed at specific, typical habitats of migratory fish species and lampreys. Design also includes Man, as a participant in ecosystem functioning basins covered by the project, particularly in terms of reducing the negative effects and animations of alternative, less harmful forms of use of the environment. The objective of the LIFEDrawaPL project is the active protection of lowland rivers in West Pomerania, including the Drawa, Grabowa, Radew and Korytnica. The project aims to improve river habitats, with the construction of fish spawning-grounds. The ultimate project goal is to positively affect biodiversity in the restored Drawa river wildlife corridor and its tributaries. The project’s specific actions, planned in Natura 2000 network sites and the Drawieński National Park, include: 1. Conservation and improvement of Habitats Directive Annex 1 listed vegetation and habitat in five Natura 2000 sites; 2. Reintroduction of opposite-leaved pondweed (Groenlandia densa); 3. Removal of existing barriers, and hydrotechnical structure adjustments, in order to make upper-river areas more accessible to migrating species, such as river lamprey (Lampetra fluviatilis) and Atlantic salmon (Salmo salar); 4. Enhancement of natural river reproduction for river lamprey, Atlantic salmon, European bullhead (Cottus gabio) and spined loach (Cobitis taenia); and 5. Creation of educational tourism activities in the Drawa river drainage basin area. thematic and poster sessions 23

Effect of grade-control structures on the stream morphology and bed sediment properties Tomáš Galia, Václav Škarpich, Jan Hradecký Department of Physical Geography and Geoecology, Faculty of Science, University of Ostrava, Ostrava-Slezská Ostrava, Czech Republic

Sequences of grade-control structures (GCSs, here including check-dams and bed sills) represent the typical management of steep mountain streams, preventing massive bed erosion and bed load transport. However, they also produce negative environmental impact in terms of decreased sediment connectivity, and altered stream bed conditions affect aquatic habitat diversity, fish migration potential and riparian vegetation. We studied bed sediment calibre and changes of channel-reach morphology in the Czech Carpathian gravel-bed Mohelnice River (A = 40 km2, W = 15 m, 0.01< S <0.02 m/m, Qa = 1.1 m3/s, 18 GCSs at various stage of destruction from the 1970s) and the headwater Bystrý Stream (A = 5 km2, W = 4.5 m, 0.01< S <0.04 m/m, Qa = 0.15 m3/s, 38 GCSs reconstructed in 2002), both managed by these traditional GCSs, stream channelization, and systematic removal of instream wood. Whereas grain sizes of former and present sedimentary wedges were evaluated by random walks and measurements of 100 particles per wedge in the Mohelnice River, an automated image-based granulometry and additional measurements of five largest grains were performed on small channel bars in the Bystrý Stream. No direct relationship existed between the bed surface grain sizes and the GCS drop heights or the present equilibrium channel slopes in both streams. However, a downstream coarsening especially of the largest grains (D95) was detected through the sequence of GCSs in the Mohelnice River. This river lost its wandering character after its first channelization in the 1950s. The significant power relationship existed between the parameters of maximum scour hole depth and the present GCS height, and linear relationships were observed between the dimensions of scour holes. In the Bystrý Stream, former pool-riffle morphology was transformed to plane beds without natural vertically-oscillating bedforms. The sediment deposits located immediately downstream scour holes produced a tendency of slow downstream coarsening. It may point up on the increased efficiency of energy dissipation of GCSs under gradual downstream decrease of related channel slopes. Other two types of deposits, located immediately upstream the GCSs crests or unattached by direct effects of these constructions, did not produced any systematic downstream trend in grain sizes despite the significant downstream decrease in related channel slopes. Thus, observed trends in sediment calibre of sedimentary wedges (the Mohelnice River) and unattached deposits (the Bystrý Stream) most likely pointed up on the selective scours of finer sediment fractions, caused by the presence of GCS sequences in the studied reaches. In addition, both studied reaches were unaffected by notable lateral sediment supply from hillslopes, tributaries or bank erosion, which could affect these grain-size trends. Possibilities of application of more environmentally friendly bed-stabilization elements with preserved high-energy dissipation (e.g., block ramps) in the studied streams will be discussed.

Hydraulic modelling requirements for river restoration: methods for minimizing (not just flood) risk Eric Gillies, Hamish Moir cbec eco-engineering UK Ltd., Inverness, United Kingdom

Hydraulic modelling for flood risk is well-established, and UK-specific research (Enviroment Agency/ Defra) lists the minimum requirements on models for flood risk assessment. However, the modelling requirements to determine the efficacy/ function of a river restoration are often overlooked. These are often different to the requirements for Flood Risk Assessment (FRA), e.g. existing conditions on straightened reaches are often satisfactorily modelled for flood risk using 1D, or 1D/2D, models; whereas restored reaches often introduce greater lateral forcing and require fully 2D models. For cost effectiveness and due diligence, it is important to use a hydraulic model that can safely assess flood risk and also asses restoration design performance, as there is little point spending money on a restoration scheme without some evidence that the design will improve habitat, natural process, social value, etc. Through our experience of modelling for restoration design, combined with mandatory flood risk assessments, we present a set of minimum modelling requirements for discussion. 24 thematic and poster sessions

River rehabilitation following mining in South West Scotland; channel design, fluvial processes and biological community recovery Dave Gilvear1, Nigel Willby2, Charles Perfect3, Ian Griffin4

1University of Plymouth, England 2University of Stirling, Scotland 3Scottish Environmental Protection Agency 4ECuS Ltd

Open cast mining of the Ayrshire coalfield in Scotland results in the realignment of streams and rivers. Tradition- ally such realignments were unregulated and were constructed with little care for the environment. Over the last two decades however strong environmental regulation, in part led by the Water Framework Directive but also an environmental ethos within the mining industry, has led to more environmentally sensitive realignments being constructed. During the period 2000 to 2013 the authors were involved in the channel design process and environmental monitoring of a number of realignments. This paper will examine the role of channel design and fluvial processes in promoting establishment of functioning river ecosystems following mining. The key channel attributes and fluvial processes required for rapid and successful establishment of channels and biological communities within the river corridor similar to their natural counterparts will be detailed.

Interfaces between natural and regulated reaches of gravel-bed mountain rivers – two case studies Tomasz Glixelli1, Paweł Janiec1, Józef Jeleński2 1Ove Arup & Partners International Ltd, Kraków, Poland 2The Upper Raba River Spawning Grounds Project Coordinator, Myślenice, Poland

Regulated alluvial mountain rivers in Poland are characterized by entrenched channels and channel capacity in excess to regime conditions. As a result, they show higher stream power and increased scour, which in turn causes further increase in channels’ volume and unit stream power, as well as floodplain drainage. These of course with environmental and economic consequences. Immediately below such regulated reaches there are erosion damages present affecting bed and banks of natural channels. It is believed that responsible is the lack of recognition of the phenomena at the interface between high-volume, regulated channel reach and a natural stable gravel-bed channel with wide floodplains. As a consequence, similarly to the regulated reach, the natural channel below becomes affected in the form of uncontrolled and unforeseeable deformations, which necessitate either further preventive measures or additional maintenance. The analysis of Krzczonówka Stream at Krzczonów was performed (1) at the end of the long reach of regulation including many check dams, with scour pool below the last stilling basin, which evolution was successfully stopped by construction of gravel-rock ramp in the form of a natural riffle. The ramp was situated well below scour pool, in a channel with wide floodplains. The analysis concerns as well the case of the Raba River at Pcim (2) where the reach of entrenched channel without floodplains (“village corset”) shows instability at the interface with a reach of the channel with one bank rendered with rip-rap in a wide floodplain.Analyses included: l simulation of stable natural channel conditions according to Hey and Thorne regime equations, l indicating and evaluation of technical solutions in relation to position and extent of existing floodplains l applying computer modelling (HEC-RAS software) in objective to confirm effects of selected solutions in the form of unreinforced rock-gravel ramps or channel widening or lowering of floodplain level. Analyses results show that Hey and Thorne regime equations are a very useful tool in recognition of gravel-bed channel instability and in evaluation of solutions undertaken in objective to its recovery. In river maintenance based on systematic monitoring of channel geometry followed by undertaking the necessary engineering interventions concerning the position of riffle crests, the regime equations estimates can be used directly. There is as well possibility of performing deeper analysis of given cases by adopting stable channel parameters or estimates resulting from the regime equations to apply in computer simulation programmes. This is especially important for searching thematic and poster sessions 25

the solutions preserving alluvial character of gravel-bed rivers in extreme conditions and always possible where the space for the river in the form of floodplains exists.

Implementation of SPeAR® assessment in multi-criteria analysis of sustainability of ‘the Upper Raba River Spawning Grounds’ project Tomasz Glixelli, Jacek Zalewski Ove Arup & Partners International Ltd, Kraków, Poland

SPeAR® (Sustainable Project Appraisal Routine) methodology was developed by Arup based on sustainable development indicators prepared by European Union and United Nations. It enables appraisal of project, plan or product and graphical presentation of results. It allows to optimise key sustainability indicators, such as use of economic, social and environmental resources. SPeAR® has been developed to provide the Investor with information on the current level of project sustainability and to allow to optimise it in subsequent phases of its execution. The appraisal is carried out in defined economic reality, which amongst others, consists of financial viability, local and national economic reality and long-term economic effect of the project. The result of an assessment is a SPeAR® report, which includes opinion on sustainability of environmental, economic and social aspects of a project and recommendations for considered options of project implementation. It can be used as management tool enabling informed decision making throughout the project life. The aim of the Upper Raba River Spawning Grounds project, implemented by Stowarzyszenie Ab Ovo, was an increase of biodiversity and improvement of habitat conditions for protected species and habitats. The SPeAR® assessment for the project was undertaken in multiple areas, following the analysis of: l data received from the Investor, l natural inventory of the project area, l methodology of mountain rivers maintenance, as a document being the basis of activities carried out within the project, and l level of implementation of project goals. The study included two essential, interweaving components: l assessment of expected results of the project, as a tool for monitoring of project goals in compliance with formal requirements, and l multi-criteria analysis and evaluation of the project sustainability using SPeAR® as a management tool, which provides the Investor with information on the current level of the project sustainability and allows project optimisation during subsequent steps of its execution. To understand the sustainability of the project at an early stage of its execution, the first analysis was carried out in 2013. Based on the results, optimisation guidelines and modifications to addressees of the project were proposed. Majority of recommendations were adopted by the project coordinators. This was demonstrated during the second sustainability analysis in 2016, at the final stage of the project execution.

Revitalization of rivers in Switzerland Christian Göldi River Consulting and Team Coaching, Schaffhausen, Switzerland

In Switzerland, the country in the heart of Europe, approximately 7 million people live within an area of 41’293 km2. Switzerland has 26 Kantons (provinces). The Kantons are responsible for water affairs. The Federal Government provides the legal framework and supports the effort of the Kantons for flood control, water protection and also for river revitalisation. Most rivers in Switzerland were canalised and many small creeks have been put in culverts during the last 150 26 thematic and poster sessions

years to protect villages and infrastructure against floods and to enlarge agricultural land. The natural character of these watercourses was therefore reduced to a monotonous and boring shape. The loss of the habitats with their great variety of animals and plants aroused a fundamental change in the way how to implement river works. Nature friendly techniques lead to an astonishing increase of ecological values. Nature friendly River Works and river revitalisation are now part of the federal law in Switzerland. Experiments for nature friendly techniques in river works started in the seventies of the last century. The most used technique then was the use of living plants like willows for embankment protection. The idea of river revitalisation was the next step: to give canalised rivers a more natural shape and allow more dynamic functioning. The Kanton Zurich and the city of Zurich have implemented programs for improving the ecological situation of the many canalised rivers and creeks. The City started in 1988 with his „Brook Program“ and the Kanton 1989 with his revitalization program for rivers and streams. Other Kantons like Solothurn, Bern, St. Gallen joined the new way. Aargau, Graubünden and then Geneva followed. Since the start of these programs many projects to change canals and culverts into more natural shape have been realised. The programs for the revitalisation of rivers were and still are successful. The early experiments were very helpful to convince people and politicians in a vivid way directly on the site for the new approach how to treat rivers in a nature friendly way. Nature friendly river engineering is now widely accepted. The support of the federal administration for revitalisation projects is essential. The protection against floods stays nevertheless important.

Can beaver activity amplify river renaturalization? The example of the Raba River Elżbieta Gorczyca, Kazimierz Krzemień, Mateusz Sobucki, Tomasz Raczkiewicz Institute of Geography and Spatial Management, Jagiellonian University, Cracow, Poland

The European beaver (Castor fiber) disappeared from Carpathian rivers and streams most likely by the end of the 16th century. The two main reasons for this were settlement pressure and hunting. Some attempts were made in the 1980s to reintroduce the beaver to rivers and streams in the Eastern Carpathians. The first effective beaver reintroduction occurred in the Bieszczady Range in the 1990s. Beavers have since colonized other habitats in other areas of the Vistula Basin in the Carpathian Mountains. One example of this is the Raba River. The study asks the following questions: Can beaver impact contribute locally to an improvement in hydrogeomorphological conditions, and can it positively affect the renaturalization process in the Raba River channel? Field surveys in 2015 in the Raba River channel confirmed the presence of beavers via dams, bites, slides, and burrows. The Raba is a larger Carpathian river and remains regulated for the most part. Ecologists consider the river damaged by regulation works. As a result, beaver habitats are found only at certain locations along the river. Sub- stantial beaver activity has been detected in the upstream and downstream sections of the river. Several beaver dams and accompanying pools were observed in multi-thread channels of the upstream section. The presence of pools in river channels affects primary fluvial processes. Beaver dams help decelerate water flow, accumulate water in pools, and retain water. Local changes in channel morphometry may also occur downstream of a beaver dam. The problem of lateral erosion increases, while substantially retarded water flow results in reduced downcutting. Beaver burrows and slides were most characteristic of the downstream section of the Raba. Beaver impact in this area produces bank damage and recession. This is aided by water-logged riverbank materials and numerous beaver burrows, which reduce riverbank stability. In effect, banks are shaped by small landslides and collapsed burrows. Another important effect of beaver activity in the functioning of a river channel system is the accumulation of mineral debris as well as plant debris – both large and small. This type of accumulation and the washing away of riverbank material may lead to local flattening of the channel floor and reductions in the gradient of river and stream channels. thematic and poster sessions 27

Agricultural rivers at risk: dredging results in a loss of macroinvertebrates. Preliminary observations from the Narew catchment, Poland Mateusz Grygoruk1, Aron Chmielewski1, Magdalena Frąk2 1Warsaw University of Life Sciences, Department of Hydraulic Engineering, Warsaw, Poland 2Warsaw University of Life Sciences, Department of Environmental Improvement, Warsaw, Poland

Ecosystem deterioration in small lowland agricultural rivers that results from river dredging entails a significant threat to the appropriate ecohydrological conditions of these water bodies, expressed as homogenization of habitats and loss of biodiversity. Our study was aimed at a comparison of abundance and taxonomic structure of bottom-dwelling macroinvertebrates in dredged and non-dredged stretches of small lowland rivers and tributaries of the middle Narew River, namely: Czaplinianka, Turośnianka, Dąb, and Ślina. The experimental setup was (1) to collect samples of the bottom material from the river stretches that either persisted in a non-modified state (dredging was not done there in the last few years) or had been subjected to river dredging in the year of sampling; and (2) to analyze the abundance and taxonomic structure of macroinvertebrates in the collected samples. The study revealed that at the high level of statistical significance (from p = 0.025 to p = 0.001), the total abundance of riverbed macroinvertebrates in the dredged stretches of the rivers analyzed was approximately 70% lower than in non-dredged areas. We state that the dredging of small rivers in agricultural landscapes seriously affects their ecological status by negatively influencing the concentrations and species richness of benthic macroinvertebrates.

Management and restoration: a parallel universe of lowland agricultural rivers in Poland Mateusz Grygoruk1, Paweł Fiedorczuk2, Jędrzej Grygoruk 2, Anna Kasjaniuk2, Aneta Kostecka2 1Department of Hydraulic Engineering, Warsaw University of Life Sciences, Warsaw, Poland 2Stowarzyszenie Niezależnych Inicjatyw Nasza Natura, Kleosin, Poland

It is believed that the 21st century will become an age of environmental restoration. Increasing demand of societies towards better quality of life, expressed by higher expectations as to the quality of the environment, allows to sus- pect that degraded aquatic ecosystems of Europe will – sooner or later – become subjected to restoration measures. Advances in ecohydrology, ecohydraulics and ecological engineering followed by progress in social sciences, land use policy and social awareness of environmental risks are likely to result in increasing number of actions oriented at restoring the most important functions of degraded ecosystems. However, internal contradictions of certain water-management-related acts of national law, followed by some world-scale opinions on non-relevance of integrated water resources management concept, result in putting the goal called “good ecological status” postponed for decades. This refers to widely reported process of ongoing lowland agricultural river degradation in Poland. In our presentation we demonstrate the background, implementation and results of day-to-day practice of agricultural river management in Poland. We refer to the well documented cases of “flood damage removal” in the Su- prasl River valley. We present the quality of environmental compliance control over the river management projects. Lastly, we present the quality of river management actions that were implemented in 2012-2014 in NE Poland. We focus on field observations, analyses of legislative acts and procedures. We also analyse the social background of river management by comparing different attitudes towards rivers and lakes in Poland. We conclude that environmental regulations in the practice of river management, although being followed in an ostensive manner, do not allow to sustain and improve the appropriate status of lowland agricultural rivers in Poland. We claim this status to be urgently changed. 28 thematic and poster sessions

Ecological state of a mountain river before and after an extreme flood: implications for river status assessment Hanna Hajdukiewicz1, Bartłomiej Wyżga1, Antoni Amirowicz1, Paweł Oglęcki2, Artur Radecki-Pawlik3, Joanna Zawiejska4, Paweł Mikuś1 1Institute of Nature Conservation, Polish Academy of Sciences, Kraków, Poland 2Department of Environmental Engineering,Warsaw University of Life Sciences, Warszawa, Poland 3Department of Hydraulics Engineering and Geotechnique, University of Agriculture, Kraków, Poland 4Institute of Geography, Pedagogical University of Cracow, Kraków, Poland

Assessment of the ecological status of rivers is key to monitoring the achievement of the environmental goal of the EU Water Framework Directive and the success of restoration projects. In 2009 and 2010, repeated assessments of the physical habitat conditions and fish and benthic invertebrate communities were performed in 10 unmanaged and 10 channelized cross-sections of the Biała River, Polish Carpathians. Between the two assessment surveys, an extreme flood event with 80-year recurrence interval occurred, significantly affecting habitat characteristics and river biocenoses. In unmanaged cross-sections, active channel width increased, whereas the degree of cross-sectional variation of flow velocity decreased. In channelized cross-sections, the increase in active channel width and the cross-sectional variation of flow velocity was accompanied by a decrease in mean grain-size of bed material. Prior to the flood, unmanaged cross-sections hosted three times more benthic invertebrate taxa than the channelized ones, whereas after the flood, the number of taxa was reduced to such a low level that both types of cross-sections became similar in terms of the taxonomic richness of benthic invertebrate communities. In comparison to pre-flood conditions, the abundance of fish juveniles (YOY) in unmanaged cross-sections was reduced nearly by half; before the flood they hosted 5 times more juvenile individuals than channelized cross-sections and only twice as many after the flood. These differences indicate that assessment carried out prior or after a large flood event may yield significantly different results for the quality of abiotic and biotic elements of the ecological status of a river. Therefore, it seems vital that the final assessment be based on repeated surveys of abiotic and biotic elements of the river ecological status to balance the effect of single, extreme hydrological events.

Development plan for rivers in South Tyrol Peter Hecher Agencia Civil Protect, Autonomous Province of Bolzano, Bolzano, Italy

In Europe the effects of global environmental, economic and social change were particularly disruptive for river systems in general and floodplain regions in particular. Before the 18th century European floodplains were scarcely populated and these areas could only partially be used for agricultural purposes. In such settings rivers were free to develop and contributed to shape the landscape. Afterwards reclamation and river regulation initiatives have increasingly allowed the progressive exploitation of the valley bottoms. In South Tyrol large-scale river engineering works left pronouncedly rectified watercourses in poor hydromorphological and ecological conditions and led to an almost total reduction in extent of riparian forests and the associated ecosystems. At present riparian forests occupy only 0,06% of the total surface area of South Tyrol. The comparison of historical maps dating back to the year 1820 with maps reflecting the current status particularly highlights the pronounced alteration of the lowland fluvial landscapes. More than 55% of lowland rivers in South Tyrol are in a heavily modified condition. In the mentioned time period the stream length of the Adige River between Merano and Salorno was reduced by 63% leading to a contraction of the riparian areas along the river by 83%. The complex land use patterns in floodplain areas exacerbate damage mechanisms in case of extreme flood events: rivers spill over their artificial borders and flood adjacent settlement and floodplain areas. The implementation of traditional flood protection approaches, which prevailingly entail the construction of structural measures to mitigate flood hazard, fails to adequately address the emerging complex challenges at a river corridor scale. The implementation of holistic river corridor management strategies is needed to find feasible syntheses amongst: thematic and poster sessions 29

i) what complies with the natural evolution patterns (i.e. river styles), ii) what is the ideal preservation of the common good and iii) what is allowed by the existing legal framework. In that regard the Department 30 of the Autonomous Province of Bolzano, the Department of Hydraulic Engi- neering, has elaborated, since 2011, a first version of a development plan for rivers in South Tyrol (EFS 30: En- twicklungsplan Fließgewässer Südtirol). This plan was meant to enhance resilience of the territory by increasing the ecosystem services in the river corridors. Moreover the EFS 30 is an instrument to coordinate river restoration initiatives in order to meet the objectives of ecological quality, which have been specified in the Directive 2000/60/CE. A fundamental principle of the EFS 30 is the notion of the stream as an interconnected system, where proper consideration is deserved not only to riverbeds but also to the adjacent floodplain areas. The wider the floodplain the higher is its potential ecosystem value but also the more intense are its land use pressures.

Making river restoration relevant – the key to delivery Martin Janes Chief Executive, the River Restoration Centre (RRC), UK

There are many questions that the river restoration community, and the wider land and water management sector, are working on: l How do our rivers and catchments work? l What are the main pressures, and what consequences to those have? l How do we mitigate/address each element that we define as impacting the health of our river systems? l What is the ecological response of these plans and actions? Progress and success varies within and across countries, as this conferences’ sessions will demonstrate. Our understanding and expertise grows with time and experience. But the level of ambition to meet the requirements and expectation of national and European legislation means that we need to do far more than just what ‘we’ can achieve alone. We need to involve, enthuse and mobilise ‘people’, because ‘we’ will always have too much to do with not enough money! We need to: l Invest time involving and working with the local community. l Funders take the push from ‘people’ to set their priorities. l Priorities get more funding and profile. l High profile and funding gets more media coverage, and interests more people. l People get involved in caring for what they are interested in. l Causes get more support locally from business and industry (corporate responsibility and PR). l Funding.

To do so we must invest in training, guidance, capacity to do works themselves, scientific and technical support and advice. We must provide access to information, experience, knowledge exchange opportunities and case studies. This is needed to make river restoration relevant to all of those who are NOT at this conference and who are critical to its delivery. The model for delivery is changing: we all need to teach, train, guide and support more. This presentation will provide examples of where local community participation and involvement in river restoration and habitat enhancement has been essential to success (measured by: awareness raising, capacity building, longevity, respect and admiration, policy changes, funding and wide-scale delivery towards WFD targets). It will also highlight the essential work that is being done to support this, nationally and at a European level. 30 thematic and poster sessions

Maintenance directed to obtain “riffle and pool” sequence of entrenched stream below a high check dam Józef Jeleński1, Paweł Mikuś2 1The Upper Raba River Spawning Grounds Project Coordinator, Myślenice, Poland 2Institute of Nature Conservation, Polish Academy of Sciences, Kraków, Poland

In the course of preparatory works concerning lowering the check-dam crest at Krzczonów, the analysis of the Krzczonówka Stream channel was performed from the dam outlet (km 2+294) to the mouth to the Raba river (km 0+000). In 2010 the channel was entrenched, with stream bed of exposed bedrock in 25 to 50% of its surface, and the gravel and cobbles were much coarser than the gravel accumulated above the dam. Historically, the channel was braided at the beginning of the 20th century and gradually forced to be single and straight in the middle of the century, following road construction along the left bank of the stream at the north side of the valley and constructing the flour mill weir in the place of the contemporary check dam. In 2000 stream channel lost its properties as a spawning destination of trout migrating from the Raba River, as the reach below the dam was devoid of suitable gravel. The dam was destined to be lowered by about 2 m and made passable for fish migration. At the same time gravel accumulated above the dam would have been washed into the stream and due to high flow energy in the entrenched channel could be transported downstream into the Raba River in a single flood event. To avoid this, the existing course of the stream channel was analysed by simulation using Hey and Thorne regime equations. This in objective to find if it is possible to find such a single-thread channel cross-section and gravel gradation parameters, which can keep channel in regime without changing its course. The results of simulation for assumed bankfull discharge of 1.5-year frequency showed that it could not be done with the gravel gradation found either above or below the dam. The material found to be suitable to form riffles in objective to accumulate gravel transported from the lowered dam was the rock material as blasted in the nearby sandstone quarry of D50 = 130 mm and D84 = 380 mm. In 2013 riffles have been formed of rock rubble, which had slope of 0.04 m/m (i.e. 0.032 m/m more than the average channel slope, five times more than bankfull slope). Riffle crests were located ca. every 120 m at the locations of thalweg inflection points. All ramps were compacted by road roller using imported gravel to close the surface of the ramps. All parameters of ramps were set on site locally, that is relative to floodplain level. Four natural riffles were found which did not necessitate corrections, others were corrected only by filling and compaction, without excavations inside the channel and almost without impact on plant growth along the stream. In 2013, some gravel passing over the dam with medium spate accumulated above the first two riffle crests. In 2014, in one single flood event, gravel filled the stream channel down to the Raba River. The whole reach became alluvial, single-thread, riffle-and-pool pattern channel. In 2016, the parameters of the channel have been checked and compared with the criteria assumed in 2010, with conclusions concerning environmental, amenity, flood control and channel retention effects of engineering intervention performed as maintenance of the stream in 2013.

The results of the ‘Upper Raba River Spawning Grounds’ Project Paweł Jeleński, Edward Stokłosa Ab Ovo Association, Kraków, Poland

The poster includes a set of photographs showing processes of attaining most important visible results of the Project, with concise comments: l removing obstacle for fish migration through the Krzczonówka cascade - before, during and after the works, l removing obstacle for fish migration through the Stróża dam - before, during and after the works, l restoring of the Krzczonówka Stream natural channel characteristics in terms of riffle and pool sequence, sketches and drawings of riffle crest demarcating as well as registration of their actual position, example picture series of one riffle evolution, l regaining the space and subjectivity of the Raba River channel and its surroundings from Lubień to Stróża: a series of aerial photographs from 2010 compared to 2016 at Lubień village, at the border of Lubień and Pcim Communes, and at the mouth of Krzczonówka Stream, thematic and poster sessions 31

l reduction of alien invasive plants area: Japanese Knotweed (Reynoutria japonica) range of proliferation in 2012 and 2016, l expansion of plant species characteristic of preserved habitats in Natura 2000 area: German tamarisk, series of pictures taken in 2016, a sketch of proliferation. l fish species preserved and desirable in Natura 2000 area: spotted barble (Barbus carphaticus), sculpin (Cottus gobio), lamprey (Lampetra planeri) and local race of brown trout (Salmo trutta dorothea), underwater pictures. Moreover, a movie ‘The Upper Raba River Spawning Grounds from the point of view of trout and gull’ will be presented during coffee breaks.

Summarizing current knowledge on river restoration effects: Placing the results of the EU-FP7 REFORM project in the broader context of restoration literature Jochem Kail Faculty of Biology, University of Duisburg-Essen, Essen, Germany

Although there are still major knowledge gaps regarding the effects of river restoration, considerable progress has been made in recent years. An increasing number of primary research studies reported monitoring results, which already have been summarized in several narrative reviews and quantitative meta-analyses. Moreover, there is a growing number of studies on multiple restoration projects and multiple organism groups. Recently, several publications on two tasks of the REFORM project (http://www.reformrivers.eu/) were added to this growing body of literature. In a top-down approach, information from literature and unpublished databases were compiled in a meta-analysis on fish, macroinvertebrates and macrophytes, and factors influencing restoration outcomes were identified. In a bottom-up approach, a harmonized dataset on 20 restored river segments was compiled and a broad range of response variables was investigated, including aquatic and terrestrial habitats, three aquatic and two floodplain-inhabiting organism groups, as well as aquatic-land interactions as reflected by stable isotopes. In this presentation, these recent studies will be placed in the broader context of restoration literature. The present knowledge on the overall effect, as well as the effect of different restoration measures on different organism groups and traits will be summarized, prior to discussing possible reasons for low or negative effects and drawing more general conclusions for river management.

Opposite effect of severe flood and hydrotechnical alterations of ecosystems on riverine biodiversity: an example of bird assemblages Łukasz Kajtoch, Tomasz Figarski Institute of Systematics and Evolution of Animals, Polish Academy of Sciences, Krakow, Poland

The influence of floods on riverine species has been studied rarely as this phenomenon is unpredictable. On the other hand, there were many studies on alteration of flow, which is the most serious threat to environments and populations of riverine ecosystems. However, most of these studies focused on floodplain habitats and species, but similar studies on riverine assemblages are missing. The aim of this study was to investigate whether – and how – a catastrophic flood (which occurred in Poland in 2010) and subsequent hydrotechnical alterations of ecosystems can shape river assemblages of breeding bird species and – if so – what kinds of effects are connected with such an event. Data on natural and regulated sections of sub-mountain rivers in southern Poland from before and after the 2010 flood and after intensive water control transformations (2012 year) were compared. Considering flood effect, the prevalence of natural features increased significantly in all the studied sections (on average fourfold increase in pre-flood regulated and 1.3-fold in pre-flood natural ones). The diversity of species increased only in the regulated sections (1.3-fold), whereas the number of breeding birds increased both in the regulated (2.3-fold) and natural channel sections (1.4-fold). The underlying cause of the observed expansion of species and increase of population sizes was thought to be a combination of increased breeding site accessibility and food abundance. Considering 32 thematic and poster sessions

alternations, these works affected approximately 36% of river sections in the studied catchments. Simultaneously, large amounts of gravel, clay, and woody debris were removed from river channels (on average 50% of gravel alluvium and clay scarps were destroyed, and more than 65% of dead wood was removed). Regulation works carried out in river channels previously restored by the severe flood led to a strong decline in breeding bird assemblages (25% loss of species richness and 33% loss of population number: 3 species perished, most declined, 1 increased and 1 settled). These results shows that river regulation can significantly alter a structure of breeding bird assemblages even from year to year, and such a change is generally negative for bird diversity, which is especially important for rare and vulnerable species. It is important to notice that among environmental variables bird diversity and abundance were mostly affected by an increase of regulated sections length and vegetation cover as well as by a loss of dead wood and scarps levelling which depends on habitat guilds. The enormous changes in sub-mountain river channels caused by flood should be appreciated and left in place, but, unfortunately, large hydrotechnical projects were started after the 2010 flood and reverse this effect. As riverine habitats are some of the most important biodiversity hotspots and major routes of migration for organisms in Europe, the degradation of riverine ecosystems can have a catastrophic impact on nature in the entire European Union.

Change in hydromorphological characteristics of river channel after introduction of plant basket hydraulic structures and their ecological effect Tomasz Kałuża1, Artur Radecki-Pawlik2, Krzysztof Szoszkiewicz3, Bartosz Radecki-Pawlik4

1Department of Hydraulic and Sanitary Engineering, Poznan University of Life Sciences, Poznań, Poland 2Department of Hydraulic Engineering and Geotechnique, University of Agriculture, Kraków, Poland 3Department of Ecology & Environmental Protection, Poznan University of Life Sciences, Poznań, Poland 4Department of Civil Engineering, Cracow University of Technology, Kraków, Poland

This paper deals with problems related to the improvement of the hydromorphological conditions of the River Flinta in its sections located in the Natura 2000 area. Based on a comprehensive study of the hydromorphological status of the river, four sections have been selected, where restoration measures can efficiently improve the river habitat conditions. For each of these sections, we propose a set of technical and biological measures. One of the proposed solutions, investigated as a pilot project, was to construct plant barriers (PBHS - plant basket hydraulic structures). On a selected section of the River Flinta near the village of Rożnowo, three plant barriers (sediment traps) were put in the river bed. Systematic measurements were carried out during two years. Before the experi- ment began, the hydrometric measurements were taken. The cross-sectional geometry was defined as well as the slope of the surface and the distribution of velocities. After the installation of trays, the hydrometric measurements were recorded systematically over a period of two years of usage (the tests were performed during five measure- ment sessions). In our calculations we used VCmaster software. Changes of sediment grain size were analysed. Additionally, the amount and size of plant debris caught in the plant barrier (plant formation) were studied. These measurements provided information on the possible consequences of such actions in terms of hydromorphological changes and ecological effect. The study of vegetative sediment traps confirms their usefulness in activation and initiation of the hydromorphological processes. The performed simulations show that the proposed measures enable the achievement of various hydromorphological improvements on the River Flinta. We were able to select sites where the restoration would have a significant influence on the hydromorphological status. Moreover, we have widely proposed the replacement of artificial building materials with local and natural materials such as wood, local cobbles and gravel. Deflectors and sediment traps were proposed on the realigned river sections to initiate meandering and other fluvial processes. thematic and poster sessions 33

Eel River restoration project in Japan – the linkages between forests, rivers, satoyama and sea Satoshi Kameyama1, Yoichi Kawagushi2, Mikio Inoue3, Yo Miyake3, Seiichi Nohara1 1Center for Environmental Biology and Ecosystem, National Institute for Environmental Studies, Tsukuba, Japan 2Institute of Technology and Science, Tokushima University, Tokushima, Japan 3Graduate School of Science and Engineering, Ehime University, Matsuyama, Japan

We estimated the spatio-temporal changes of habitat potential for endangered Japanese eel (Anguilla japonica) living in Japanese watersheds. Additionally, we tried to find out the cause of the decreasing of freshwater eel resource through statistical data analysis and GIS procedure. Japanese eel is very important traditional indicator species that is directly affected by both watershed and marine ecosystem. We are regarding this specific life history as “The linkages between forests, rivers, SATOYAMA and sea” symbolically. These days, critical decreasing of eel resource is not only a Japanese domestic issue but serious international concerns. For Japanese consuming excessive amounts of eel resources as traditional food has a responsibility for habitat conservation (or restoration) to maintain sustainable use. Nowadays, main reasons for decreasing of temperate Anguilla eels are recognized as global scale environmental changes, overfishing and habitat degradation in the watersheds. For these concerns, we are focusing on habitat degradation by anthropogenic impacts on inland water. Watershed fragmentation by dams and loss of connectivity in irrigation channels are especially extensive impacts on eel migration. These points of view have not been recognized particularly compared to the discovery of the spawning area for Japanese eel or full-life cycle aquaculture in Japanese eel. The objectives of our research are as follows: 1) The construction of nationwide scale GIS databases on long term eel habitat distribution, statistics of fisheries and artificial river structures. 2) The analysis of the spatio-temporal changes of eel habitat and its relation to watershed structure. 3) GIS mapping to understand the present status of Japanese eel populations and to detect potential site for eel habitat restoration in the target region “Seto Inland Sea of Japan”. Through these approaches, we grasp the change of long-term eel habitat, further we detect some remarkable area including habitat loss and degradation. Finally, we discuss about candidate restoration sites for Japanese eel in an effective and efficient manner.

Assessing climatic and dam-induced impacts on river water temperature Mariola Kędra1, Łukasz Wiejaczka2 1Institute of Engineering and Water Management, Cracow University of Technology, Kraków, Poland 2Institute of Geography and Spatial Organization, Polish Academy of Sciences, Kraków, Poland

Water temperature in streams and rivers is an underlying determinant for aquatic ecosystems. A range of temperature values and their cyclic alterations during a day and throughout a year determine the ability to survival and development of aquatic organisms. Of different kinds of anthropogenic activities carried out on rivers, dam reservoirs appear to have a marked effect on the river environment, and in particular on thermal regime of rivers. Changes in water temperature below dams, caused by the operation of reservoirs and deep water releases, can be a serious threat to the proper reproduction and development of aquatic biota. Moreover, in a changing climate with global warming, river water temperature increases due to heat exchange with the atmosphere. It seems therefore desirable to recognise and assess the impact of these two distinct sources of water temperature distortion in relation to the natural thermal conditions of rivers. For that purpose, the linear trend analysis and a continuous complex wavelet transform were used. The analyses are focused on daily river water temperature data from disjoint time periods before and after the construction of selected reservoirs in the Polish Carpathian Region, and on daily surface air temperature data from neighbouring meteorological stations. The assessment methods used allow for making suitable comparisons and a consistent interpretation of research results, together with the differentiation between the two distinct sources of thermal pollution in rivers. 34 thematic and poster sessions

Quantification of morphological changes in river channels and its impact on flood risk (case studies of the Topľa and the Bečva rivers) Anna Kidová1, Miloš Rusnák1, Stanislav Ruman2, Milan Lehotský1, Václav Škarpich2, Tomáš Galia2, Milan Trizna3 1Institute of Geography, Slovak Academy of Sciences, Bratislava, Slovakia 2Faculty of Science, University of Ostrava, Ostrava, Czech Republic 3Faculty of Natural Sciences, Comenius University, Bratislava, Slovakia

Rivers are dynamic systems, where changes in their morphology can affect floods and play a crucial role in flood risk identification. Morphological changes of channels were caused in history by increasing urbanization around the rivers, human interventions and climate or land use changes, which leads to modification of channel capacity. The research project focuses on the selected parts of two Carpathian rivers (Bečva River in Czech Republic and Topľa River in Slovakia). Quantification of morphological changes in the river channels and their impact on flood risk were main targets of this project. Geometric cross-section profiles, detailed digital terrain models, historical maps and aerial photos (for identification of land use) were used for hydraulic modelling of historical and current channel shape scenarios by two-dimensional HEC-RAS software. Historical channel shapes were created from historical maps and aerial photographs by interpolation and modification of present channel cross-sections. Chan- nel narrowing and channelization speed up the timing of flood peaks and lead to an increase of flow velocities and flood risk in surrounding towns, especially during floods with lower recurrence time. Decrease in channel capacity destroyed the connection between the river and floodplain mainly in rural areas where these changes were not necessary. Understanding channel morphology changes and their effect on floods is important for flood risk management what helps us to find the strategy to mitigate the floods for the future.

Hydromorphological methods for assessing river width: application to the River Elbe, Germany Frauke Koenig1, Ina Quick1, K.-H. Jaehrling2 1The German Federal Institute of Hydrology, Koblenz, Germany 2The State Agency for Flood Defence and Water Management of Saxony-Anhalt, Magdeburg, Germany

The investigation of spatial and temporal changes of river width and width variability is a suitable tool for analysing morphological changes and estimating the ecological quality of a river, e.g. for the European Water Framework Directive. However, width and width variance interact closely with the varying hydraulic and sedimentological conditions in the river. In general, a high width variance is often accompanied by a high depth, flow and sediment diversity which in turn is an indicator for the existence of different micro- (river bed) and mesohabitats (e.g. riffles and pools). The width variance provides information on the morphodynamics and resilience of a river. It also gives some indication of the length of the river banks and the number of diverse and ecologically vital habitats in the river bed, along the riparian zone and in the floodplain. This study examines changes of the channel width and width variation of the river Elbe and compares different methods, while quantitatively assessing these hydromorphological parameters. Dependent on the discharge, width and width variation for different spatial situations (e.g. river bed, floodplain) are determined for a historical (1830–1850) and a current condition. These data are statistically analysed and compared to obtain a five-point scale evaluation. As expected, anthropogenic alterations of the river bed, the riparian zone and the floodplains lead to a lower width and width variability of the current condition. The river width and width variation are suitable indicators and reflect deficits in several areas. The importance of the width variability and its various conditions is shown for the sediment regime and the ecology of river systems. Furthermore, this study illustrates the importance of the right choice of methods describing the physical changes of a river dependent on the focus of the investigation (width variation, sediment management, EC-WFD, ecological aspects of river ecosystems, nature conservation and so forth) and makes recommendations as to which method should be used. thematic and poster sessions 35

The influence of restoration works on morphology of Krzczonówka Stream channel (Western Carpathians, Poland) Joanna Korpak, Anna Lenar-Matyas Institute of Engineering and Water Management, Cracow University of Technology, Cracow, Poland

The research was conducted in Krzczonówka, a gravel-bed mountain stream, belonging to the Raba River drainage basin. The Krzczonówka Stream channel has been regulated many times over the last 60 years. As a result of the regulation works, the lower course of the stream has been transformed from a braided, depositional one into a sinuous, narrow, erosional one. A check dam, which was constructed in the channel, interrupted the continuity of material transport and prevented fish of the Salmonidae family from traveling upstream to their spawning grounds. This type of channel was characterized by a poor ecological state. An innovative restoration project was implemented in the years 2013-2014, which included the construction of artificial riffles (rapid hydraulic structures) and the lowering of the check dam. As a result, a greater diversity of morphological forms was obtained, the process of erosion was reduced, and the continuity of the stream corridor was restored. A major flood occurred in May of 2014, just before the implementation of the project had ended. The flood reshaped the part of the stream channel where restoration works were performed and the part upstream from it. The magnitude of the transport and deposition of river sediment, which resulted due to the performed works and due to the flood, surprised the engineers. This paper presents the results of geomorphological monitoring, performed both during the implementation of the project and after it had ended. The main purpose is to describe the magnitude of changes in the morphology and functioning of the stream channel, which occurred starting from the beginning of the project implementation, against the backdrop of slow changes in the channel occurring over a longer period lasting several decades.

Parameters of natural channel behavior in various physiographic conditions of the Czech Republic – the steps for establishing reference conditions Kateřina Kujanová, Milada Matoušková, Zdeněk Kliment Department of Physical Geography and Geoecology, Faculty of Science, Charles University in Prague, Praha, Czech Republic

A fundamental prerequisite for assessing the current ecological status of streams is the establishment of reference conditions for each stream type that serve as a benchmark and represent the target status of restoration and mitigation measures. Determining of reference conditions also serves for identification of valuable natural stream reaches which require preservation. The hydromorphological reference conditions reflect the natural channel behavior, which is extremely variable although they must also be understood in terms of cultural-landscape changes. From the perspective of water management, classifying channels into groups and understanding the natural behavior of channels facilitates the forecasting of changes related to the development of fluvial systems, especially as concerns their instabilities and risks. The objectives of the presented methods were to classify channels into groups based on determined significant parameters of natural channel behavior in physiographic conditions of the Czech Republic that would subsequently facilitate the establishment of reference conditions. Statistically classified groups were validated in the field survey and the morphological characteristics of channels were compared between the Hercynian System and the flysch belt of the Western Carpathians. Significant parameters of natural channel behavior at macroscale level were determined using a combination of four selected statistical methods: Principal Component Analysis, Agglomerative Hierarchical Clustering, correlation, and regression. Macroscale analyses of data about altitude, stream order, channel slope, valley floor slope, sinuosity, and characteristics of the hydrological regime were conducted for 3197 reaches of major rivers in the Czech Republic with total length of 15,636 km. On the basis of four selected significant parameters (altitude, valley floor slope, sinuosity, and Strahler number) and their threshold values, channels were classified into groups of river characteristics based on shared behaviors. At the microscale level the channel behavior within these groups 36 thematic and poster sessions

was validated using hydromorphological characteristics of natural channels determined during field research and measurements at reference sites. Reference sites were identified that met the six selected criteria of having minimal anthropogenic impact. Classification of channels into groups confirmed the fundamental differences between channel behavior under conditions of the Hercynian System and the flysch belt of the Western Carpathians in the Czech Republic and determined a specific group of streams located in the flattened high areas of mountains in the Bohemian Massif. Validating groups of river characteristics using field data from natural reaches confirmed the distinctions between groups of river characteristics and the uniqueness of each one; it also emphasized the benefits of using qualitative data to establish channel and riparian zone characteristics (e.g. valley type, flow characteristics, characteristics of bank and riparian vegetation, channel roughness etc.) for describing channel behavior. Channel slope, entrenchment ratio, bed structure, and d50 were determined as significant quantitative characteristics of natural channel behavior. The classification of channels into groups and the establishment of significant hydromorphological characteristics of natural channel behavior should be followed by establishing type-specific reference conditions.

Erosion-deposition feedback in base-level raised zone of a gravel-bed river with erodible banks: the Dunajec River upstream from the Czorsztyn Reservoir, southern Poland Maciej Liro

Institute of Geography and Spatial Management, Jagiellonian University, Kraków, Poland

Studies of gravel-bed rivers have shown that in-channel sedimentation may cause flow divergence around deposited bars, that leads to localized bank erosion and additional bar growth (bar-bank interactions). These processes may be of high importance for the river management in the backwater zones upstream of dam reservoirs on gravel-bed rivers. Bar-bank interactions were thus investigated in the backwater of the Czorsztyn Reservoir built in 1997 on the gravel-bed Dunajec, southern Poland, where the river has erodible banks and the forced in-channel sedimentation occurred after the reservoir construction. Analysis of the changes in channel morphology caused by bank erosion and in-channel sedimentation from aerial images (1994-2012) and contemporary LiDAR data (2013) indicated that the variation in bar area was in 40-77% explained by local bank erosion in the previous 9 years and that 80% of the variation in width/depth ratio of the channel was explained by bank erosion. Flow divergence around deposited bars led to localized bank erosion and further bar growth promoting a relatively rapid development of channel bends. These processes, propagating upstream with time, were facilitated by a large amount of easily remobilized sediment stored in the floodplain, connected with the sedimentation zone from the end of the nineteenth century. The developed channel bends tended to translate downstream in the narrower valley-confined section and to increase in amplitude in the wider unconfined river section with erodible banks. The results suggest that backwater zones upstream of dam reservoirs on gravel-bed rivers with erodible banks, where low transport competence forces in-channel sedimentation, may be the locations of morphologically effective bar-bank interactions resulting in lateral channel instability and the development of large bars within the channel.

Changes to the functioning of a mountain stream following installation of boulder riffles and check-dam lowering: Krzczonówka Stream, Polish Carpathians Maciej Liro1, Bartłomiej Wyżga1, Paweł Mikuś1, Artur Radecki-Pawlik2, Józef Jeleński3, Antoni Amirowicz1, Paweł Oglęcki4, Karol Plesiński2 1Institute of Nature Conservation, Polish Academy of Sciences, Kraków, Poland 2Department of Hydraulics Engineering and Geotechnique, University of Agriculture, Kraków, Poland 3The Upper Raba River Spawning Grounds Project Coordinator, Myślenice, Poland 4Department of Environmental Engineering, Warsaw University of Life Sciences, Warszawa, Poland

An increasing number of dams and check dams are removed from rivers to re-establish their longitudinal continuity thematic and poster sessions 37

for biota migration and sediment transport. Because of long-lasting sediment starvation, channel reaches downstream of the dams are typically deeply incised and thus the sediment flushed out from the demolished dams may not be trapped in these reaches but transported far downstream. To enable entrapment of sediment in such a deeply incised channel, artificial boulder riffles were constructed before check-dam lowering in Krzczonówka Stream, Polish Carpathians. Channel morphology, physical habitat conditions, and fish and benthic macroinvertebrate communities in the stream were surveyed prior to restoration activities (2012), after the installation of boulder riffles but with still existing check dam (2013), during (2014) and after the check-dam lowering (2015). In May 2014, when the check-dam lowering was underway, a large flood occurred, delivering considerable amounts of bed material to the downstream part of the stream. The material was efficiently trapped by the boulder riffles which became buried on the distance of ca. 1.2 km from the check dam, whereas the sediment wave reached 1.6 km from the dam. About 14000 m3 of bed material were retained in the stream, with an average increase in bed elevation amounting to 0.37 m. A maximum increase in the average elevation of bed surface in surveyed cross-sections equalled 0.72 m at a distance of 470 m from the dam, whereas a maximum increase of the water surface at low flows reached 1 m. Because the sediment was trapped in deeply incised channel, bed aggradation was not associated with channel widening. The part of the stream with considerable bed aggradation was typified by considerable coarsening of the bed material and a marked decrease in the cross-sectional variation in maximum and depth-averaged flow velocity. In the distal part of the sediment wave, where the change in bed elevation was small, no significant change in sediment size and the cross-sectional variation in flow velocity occurred. The average number of fish individuals, especially juveniles, in a stream cross-section decreased in the years with the construction of boulder riffles, lowering the check dam and the large flood (2013-2014) but returned to the initial values in 2015. The average number of macroinvertebrate taxa in a cross-section decreased in the year with the works to lower the check dam and the large flood but in 2015 increased to a greater number than before the restoration works. This study demonstrated effectiveness of boulder riffles in the entrapment of bed material in the incised channel. It also showed that the restoration works only initi- ated the change in physical structure of the mountain stream that may lead in future to the significant improvement of its biocoenosis.

Temporal effects in river restoration – How many years do we need to achieve good ecological status? Armin Lorenz1, Kathrin Januschke1, Moritz Leps2, Andrea Sundermann2, Peter Haase2, Daniel Hering1, Stefan Stoll2 1University of Duisburg-Essen, Faculty of Biology, Department of Applied Ecology, Essen, Germany 2Senckenberg Research Institute and Natural History Museum Frankfurt, Department of River Ecology and Conservation, Gelnhausen, Germany

The factor time is often suggested as one of the most important factors when discussing the improvement of biological quality elements through restoration measures. This designation is based on the mere hope and desire that time heals the wounds of previously degraded and now restored stretches. Scientific studies of time series of restored sections are hitherto rare or relate only to short periods of a few years on a specific site. General conclusions on the ecological effects of restoration measures in the course of time cannot be drawn yet, but are urgently needed in the context of river basin management planning. In the past three years, a joint project of the Senckenberg Research Institute and the University of Duisburg-Es- sen has tried to find answers to the question on the factor time in river restoration ecology. Two different data sets were analyzed from restored river reaches. On the one hand, a large data set, which contained standardized sam- plings of fish, benthic invertebrates, macrophytes, floodplain vegetation and ground beetles of about 60 restored reaches. This data set was analyzed in relation to the time past since the restoration measures were conducted. On the other hand, 18 restored sites were sampled twice in an interval of 5 years, which allows for the exploration of the direct effect of the factor time on biological organism groups. This talk will present the main results of the project. 38 thematic and poster sessions

Best practices in the protection of batrachofauna during the oxbows revitalization in the Upper Vistula River Valley Małgorzata Łaciak1,2, Tomasz Łaciak1,3 1The Society for Earth, Oświęcim, Poland 2Institute of Nature Conservation, Polish Academy of Sciences, Kraków, Poland 3Institute of Biology, Pedagogical University of Cracow, Kraków, Poland

In 2012-2015 The Society for Earth and the Institute of Nature Conservation PAS carried out the project entitled ‘Revitalization, biodiversity protection and usage of the Vistula River oxbows; Preventing degradation of Upper Vistula River Valley as an ecological corridor’ financed by the Swiss-Polish Cooperation Programme. One of the main objectives of the project was to make a detailed inventory and evaluation of nature along the Vistula channel in Małopolska region (205 oxbows selected in total). Oxbows are specific and unique habitat type for amphibians. Located on the axis of the river valleys create ecological corridor for batrachofauna, providing continuity of amphibian populations inhabiting oxbow lakes. Diversity of oxbows provides a rich habitats for different species of amphibians. The best practices in the protection of batrachofauna included, among others, the following actions: l A detailed inventory of amphibians and evaluation of their habitats on the 205 oxbows in the Vistula valley. The study was conducted for three years (pilot study was made before starting the project to test methodology). Ac- tually data on the distribution and abundance of species of amphibians was obtained through the research, which allowed to choose oxbows to revitalization; l Basing on the results, the current data base of species of amphibians was made, with exact coordinates and estimated number. The graphical form of the results is also presented on the website; l Oxbows which were especially valuable for batrachofauna, were selected for the procedure of legal form of protection; while on the oxbows neglected and heavily littered - cleaning works and revitalization were made; l Fifteen oxbows were revitalized; – Revitalization actions on all oxbows were done under the supervision of herpetologist – Earthworks were carried after securing the area of work (eg. migration barriers); during the off-season of amphibians activity – Oxbows were deepened and habitat molded in an optimal way for amphibians (variable depth, the presence of extensive shallows, mildly sloping edges, suitable vegetation) – Work was performed by using a special equipment (excavators with a long arm, which performed works from the shore or a small excavator on a special pontoon bridge) – In the oxbows located close to roads animal mortality monitoring was made. Because the main goal of the revitalization of oxbow lakes was to restore the lost ecological functions, proper planning and execution of earthworks was very important. Amphibians were here umbrella species and thanks to them, a number of habitats suitable for other taxa were created. The works contributed to the increase of the biodiversity on a larger scale. Above all, the revitalization of oxbows showed good practices for the protection of amphibians.

Check dam removal modelling: experience on Krzczonówka Stream Marta Łapuszek Institute of Water Engineering and Water Management, Cracow University of Technology, Kraków, Poland

In the Upper Vistula Basin there are a lot of check dams located on mountain streams. Most of these streams are currently deeply impacted by the presence of the dams, because they completely disrupt fauna migrations, and the channels of small mountain river downstream which had to be armoured against erosion are inhospitable for both flora and fauna and the imbalance of sediment transport downstream the dams is observed. Moreover, they are now inefficient because their reservoirs are filled up with sediment, so they cause the flood hazard increasing upstream. Furthermore, the dams are in poor technical condition. The research area presented in the current paper comprises thematic and poster sessions 39

Krzczonówka, left-side tributary of Raba River, where rehabilitation works – lowering of a check dam – have been undertaken recently. This activity is a part of the project called ‘The Upper Raba River Spawning Grounds’, which main goal is to restore the continuity of the stream corridor in order to make it possible for fish of the salmon species to travel up the stream again to their spawning grounds in the upstream sections of stream channels. Because of its novelty, the works were in 2013 put under monitoring with the purpose of assessing the morphological changes in stream beds. The paper shows the results of the comparative research on the evolution of stream beds, and sediment transport, when river continuity is broken and after it is restored. The research gives the possibility to assess impact of attaining continuity on the geomorphological state of the channel. The one-dimensional sediment transport model was used to estimate the quantity of sediments transported by balancing inputs, outputs and exchanges with the bottom. High transport of sediments occurs during floods and, particularly in small mountain rivers, one flood may significantly change the morphology of the riverbed. It implies that the model had to integrate unsteady flow and cross-sections changes with time. Modelling the flood event which starts emptying sediment from a dam reservoir was very important part of the study, because the flood flow appeared during the process of removing the dam. The result of the computation acquires knowledge about type and rate of change of stream bed morphology upstream and downstream of removed check dam and makes it possible to verify the existing mathematical model and confirm its validity to similar simulations.

Flood hazard maps and historical inundation maps as a tool for building social consciousness Michał Łyp, Joanna Depta, Jan Nadachowski Institute of Meteorology and Water Management, National Research Institute, Kraków, Poland

Defining and mapping the flood-prone areas is one of the basic tools of spatial quantity of flood hazard and an important scope of spatial management. Necessity of preparation these areas is explicitly expressed in EU and national legal regulations – The EU Flood Directive and the Water Law Act. In the Upper Vistula region the very first activities on that issue were started by the Regional Water Management Board in Krakow with some involvement of the Institute of Meteorology and Water Management as well. The most frequently used solution to determine the flood-prone areas is spatial analysis of one-dimensional hydraulic modelling results. Currently used hydraulic models usually allow to analyze a flood wave transformation in a single- or multi-thread solution. For the areas of a complex cross-sectional geometry, such as wide and flat valley bottom, sub-mountain basins and especially levee-protected areas, usually a multi-thread solution is used. To perform a high hydrological accuracy of model structure, a wide spectrum of spatial data and an experienced hydrologist-modeller are required. Two-dimensional models, especially for vast areas, are much more demanding, due to required compromise between level of generalisation of terrain morphometry and highly time-consuming calculations. For the last 4 years in the Flood and Drought Modelling Center of the Institute of Meteorology and Water Man- agement a set of hydraulic models has been constructed. The models results were used to deliver the flooding maps of 5 types: the map of the flood extend in 2010, the flood hazard maps for selected probabilities of exceedance for embanked and unembanked rivers, the maps of the potential flood zone for embanked rivers, the dike breach flood maps. These maps can be differentiated by type of simulated flow (steady and unsteady) and internal model structure (1D single-thread, multi-thread and 2D). In the rivers free of embankments, which predominate in the upper reaches of upland and mountainous rivers, stream flow is typically concentric and single-threading. In these cases there are no major difficulties in cartographical presentation of flood-prone areas. On the opposite, simulation of flow in embanked rivers is challenging. Despite of existence of above-mentioned variety of flood maps, correct presentation of flood-prone areas remains an actual and unsolved issue. The reason for that can be sought in necessity to maintain constant discharge probability of exceedance along river long profile and hydrological isolation of areas protected by dikes. This is for the practical reasons that river dynamic observations and hydrological processes analysis for embanked rivers are carried out for a cross-section limited by dike crests. Extension of hydraulic and hydrological investigation for embanked zone of valley bottom suffers from strong technical difficulties and methodical restrictions. The purpose of the presentation is to describe and compare historical inundation maps and flood maps for selected scenarios. It also highlights the importance of social perception of dikes as objects which reduce flood 40 thematic and poster sessions

hazard and further, leads to the reduction of social cautiousness and intensification of urbanisation pressure in the flood-prone areas. It is crucial to conduct further research on this problem to gain the best of Flood Hazard Maps. The example of the map considering enhancement of the social flood hazard consciousness, will be presented by the author.

Assessing the potential for hyporheic exchange in river restoration Chiara Magliozzi1, Robert Grabowski1, Martin Janes2 1Cranfield University - School of Energy, Environment and Agrifood, Cranfield, United Kingdom 2The River Restoration Centre, Cranfield University, Cranfield, United Kingdom

The hyporheic zone is an area of ground-surface water mixing within the bed and banks of rivers. It plays an important ecological role as a habitat and region of biogeochemical cycling, and is believed to support water quality improvement (e.g. nutrient and toxin removal). Therefore, a functioning hyporheic zone may be an important component to sustainable river restoration. However, before recommending hyporheic restoration measures, we first need to establish what factors influence the presence and hydraulic functioning of the hyporheic zone, and how existing stream and catchment-scale restoration measures interact to have a cumulative impact. In this study we outline a physical-based framework that links hydrological and geomorphological attributes of the river system to potential hyporheic exchange at a restoration site. From larger to smaller scales, the hyporheic exchange is related to hydroclimatic, hydrogeological and topographical variables that differently enhance or constrain the hyporheic functioning. The framework was developed based on a conceptual understanding of surface-groundwater interactions from recently published reviews, supported by previous studies on hyporheic exchange. The framework was developed and tested by using a range of topographical, geological and hydrological data across restored and unrestored rivers in the UK. Although hyporheic functioning is influenced by numerous variables, multivariate techniques identified the key factors that make the most profound impact on hyporheic exchange. The outcomes of the study directly benefit both our conceptual understanding of the drivers of the hyporheic exchange, and how they interact across spatial and temporal scales. Also it provides a method to preliminarily predict hyporehic exchange and raising the opportunity for targeting restoration sites, methods and criteria for maximizing hydrological and ecological benefits. Finally, the hierarchical approach of the framework would help restoration practitioners approaching the hyporheic zone for a cross-scale perspective, with possible catchment-scale solutions to reach-scale problems.

Flood risk management and governance arrangements in Poland Piotr Matczak, Jakub Lewandowski, Adam Choryński, Małgorzata Szwed, Zbigniew W. Kundzewicz Institute for Agricultural and Forest Environment, Polish Academy of Sciences Poznan, Poland

River floods, in particular caused by rain, are the predominant natural disaster in Poland that cause large material and human losses and are likely to remain a serious hazard also in future. It is assessed that more than 1000 munic- ipalities (out of 2500 in the country) are exposed to flood risk. Urbanisation and urban sprawl processes are likely to increase the amount of impermeable surface, accelerating runoff and growing incapacities of sewage systems in cities are likely to elevate the flood risk. Increase of extreme precipitation in the warming climate is very likely. The present paper thoroughly reviews flood risk management strategies and flood risk government agreements in Poland, The general notion of flood risk management strategies can be divided into such categories as: flood risk prevention; flood defence; flood risk mitigation; flood preparation and recovery. Each strategy embraces a number of measures. Shifts in significance and diversification of strategies have been observed in Poland in last decades. In addition to structural defences (levees, embankments, storage reservoirs) that traditionally dominated, some advances have been noted in flood risk prevention (e.g. zoning) and flood preparation (e.g. flood forecasting and warning). thematic and poster sessions 41

Flood risk governance arrangements can be defined as institutional constellations resulting from an interplay between actors involved in all policy domains relevant for flood risk management, including water management, spatial planning and disaster management. Arrangement embraces dominant discourses; formal and informal rules of the game; and the power and resource base of the actors involved. The Polish flood risk governance arrangement can be characterised as having a strong capacity to buffer shock events, as shown by the 1997 and 2010 floods. Failures of dikes did not shorten financing in the defence-oriented flood risk management – recovery and EU funds were reinvested in hydro-technical infrastructure. Although certain progress has been achieved in terms of institutional learning, much inertia and reliance on the well-established approaches (path dependence) could also be observed. In general, the resilience has not changed dramatically in recent decades, but development was observed in terms of ability to buffer and recover. The Polish flood risk governance arrangement is fragmented with rather underdeveloped bridging mechanisms. Particular parts of the flood risk management are linked to different institutions, with their own interests. There is lack of a national flood risk reduction strategy in Poland, partly compensated by efforts to implement the Floods Directive of the European Union (EU). The accession to the EU in 2004 involved transposition of EU legislation, such as the Floods Directive. It strengthened the position of some actors (such as NGOs) emphasising environmental concern, and the new ideas in flood management (such as diversification of strategies). Indeed, the Floods Directive has had a significant impact on the flood risk management in Poland. Improvements relate to the obligation connected with the preparation of flood hazard and flood damage maps, as well as flood risk management plans. It could be argued that very little improvement in terms of prevention would have occurred without the Directive.

Effect of weirs on ecological integrity of the Biała Tarnowska River Grażyna Mazurkiewicz-Boroń, Ewa Szarek-Gwiazda, Elżbieta Wilk-Woźniak, Elżbieta Dumnicka Institute of Nature Conservation, Polish Academy of Sciences, Kraków, Poland

Regulation and modification of rivers change their hydrology and often deteriorate water ecosystems. Building of dams, weirs, channelizing of rivers, and unsuitable usage of catchment cause decrease of ecological integrity of rivers. Moreover, weirs as physical barriers disrupt the continuity of the river and migration of animals, among them migration of fish. In Poland many submontane rivers have been modified by building of weirs. One of examples is the Biała Tarnowska River with 14 weirs, which occur along the river (total length of the river is 101.8 km). The aim of studies was to determine the ecological integrity of the Biała Tarnowska River before destroying of the weirs. Therefore, during the 2010-2011 several tasks were done: (1) assessment of the impact of catchment basin on the physicochemical and biological (algae, invertebrates) parameters of the river; (2) estimation of the impact of four weirs on the physicochemical parameters of water and concentration of heavy metals in water and bottom sediments. Results of analysis showed increased concentrations of HCO3-, SO42-, Cl-, Ca2+, Mg2+, K+, Na+, NO3-, NH4+, BOD5 and heavy metals (Mn, Fe, Cd, Pb, and Ni) along the river course indicated contamination of river (sewages from cities, wastewaters from villages, and non-point sources difficult to describe) and slow down of self-purifiction processes of the river. Similar to above mentioned factors, also taxons of algae and benthic fauna indicated a considerable contamination of the river. Most of the diatoms and cyanobacteria species are typical for meso- and eutrophic waters, and for α – mezosaproba and ß – mezosaproba zones. Among the benthic fauna, Chironomidae and Oligochaeta dominated in all studied stations, whereas taxa sensitive to pollution (Plecoptera, Ephemeroptera, Trichoptera, and dragonflies from family Gomphidae) were found sparsely. Although small weirs only to a small degree effected concentrations of physicochemical factors and heavy metals in water, they showed slightly stronger impact on increase of concentrations of heavy metals in the bottom sediments. Communities structure of algae and benthic invertebrates did not differ significantly, regardless the sampling sites, but the scarce occurrence of some taxons such as Gammarus sp. and Sphaeriidae may indicate the possible effect of barriers. We stated that weirs in the Biała Tarnowska River were responsible for a slight decrease of ecological integrity of the river. 42 thematic and poster sessions

An original approach to assess river restoration in France: the demonstration sites network Gabriel Melun1, Laetitia Boutet-Berry2, Yorick Reyjol1, Anne Vivier1 1Office National de l’Eau et des Milieux Aquatique, Vincennes, France 2Office National de l’Eau et des Milieux Aquatique, 9, Orléans, France

Many hydromorphological river restoration works have been achieved over the last 15 years under the impulse of the Water Framework Directive (WFD). However, an important lack in the monitoring and assessment of the efficiency of those works still remains and is often reported. In 2010, The French National Agency for Water and Aquatic Environments (Onema) developed a specific methodology to monitor river restoration projects, named “Minimal Scientific Monitoring” (Suivi Scientifique Minimal or SSM). The SSM focuses on the multi-annual evolution of three components of the river environment (hydromorphology, physico-chemical parameters and biota) from an initial state – prior to restoration – till, at least, 6 years after the restoration. On each sites studied, the restored reach is compared to an unaltered one, considered as reference. In addition, all field protocols implemented are standardized (WFD standards) to ensure homogeneous data collection on all stations. The frequency of each type of measurements is also defined. All stations on which monitoring is implemented constitute the “demonstration sites network”, a national project involving water agencies and local water managers. Currently the network has 30 monitoring stations, uniformly distributed on the French territory, and this number is increasing year after year. This approach has a double purpose, both scientific and operational. Scientifically, it aims to generate standardized data on the long term and, more generally, to increase knowledge about the efficiency of the river restoration works at the national scale. Operationally (and therefore at the local scale), this monitoring network will (i) allow the assessment of the physical and biological responses to a particular restoration project, (ii) improve the monitoring methodologies adapted to each restoration measure (remeandering, dam removal, gravel injection, etc.), and (iii) facilitate communication of stakeholders and river managers in a communication purpose regarding restoration measure benefits. If the time scale of restoration adjustments is long, our first data analysis already allows highlighting the effects of rivers restoration on the physical and biological characteristics at the intra- and inter-sites scale.

Island development in a mountain river recovering from channelization and channel incision: the Raba River, Polish Carpathians Paweł Mikuś1, Edward Walusiak1, Bartłomiej Wyżga1, Maciej Liro1, Joanna Zawiejska2 1Institute of Nature Conservation, Polish Academy of Sciences, Kraków, Poland 2Institute of Geography, Pedagogical University of Cracow, Kraków, Poland

Investigations of islands in an undisturbed reach of a Polish Carpathian river indicated that islands are very dynamic landforms and greatly contribute to the overall plant diversity of the river corridor. This was the basis of supposition that re-establishment of islands may be an important factor in the restoration of hydromorphologically degraded mountain rivers. This hypothesis was verified in a study of the Raba River, Polish Carpathians. In the 20th century the Raba was heavily channelized and incised deeply in its mountain course, but a few years ago an erodible river corridor was established in its 3 km-long reach. Resignation from the maintenance of channelization structures about 10 years ago and the passage of two large floods in 2010 and 2014 resulted in up to threefold increase in channel width, re-establishment of a multi-thread channel pattern and development of islands in the river reach in the erodible corridor. Observations in the Raba confirmed previous findings from the Czarny Dunajec that in a highly dynamic mountain river, islands originate as a result of deposition and sprouting of living driftwood of Salicaceae. Moni- toring of islands performed every year between 2011 and 2015 documented an increase in the number of islands in the studied river reach from 28 to 42, in average island age from 2.8 to 4.0 years, in total island area from 0,39 ha to 1,57 ha and in average island area from 139 m2 to 375 m2. However, the increase in these parameters was not steady, but moderated by processes of island erosion by flood flows, island establishment shortly after major floods (increasing the number and reducing the average age and area of islands) and island coalescence in the years without major floods (with the opposite effects on the island parameters). The total number of vascular thematic and poster sessions 43 plant species fluctuated between 158 and 202 in particular years. An inventory of plant species on islands and plots of riparian forest performed in 2012 indicated that islands supported a greater total number of species than riparian forest and that particular islands supported a significantly greater number of biennial and annual plants than riparian forest plots. An inventory performed in 2015 documented similar total numbers of plant species in the two types of habitats and indicated that for any life form of plants, the number of their species on islands did not exceed that on riparian forest plots. These results suggest that at early phases of island re-establishment in a mountain river, when the availability of propagules dispersed by hydrochory is limited, the contribution of islands to the overall species richness of the riparian corridor can be highly variable depending on hydrological conditions and the state of islands in a given year. This study has been prepared within the scope of the restoration project KIK/37 ‘The Upper Raba River Spawning Grounds’ supported by a grant from Switzerland through the Swiss Contribution to the enlarged European Union.

Applying the correct river restoration approach: the importance of reference state and the assessment of potential for geomorphic work Hamish Moir cbec eco-engineering UK Ltd., Inverness, United Kingdom

Successful river restoration cannot be applied with a ‘one size fits all’ type of approach. Different types of river environment and degree of constraint of natural processes require the application of different approaches to delivering restoration. Not only must the specific configuration of a specific river restoration reflect the imposed physical controls at a site (i.e. reflect the reference condition), but there are different general approaches that are best suited to delivering that configuration. These can be summarised through an increasing degree of intervention of ‘do nothing’ – ‘assisted recovery’ – ‘initial condition design’ – ‘functional design’, associated with gradients of increasing physical constraint and decreasing potential for geomorphic work. However, to date, there have been few attempts to quantitatively define and apply this type of framework. In this paper we present an application of such an approach on the River Leven catchment, Scotland. Catchment-wide data on the degree of engineering pressure [based on the Scottish Environment Protection Agency’s Morphological Impact Assessment. System’s (MImAS) ‘capacity used’ score] and indicators of the potential for geomorphic work (combining information of specific stream power and unit channel length sediment supply and storage) are integrated to provide a standardised metric that, 1) prioritises restoration for greatest WFD benefit, and, 2) identifies what type of general restoration approach is appropriate for those prioritised areas.

Social and legal aspects of river restoration and maintenance in Poland Elżbieta Nachlik Institute of Engineering and Water Management, Cracow University of Technology, Cracow, Poland

This paper is an overview of the present-day legal regulations and organizational conditions for river restoration and maintenance in Poland. The following aspects are discussed: (a) regulations used in spatial planing and provisions of the Water Law and the Environmental Protection Law in the context of restoration of natural conditions to enhance river ecosystems and to re-establish floodwater retention in river valleys, (b) provisions regulating the implementation of actions and works regarding restoration of river reaches, (c) provisions regulating the scope and conditions of river maintenance, (d) legal and organizational regulations regarding monitoring of the status of aquatic ecosystems as well as the evaluation of their applicability to control the effects of river restoration and river maintenance. The analysis is presented with reference to the legal and economic regulations pertaining to the regional development policy, conservation of natural resources and biodiversity, flood risk management, energy policy involving the use of hydropower, conditions for the development of tourism and recreation, and urban management aimed at 44 thematic and poster sessions

improving the quality of life. The analysis and the assessment of the social and legal aspects of river restoration and maintenance are illustrated with (a) discussion of the legal regulations enabling public initiative and consultation, and of the effects of the public involvement; (b) practical examples of the plans and implemented river restoration projects in Poland. The examples considered here aimed at (a) improvement of river ecological state (including those in urban areas), (b) enlargement or re-establishment of floodwater retention, (c) providing access to reservoir shoreline zone for the purpose of recreation without degradation of the reservoir’s ecological potential. Finally, the legal and organizational aspects as well as the guidelines for the implementation of river restoration and maintenance actions are discussed in comparison with similar legal regulations, conditions and guidelines in other European countries. The assessment is complemented by indicating a range of necessary manuals and toolbox documents that allow a) enlarging the scope of these actions and (b) their correct implementation and monitoring of their results with regard to the requirements related to river morphodynamic processes and sediment budget.

A collection of river restoration examples in France: building, sharing and updating it, a role for the French national centre for river restoration Josée Peress

ONEMA, French National Agency for Water and Aquatic Environments, Vincennes, France

In order to facilitate the engagement of local river syndicates in charge of implementing river projects into restoring river’s hydromorphology, one of the key requirements for the WFD objective for good ecological status, ONEMA and the six water agencies, decided in 2009 to build together a collection of examples of river restoration projects in France. This selection gathers cases that aimed to restore the river hydromorphology processes through ambitous actions such as weir removal, watercourse remeandering or deculveting. Each case explains what were the motivations to carry out the project, what were the initial objectives of the project, holder and what benefits resulted from the restoration, as well as ecological or social benefits. The examples are written in a non technical manner and are primarily aimed towards river syndicates, their decision makers, who could be interested to find out more about the restoration carried out directly from the project holder, whose contacts details are included in each sheet. The collection is being updated regularly with new restoration cases in order to increase the geographical coverage and to get local examples available for most, totalling now over 100. A search engine allows consulting a selection of cases using simple criteria. A high proportion of the examples concerned weir removal or were aiming also to respond to non ecological objectives such as flood risk reduction or amenity development. Thanks to the creation of the French national river restoration centre, led by Onema and the water Agencies, this collection will be better shared within the networks in France.

“Salmon nursery” creation in the Maronne River Hugues Peyret1, Bernard Mas2, Francois Vandenwalle3, David Clave4 1Hydro Engineering Center, EDF, Le Bourget du Lac, France 2Centre Hydro Production Unit, EDF, Tulle, France 3ECOGEA, Muret, France 4MIGADO, Mouleydier, France

The Maronne River is a tributary of the Dordogne River in the South-West of France. This 92 km long river is equipped with 3 large dams supplying 3 hydroelectric power plants. A 10 km portion of the river downstream of the last dam is accessible for migratory fish, including Atlantic salmon. 30 % of the salmon from the Dordogne basin reproduce in the Maronne River. thematic and poster sessions 45

The 7 km river section above the last power plant is already suitable for fish spawning, but this section is impacted by water level variations due to hydropeaking. Upstream from the power plant, the 3 km river section immediately downstream of the dam is fed with a minimum guaranteed flow and is protected from frequent water level variations. The hydraulic conditions for spawning are good but there is a lack of gravel in the river bed. As a hydropower operator, EDF has developed a project to convert this 3 km river section into a “salmon nursery”. The project consists of gravel supply in the zones of the river where the water depth and velocity conditions are suitable for fish spawning. The first step of the project was developing a hydraulic model of the whole river section in order to identify favourable zones for introducing gravel supply. Following the modeling phase, a 4 year work program was established to supply gravel to the 10 favourable areas. Over the first 3 years of the project (2013-2015), 3000 m2 of potential spawning grounds have been created. Gravel coming from a quarry in the Dordogne floodplain is added to the river with a mechanical digger in autumn, after saving the fish of the concerned area (electrofishing). The biological monitoring of the project has showed that trout and salmon did not need long to take advantage of these new conditions: during the last winter, 159 redds have been counted in this river section. By the end of the program (end of 2016), the river section will have 4500 m2 of spawning grounds, compared to 150 m2 before the project, with a total input of gravel of 1930 m3. The project will extend the possibilities for fish reproduction on the Maronne River and secure spawning, the newly created areas being protected from frequent water level variations. This program is complementary to the mitigation of hydropeaking in the 7 km downstream section, where 200 redds were also counted in recent years.

Block ramps in a mountain stream: how do they fit a natural pool and riffle pattern? Karol Plesiński1, Artur Radecki-Pawlik1, Bartłomiej Wyżga2 1Department of Hydraulics Engineering and Geotechnique, University of Agriculture, Kraków, Poland 2Institute of Nature Conservation, Polish Academy of Sciences, Kraków, Poland

Block ramps are environment-friendly drop hydraulic structures that are increasingly used in grade control of watercourses instead of classical weirs. Well designed block ramps not only reduce channel slope and stabilize the vertical position of streambed but they also enable upstream and downstream fish migration and fit a natural pool and riffle pattern of the watercourse. As such, they should play a role of artificial riffles with pools developed between them, and the distance between particular ramps should be on the order of 5 to 7 channel widths, equal to an average riffle spacing in rivers. We studied a sequence of 25 block ramps constructed in the 2000s on Porębianka – a fourth-order stream draining a 72 km2 catchment in the flysch Polish Carpathians. Four orthophotos of the stream from the period 1999-2015 were analysed to determine how the average spacing between successive ramps was related to stream width and how the channel width and a proportion of gravel bars in the total channel width changed as a result of the construction of the sequence of ramps. During the period of ramp construction, the distance between only 1 pair of ramps corre- sponded to the range of 5-7 channel widths. After 16 years of functioning of the channelization scheme, the channel narrowed markedly and the spacing between three further pairs of ramps became adjusted to the natural spacing of riffles, whereas a vast majority of ramps did not fit it. Two decades ago mid-channel bars and side bars represented 6% and 77% of the total channel area, respectively. After the construction of the channelization scheme, a proportion of mid-channel bars in the total channel area remained similar, whereas that of side bars decreased to 31%. However, too close spacing of the ramps prohibited formation of a pattern of alternate channel bars with a sinuous thalweg between successive ramps and channel bars occur at random positions. The study shows that not only the design of hydraulic drop structures themselves but also their adequate spacing is necessary for the close-to-nature functioning of the structures. 46 thematic and poster sessions

Protecting the habitats of priority bird species of the Vistula River Valley under conditions of intensive pressure of the Warsaw agglomeration Łukasz Poławski Warsaw Property City Management, Warszawa

For the last few years, the City of Warsaw, in cooperation with NGOs, has been making efforts to reconcile the needs of protecting the Natura 2000 areas located within Warsaw borders with the pressure of the developing city. The main activities concern the Special Protection Area Natura 2000 “Dolina Środkowej Wisły” (Middle Vistula Valley). The biggest one is supported by the Financial Instrument for the Environment (LIFE+) and is focused on priority species of birds. The main project objectives are: l restoration of breeding colonies of terns, gulls and other waders belonging to the order Charadriiformes, including the construction of natural and artificial nesting sites, l the improvement of internal cohesion of the SPA Natura 2000 “Dolina Środkowej Wisły” (Middle Vistula Val- ley) by restoration of habitats characteristic for braided rivers, l the improvement of nature protection quality in the Middle Vistula Valley by means of: enhancing the ecological awareness of the citizens of Warsaw in the field of threatened bird species protection, shifting their land-use behaviour in the Natura 2000 area and engaging them in protection actions aimed at birds and natural habitats of the Vistula Valley, l maintenance and enhancement of formal and institutional collaboration between public bodies managing the area, in order to assure the proper nature protection in the SPA Natura 2000 in Warsaw. The above-mentioned activities are implemented also in the Vistula Valley sections in the suburbs and areas surrounding the capital city, which are some of the most important nesting sites for terns and gulls in Poland. About 2-10% of the Polish population of the little tern, the Mediterranean gull and the ringed plover are nesting in this section of the river. The most important breeding sites are located on natural sandy islands in the southern part of the city.

Technical activities in lowland rivers in protected areas - case studies Zbigniew Popek, Michał Wasilewicz Department of Environmental Enginering, Warsaw University of Life Sciences, Warszawa, Poland

In order to improve the environment in rivers and valleys are often necessary technical measures that do not always have the nature of the typical restoration activities. The paper discusses two examples of technical measures, proposed on rivers flowing in protected areas. Estuary section of the Świder River is located partly in the Natura 2000 site “Valley of the Middle Vistula River” and close to the nature reserves area in the Vistula riverbed “Świderskie Islands” and the “Zawadowskie Islands”. The purpose of the proposed action on the Świder River is inhibition of riverbed erosion, by restoring the former natural reach of the river estuary. These actions can therefore be classified as a typical river restoration measures. The second example concerns the River Rawka, that the entire length lies in the nature reserve “Rawka River”. In addition, the lower reach of the river is located in Natura 2000 site “Valley of the Rawka River” and Bolimów Landscaped Park. The Rawka River preserves the natural character of meandering lowland river bed, but in many places there were damming for mill. Long-term impact of dams resulted in the formation of a number of valuable natural habitats, both in the riverbed and in the valley. As a result of the lack of attention to proper technical condition of dams, over time some of them were partially or completely destroyed. In order to inhibit disappearance of valuable natural riverbed and valley habitats, it is necessary to restore the former water level in the river, through the reconstruction of old and construction of new dams. So, improvement of the natural environment requires a “non-standard” measures of restoration in the case of the Rawka River. thematic and poster sessions 47

Fish migration in a European perspective, threats and opportunities Peter van Puijenbroek1, Martin Kroes2 1PBL Netherlands Environmental Assessment Agency, Den Haag, The Netherlands 2Kroes Consultancy, Amsterdam, The Netherlands

Dams are a major problem for migratory fish species, as dams can block entire rivers. Most migratory fish species are protected in the Habitat Directive and are listed in the IUCN Red list as extinct or threatened. In the Water Framework Directive (WFD) fish migration is important to achieve a good ecological status. Water authorities are working hard to improve fish migration, but there is also the risk of building new dams for energy production, shipping or irrigation. Although there is much information available about rivers or fish passages, a European overview including plans is not available. In this project, we made a detailed study of fish migration in some major river basins of nearly all European countries and of plans to improve or deteriorate fish migration possibilities. Energy production is the most important driver and with an increasing demand for electricity, more hydropower is needed. Policy to mitigate climate change results in more electricity from solar and wind, which will lead to more fluctuating electricity prices. Fluctuating prices are an incentive for cascade and water storage systems and more intensive use of water systems. Current plans show many major dams, mostly in former Yugoslavia, and many small hydropower dams in all countries of the EU. With climate change, more summer droughts are expected in south Europe, which will led to a higher demand for irrigation water. The Loire in France and the Torneälven on the border of Sweden and Finland are examples of two of the few rivers that are accessible for migratory fish. Responses to mitigate fish migration have taken place in the Rhine and Elbe, and in the Vindelälven in Sweden, which are partly or fully accessible again. The Iron Gate dams in the Danube have the most impact on migratory fish as they block the middle and upper reaches of the Danube from the Black Sea. Adaptation responses are stocking of hatchery reared fish or stocking of fish caught before the hydropower dam and stocked up- or downstream. Angling is an important driver for adaptive responses, as in many rivers are salmon smolts stocked, or mitigation responses on a small scale, for example the island Fyn in Denmark. We conclude that lowland rivers in west and middle Europe have opportunities to improve fish migration; in southern Europe, the intensive use of water will further compete with ecological demands. The downstream part of the Danube and tributaries are still accessible for migratory fish, but most plans for new hydropower dams are planned in the Balkan and Danube region. The two Iron Gate dams in the Danube are the barriers with utmost priority in Europe for fish migration, as they enclose a major part of the Danube catchment and block migration for several endangered sturgeon species. Environmental policy, standards for ecological flow and fish migration, spatial planning of hydropower and research for measurements for downstream migration in combination with hydropower are needed for sustainable populations of migratory fish species.

Integrating the Geomorphic Units survey and classification System (GUS) with mesohabitat simulation models Massimo Rinaldi1, Paolo Vezza2, Barbara Belletti1, Martina Bussettini3, Francesco Comiti4 1Dipartimento di Scienze della Terra, Università di Firenze, Firenze, Italy 2International Centre for Ecohydraulics Research, University of Southampton, Southampton, United Kingdom 3Dipartimento Tutela Acque Interne e Marine, Istituto Superiore per la Protezione e la Ricerca Ambientale (ISPRA), Roma, Italy 4Facoltà di Scienze e Tecnologie, Libera Università di Bolzano, Bolzano, Italy

The spatial scales of geomorphic and smaller (hydraulic, river element) units are the most appropriate to assess the presence and diversity of physical habitats. Geomorphic units (e.g., riffles, pools, etc.) constitute distinct habitats for aquatic fauna and flora, including temporary habitats (e.g., refugia from disturbance or predation, spawning, etc.). In ecohydraulics, geomorphic and hydraulic units are generally associated with the mesohabitat or biotope scale, while river elements coincide with the microhabitat scale. To clarify concepts and linkages between disciplines, a Geomorphic Units survey and classification System (GUS) was developed in the framework of the REFORM 48 thematic and poster sessions

project. The system is fully incorporated within a multi-scale, hierarchical framework for the analysis of river hydromorphology, can be integrated with the Morphological Quality Index (MQI), and allows the establishment of links between hydromorphological and biological conditions. In this work, GUS is used to integrate a mesohabitat simulation model (MesoHABSIM) and to assess spatio-temporal alterations of habitat structure in Italian rivers. Specifically, two habitat indices, based on GUS and MesoHABSIM, were developed and applied to assess habitat integrity in different river environments. Results show the potential of linking this classification of geomorphic units to habitat evaluation, in order to provide useful indicators that can be used for both hydro-morphological and ecological status assessment.

Spatial patterns and temporal dynamics of fine sedimentation in estoredr floodplain channels (Rhône River, France): actual trends and assessment of their potential persistence as aquatic habitat Jérémie Riquier1, Hervé Piégay1, Nicolas Lamouroux2, Lise Vaudor1 1CNRS, UMR 5600 – Environnement-Ville-Société, Université de Lyon, Site ENS de Lyon, Lyon, France 2IRSTEA – UR MALY, Villeurbanne, France

The design of floodplain channel restoration projects is poorly informed by theoretical or empirical experiences, even if we observe an increased number of such projects in recent decades. Moreover, feedbacks regarding their hydromorphological adjustments are rarely shared, despite the importance of such processes in controlling the persistence of floodplain channels as aquatic habitats. In this study, we used between five and seven monitoring campaigns, ranging from 7-15 years after restoration, to describe spatial patterns and temporal dynamics of fine sedimentation in 16 floodplain channels of the Rhône River (France), which were restored between 1999 and 2006. During surveys, water depth and fine sediment thickness were measured longitudinally along the centerline of channels. We also quantified the upstream overflow frequency and magnitude (i.e. maximum shear stress) and the maximum magnitude of backflow events to explore statistical relationships between forms and processes and identify geomorphic types and laws. We found a high variability of average fine sedimentation rates both in space (i.e. between channels) and time (i.e. from restoration to the final survey). Overall, average rates ranged from 0 cm to 40.3 cm.yr-1, with a maximum of 90.3 cm.yr-1 observed in a particular side-channel. Scouring processes were detected in all floodplain channels, except one. Several channels exhibited a significant decline in sedimentation rates over time, whereas others maintained rather constant rates. For the 16 studied channels, six channels exhibit no dependence upon the time span since restoration (i.e. self sustainable channels) and the 10 others are time-dependant (i.e. they tend to accumulate more and more fine sediment deposits as post-restoration time elapses). Among these 10 channels, four are high life-duration channels (i.e. more than 100 years), three are intermediate life-duration channels (i.e. likely from about 40 to 80 years) and three others are low life-duration channels (i.e. likely from about 15 to 50 years). We also demonstrate that the propensity of restored floodplain channels to sequester fine-grained deposits can be well predicted using simple hydrological and/or hydraulic metrics (i.e upstream overflow frequency, maximum shear stress and maximum magnitude of backflow events). These metrics reflect the control exerted by the geometry of floodplain channels (i.e. morphology of the upstream alluvial plug, slope conditions) on their flooding regime. By allowing the quantification of how technical decisions relative to the design of channels can affect their propensity to accumulate fine sediments, empirical relationships developed in this study are of great interest for managers. The associated estimates of potential life span ranges can be very useful to provide a design life estimate for constructed floodplain channels and to guide project design for future restoration efforts in the Rhône River. thematic and poster sessions 49

Short and mid-term fish community monitoring of a recently created reach of a lowland river, by-passing a gravel-pit Nicolas Roset1, Sandro Parussatti1, Michael Sadot1, Francis Lorieau1, Pascal Brochard2 1The French National Agency for Water and Aquatic Environments, Bron, France 2The French National Agency for Water and Aquatic Environments, Bourg-en-Bresse Cedex, France

In order to reduce the impact of a gravel-pit, built in the riverbed of the Veyle River, a 4-order lowland river of the Rhone-Alps region in the east of France, a new 2 km reach has been created to by-pass the gravel-pit. A fish community monitoring has been designed to : – study the short-term colonisation dynamic of the new reach by fishes ; – start a long-term assessment of ecological benefits of the restoration. 1/ The short-term survey program started few weeks after flowing the new reach (November 2009). Four electrofishing sampling sessions were carried out in March, May, July and September 2010 at 5 sampling sites: 3 located in the restored river bed and 2 controls (upstream and downstream restored reach). Our results show that few weeks after flowing the created riverbed, a multispecies fish community settled, despite the hard winter hydro-climatic conditions and the very poor habitats. Dominant species are either pioneer exotic species such as Pseudorasbora or the most frequent species in the area such as gudgeon, roach, stone loach, chub and dace. Those species show a huge density increase reaching a maximum in summer. Dominance between species is changing from date to date, leading to a kind of temporary balanced community in September. During that short-term survey, small-size fishes were strongly dominant, due to the high “colonisation” capacity of those cohorts, in relation to the poor habitats. 2/ The mid-term monitoring consists of sampling every year during the first three years after flowing and then every three years. We examine the results of the fish community sampling in 2010, 2011, 2012 and 2015. The results show that for two sites (upstream and downstream parts) of the restored reach, the densities of the dominant species (chub, gudgeon, and at a lesser extent stone loach) strongly decreased during the first three years (2010->2012) and then stabilised. For the third restored site, chub and gudgeon increased between the first two years before decreasing; while stone loach and Asian-gudgeon (Pseudorasbora parva) increased during the first three years (2010- >2012), before strongly decreasing three years after (2015). But during the same period, control sites also exhibit similar temporal evolution suggesting the influence of common hydroclimatic conditions at the basin scale, and/or that colonisation process took place from adjacent control sites to restored sites during first two-years; and was then reverse from restored to controls. As a first conclusion, we can say that the colonisation of fish in the restored river bed was very fast, due to pioneer species and/or juveniles. The fish community reached a first equilibrium within a couple of years; but the mid-term samples five years after flowing suggests that competition and/or emigration processes still occur and that equilibrium is not fixed but dynamic. The restoration success is then a temporally relative concept.

Natura 2000 and overall biodiversity in the context of the river maintenance in Croatia – Are nature protection measures a guarantee for sustainable management? Marija Sabolić1, Daniela Schneider1, Petra Lunko1, Neven Trenc1, Aljoša Duplić2 1Croatian Agency for Environment and Nature, Zagreb, Croatia 2Aljoša Duplić, Karlovac University of Applied Sciences, Karlovac, Croatia

In Croatia, all natural and artificial watercourses are managed by State’s water management agency Croatian waters. At the end of each year, Croatian waters prepare the annual Programme of maintenance works regarding protection against adverse effects of water (flood protection) for the following year. In accordance with the nature protection legislation in Croatia, natural resources management plans include nature protection conditions, and appropriate assessment is conducted for those plans which can have a significant impact on conservation objectives and integrity of Natura 2000. National expert institution for nature protection, Croatian Agency for Environment and Nature (CAEN), participates in this procedure by proposing nature protection measures and giving an expert opinion within the appropriate assessment procedure. For the purpose of evaluating this Programme, CAEN has developed 70 stan- 50 thematic and poster sessions

dardized nature protection measures for 11 groups of maintenance works, based on good practice examples from the literature as well as best available scientific data. These measures address to the conservation of biodiversity in general and ecological needs of the Natura 2000 target species and habitat types, with respect of conservation objectives of sites. Issuing of nature protection measures has started in 2012. Experiences so far had shown that in some cases nature protection measures were taken into account, fully implemented and have helped to maintain natural values of areas. On the other hand, in some cases valuable natural habitats were adversely affected by failing to implement proposed protection measures, while at the same time flood protection system was not significantly improved. The most important factors in good practice examples were effective dialogue between water and nature protection sectors as well as collaboration with nature protection public institutions on the county level. The biggest problems were and still are: the lack of education and training for contractors implementing the water management works, lack of control of implementation of issued measures as well as lack of monitoring of their efficiency. Fur- thermore, assessment of cumulative effects of the Programme is a demanding task that represents a challenge for nature protection sector and has not yet been fully addressed. Although a step forward has been made in a short time regarding nature conservation in the context of flood protection, this issue should be brought on a long-term strategic level at which solutions with less significant nature impacts could be devised.

Application of large wood in navigable rivers to increase biodiversity Margriet Schoor1, Wendy Liefveld2, Miguel Dionisio Pires3, Alexander Klink4, Prisca Duijn5, Henk van Rheede1, Luc Jans1, Arjen Sieben5, Wijnand Blaauwendraat6 1Rijkswaterstaat, Maastricht, The Netherlands 2 Bureau Waardenburg, Culemborg, The Netherlands 3Deltares, Delft, The Netherlands 4Hydrobiologisch Adviesburo Klink, Wageningen, The Netherlands 5Rijkswaterstaat, Lelystad, The Netherlands 6Blaauwendraat Landschapsverzorging, Renswoude, The Netherlands

In the river Rhine in the Netherlands, flood control, water quality and navigation are important functions that have to co-exist. To improve the ecological status of the river, several side channels have been restored in the floodplains over the last twenty years. These new habitats locally increased riverine biodiversity, but at the same time were invaded by alien species, both fish and macroinvertebrates. One of the reasons these invasive species dominate the river communities may be the absence of natural substrate, such as wooden logs that are removed from the water for safety reasons, but is crucial for the settlement of endemic species. Therefore, in 2013 and 2014, we placed fixed trees with branches and roots on the river bed in several groyne fields and side channels. The goal of this innovative restoration method is to add diversity in structure and substrate under water and to increase habitat and hydro-morphological variation. These large woody structures are properly secured, to exclude hinder of shipping and are placed parallel to the river flow to minimize increase in flood levels. We collected data on macroinvertebrates and fish on the wood and in reference locations. Macroinvertebrates were sampled by either subsampling, or lifting an entire tree and collecting all animals on it. Fish were sampled by a combination of electro, beach seine net and fike fishing. Macroinvertebrate community was assessed by comparing the number of native versus alien species on wood and comparing that to samples of stones and by calculating the Ecological Quality Ratio (EQR) for these habitat types. For fish, densities, composition and Shannon-Wiener indices were calculated at both habitat types. Additionally, the differences between day and night were investigated. The preliminary results of two years of monitoring will be presented at the conference and the different functions of the large wood will be discussed. thematic and poster sessions 51

Innovative wood constructions for river maintenance and ecology in the Dutch Rhine Margriet Schoor1, Miguel Dionisio Pires2, Wendy Liefveld3, Arjan Sieben4, Henk van Rheede1, Luc Jans1, Prisca Duijn4, Alexander Klink5, Wijnand Blaauwendraat6 1Rijkswaterstaat, Maastricht, The Netherlands 2Deltares, Delft, The Netherlands 3Engineering, University of Bureau Waardenburg, Culemborg, The Netherlands 4Department of Geosciences, University of Padova, Rijkswaterstaat, Lelystad, The Netherlands 5Hydrobiologisch Adviesburo Klink, Wageningen, The Netherlands 6Blaauwendraat Landschapsverzorging Renswoude, The Netherlands

Traditional river maintenance in the Dutch Rhine is mainly focused on ensuring that navigation is not hampered and flood waves are rapidly discharged. Therefore, groynes have been constructed, parts of shorelines are protected by rip-rap and the river is frequently dredged. At the same time however, water managers also aim to improve the ecological functioning of rivers, especially under the Water Framework Directive (WFD). In the Netherlands, Rijkswaterstaat recently combined river maintenance and biodiversity goals by utilizing different types of wood constructions. Two examples are discussed below. Erosion of ecological valuable riparian grasslands is a frequently occurring problem in the Beneden Lek, a freshwater tidal branch of the Rhine with a tidal amplitude of 1.5 metre. The floodplains are small and therefore land loss should be avoided. Traditional river maintenance would apply rip-rap as a protective structure, but as this is an unnatural substrate in a tidal lowland river, rip-rap mainly attracts alien species. Therefore, an innovative wood construction is designed, which, besides rehabilitating riparian grasslands, will probably also be beneficial to aquatic life as well. The River Rhine is characterized by high concentrations of suspended sediment. Locally the sediment deposits on the river bed, reducing navigability of the fairway. Frequent dredging is therefore necessary, but this is costly. If the flow direction of suspended sediment can be steered towards the river banks (away from the fairway) by some kind of physical structure in the river, then less dredging is required to keep the fairway navigable. Additionally, deposition of sand along the river banks may have positive effects on the ecology and the physical structures may provide shelter and natural substrate for several aquatic species and hence contribute to the biodiversity of the river. Therefore, at the location Redichem in the River Rhine, a set of four wooden screens were constructed in an inner bend of the river. If there is a positive morphological effect, more sets will be placed. In the poster, both designs will be explained.

Evolution of channel morphology and controlling factors in a large alpine river over the last 250 years Vittoria Scorpio1, Marco Mastronunzio2, Matteo Proto2, Simone Zen3, Walter Bertoldi3, Elena Dai Prà2, Francesco Comiti1, Nicola Surian4, Guido Zolezzi3 1Faculty of Science and Technology, Free University of Bozen-Bolzano, Bolzano, Italy 2Department of Humanities, University of Trento, Trento, Italy 3Department of Civil Environmental and Mechanical Engineering, University of Trento, Trento, Italy 4Department of Geoscience, University of Padova, Padova, Italy

The knowledge of evolutionary trajectory and the evaluation of its control factors are largely recognized as fundamental prerequisites for correctly interpreting current channel conditions and for the prediction of future scenarios. Furthermore, they allow the assessment of potentials and limitations for channel recovery in the process of proposing sustainable policies of river restoration and management that fully account for past, present and desired system trajectories. Many large rivers in Europe have been subject to heavy modifications for land reclamation and flood mitigation through centuries. As a consequence, the study of the pre-alteration morphological patterns and of the related channel evolution following the anthropic modifications is rather challenging. 52 thematic and poster sessions

This study aims at the reconstruction of the Adige River’s evolutionary trajectory over the last 250 years and the comprehension of key control factors driving channel evolution. Those analyses are particularly difficult because of the long duration of human effects and the heavy channel engineering occurring since the first decades of the 19th century. Currently, the Adige features a straight to sinuous pattern and an average channel width of 40-60 m, it can be considered one of the most altered rivers in Italy, not only due to channelization but also to the presence of many hydropower reservoirs and check-dams along its tributaries. A multi-temporal analysis of historical maps and orthophotos from 1776 to 2006 was performed in order to assess channel modifications. In addition, land use changes at the basin scale, years of occurrence of most relevant flood events, and climate variability were analyzed. The detailed topographical map surveyed in 1803 was taken as a reference, and the study sector (115 km long) was divided into 39 reaches. Active channel, bars, riparian vegetation and channel control works were geo-processed. Results show that the Adige River suffered the most intense alteration from 1803 to 1855, and especially from 1847 to 1855. During this period channel narrowing ranged from 14% to 70%, coupled with pattern changes and decreases in the braiding, sinuosity and anabrancing indices. Most important alterations occurred in the reaches pre- senting a multi-thread morphology in 1803, as their average width declined from 220 m to 110 m. On the contrary, reaches originally sinuous remained quite stable. Overall, relevant channel morphology modifications took place by 1855, when channel configuration had shifted from alternating longitudinal sequences of multi-thread and single-thread, at the beginning of the 19th century, to mainly single-thread. Total length of multi-thread reaches shifted from 31% in 1805, to 22% in 1847, and to 8% in the 1855. On the contrary, sinuous and straight patterns increased from 26% (in 1803) to 62% (in 1847), up to 77% of the whole studied river length in 1855. Nevertheless, overall increases in channel braiding and mean channel width were observed downstream of the confluences with the main tributaries. Analysis of the evolutionary trajectory of channel morphology and of controlling factors shows that human disturbances have largely prevailed over climatic influences in constraining the Adige’s dynamics and morphology, mainly because of channelization. Future perspectives aim to the prediction of possible morphological evolution under the scenario of no channelization, and the assessment of the effects of possible restoration actions.

Recent channel adjustments in a major river of southern Italy: state of degradation and recovery potential Vittoria Scorpio1, Carmen Maria Rosskopf2 1Faculty of Science and Technology, Free University of Bozen-Bolzano, Bolzano, Italy 2Department of Biosciences and Territory (DiBT), Molise University, Pesche, Isernia, Italy

Recent river corridor changes and recovery potential of the Fortore River (southern Italy) are analyzed in this study. The Fortore River, ca. 110 km in length, flows to the Adriatic Sea cutting transversally the Apennine chain, and is affected by the Occhito Dam located about 60 km from the river mouth. A multi-temporal GIS analysis covering the period 1954-2014 was performed using topographic maps, aerial photos and orthophotos and integrated by field surveys and DGPS topographic measurements with the main aim to assess the present river morphology and dynamics. The obtained results highlight that the Fortore, as many other Italian rivers, has undergone relevant river corridor adjustments over the last 60 years which have occurred in two distinct phases. During the first phase, from the 1950s to the end of the 1990s, all study reaches, located both upstream and downstream the Occhito Dam, were affected by channel degradation and very intense alterations, particularly channel narrowing from 51% to 98%, channel configuration changes from multi-threaded to single-threaded pattern, considerable reduction of the number and surface of bars, and channel-bed lowering of 1 to 4.5 m. Meantime, floodplain and terrace areas increased highlighting the lowering of the water level and alterations of sediment regimes. The reduction of the hydrological functionality caused also the degradation of the riparian habitats. Adjustments are considered to be primarily driven by human disturbances, especially gravel mining, construction of weirs and levees and the closure of the Occhito dam in 1967. During the second phase, from 2000 to 2015, the reaches located upstream the dam were affected by channel widening of up to +15%, the increase of bars and the reduction of floodplain areas. This trend inversion seems to be primarily linked to major flood events from 2000 onwards, especially those occurred in 2003, 2005, 2010 and October 2015. The reaches located downstream the Occhito dam, instead, are completely stable since the 1990s. thematic and poster sessions 53

Recent channel recovery and the moderate to high connectivity of reaches located upstream the Occhito dam allow considering them as reaches with a relatively high recovery potential. Good connectivity conditions are especially due to the main channel well coupled with the hillslopes and tributaries and the scarce to nil influence of bank protection structures being no longer in contact with the river banks. In these reaches, interventions aimed at river restoration could produce positive effects on both morphological functionality and biological communities. The reaches located downstream the dam, instead, are characterized by very low connectivity due to overall very scarce lateral and longitudinal sediment inputs and consequently nil recovery potential. For these reaches, only some interventions in order to avoid further channel degradation can be currently considered, also considering that they present priorities in flood risk management.

Modelling river channel response to changes in discharge and riparian vegetation at the reach scale Kalina Sikorska Queen Mary University of London, London, United Kingdom

Flow magnitude, slope, sediment dynamics and vegetation are the most important controls of river morphology. Cli- mate change is predicted to increase river flows in the future, however vegetation can possibly mitigate the effects of increased flow magnitude. The aims of the study were: l to explore the effect of increasing flow magnitude in steady state on channel planform and sediment yield, l to explore the impact of bank stability on channel planform and sediment yield, l to explore the extent to which the bank stability will mitigate the effects of increased flow. The reach modelled was a braided section of the River Liza located in the Lake District, Cumbria, UK. Its flashy regime makes it highly responsive to climate change. The site is undergoing reforestation, that could potentially increase bank stability of the river. CAESAR-Lisflood was used to model the reach response to the 2-year flood increased up to 60%, in steady state. Three values for lateral erosion rate were chosen as a proxy for bank vegetation. Low stability category showed little response to climate change, with the widest and shallowest channels, and a classic braided planform across all the runs. Medium stability category showed the highest sediment dynamics’ variability and medium results otherwise. Very stable banks led to the highest sediment yield, the least amount of total deposition, the deepest channels and planforms resembling the anabranching type across all the runs. More stable banks favour bed degradation and result in increased channel capacity. This, together with higher sediment yield, can increase flood risk downstream. It is recommended to conduct a similar study in catchment mode, where important hillslope processes are accounted for. Also variable flow analysis may be required to cause channel avulsion. Similar research could prove vital in restoration planning.

Energy of flowing water of flysch gravel-bed stream – a way to the smart management of incised rivers? Václav Škarpich, Tomáš Galia, Jan Hradecký Department of Physical Geography and Geoecology, Faculty of Science, University of Ostrava, Ostrava-Slezská Ostrava, Czech Republic

The rivers draining the Czech part of the flysch Carpathians have deeply incised their beds over the last 60 years. The original gravel-bed character of these anabranching rivers, with a high amount of transportable material, was changed to an incised single-channel pattern. This contribution focuses on the Olše River in the Czech part of the flysch Carpathians and summarises the results of the increased energy of flowing water of contemporary channel. Comparison of geodetic measurements from 1960 and 2003 was used together with assessment of aerial photos from 1950s and present. The average width of the studied reach of the active Olše River channel narrowed from 35 m in 1955 to 24 m in 2010. In some locations, the original river bed has lowered as much as 2.3 m between the 54 thematic and poster sessions

years 1960 and 2003. The average incision in the studied reach is approximately 0.54 m between 1960 and 2003. Morphology of the channels has accelerated these erosion processes. The main reason for this is an adjustment of flow dynamics. The parameter of stream power is commonly used to express the energy exerted against the channel boundaries (i.e., banks and river bed). The unit stream power and hydraulic radius values of analysed cross-sections have increased two to three times from 1960 to 2003 for 5, 20, 50 and 100 recurrence interval discharge. All studied cross-sections show the progressive incision, however some of them show decreasing values of the unit stream power from 1960 to 2003. Total incision for those cross-sections with the decreased unit stream power values from 1960 to 2003 is 0.10-0.21 m. It may reflect that the incision of channel greater than ca. 0.2 m for the studied period was affected especially by the additional change in cross-sectional geometry (i.e., channel narrowing). The lower values of incision (ca. <0.2 m) may reflect other factors such as the sediment disruption operating in the basin (e.g., they are linked with the land-use changes, sediment stabilisation in the basin, and effect of hungry water). Thus, the energy of flowing water is the leading factor influencing the propagation of incision of flysch gravel-bed channels.

Assessment of dam impact on longitudinal sequences of in-stream habitats

Marie Spitoni, Hervé Piégay, Lise Vaudor University of Lyon, Environnement - Ville - Société Laboratory; CNRS-UMR 5600, ENS of Lyon, Lyon, France

Mesohabitat characterization is a key issue for evaluating river physical status. Nevertheless, riffle-pool frequency is sensitive to human pressure, such as a modification of sediment transport, following damming. Most of the studies assessing morphological impacts of dams focused on bed incision or bar grain size. Only very few studies assessed impacts on flow channel (macromorphology of the bed, submerged grain size). It is nowadays shown that it is possible to extract water depth from aerial images. This technique allows to characterize bedforms and their evolution considering the increase of the number, quality, frequency and accessibility (i.e. cost and authorizations) of remote sensing data over the last decades. The present study focuses on the lower Ain valley, upstream of which a series of dams were built from 1930 to 1970. The 20 km long study reach integrates both a dams-impacted section and a natural one, not affected by damming yet. Our aim is then to assess whether longitudinal changes in water depth have evolved following dam building. The hypothesis to validate is that pool-riffle sequence is well developed over the whole study section in 1963, while it is no longer so in the upstream section in 2012 which is affected by sedimentary deficit and morphologically simplified due to sediment starvation. Water depth was extracted from pixels intensity of each aerial image (IGN, 50 cm resolution) to get a signal of the longitudinal depth profile. One was selected in 1963 and another in 2012. A field survey done in 2012 has been used to check accuracy of radiometric depth extraction. Next, differences of amplitudes obtained from signal processing were analyzed in order to differentiate bedform diversity on the reach under study. In the same time, riffle-pool detection from both photo-interpretation and semi-automatic procedure was performed. Both methods were compared in order to validate the semi-automatic method. The analysis of the bathymetric signal confirms that in 1963 and downstream in 2012, Ain water depth structure is diversified but homogenized upstream in 2012. Mesohabitats extracted by photo-interpretation overlap successfully both depth signal and semi-automatic extraction. These results provide a significant potential for applications to other rivers. Such a methodological framework could be extended at a regional scale for responding to managers and decision maker expectations for implementing the Water Framework European Directive. Indeed, understanding morphological impact is a challenge to better locate and prioritize restoration actions. thematic and poster sessions 55

Numerical modelling of flow dynamics on a gravel bar during high discharge: mountain river Andrzej Strużyński1, Ludivine Bouchet2, Dorota Giriat 3, Maciej Wyrębek1, Krzysztof Kulesza4 1Department of Water Engineering and Geotechnics, University of Agriculture, Kraków, Poland 2National School for Water and Environmental Engineering, Strassbourg, France 3Faculty of Geography and Regional Studies, University of Warsaw, Warsaw, Poland 4Institute of Meteorology and Water Management - National Research Institute, Board of Water-Management Systems, Kraków, Poland

Channel bars are important features in river morphology. Their form and composition reflect the river flow as well as valley morphology. Different kinds of bars exist. They could be e.g. mid-channel, transverse or side-bars, with or without vegetation and with different size particle. The structure and formation of bars can provide an information about sediment discharge activity at a reach scale. Their shape or number depend on sediment discharge. Modelling bars, river flow or sediment transport is an easy way for helping engineers to predict consequences or to oversee river activity. Recently, thanks to the development of data technology acquisition, numerical terrain modelling and GIS software, in many studies modelling of channel evolution and sediment transport is performed. This paper focuses on a typical gravel bar located in a Carpathian river, the upper Wisłoka. This gravel bar has quickly grown within the five last years and no modelling was done before. Presented one was made with CCHE2D software, created and designed by NCCHE (National Center for Computational Hydroscience and Engineering) of the University of Mississippi School of Engineering. The model represents the bar feature as well as the river itself and tries to be the most representative possible. Field data was gathered in 2015. In the paper the velocity and shear stresses during different flows were analyzed. These flows were in a range of low, average and high annual ones (including 1% flow). Additionally the bed size data has been gathered here. Modelling results have been analyzed in two stages. First is the values and the second is the energy spread analysis. During the smallest discharges (3 and 30 m3/s) water flows only trough the main channel. Since 45 3m /s also left branch starts conducting water. The modelled velocities and shear stresses indicate the strong influence of the bar shape on the distribution of water flowing in the Wisłoka River during floods. Maximum stresses location and flow direction during flood rise change in different way within channels and the bar itself.

Potential impact of deflectors on sediment transport in the downstream part of the Flinta River assessed on the basis of modelling and simulation Ewelina Szałkiewicz, Tomasz Dysarz, Tomasz Kałuża, Albert Malinger Department of Hydraulic and Sanitary Engineering, Poznan University of Life Sciences, Poznań, Poland

The main purpose of the presented research is assessment of deflectors impact on sediment transport in the downstream part of the Flinta River. Deflectors are designed to change longitudinal profile of the watercourse in such a way that the stream meanders. It is assumed that the modification of flow area initiates sediment accumulation in zones between deflectors. The final expected effect is the formation of real meanders, what should be an element of river restoration. Due to the fact that the deflectors do not exist yet, the analysis is mainly based on simulation with specially prepared hydrodynamic model. The research is conducted on a selected reach of the Flinta River located in the north-western part of Poland. There are four types of data used in the preparation of the simulation model. These are (1) digital terrain models, (2) river geometry data, (3) hydrologic data and (4) sediment samples. The digital terrain models (DTM) are obtained from Geodesic and Cartographic Documentation Centre (in Polish. Centralny Ośrodek Dokumentacji Geo- dezyjnej i Kartograficznej – CODGIK) according to acts determining access to public information. The results of the field measurements made by BIPROWODMEL company are the basis for elaboration of cross-section data. The hydrologic data are obtained from the Institute of Meteorology and Water Management (in Polish. Instytut Meteorologii i Gospodarki Wodnej – IMGW) on the basis of written agreement between our University and IMGW. Additionally, the samples of the bed sediments were taken along the selected river reach. 56 thematic and poster sessions

The well known HEC-RAS software is used to prepare the hydrodynamic model. Preliminarily, the terrain and cross-section data were processed with help of ESRI software, ArcGIS 10.3 with GeoRAS plug-in. Two computational geometries are used: (a) without deflectors representing current stage of the river reach, (b) with deflectors representing designed stage. Because the deflectors are non-standard hydraulic structures, they are represented by specially constricted cross-sections in the computational geometry. The computations are made for 5 periods of 10 years length. The intensity of sediment transport is calculated with two formulae, namely (1) Meyer-Peter and Muller, and (2) Engelund-Hansen. Due to the problems with calibration of the model roughness, the basic uncertain- ty assessment is performed. On the basis of obtained results, the average expected changes of the bed elevations and amounts of transported sediment are determined. The results are presented as longitudinal profiles and cross-section graphs.

‘Commando’ among plants – Petasites kablikianus as an example of plant useful in bioengineering methods Aldona K. Uziębło, Wojciech Zarzycki Faculty of Biology and Environmental Protection, Silesian University, Katowice, Poland

This presentation is aimed to present glabrous butterbur (Petasites kablikianus) as a species perfect to use in bioengineering methods in the valleys of mountain streams and rivers. The species is seemingly quite common in montane areas of the Carpathians. Seemingly, because it is being during expansion on lower altitudes, occurs numerously only along some streams, most of which have sources in high mountains. It indicates its high-mountain character and its potential to spread along watercourses. His specific habitat requirements make it inhabit most numerously gravel bars of mountain streams (habitat Natura 2000 code 6430-2), landslides and gravel roadsides. Many years of research have shown that it is a typical pioneer species, very efficiently colonizing initial habitats which appeared after floods or after prolonged rainfall leading to destabilization of steep slopes in river valleys. On the other hand, natural existence of butterbur communities in such places is threatened by excessive human impact (trampling, regulation of riverbeds). The fact that the glabrous butterbur is a clonal plant with modular type of growth, characterized by thick, extremely fast-growing rhizomes, strong root system, easily renewing from even small fragments of rhizomes, distinguished by significant production of biomass, as well as producing a huge number of anemochorous seeds. All of this makes it an ideal plant to use in so-called bioengineering methods to strengthen loose and stripped of vegetation cover areas, especially those with a greater slope on which the succession could be difficult. This is facilitated by the appropriate root-shoot ratio, which ranks it near willows, so often used in bioengineering. The use of easy to obtain diaspores (fragments of rhizomes, seeds) of this species to support faster restoration of plant cover in areas damaged by natural disturbances or anthropogenic pressure (gravel exploitation) on the one hand would give the opportunity to relatively cheap repair of the damage, allows to quickly overcome the effects of surface erosion and stabilization of the substrate. At the same time, it could be a form of conservation of the species within its natural range of distribution, but in places where it would not be able to appear because of the distance from the nearest natural sites. Similar abilities to colonize initial habitats exhibit closely related species Petasites hybridus (occurring at lower altitudes in Europe) and P. paradoxus (native to the Alps).

Making a change in the life of riverine species – removal of 300 barriers in northern Sweden Tommy Vennman, Henrik Karlborg County Administration Board of Västerbotten, Sweden

Many animals and plants that live in streams are dependent on migration during certain stages of their lives, to spread and to reproduce. For fish, migration is vital in order to move between spawning grounds, nursery grounds and feeding grounds. thematic and poster sessions 57

The project Remibar has removed migratory barriers in five larger water systems in the northern part of Sweden. The work was conducted within the network of Natura 2000, and the goal was to improve the conditions for the target species salmon, freshwater pearl mussel, bullhead and otter, along with their habitats. The project represents one of the largest freshwater initiative in Sweden. A total of 300 migratory barriers, both culverts and dams, have been removed. In Sweden there is a road crossing approximately every second kilometer of a stream and of these at least 30% are barriers to fish and other aquatic species. There are also dams, remaining from the log-driving period, which are no longer in use but still make barriers. Through removing barriers we have created connectivity within the streams and thereby improved and secured the conditions for the targeted species as well as for other species that thrive in or along the streams. What are the problems? Culverts can cause different kinds of migration barriers. Some of the most significant are: l water velocity is high; l lack of resting sites for fish; l low water level within the culvert; l perched crossings – that is, the culverts level is above the river bed at the outlet; l bridges or culverts lack natural shores, and are thereby a barrier to terrestrial animals. The solutions! There are several solutions to the problems: l replacing the existing culvert with a bridge or an arch so that a natural riverbed can be remediated. The water velocity will decrease and resting places for fish are created; l replacing the existing culvert with a larger dimension lower the water velocity; l lowering the existing culvert, this is only possible if the dimension of the existing culvert is correct; l step-pools downstream the culvert will raise the water level and lower the water velocity; l constructed shores, shelves or marking stones will lead small animals like otters to pass under the road. Dissemination and information has been an important part of the project. Through information on our website, in brochures, signs etc., we increased awareness of problems and solutions to barriers in streams. We have had excursions and education to targeted groups such as entrepreneurs, consultants, authorities, foresters, land owners and children. During the project time (2011-2016) 300 barriers have been removed in the northern part of Sweden. The project budget is € 8 million and EU’s LIFE nature-fund contributes with half the sum. Remibar is a cooperation project between the Swedish Transport Administration, The County Administrative Board of Norrbotten and Västerbotten, the Swedish Forestry Agency, The Swedish Agency for Marine and Water Management, the forest companies Sveaskog, Holmen and SCA.

Evaluation of shallow water zones as aquatic habitat for fish populations Sophie Vermeersch, Ans Mouton, Johan Coeck Research Institute for Nature and Forest, Brussels, Belgium

Although the chemical water quality improved substantially during the last decades, many waterways in Flanders (Belgium) still show a poor ecological quality. Since habitat loss and fragmentation have been widely accepted as the key factors affecting the ecological status of waterways, additional efforts are needed to achieve the objectives of the Water Framework Directive. Such efforts include the use of ecological bank protection techniques, considering economical preconditions such as navigation. Canal banks are particularly relevant for restoration, since their reinforced banks form a significant migration barrier between the water environment and the riparian habitats. Ef- ficient allocation of these efforts thus requires a sound evaluation of the different restoration projects and therefore contribute to integrated water management in Flanders. This study evaluates the suitability of nature friendly banks, more specifically shallow water zones, as an aquatic habitat for fish communities in three different canals. Furthermore, different riparian habitat types (concrete, ga- bions, ripraps, eroded banks, grasslands, marsh vegetation, reed beds) were evaluated. The results indicate that nature friendly banks provide the best habitat for juvenile and adult fish. An appropriate construction and management of the shallow water zones, maximising heterogeneity in depth, bank structure and 58 thematic and poster sessions

vegetation cover, is a crucial factor for their efficiency. Meanwhile, shallow water zones are an anchorage for the more sensitive species. A relatively high number of species were observed in the canals (between 12 and 23). At least half of this number developed a healthy and sustainable population. The results confirm the importance of nature friendly banks for the development of populations, since the majority of species and the totality of the sensitive species are exclusively observed near shallow water zones. These riparian structures seem to have a high efficiency thanks to a high habitat heterogeneity. Shallow water zones also enhance the potential of the reaches further downstream and act as an anchorage for populations of marine (seabass, thinlip mullet), catadromous (eel) and amphidromous species (flounder).

Floating drones used for river bed mapping Andrzej Wolak Institute of Water Engineering and Water Management, Cracow University of Technology, Kraków, Poland

Currently available computer models of water flow in river channels require more and more data, concerning among others detailed measurements of the valley layout, especially for flood events. For areas outside the actual water body it can be done in a quite straightforward way – be it classic geodetic measurements or by some other means, like lidar (Light Detection and Ranging – that is laser altimeter). For the areas under water it is more complicated. Small streams and ponds are not a problem – a person may enter that water body and do some work as required, including simple depths and position assessment. For bigger rivers and reservoirs it may not be possible. At this case the solution is to use a small boat with a depth measuring device (like an echosounder or a sonar) coupled with another device used for position determination (like GPS receiver). The water body is then crisscrossed continually and a mesh of points is collected (the denser the better), used then to create a map of the underwater area. For still bigger reservoirs it may even be a small cutter (like those used for marine research), for others a small boat may be enough (there is a problem with lateral stability of small crafts, but it can be overcome to a degree by careful navigation). There is a problem, however, with smaller rivers where a boat cannot be practically used, and nevertheless they are big enough, or with currents strong enough, that “manual” measurements cannot be possibly made. This is a case for many mountain rivers, like the Dunajec River, near the city of Nowy Sącz. In this case a solution is to use a floating drone – a small boat, without human crew, but equipped for bathymetric research – echosounder, GPS receiver together with propulsion and control systems. An example is a UPP-1E device, developed by employees of the Institute of Water Engineering and Water Management of Cracow University of Technology. The name is a Polish acronym meaning Universal Measuring Platform with Single Beam Echosounder (thus the 1E marking). The device consists of a small floating hull (in a shape of a small boat – 2 m length, 0.8 m width), with a high-resolution echosounder (NaviSound 215 made by Teledyne RESON A/S of the Netherlands), two GPS receivers (made by Garmin). The integral part is a data formatting unit and an exceptionally efficient propulsion subsystem. Control and telemetry transmissions are managed by an original system (computer with related electronics and switches, developed by DELTA PROTOTYPES of Warsaw, Poland). It has been successfully tested on water retention reservoirs (like Wapienica Dam in Bielsko-Biała, Poland), and on the Dunajec River, as mentioned above. The results of the measurements are quite encouraging and will be presented in the paper. The system is under development, but in its current state is able to do the work, as required, albeit with some limitations. If the teething problems are to get finally resolved, it may be a game-changer for bathymetric measurements industry, especially for mountain rivers.

Rehabilitation effort derived from historic changes of large European rivers Christian Wolter Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Berlin, Germany

Although river rehabilitation has become a widely accepted societal objective and numerous river sections have been restored in the past decades, only few projects have been monitored with largely contrasting results. Accord- thematic and poster sessions 59

ingly, there is still debate about efficiency of different measures and the spatial scale of application. Especially the minimum size of single measures and the total amount of rehabilitated sections for an ecological improvement of whole river catchments are unknown. This study used a landscape history approach (i) to characterise the temporal trajectory of river modification, (ii) to quantify the modifications of large river systems and the related habitat loss for aquatic biota, (iii) to identify spatio-temporal turning points of aquatic communities in response to changes, and (iv) to derive suggestions on the spatial scale of river rehabilitation. The Central European lowlands have been colonised immediately after de-glaciation about 8000 years ago. Four millennia later, first signs of anthropogenic impact and hydraulic engineering have been dated in the late Bronze Age 3500 years BP: artificial fosses for navigation, followed by first canals about 2000 years ago and the first successful attempts to connect different river catchments in the years 793 (rivers Rhine and Danube) and 1391-1398 (rivers Trave and Elbe). In Europe, water mills exist since the 7th century and had their largest numerical spread between 1100 and 1200. After 1200 increasing numbers of fishing weirs added to river fragmentation. While all these early river engineering works were probably of rather local impact, the situation changed completely with the “Wiener Congreß-Acte” signed on June 08, 1815 and the foundation of the German Tariff Union on January 01, 1834. For the first time a convention was adopted to allow for free inland navigation, to set up common navigation commissions for multinational river systems, and to maintain the river systems to improve inland navigation. Follow- ing this arrangement many rivers became regulated by groynes to increase the fairway depth during mean flow to allow for longer traffic of larger barges. The foundation of the German Tariff Union was the beginning of the industrialization period, accompanied by the development of a competing mode of transport; the first railway started operation in 1835. After that, the navigation paradigm has completely shifted from the historical adaptation of numerous vessel types to the specific river conditions to an adaptation of the rivers by river engineering works to continuously increasing vessels. Up to the 17th century the average river depth required for navigation was 0.7-0.8 m. With raising traffic volumes on the railways vessels had to increase their loads and reduce their non-traffic times to remain competitive. This led to the low water regulation of all major European waterways in the second half of the 19th century. At the beginning of the 20th century, navigable European rivers have lost on average 21% (8-45%) of their length, 89% of their islands, 90% of their floodplains, and 98% of their braided reaches. By that, >50% of the natural bank lines and littoral habitats disappeared. The remaining banks are commonly covered by embankments on >60% of their length, in canals up to 100%. The global inland waterway network has been enlarged from 8750 km canals and 3125 km regulated rivers before 1900 to 671,868 km today.

Environment-friendly reduction of flood risk and infrastructure damage in the Czarny Dunajec River, Polish Carpathians Bartłomiej Wyżga1, Paweł Mikuś1, Artur Radecki-Pawlik2, Joanna Zawiejska3, Antoni Amirowicz1, Paweł Oglęcki4 1Institute of Nature Conservation, Polish Academy of Sciences, Kraków, Poland 2Department of Hydraulics Engineering and Geotechnique, University of Agriculture, Kraków, Poland 3Institute of Geography, Pedagogical University of Cracow, Kraków, Poland 4Department of Environmental Engineering,Warsaw University of Life Sciences, Warszawa, Poland

Migration of a mountain river channel may cause erosional risk to infrastructure or settlements on the valley floor. Following a flood of 2010, a cutbank in one of the bends of the main channel of the Czarny Dunajec, Polish Car- pathians, approached a local road by 50 m. To arrest the erosion of the laterally migrating channel, water authorities planned construction of a ditch cutting the forested neck of the bend, reinforcement of the ditch banks, and damming the main channel with a boulder groyne. In order to avoid channelization of the highly valued, multi-thread river reach that would deteriorate its ecological status and cause increased flood risk to downstream reaches, an alternative approach to prevent bank erosion was proposed. The new scheme, applied in 2011, included opening of the inlets to inactive side braids located by the neck of the bend of the main channel. This solution re-established the flow in the steeper low-flow channels, allowing us to expect a cut-off and abandonment of the main channel during subsequent floods. Gravelly deflectors were constructed directly below the inlets to the reactivated side channels to divert the flow into the channels and prevent the water from entering the main channel. Hydraulic measurements performed before and after the implementation of the scheme confirmed that it enabled shifting the main water 60 thematic and poster sessions

current, with the highest average velocity and bed shear stress, from the braid closest to the road to the most distant braid. Similar surveys of fish and benthic macroinvertebrate communities indicated that flow reactivation in the side channels was beneficial for these groups of river biota, increasing their abundance and taxonomic richness in the reach. Not only was the implemented solution significantly less expensive, but it also enhanced ecological functions of the multi-thread channel and the variability of physical habitat conditions and maintained the role of the reach as a wood debris trap. However, avulsion of the main channel in the river bend immediately upstream during the flood in May 2014 again caused erosional risk to the road, although at another location. This indicates that with the highly unstable, multi-thread channel pattern of the Czarny Dunajec, the best practice of river maintenance in a relatively unmanaged valley reach would be allowing free channel migration within the floodplain area and reinforcing, where necessary, the boundary between the erodible river corridor and the managed terrace.

Where can multi-thread morphology of Polish Carpathian rivers be restored? An insight from a paleogeographical analysis Bartłomiej Wyżga1, Joanna Zawiejska2, Hanna Hajdukiewicz1 1Institute of Nature Conservation, Polish Academy of Sciences, Kraków, Poland 2Institute of Geography, Pedagogical University of Cracow, Kraków, Poland

Restoring river morphology that existed in historical times is an important issue in restoration activities and requires testing the validity of historical reference conditions under contemporary environmental conditions in the river catchment. Multi-thread rivers are typified by the presence of interconnected channels separated by mid-channel bars or the islands forming as a result of vegetation encroachment on mid-channel bars. Environmental conditions favouring the development of braided channel pattern comprise high channel and valley gradients, high discharge variability, relatively low content of fine, cohesive sediments in the alluvial plain, coarse bed material and high sediment supply. Under natural conditions of the Holocene, island-braided channel pattern was typical of the rivers in the foreland of the Tatra Mountains and most likely also those draining the parts of the flysch Outer Carpathians underlain by thick-bed- ded sandstone complexes. These braided channels formed in the rivers flowing through mostly non-cohesive floodplains and fed with coarse-grained material exceeding competence of the rivers. Progressive deforestation of the Polish Carpathians with the increasing area of cultivated hillslopes resulted in higher flood peaks and substantially increased sediment supply to river channels. Coupled with greater humidity of the final stages of the Little Ice Age, this led to the transformation of the island-braided rivers into bar-braided ones over the last few centuries. Throughout the nineteenth century the braided channel morphology expanded downstream to the foreland river reaches and was widespread in Polish Carpathian rivers. However, over the twentieth century the braided morphology nearly disappeared from Polish Carpathian rivers, mostly as a result of their channelization. The effectiveness of these works was, however, strengthened by a decrease in sediment supply to the rivers caused by hillslope reafforestation and by the reduced availability of bed material for fluvial transport resulting from in-channel gravel mining and partitioning of rivers with dam reservoirs. Environmental changes which have since occurred in the river catchments and disruption of the continuity of sediment by dams limit the feasibility of the restoration of braided channel pattern in Polish Carpathian rivers to their reaches that supported such morphology under natural conditions of the Holocene.

Active conservation of freshwater mussels – the case of Unio crassus in the Biała River Katarzyna Zając1, Tadeusz Zając1, Paweł Adamski1, Adam Ćmiel1, Wojciech Bielański1, Jacek Florek2, Andrzej Strużyński2, Mariusz Klich3 1Institute of Nature Conservation, Polish Academy of Sciences, Kraków, Poland 2Departament of Water Engineering and Geotechnics, Agricultural University, Kraków, Poland 3Department of Enrionmental Protection, State Higher Vocationary School in Tarnów, Tarnów, Poland

The Biała River harbours one of the largest populations of Unio crassus in Poland. However, the upper part of the thematic and poster sessions 61 river was isolated in the past by dams and U. crassus died out there, mainly due to water pollution and isolation from the other parts of the river inhabited by viable population of the species. In 2012 we restored the species occurrence in the upper part of the river, in a series of 16 stepping stones in order to speed up re-colonization of the upper reach and to restore the historical distribution of the species after removal of the barriers for fish migration. We analyzed water chemistry, fish distribution and morphology of the river in order to find out, which factors are responsible for successful re-establishment of the species. The research on fish is always important, because the mussel to complete its life cycle needs fish as host for parasitic larvae. For the next years we observed the process of young dispersal and dynamics of adults populations introduced into stepping stones. It appears that a crucial role is played by microhabitat: local site morphology and local hydrology. The most successful (in terms of young recruitment) are straight sections of the channel, with small areas of still water and fine sediment, protected from the influence of main water current, where both adult survival and young recruitment are the highest. The role of fish is restricted to local habitats; despite the higher density of appropriate fish hosts in some parts of the river, the host abundance was not related to abundance of the mussel, however, it was related in the scale of microhabitat. The optimal habitat features were identified on the basis of mussels’ behaviour: the analysis of movements of individuals marked with radio-transmitters revealed that in unfavorable conditions individuals disperse, which is likely to hamper mating and survival of adults and young recruitment. In successive years stepping stone population had very good reproduction. The dispersal of young mussels in next year reached range of hundreds of metres, after two years the recruitment and young dispersal was far enough to join separated stepping stones. At the moment almost all initial stepping stones are destroyed by lateral erosion of the main channel, whereas the species persisted due to juveniles dispersal to new microhabitats.

Increasing ox-bow biodiversity: plant reintroduction in the Vistula Valley

Joanna Zalewska-Gałosz1,2, Wojciech Gałosz2

1Jagiellonian University, Kraków, Poland 2The Society for Earth (Towarzystwo na rzecz Ziemi), Oświęcim, Poland

River valleys as usually very rich in species are regarded as regional hotspots of biodiversity. Unfortunately, rivers and their surroundings have been subjected to severe human-induced changes for centuries. These mainly include river flow regulation, water pollution, expansion of agriculture, building development and recreation. As a consequence, the extensive loss of natural riverine vegetation has been observed in Europe, locally reaching up to 95% of its original coverage. Simultaneously the existence of many organisms confined to river valleys has become threatened. In Poland, for example, over 30% of vascular plant species which grow exclusively or predominantly in the valleys of large rivers are red-listed. In Switzerland, almost 56% of the animal floodplain obligates are listed as endangered. One effective way to conserve these rare and endangered species is through reintroduction. Reintroduc- tion of wild aquatic plants was one of the tasks under the project ‘Revitalization, biodiversity protection and usage of the Vistula River oxbows; preventing degradation of Upper Vistula River Valley as an ecological corridor’, realised by Towarzystwo na rzecz Ziemi and supported by a grant from Switzerland through the Swiss Contribution to the enlarged European Union. In the project we reintroduced three aquatic plants which were used to be quite common in ox-bows in the Vistula Valley but now are rare or endangered in Poland. The project covered: water chestnut Trapa natans, yellow floating heartNymphoides peltata and white waterlily Nymphaea alba. A few individuals per each species were collected from the native, wild populations occurring in the fish ponds near Spytkowice. Plants were cultivated and multiplicated in Botanical Garden of the Jagiellonian University in Kraków. In spring of 2014 a few individuals of each species were introduced to three ox-bows (two at Czernichów and one at Ochodza). Since the time of planting the new populations are established. Similar, successful project was conducted by Towarzystwo na rzecz Ziemi in 2004, when seeds of Trapa natans were reintroduced into ox-bows near Oświęcim. As a result, especially rich population was restored in ox-bow Chropań. Wild plants reintroduction in the river valleys is an important tool for biodiversity conservation which can increase local genetic diversity. Additionally, in the course of the project, we planted native trees in the surrounding of the ox-bows. Planted trees representing three species: Quercus robur, Salix alba and S. fragilis will increase habitat heterogeneity what – in turn – should positively influence local biodiversity. 62 thematic and poster sessions

The image of rivers in school textbooks: implications for public support of restoration efforts Joanna Zawiejska Institute of Geography, Pedagogical University of Cracow, Kraków, Poland

Visual content on riverscapes and river morphologies in secondary level geography textbooks published over the last decade and approved for use in Polish schools is considered. The aim of this study is to (i) analyse the content and context of illustrative material on rivers and fluvial processes in geography textbooks, (ii) compare the overall image of rivers conveyed (via textbooks) in the course of geography education at a secondary level, (iii) confront that image with the state-of-the-art fluvial geomorphology and ecohydromorphology to infer about possible effects of geography education on pro-environmental attitudes. In general, few textbooks make a distinction between natural and heavily modified rivers. The images of the latter are more common than those of natural channel morphologies, with channelized rivers frequently depicted in chapters dealing with natural processes. Majority of the pictures present narrow single-thread channels, usually lacking channel forms. Mountain rivers are typically shown on photos of bedrock and gorge sections, which though picturesque, are representative of only some reaches and are not necessar- ily typical natural channel morphologies, especially in the Polish mountains. In all examined textbooks, only three photographs were found that depicted actual bed material flux in mountain rivers (one of a Polish gravel-bed rivers and the other two from different climatic zones). Interestingly, examples of the most natural channels are commonly used to illustrate chapters on vegetation and climatic zones; however, no reference is made in the text to the somewhat accidentally depicted rivers and the captions only point to the discussed objects e.g. vegetation (usually forests). Information on natural river dynamics, inherently involving the occurrence of floods, channel mobility or bank erosion, is lacking or typically placed in sections on flooding and illustrated with examples of damage, in some cases only to infrastructure. This not only instigates only negative associations with natural river function (of danger and degradation) but also by conveying partial information, distorts the idea of its actual role in the environment. Finally, the photographs of rivers are often placed in sections on transport or energy production, where rivers are presented and discussed solely as resource and typically shown in a heavily modified state described as beneficial. Despite years of efforts to restore rivers worldwide and relevant legislation (e.g. in EU), no information or pictorial content was found in the textbooks on the adverse effects of human interventions into physical river structure. This shows that although geography education is intended to enhance pro-environmental attitudes, it is unlikely to have that effect in relation to rivers and riverscape perception as the information and the image of rivers imparted in the textbooks is largely outdated and non-representative of the actual role they play in the natural environment. TECHNICAL FIELD TRIP – 23 September 2016

During the technical field trip you will visit sites on the Upper Raba River and its tributaries: Trzebuńka and Krzczonówka Streams as well as on the Czarny Duna- jec River. The upper Raba and its tributaries drain flysch Outer Carpathians. In the 20th century they were heavily impacted by channelization, channel incision, and the disruption of continuity by check dams. In recent years a restoration project ‘The Upper Raba River Spawning Grounds’ was conducted in these watercourses by a non-profit organizationAb Ovo with a financial support from Swiss Contribution to the enlarged European Union, and the first part of the field trip will focus on the outcomes from the project and the associated scientific studies. At Site 1 we will present restoration of longitudinal continuity of a tributary stream for biota migration and sediment transfer with the simultaneous maintenance of the stream level upstream of the former check dam. Site 2 is focused on the restoration of dynamic equilibrium and alluvial boundary conditions in a deeply incised stream below a check dam. Sites 3 to 5 will illustrate establishing of an erodible corridor of the Raba and some effects of the initiation of more natural processes in it: changes in ground beetle communities and early stages of re-establishment of islands in the river. The Czarny Dunajec drains the Inner Carpathians. Some sections of this river avoided considerable human impact and thus do not require restoration activities; however, this river was a subject of a number of scientific studies with the results of importance for river restoration Location of sites presented during the technical field trip and maintenance activities. Sites 6 and 7 are closely lo- shown on the background of river network and major cated in an unmanaged, multi-thread river reach. At site roads. 6 we will present experiences from environment-friendly approach to the reduction of the erosional threat posed Czarny Dunajec. Here we will present results of the stud- by free migration of the river channel to the nearby lo- ies comparing hydromorphological river quality and the cal road. Site 7 will provide an opportunity to consider condition of fish and benthic macroinvertebrate commu- the concept of reference conditions for river restoration. nities between unaffected river reaches and reaches mod- Site 8 is located in the heavily channelized reach of the ified by channel regulation or channel incision. 64 technical field trip

Site 1. Trzebuńka Stream at Stróża – restoration of spawning grounds access in a tributary stream cut off by a high check dam

Józef Jeleński

S i t e l o c a t i o n : N 49°47’38.558” E 19°55’08.263”

Following the construction of a high check dam in a narrow, deeply incised section of Trzebuńka Stream, only 400 metres of the stream was accessible to fish migrating from the Raba River. The dam was constructed in 1935, probably as a support for road embankment, and in 1936 it was equipped with simple electric generators that sup- plied power for few light bulbs – in the local school and the church. The generators had operated until 1945 and the useless dam was then an obstacle to stream continuity for the following 70 years (Fig. 1.1.A). Stream continuity was restored only in 2015 within the project ‘The Upper Raba River Spawning Grounds’. One of the tasks of the project consisted in the removal of the part of the dam disrupting stream continuity and in reconstruction of the streambed in this section designed so as to maintain the level of the adjacent upstream and downstream sections typified by gravel gradation favourable for fish spawning. This lower two-kilometre section of the stream is of the utmost importance for spawning of the fish migrating from the Raba River as, even if made accessible to fish, the uppermost reaches of the stream are characterized by cobble and boulder bed with few, widely spaced gravel bars. The 8-m-high dam was substituted with a 96-m-long structure consisting of a 65-m-long rocky rapid (with the slope of 0.055) in its downstream part (Fig. 1.1.B) and a 30-metre-cascade of 12 pools with 0.3 m high steps (Fig. 1.1.C). The rocky rapid was constructed with so called ‘grouted rock’ resembling natural bedrock. The final design maintains full stream continuity, enabling upstream fish migration from the Raba River, and also provides side access to the stream for people and all species of animals. This structure is capable of conveying floodwater and bedload and it has the channel dimen- sioned for very low, low, average and high flows. Not only does it fulfill the criteria of stability and flood control, but it is also environmentally friendly and increases amenity value.

Fig. 1.1. (A) View of the check dam on Trzebuńka Stream shortly before its removal. (B) The lower part of the water head of the check dam replaced by a rapid with ‘grouted rock’ on the stream bed. (C) The upper part of the check dam replaced by a cascade of concrete steps and pools. technical field trip 65

Site 2. Krzczonówka Stream at Pcim – formation of stone riffles to trap bed material and re-establish riffle-and-pool pattern downstream of a lowered check dam

Józef Jeleński, Bartłomiej Wyżga, Paweł Mikuś, Maciej Liro

S i t e l o c a t i o n : N 49°44’14.917” E 19°58’24.823”

An increasing number of dams and check dams are reaches downstream of the dams are typically deeply removed from rivers to re-establish their longitudinal incised and thus the sediment flushed out from the de- continuity for biota migration and sediment transport. molished or lowered dams may not be retained in these Because of long-lasting sediment starvation, channel reaches but transported downstream. A check dam in Krzczonówka Stream located ca. 2 km upstream from the stream junction with the Raba River was destined to be lowered by about 2 m to become passable for fish migration. To trap the sediment flushed out from above the dam in the deeply incised channel, formation of stone riffles in the stream was planned before lowering of the check dam. The works were preceded by the analysis of sedimentary/hydraulic conditions in the incised channel and channel stability conditions were determined by means of Hey and Thorne regime equations (Thorne et al., 1997).

Fig. 2.2. Krzczonówka Stream channel about 200 m downstream of the check dam before the installation of Fig. 2.1. Krzczonówka Stream channel at the location of stone riffle 3 (A) and a year after the passage of the major stone riffle 15 before (A) and immediately after the riffle flood of May 2014 (B). Visible a bedrock channel prior to installation in March 2013 (B), and a few months after the the riffle installation and restoration of a gravel bed fol- passage of a major flood in May 2014. lowing the entrapment of bed material by the stone riffle. 66 technical field trip

Fig. 2.3. The lowermost reach of Krzczonówka Stream downstream of the check dam with indicated location of riffle crests as set in 2013 (blue) and found in 2016 (red). Yellow dots show the position of nods of braids surrounding mid- channel bars in 2016.

Before the works the channel was up to 2 m deep from upstream of the dam and deposited it in the lower (Fig. 2.1A), with bedrock exposed on 25-50% of the bed part of the stream. Close to the check dam, an increase area (Fig. 2.2A). Simulations using the Hey and Thorne in the average bed elevation reached 0.7 m, resulting in regime equations indicated that with the current stream complete burying of the stone riffles by the trapped gravel slope, the bed material stored upstream of the check dam (Fig. 2.2B) and an increase in low-flow water surface up was 3-4 times finer than that necessary to form stable to 1 m. The lowermost riffles were not buried (Fig. 2.1C), riffles in the channel downstream of the dam. Substi- but they trapped between 0.1 and 0.3 m of gravel on their tute rock material that could form riffles trapping gravel upstream side. Following the flood, the whole channel transported from the lowered check dam was obtained bed downstream of the check dam became alluvial and from the nearby sandstone quarry. Parameters of the mid-channel bars started to form in the channel (Fig. 2.3) rocky, continuous gradation material for riffle formation despite a lack of increase in its width. The configuration and of riffle dimensions (minimum bankfull width and of riffle crests started to be adjusted by the stream itself average and maximum bankfull depth at the riffle crests, and currently, 3 years after the onset of the works, some and average spacing between riffles) that would ensure riffle crests occur upstream and some downstream from their persistence at different rates of bedload supply from the location of the crests of artificially formed stone rif- upstream, were obtained from calculations using Hey fles (Fig. 2.3). and Thorne regime equations. The assessment of hydromorphological quality of The riffles, formed in March 2013 (Fig. 2.1B) of the stream performed in 2012 and 2015 indicated its im- rock rubble from the quarry with a topping of coarse provement at 4/5 of the evaluated cross-sections, with gravel compacted by a road roller, were spaced every a shift to a higher quality class for 3/5 of the evaluated 120 m and located at thalweg inflection points. The rif- cross-sections. The improvement of hydromorphological fles were designed as ramps with a slope a few times quality of the stream was reflected in an improvement of steeper than the average channel slope. All parameters its ecological status indicated by the invertebrate-based of the ramps were set on site in relation to the local BMWP-PL index. The improvement in the ecological floodplain level. status was especially apparent close to the lowered check In May 2014 a major flood occurred on the stream dam, that is where the increase in bed elevation (and thus during the course of works aimed to lower the check the formation of a relatively thick layer of alluvium over dam. The flood flushed out about 143 000m of gravel the bedrock) was especially large. technical field trip 67

Sites 3-5. The Raba River at Lubień

S i t e l o c a t i o n : N 49°43’20.946” E 19°58’48.622” 3. Erodible river corridor as a restoration measure for mountain rivers

Józef Jeleński, Bartłomiej Wyżga

Stabilisation of river course by bank-protection ridor”, an area where free channel migration is allowed structures brings about several negative hydrological, (Piégay et al., 2005). The concept was introduced to Po- ecological, and economic effects. Without progressive land by Bojarski et al. (2005) who indicated that in valley bank erosion during channel migration, sediment accu- sections with limited development, free channel migra- mulation on the river banks increases flow capacity of tion should be allowed within a corridor which is defined the channel and reduces the potential for flood water by the extent of floodplain and the location of buildings storage on the valley floor. The increase in flow capac- and infrastructure under protection from erosion (Fig. ity of the channel frequently induces bed degradation 3.1). Allowing free channel migration within so delimit- which further enhances flow concentration in the deep- ed corridor would reduce the costs of river maintenance ening channel and the positive feedback may lead to and flood defence of the riparian land. At the same time, considerable channel incision until the resultant bed the existing bank-protection structures could be substi- armouring or bedrock exposure arrest bed degradation tuted with anti-erosion revetments constructed along the (Wyżga, 1993). Reduction or loss of water storage in boundaries of the corridor (Fig. 3.1). the floodplain areas decreases attenuation of flood The concept was first applied in the meandering reach waves, resulting in increased peak discharges of floods of the Oder River at the Czech-Polish border (Nieznań- in downstream river reaches (Wyżga, 1997). A reduc- ski et al., 2008) and in recent years, works aimed at de- tion in habitat complexity resulting from river channel- limiting erodible river corridor have also been undertak- ization decreases the abundance and diversity of river en in the valleys of two Carpathian rivers: the Biała and biota (Wyżga et al., 2009, 2011). Riparian forests be- the Raba. Investigations in the Biała River indicated that come progressively more mature and typical of high- despite a short time of free development of its channel er terraces, whereas a complete succession of riparian within the erodible corridor, it already brings beneficial communities does not occur here as it normally would effects for flood risk management, reducing flow energy along actively migrating channels. Importantly, bank and shear forces exerted on the bed and banks of the chan- stabilisation involves considerable costs of construc- nel (Czech et al., 2016). In the vicinity of Lubień village, tion and maintenance of bank-protection structures, es- a few kilometres-long erodible corridor of the Raba River pecially where considerable narrowing of the channel was delimited within the project ‘The Upper Raba Riv- resulted in a marked increase in unit stream power of er Spawning Grounds’ (KIK/37 – supported by a grant flood flows. from Switzerland through the Swiss Contribution to the High environmental and economic costs of the con- Enlarged European Union). At the same time, the works struction and maintenance of regulated channels resulted aimed at reinforcement of the corridor boundaries were in the formulation of a concept of “erodible river cor- conducted without a disturbance for the river channel

Fig. 3.1. The concept of erodible river corridor with free channel migration possible within the floodplain area and channel bank reinforcements replaced by anti-erosion revetments constructed on the boundary between river floodplain and managed terraces (after Bojarski et al., 2005). 68 technical field trip

Fig. 3.2. Reinforcement of the boundary of the erodible river corridor by substituting the gravelly material with coarse sandstone rubble (A) with laterite matrix (B). The works were conducted without the traffic of heavy machinery within the low-flow channel. Following the construction works, trees were planted on the external side of the revetments.

Fig. 3.3. Oblique aerial photo of the Raba channel within the erodible corridor taken after a major flood in 2010. The flood doubled the channel width in this reach and the increase in river width continued in the following years (photo credit: Łukasz Ślusarski).

(Fig. 3.2). Establishing an erodible corridor in this river l the formation of early successional stages of riparian reach was based on the fact that roads and settlements are vegetation. located close to valley slopes and a few hundred metres The process of river restoration within the erodible wide, undeveloped corridor was left for the river (Fig. corridor should be spontaneous and self-operating as no 3.3). Over the 20th century, the river incised up to 2 m removal of bank-protection structures is intended. As the in this reach. The free migration of the river channel is mountain river has relatively high energy, the existing expected to bring about the following beneficial effects: structures are to be destroyed by the river, whereas their l increased retention of floodwater in the reach due to removal would require the use of heavy machinery and the formation of low-lying floodplain areas; thus would be costly and harmful for the environment. l increased morphological and hydraulic complexity of Observations in the river corridor indicate that channel the river, reflected in increased variability of habitat sections that already lack bank reinforcements tend to conditions for river biota; widen, and up to three-fold channel widening has oc- l reduction in transport capacity of the river resulting curred in some cross-sections since 2009. from increased channel-form resistance to flow in the At the Lubień site, changes in the functioning of the natural channel; mountain river resulting from the initiation of free migra- l reduction of the costs of channel maintenance, and tion of its channel will be presented. technical field trip 69

4. Ground beetle communities in a mountain river subjected to restoration

Agnieszka J. Bednarska, Bartłomiej Wyżga, Paweł Mikuś, Renata Kędzior

Ground beetles (Coleoptera: Carabidae) are a group of water level to cover the whole range of microhabitats. organisms characteristic of exposed riverine sediments. The examples of cross-sectional morphology of the As such, they negatively respond to river channelization Raba River together with the location of the sites in the and incision which limit or eliminate the availability of unmanaged (upper) and the channelized cross-section such habitats in rivers (e.g. Skalski et al., 2016). Ripari- (lower) are illustrated in Figure 4.1. The sampling sites an ground beetles are potentially good indicators of hy- were described by surface slope, the distance from and dromorphological restoration as they respond strongly the height above the nearest low-flow channel, sedi- to habitat management and disturbance in microhabitat ment size class and the degree of plant cover. Addition- conditions such as moisture content, light intensity or ally, bankfull channel width, the number of low-flow vegetation density. Resignation from further maintenance channels and the number of actively eroded cutbanks of bank reinforcements of the Raba within the erodible were determined for each cross-section. Unmanaged corridor delimited in its upper course enabled self-re- cross-sections had significantly larger channel width covery of the river. Two large floods, one in 2010 and than channelized cross-sections and were typified by the second in 2014, caused up to a threefold increase in greater numbers of low-flow channels and eroded cut- channel width, with the resultant re-establishment of the banks. Moreover, sample sites from the unmanaged multi-thread channel pattern and a considerable increase cross-sections were typified by significantly larger av- in the area of gravel bars. The effect of self-recovery of erage distance from low-flow channels and steeper av- the river on ground beetle communities of exposed riv- erage surface slope than sample sites from the channel- erine sediments was investigated in 2015 by comparing ized cross-sections. 6 unmanaged cross-sections and 6 cross-sections from Adult ground beetles were collected on three sampling adjacent channelized reaches. occasions (spring, summer and autumn) and identified to In each cross-section, 12 sampling sites of 1 m2 each the species level. Each cross-section was described by were selected at various elevations above the low-flow the total number of individuals (n), species richness (i.e.,

Fig. 4.1. Examples of cross-sectional morphology of the Raba River together with the location of 12 sites (indicated by arrows) in the unmanaged (upper) and the channelized (lower) cross-section. 70 technical field trip

Fig. 4.2. Mean (± standard deviation, SD) values of the number of individuals, the number of taxa, and of the diversity indices of ground beetle assemblages collected in unmanaged (UN) and channelized (CH) cross-sections of the Raba River. Statistical significance of the differences between the two types of river cross-sections, determined by Mann- Whitney test is indicated. the number of taxa, S), and diversity indices: the Marga- influenced the effect of restoration on ground beetles, the lef’s richness index (D = (S-1)/ln(n)), and the Berger- comparison between unmanaged (UN) and channelized Parker dominance index (calculated as the number of (CH) cross-sections was done using Mann-Whitney test. individuals in the dominant taxon relative to n). To test Altogether, above 4000 individuals were collected whether the river restoration had an overall positive ef- during three seasons. Taxonomic study is underway but fect on different biodiversity metrics and to identify the results for beetles collected in spring (1055 indi- which factors (river characteristic, habitat differences) viduals from 53 taxa) showed that the average number

Fig. 4.3. Box plots for the abundance of three dominant species in ground beetle assemblages for which significant differences between unmanaged (UN) and channelized (CH) cross-sections of the Raba River were found. The bottom and top of the box indicate the first and third quartiles, respectively, the line inside the box is the median and whiskers indicate extreme values. Statistical significance of the differences between the two types of river cross-sections, determined by Mann-Whitney test is indicated. technical field trip 71

Table 4.1. The Bray-Curtis similarity matrix for 12 cross-sections of the Raba River describing compositional similarity in the assemblages of ground beetles between two cross-sections. Unmanaged cross-sections are indicated in blue and channelized cross-sections in red. The degree of similarity between two unmanaged cross-sections is indicated by dark grey colour, between two channelized cross-sections by light grey colour and between unmanaged and channelized cross-sections in white.

R01 R02 R03 R04 R08 R09 R05 R06 R07 R10 R11 R12 R01 R02 0.32 R03 0.46 0.47 R04 0.30 0.36 0.49 R08 0.43 0.58 0.52 0.41 R09 0.39 0.45 0.47 0.40 0.56 R05 0.35 0.28 0.53 0.34 0.31 0.25 R06 0.41 0.44 0.49 0.48 0.69 0.60 0.32 R07 0.14 0.20 0.20 0.08 0.18 0.40 0.10 0.13 R10 0.16 0.33 0.33 0.23 0.17 0.36 0.31 0.10 0.50 R11 0.24 0.24 0.24 0.17 0.21 0.17 0.20 0.18 0.22 0.38 R12 0.15 0.28 0.34 0.25 0.21 0.24 0.38 0.29 0.19 0.35 0.29

of taxa as well as the average number of individuals ue of 0.44) than for pairs of channelized cross-sections were significantly higher in unmanaged cross-sections (the average value of 0.26). Thus, the pairs of channel- than in channelized cross-sections (p ≤ 0.02, Fig. 4.2). ized cross-sections had less similar composition (i.e., The unmanaged and channelized cross-sections dif- they shared less species) than the pairs of unmanaged fered also in terms of Berger-Parker dominance index cross-sections. The average similarity index for the pairs (p = 0.01), but not in terms of Margalef’s richness index of unmanaged and channelized cross-sections equalled (p = 0.09) (Fig. 4.2). The results indicated that although 0.30 (Table 4.1). the two types of cross-sections were similar in terms of To sum up, the results for samples collected in May species richness, there was a lower proportion of dom- 2015 indicated that the ground beetle assemblages were inant species in ground beetle assemblages from un- significantly more abundant in unmanaged cross-sec- managed cross-sections than in those from channelized tions than in channelized cross-sections. Unmanaged cross-sections. cross-sections supported more taxa and at the same time To test for statistical differences in the average number were characterised by a lower proportion of dominant of dominant species in assemblages of beetles between species in assemblages than channelized cross-sections. the two cross-section types, species for which at least 10 As unmanaged cross-sections supported a greater pro- individuals were collected in at least one cross-section portion of the reach-wide pool of ground beetle taxa, were chosen. From among 13 dominant species, differ- assemblages found in these cross-sections exhibited a ences between unmanaged and channelized cross-sec- higher degree of similarity than assemblages collected in tions were found only for Bembidion ascendens, B. testa- channelized cross-sections. ceum, and B. decorum (Fig. 4.3). The study in the Raba River thus confirmed that The Bray-Curtis similarity index was used to quanti- ground beetles relatively rapidly respond to the resto- fy the compositional similarity in assemblages of beetles ration of gravel-bed rivers that increases availability of between two river cross-sections; it appeared higher for exposed riverine sediments and the complexity of physi- pairs of unmanaged cross-sections (with the average val- cal habitat conditions (cf. Jähnig et al., 2009). 72 technical field trip

5. Island development in a mountain river recovering from channelization and channel incision

Paweł Mikuś, Edward Walusiak, Bartłomiej Wyżga, Maciej Liro, Joanna Zawiejska

Investigations of islands in an undisturbed reach of the Czarny Dunajec River, Polish Carpathians, indicated that islands are very dynamic landforms and greatly contribute to the overall plant diversity of the river corridor (Mikuś et al., 2013). This allowed us to suppose that re-establishment of islands may be an important factor in the restoration of hydromorphologically degraded mountain rivers. This hypothesis was verified in the reach of the Raba in which establishing of an erodible corridor induced self-restoration of the river. A considerable increase in channel width during the large floods in 2010 and 2014 resulted in the re-establishment of a multi-thread channel pattern and islands started to develop within the river. Fig. 5.1. Widening of the river channel provides conditions Observations of island development in the Raba con- for wood accumulation on gravel bars. The sprouting firmed previous findings from the Czarny Dunajec that willow driftwood initiates the formation of pioneer islands in a highly dynamic mountain river, islands originate as in the river. a result of deposition and sprouting of living driftwood of Salicaceae (Fig. 5.1). Morphometric parameters and ue of 2.7 years recorded in 2014. Between 2011 and species composition of islands in the Raba were mon- 2016 total island area increased from 3.9 to 17.5 ha itored every year between 2011 and 2016 (Table 5.1). and average island area from 139 to 418 m2, but in 2014 Over this period the number of islands in the 2.6-km- a rapid decrease in both parameters was recorded. Gener- long reach of the erodible corridor increased from 28 ally, the increase in the above parameters was not steady to 42, with the highest number of 59 islands recorded (Table 5.1), but moderated by processes of island erosion a few months after the large flood of May 2014. The by flood flows, initiation of island development shortly number of pioneer islands (≤ 4 years in age) fluctuat- after major floods (increasing the number and reducing ed over the study period, but in 2016 it was the same the average age and area of islands), and island coales- as in 2011. By contrast, the number of building islands cence in the years without major floods (with the oppo- (> 4 years) progressively increased over the study pe- site effect on the island parameters). riod. The average island age (year) changed from 2.8 The total number of vascular plant species on the years in 2011 to 5 years in 2016, with the lowest val- islands fluctuated between 142 and 202, with the great-

Fig. 5.2. Changes in the extent and class of islands within the active zone of the Raba River in the lower part of the erodible corridor between 2011 and 2016. Pioneer islands (1-4 years old) are indicated in light green and building islands (5-15 years old) in dark green. technical field trip 73

Table 5.1. Morphometric parameters of islands and the total number of plant species on islands and plots of riparian forest recorded in the erodible corridor of the Raba River between 2011 and 2016.

Year 2011 2012 2013 2014 2015 2016 Number of islands: total and 28 28 40 59 42 42 (pioneer/building islands) (24/4) (22/6) (33/7) (43/16) (24/18) (24/18) Average island age (year) 2.8 3.6 3.4 2.7 4.0 5.0 Total island area (ha) 3.9 4.6 14.6 9.5 15.7 17.5 Average island area (m2) 139 166 367 162 375 418 Total number of plant species on islands 161 198 202 195 158 142 Total number of plant species on plots of riparian forest – 161 – – 156 142 er number of species recorded in the years with higher occurrence of relatively low flood flows in these years flood flows and lower in the years with low flood flows. that limited the dispersal of propagules by floodwaters, Inventories of plant species on the plots of riparian for- especially in the case of higher located islands. These est were conducted in 2012, 2015, and 2016 and indi- results suggest that at early phases of island re-estab- cated the total number of plant species in the riparian lishment in a mountain river recovering from channel- forest to be less variable, ranging from 142 to 161 (Ta- ization and channel incision, when the availability of ble 5.1). In 2012 islands supported a greater total num- propagules dispersed by hydrochory is limited, the con- ber of plant species than riparian forest and a signifi- tribution of islands to the overall species richness of the cantly greater number of biennial and annual plants was riparian corridor can be highly variable depending on recorded on particular islands than on individual ripar- hydrological conditions and the state of islands in a giv- ian forest plots. In turn, inventories performed in 2015 en year. This contrasts with the situation existing in the and 2016 documented similar numbers of plant species unmanaged, multi-thread reach of the Czarny Dunajec in the two types of habitats; they also showed that on where numerous older islands are an efficient source of islands, the number of species from any life form of propagules and the occurrence of a relatively shallow plants did not significantly exceed that recorded on ri- channel facilitates their deposition on islands by flood- parian forest plots. This situation can be linked with the waters (cf. Mikuś et al., 2013). the Czarny Dunajec River

Site 6. Wróblówka – environment-friendly reduction of flood risk in a mountain river

Paweł Mikuś, Bartłomiej Wyżga, Artur Radecki-Pawlik, Joanna Zawiejska, Antoni Amirowicz, Paweł Oglęcki

S i t e l o c a t i o n : N 49°27’50.018” E 19°53’55.996”

Migration of a mountain river channel may pose ero- one of the bends of the main channel approached a local sional threat to infrastructure or settlements on the val- road by 50 m. To arrest erosion of the laterally migrating ley floor. The unmanaged, multi-thread channel of the channel, local water authorities proposed construction of Czarny Dunajec in the middle river course exhibits dif- a ditch with reinforced banks, cutting the forested neck of ferent development tendencies during large floods and in the bend, and damming the main channel with a boulder the periods with minor floods. In the longer periods with groyne (Fig. 6.1). minor floods, the main active channel tends to form rel- However, this hard-engineering solution would af- atively tight bends, whereas secondary braids operate as fect the environment and was disapproved of by envi- chutes. During large floods, the bends of the main chan- ronmental authorities. This river reach is typified by the nel are cut off and the channel is straightened. The occur- high abundance and diversity of fish fauna (Wyżga et rence of longer periods without large floods may result in al., 2009) and the high taxonomic diversity of benthic the formation of high-amplitude bends of the main chan- invertebrates (Wyżga et al., 2011, 2012b), which reflect nel. Such a situation occurred in 2011, when a cutbank in considerable complexity of physical habitat conditions 74 technical field trip

Fig. 6.1. Situation in the hitherto unmanaged, multi-thread reach of the Czarny Dunajec River near Wróblówka in September 2011 resulting in the erosional threat to a local road, and channelization works planned at the site by the local water authorities. After Mikuś et al. (2016), reproduced with permission of Elsevier. within the multi-thread channel. The reach is character- channel would preclude ‘filtering’ of large wood from ized by high hydromorphological quality and may be floodwaters and facilitate its downstream transfer to ur- considered as representing hydromorphological refer- banized valley reaches, where it could constitute a con- ence conditions for river restoration projects undertak- siderable flood hazard. en in the Carpathians (Wyżga et al., 2012a). Channel A different solution to limit the erosional risk to the regulation in the so far unmanaged reach would cause nearby road was thus proposed (Mikuś et al., 2016). The deterioration of the ecological status of the river, thus inlets to side braids located by the neck of the bend of contradicting the requirements of the EU Water Frame- the main channel, silted with gravel or plugged up with work Directive. wood jams, would be opened to re-establish the flow in Notably, the multi-thread reach traps much large the low-flow channels typified by higher slope, leading to wood delivered by floodwaters from upstream (Wyżga, the natural cut-off of the main channel and its abandon- Zawiejska, 2005; Ruiz-Villanueva et al., 2016) and re- ment. This solution was approved by the water authorities tains it away from urbanized sections of the valley. This and implemented in the autumn 2011 at the cost of 9000 is enhanced by the presence of narrow side channels in euro. The inlets to four side braids were re-opened and which the wood is easily anchored (Fig. 6.2). Substitut- flow within the braids was reactivated (Fig. 6.3). Directly ing the network of narrow braids with a wide, regulated below the inlets to the side channels, deflectors made of gravel material were constructed (Fig. 6.3) to divert the flow into the reactivated side channels to take over most of the flow during the next flood, hence leading to the abandonment of the main channel bend. Following the implementation of the scheme, river cross-sections located at the upstream end and in the middle of the main channel bend were surveyed to compare hydraulic characteristics of flow and the composition of fish and benthic macroinvertebrate communities with those recorded prior to the project. The hydraulic measurements confirmed that the scheme allowed to shift the main water current, with the highest average velocity and bed shear stress, from the braid closest to the road to Fig. 6.2. Narrow braids in the multi-thread river reach the most distant braid. The biotic surveys indicated that operate as natural traps for large wood transported by the re-activation of the flow in the side channels was ben- flood flows, preventing its further transfer to urbanised eficial for fish and benthic macroinvertebrate communi- valley reaches. ties, increasing their diversity in the reach. technical field trip 75

Fig. 6.3. Environment-friendly solution to the erosional thread to the local road implemented in November 2011. Inlets to blocked braids distant from the road were opened and gravelly deflectors were formed in the main channel to direct flow to the reactivated braids. After Mikuś et al. (2016), reproduced with permission of Elsevier.

Fig. 6.4. Sketch of principal geomorphic units in the part of the multithread reach of the Czarny Dunajec River with the erosional threat to the local road (situation in September 2014). 1 – low-flow channels; 2 – exposed gravel surfaces; 3 – islands. After Mikuś et al. (2016), reproduced with permission of Elsevier.

In May 2014, a 20-year flood occurred on the river. without negative effects on physical habitat conditions The flood resulted in the cut-off of the former main chan- and river biota, was significantly less expensive than the nel bend, directing most of the flow to one of the opened traditional, hard-engineering solution, and it maintained braids (Fig. 6.4). However, avulsion of the main chan- the role of the reach as natural wood trap. However, nel in the river bend immediately upstream again caused with the highly unstable flow pattern in the multi-thread erosional risk to the road, although in another location reach, a better management approach might be to avoid (Fig. 6.4). interventions within the active river zone and to locally The implemented environment-friendly solution al- reinforce the channel bank where the migrating channel lowed relocation of most flow away from the local road approaches the valley-floor infrastructure. 76 technical field trip

Site 7. Wróblówka – reference conditions for the restoration of mountain rivers

Bartłomiej Wyżga, Joanna Zawiejska, Artur Radecki-Pawlik, Hanna Hajdukiewicz

S i t e l o c a t i o n : N 49°27’45.356” E 19°53’56.133”

In the 20th century most rivers in the Polish Carpath- Moreover, Dufour and Piégay (2009) expressed an ians were heavily modified by channelization and chan- opinion that the concept of reference conditions should nel incision. These impacts have induced a number of be abandoned as rivers follow a continuous trajectory of detrimental effects, particularly the degradation of the changes in response to continuously changing boundary ecological integrity of the rivers and an increase in flood conditions. hazard to downstream river reaches. Restoration of the While all the above presented concepts have apparent rivers is thus necessary to improve their ecological status, advantages justifying their formulation, each of them has re-establish an undisturbed course of fluvial processes, also serious deficiencies (Wyżga et al., 2012a). Abandon- and increase flood water storage in the floodplain areas ment of the concept of reference conditions and target- wherever it is possible without threats to settlements and ing restoration to maximise riverine ecosystem services infrastructure on the valley floors. for humans might easily be used by some river manag- Reference conditions describe the best attainable fu- ers to continue technical pressure on rivers camouflaged ture state of a river targeted for management/restoration as river restoration. An important objection against the action. Despite general agreement that restoration activ- way of defining reference conditions in RHS method is ities should be based on a pre-defined reference state, the incorporation of habitat quality in the assessment of no common approach to the identification of reference hydromorphological quality of rivers, whereas many un- conditions exists and various concepts of their definition modified river reaches, such as gorges or straight river have been proposed so far: sections developed along tectonic faults, may naturally l contemporary conditions existing at the sites/reaches exhibit relatively simple morphological conditions and, with the lowest degree of habitat modification due to hence, little abundance and diversity of habitat features. human disturbance and the highest abundance of fea- Reconstruction of pristine conditions in rivers and their tures considered to benefit riverine and riparian wild- catchments is of little use for the practice of river resto- life (River Habitat Survey); ration as their re-establishment in Europe is complete- l pristine conditions which existed at pre-human or ly unlikely. Moreover, many changes in river systems, prehistoric times; either induced by anthropogenic or natural causes, are l historical conditions which existed before major irreversible and river restoration considered as a recov- channelization works, especially those shown on the ery to the pre-disturbance conditions is impossible. The maps from the 19th century. concept of map-derived, historical reference conditions

Fig. 7.1. Changes in the extent of riparian forest in the 8-km-long reach of the Czarny Dunajec River between the villages of Czarny Dunajec and Długopole, shown on the map of 1878 (green areas) and the orthophoto from 2002. After Wyżga et al. (2012a), reproduced with permission of Wiley. technical field trip 77

Fig. 7.2. Contemporary view of the Czarny Dunajec River in the unmanaged, heavily island-braided section. Arrows indicate the position of low-flow channels. After Wyżga et al. (2011), reproduced with permission of Wiley.

benefits from good cartographical documentation of from 42% to 17.5%, whereas the forest cover increased channel patterns which is available for the 19th century from 27.3% to 42%. These environmental changes were throughout Europe. However, in many regions, including reflected in a decrease of the annual maximum discharg- all mountain areas in Europe, the 19th century was the es documented by the instrumental record in the low- period of the highest pastoral and agricultural pressure est river course (Wyżga et al., 2012a), and a decrease in on river catchments and thus rivers of that time did not the magnitude of flood waves over the century was also represent natural conditions. Notably, the environmental shown by a dendrochronologically-based reconstruc- conditions in river catchments have changed consider- tion performed in Tatra Mountain streams (Ballesteros- ably since the 19th century, hence inducing remarkable -Cánovas et al., 2016). river adjustments and precluding the recovery to the With the reduced dynamics of the Czarny Dunajec 19th-century river state in human-modified reaches. under contemporary environmental conditions in the Such a situation is well illustrated by changes that catchment, there is no possibility to restore the river occurred in the Czarny Dunajec River (Wyżga et al., reaches modified by channelization and channel- inci 2012a). Throughout the 19th century and until the mid- sion to the former, bar-braided morphology. At the same 20th century, the river flowed in a wide, braided channel time, the island- to heavily island-braided reaches of the that practically lacked riparian forest on its banks. This Czarny Dunajec, which developed during the past few reflected high sediment yield and high flood flows gen- decades, represent freely formed river morphology, to erated by the largely deforested catchment. In the 20th which the modified reaches might possibly be restored. century and especially in its second half, the river experi- This enables us to define hydromorphological reference enced a considerable reduction in flow and sediment dy- conditions as those associated with the lack of human in- namics. This resulted in narrowing of the active zone of fluence on the channel, riparian zone and floodplain of the river and the expansion of riparian forest on its banks the river under present environmental conditions in the and within the active river zone (Fig. 7.1). As a result, catchment (Wyżga et al., 2012a). the contemporary river exhibits island-braided channel This assumption was tested during the evaluation of pattern in its unmanaged sections (Fig. 7.2). Several fac- hydromorphological quality of the Czarny Dunajec actors contributed to the change in the river dynamics. The cording to the European Standard EN-14614. The eval- previously intensive pasture and forest grazing ceased uation confirmed a high-status hydromorphological riv- and the state of forests in the high-mountain part of the er quality in an unmanaged, multi-thread river reach in catchment improved after the establishment of a national the vicinity of Wróblówka village (Fig. 7.3), which can park in the Tatra Mountains in 1955. Outside the Tatras thus be used as a reference for the restoration of impact- considerable changes in land use took place over the ed river reaches. Among many valuable attributes of 20th century; the proportion of arable lands decreased the river in the reach (Wyżga et al., 2010, 2012a), espe- 78 technical field trip

Fig. 7.3. Averages of the scores given for particular assessment categories and average scores of the hydromorphological quality in the surveyed cross-sections of the Czarny Dunajec. All scores are shown against hydromorphological quality classes. The vertical scale for each assessed category ranges between 1 (for near-natural conditions) and 5 (for extremely modified conditions). After Wyżga et al. (2012a), reproduced with permission of Wiley. cially important is that here the river maintains vertical Importantly, in the mode of defining reference condi- stability of its channel, exhibits undisturbed three-di- tions we propose, they are considered in a dynamic way mensional connectivity of the river ecosystem and high and thus can be continually modified with changing en- heterogeneity of the habitat conditions for aquatic biota. vironmental conditions in the catchment.

Site 8. Czarny Dunajec – impact of changes in hydromorphological river quality on mountain river communities

Bartłomiej Wyżga, Artur Radecki-Pawlik, Joanna Zawiejska, Antoni Amirowicz, Paweł Oglęcki

S i t e l o c a t i o n : N 49°26’01.651” E 19°51’19.915”

Restoration of good ecological status of modified wa- (Wyżga et al., 2009, 2010), and (ii) the relations between tercourses requires recognition of the relations which exist the abundance and diversity of fish fauna as well as the between the structure of river biocoenoses and morpho- taxonomic richness of benthic invertebrate communi- logical and hydrological habitat characteristics, i.e. hy- ties on one hand and the complexity of physical habitat dromorphological river quality. In the second half of the conditions on the other hand (Wyżga et al., 2009, 2011, 20th century, the Czarny Dunajec River was substantially 2012b). The studies were performed in several cross-sec- changed as a result of channelization and channel incision; tions located in an incised river reach with unmanaged, at present, particular river reaches substantially differ in single-thread channel, in a channelized reach, and in an terms of morphology and the style of channel manage- unmanaged reach with a multi-thread channel. ment. Therefore, the river was examined to determine: (i) Measurements of water depth, flow velocity, and the impact of human-induced changes of the river channel mean grain size of surface bed material, performed at 1 and riparian zone on the hydromorphological river quality m intervals across the low-flow channels, indicated that technical field trip 79

Fig. 8.1. Examples of cross-sectional morphology of the Czarny Dunajec in a channelized river reach (upper) and an unmanaged, multi-thread reach (lower). For low-flow channels, mean grain size of the sediment on the bed surface and mean flow velocity are indicated at 1 m intervals. The scale for velocity commences at the water surface for each low- flow channel. After Wyżga et al. (2009), reproduced with permission of Wiley. multi-thread river cross-sections exhibit significantly tions) to 5 (for extremely modified conditions); based on higher variability in the physical habitat parameters than averaged scores for each of the assessed categories, the single-thread cross-sections (Fig. 8.1). In single-thread cross-sections were associated with particular classes of cross-sections, flow velocity generally increased with hydromorphological quality (Fig. 7.3). increasing water depth and the bed consisted entirely The scores for all the cross-sections ranged from of gravel. In multi-thread cross-sections, no relation be- 1.08 to 3.96, indicating high variability of hydromorpho- tween water depth and flow velocity was observed and logical river quality. Cross-sections H to K, represent- the dominant gravelly parts of the bed were accompanied ing island- to heavily island-braided river morphology, by the patches of sandy or muddy substrate (Fig. 8.1). were assigned to class 1 of hydromorphological quality; Assessment of the hydromorphological river quality cross-sections A-C with an unmanaged, deeply incised in the studied cross-sections was carried out simultane- channel fell into class 2 and regulated channel cross-sec- ously by specialists in fluvial geomorphology, river engi- tions (D-F and L) into class 4 (Fig. 7.3). neering and freshwater ecology. They scored 10 groups Single-thread cross-sections hosted 2 species (brown of features of the channel, river banks, riparian zone, and trout and Alpine bullhead) and, on average, 13 individ- floodplain according to their specification in the Euro- uals of subadult and adult (≥1 year old) fishes. In the pean Standard EN-14614 (CEN, 2004). Each category cross-sections with four low-flow channels, 3-4 fish spe- was assessed on the scale from 1 (for near-natural condi- cies (brown trout, Alpine bullhead, European minnow, 80 technical field trip

gle-thread cross-sections hosted 4-7 eurytopic taxa that represented 2-3 functional groups. In turn, multi-thread cross-sections were found to host 8-20 taxa representing all functional groups and comprising not only widely tolerant but also rheophilic and limnophilic taxa. The number of taxa increased linearly with increasing number of low-flow channels (Fig. 8.3) and variability in water depth, flow velocity, and bed material grain-size in a cross-section. Both the channelized river reach at Czarny Dunajec (site 8) and the upstream located incised reach are typified by little variability in physical habitat conditions and supported a two-species fish assemblage and a low number of benthic invertebrate taxa. By contrast, the multi-thread reach at Wróblówka (sites 6-7) supported the four-species fish assemblage with a relatively large number of individuals as well as the most diverse assemblage of benthic invertebrates. The studies have shown that the human-induced sim- plification of channel pattern in a mountain river and the resultant degradation of its hydromorphological quality are reflected in the reduced diversity of fish and benthic invertebrate communities, indicating considerable deterioration of the ecological status of the river. A common situation in the Polish Carpathians is a regulated channel running at a considerable distance from developed areas on the valley floor, with flood embankments providing protection for Fig. 8.2. Scatter plots and estimated regression relation- riparian forest. In such cases, further maintenance of chan- ships between the number of subadult and adult fish nelization structures cannot be justified by a public inter- caught in the investigated cross-sections of the Czarny est and undertaking actions aimed at improvement of the Dunajec River and the coefficient of variation of flow ecological status of rivers is of essence. Re-establishing of depth (upper) and hydromorphological river quality good ecological status of rivers may be achieved only if (lower) in the cross-sections. After Wyżga et al. (2009), reproduced with permission of Wiley. their morphological complexity is significantly increased and their hydromorphological quality improved. and stone loach) were recorded with the average of 82 subadult and adult individuals. Even larger differences were related to the abundance of juveniles: single-thread channels hosted 2 juveniles compared to the average of 241 such individuals found in the cross-sections with four low-flow channels. The occurrence of two-species fish assemblage with low abundance was typical of single-thread cross-sections located both upstream and downstream of the unmanaged, multi-thread channel reach. None of the cross-sections hosted grayling, a fish still common along the studied reach of the Czarny Dunajec in the 1970s. The regression analysis indicated the number of fish species and individuals to increase linearly with increasing variability in water depth in a cross-section and exponentially Fig. 8.3. Scatter plot and estimated regression relation- with improving hydromorphological river quality (i.e. de- ship between the number of invertebrate taxa recorded in creasing quality scores) (Fig. 8.2). the investigated cross-sections of the Czarny Dunajec and Benthic invertebrate communitities were investigat- the number of flow threads in the cross-sections. After ed in 18 cross-sections, with 21 taxa found in total. Sin- Wyżga et al. (2011), reproduced with permission of Wiley. technical field trip 81

REFERENCES

BALLESTEROS-CÁNOVAS J. A., 2016. Paleoflood dis- observations. Earth Surface Processes and Land- charge reconstruction in Tatra Mountain streams. Geo- forms, 41, 446–459. morphology, DOI: 10.1016/j.geomorph.2015.12.004 SKALSKI T., KĘDZIOR R., WYŻGA B., RADEC- BOJARSKI A., JELEŃSKI J., JELONEK M., LITEW- KI-PAWLIK A., PLESIŃSKI K., ZAWIEJSKA KA T., WYŻGA B., ZALEWSKI J., 2005. Zasady J., 2016. Impact of incision of gravel-bed rivers on dobrej praktyki w utrzymaniu rzek i potoków górskich ground beetle assemblages. River Research and Ap- (Good-practice manual of sustainable maintenance plications, DOI: 10.1002/rra.3027. of mountain streams and rivers). Ministerstwo Środo- THORNE C.R., HEY R. D., NEWSON M. D., 1997. wiska, Warszawa. Applied fluvial geomorphology for river engineering CEN, 2004. Water quality – Guidance standard for as- and management. Wiley, Chichester. sessing the hydromorphological features of rivers. WYŻGA B., 1993. River response to channel regulation: EN-14614. CEN, Brussels. case study of the Raba River, Carpathians, Poland. CZECH W., RADECKI-PAWLIK A., WYŻGA B., HAJ- Earth Surface Processes and Landforms, 18, 541–556. DUKIEWICZ H., 2016. Modelling the flooding ca- WYŻGA B., 1997. Methods for studying the response of pacity of a Polish Carpathian River: A comparison flood flows to channel change.Journal of Hydrology, of constrained and free channel conditions. Geomor- 198, 271–288. phology, DOI: 10.1016/j.geomorph.2015.09.025 WYŻGA B., ZAWIEJSKA J., 2005. Wood storage in a DUFOUR S., PIÉGAY H., 2009. From the myth of a lost wide mountain river: case study of the Czarny Duna- paradise to targeted river restoration: forget natural jec, Polish Carpathians. Earth Surface Processes and references and focus on human benefits. River Re- Landforms, 30, 1475–1494. search and Applications, 25, 568–581. WYŻGA B., AMIROWICZ A., RADECKI-PAWLIK A., JÄHNIG S., BRUNZEL S., GACEK S., LORENZ A. W., ZAWIEJSKA J., 2009. Hydromorphological condi- HERING D., 2009. Effects of re-braiding measures tions, potential fish habitats and the fish community on hydromorphology, floodplain vegetation, ground in a mountain river subjected to variable human im- beetles and benthic invertebrates in mountain rivers. pacts, the Czarny Dunajec, Polish Carpathians. River Journal of Applied Ecology, 46, 406–416. Research and Applications, 25, 517–536. MIKUŚ P., WYŻGA B., KACZKA R. J., WALUSIAK J., WYŻGA B., OGLĘCKI P., RADECKI-PAWLIK A., ZA- ZAWIEJSKA J., 2013. Islands in a European moun- WIEJSKA J., 2011. Diversity of macroinvertebrate tain river: Linkages with large wood deposition, flood communities as a reflection of habitat heterogeneity flows and plant diversity. Geomorphology, 202, 115– in a mountain river subjected to variable human im- 127. pact. [w:] A. Simon, S. J. Bennett, J. M. Castro (eds), MIKUŚ P., WYŻGA B., RADECKI-PAWLIK A., ZA- Stream Restoration in Dynamic Fluvial Systems: Sci- WIEJSKA J., AMIROWICZ A., OGLĘCKI P., entific Approaches, Analyses and Tools. American 2016: Environment-friendly reduction of flood risk Geophysical Union, Washington, 189–207. and infrastructure damage in a mountain river: case WYŻGA B., ZAWIEJSKA J., RADECKI-PAWLIK A., study of the Czarny Dunajec. Geomorphology, DOI: AMIROWICZ A., 2010. A method for the assessment 10.1016/j.geomorph.2015.11.003 of hydromorphological river quality and its applica- NIEZNAŃSKI P., WYŻGA B., OBRDLIK P., 2008. tion to the Czarny Dunajec, Polish Carpathians. In: Oder border meander: A concept of the erodible riv- A. Radecki-Pawlik, J. Hernik (eds), Cultural Land- er corridor and its implementation. In: B. Gumiero, scapes of River Valleys. Agricultural University in M. Rinaldi, B. Fokkens (eds), IVth ECRR Interna- Kraków, Kraków, 145–164. tional Conference on River Restoration. European WYŻGA B., ZAWIEJSKA J., RADECKI-PAWLIK A., Centre for River Restoration, Venice, 479–486. HAJDUKIEWICZ H., 2012a. Environmental change, PIÉGAY H., DARBY S. E., MOSSELMAN E., SURIAN hydromorphological reference conditions and the res- N., 2005. A review of techniques available for de- toration of Polish Carpathian rivers. Earth Surface limiting the erodible river corridor: a sustainable Processes and Landforms, 37, 1213–1226. approach to managing bank erosion. River Research WYŻGA B., OGLĘCKI P., RADECKI-PAWLIK A., and Applications, 21, 773–789. SKALSKI T., ZAWIEJSKA J., 2012b. Hydromor- RUIZ-VILLANUEVA V., WYŻGA B., HAJDUKIE- phological complexity as a driver of the diversity of WICZ H., STOFFEL M., 2016. Exploring large benthic invertebrate communities in the Czarny Du- wood retention and deposition in contrasting river najec River, Polish Carpathians. Hydrobiologia, 696, morphologies linking numerical modelling and field 29–46. 82

LIST OF AUTHORS*

Adamski Paweł 60 Giriat Dorota 55 Albanakis Konstatinos 17 Glixelli Tomasz 24, 25 Amirowicz Antoni 12, 28, 36, 59, 73, 78 Göldi Christian 25 Bączyk Anna 12 Gorczyca Elżbieta 26 Bednarek Borys 13 Grabowski Robert 40 Bednarska Agnieszka J. 14, 69 Grant Gordon E. 16 Belletti Barbara 47 Griffin Ian 24 Bertoldi Walter 51 Grygoruk Jędrzej 27 Bielański Wojciech 60 Grygoruk Mateusz 12, 27, 27 Bithell Claire 14 Gurnell Angela 7 Bizzi Simone 16 Haase Peter 37 Blaauwendraat Wijnand 50, 50 Hajdukiewicz Hanna 18, 28, 60, 76 Bouchet Ludivine 55 Hammond Di 20 Boutet-Berry Laetitia 42 Hecher Peter 28 Brochard Pascal 49 Hering Daniel 37 Buijse Tom 7 Hradecký Jan 23, 53 Bussettini Martina 16, 47 Inoue Mikio 33 Carlson Peter 17 Jaehrling K.-H 34 Chmielewski Aron 27 Janes Martin 29, 40 Chormański Jarosław 16 Janiec Paweł 24 Choryński Adam 40 Jans Luc 50, 50 Chronis Ioannis 17 Januschke Kathrin 37 Clave David 44 Jeleński Józef 12, 24, 30, 36, 64, 65, 67 Coeck Johan 57 Jeleński Paweł 30 Coghlan Brian 15 Jormola Jukka 8 Comiti Francesco 47, 51 Kail Jochem 31 Czech Wiktoria 18 Kajtoch Łukasz 31 Ćmiel Adam 60 Kałuża Tomasz 32, 55 Dai Prà Elena 51 Kameyama Satoshi 33 Degerman Erik 17 Karlborg Henrik 56 Delanty Karen 15 Kasjaniuk Anna 27 Delgado-Merlo Expectacion 21 Kawagushi Yoichi 33 Demarchi Luca 16 Kędra Mariola 33 Depta Joanna 39 Kędzior Renata 14, 69 Duijn Prisca P. 18, 50, 50 Kidová Anna 34 Dumnicka Elżbieta 41 King James J. 15 Duplić Aljoša 49 Klich Mariusz 60 Dysarz Tomasz 55 Kliment Zdeněk 35, Edmaier Katharina 19 Klink Alexander 50, 50 England Judy 20, 20 Koenig Frauke 34 Fernandez-Oliveras Paz 21 Korpak Joanna 35 Fiedorczuk Paweł 27 Kostecka Aneta 27 Figarski Tomasz 31 Kroes Martin 47 Florek Jacek 60 Krzemień Kazimierz 26 Franczak Paweł 21 Kujanová Kateřina 35 Frąk Magdalena 27 Kulesza Krzysztof 55 Furdyna Artur 22 Kundzewicz Zbigniew W. 40 Galia Tomáš 23, 34, 53 Lamouroux Nicolas 48 Gałosz Wojciech 61 Lehotský Milan 34 Gąsiorowska Beata 22 Lenar-Matyas Anna 35 Gillies Eric 23 Leps Moritz 37 Gilligan Nathy 15 Lewandowski Jakub 40 Gilvear David 8, 14, 24 Liefveld Wendy 50, 50 83

Liro Maciej 36, 36, 42, 65, 72 Sandin Leonard 17 Lopez-Alonso Monica 21 Schneider Daniela 49 Lorenz Armin 37 Schoor Margriet 50, 50 Lorieau Francis 49 Scorpio Vittoria 51, 52 Lunko Petra 49 Sieben Arjan 50, 50 Łaciak Małgorzata 38 Sikorska Kalina 53 Łaciak Tomasz 38 Škarpich Václav 23, 34, 53 Łapuszek Marta 38 Sobucki Mateusz 26 Łyp Michał 39 Spitoni Marie 54 Magliozzi Chiara 40 Stokłosa Edward 30 Malinger Albert 55 Stoll Stefan 37 Mas Bernard 44 Strużyński Andrzej 55, 60 Mastronunzio Marco 51 Sundermann Andrea 37 Matczak Piotr 40 Surian Nicola 51 Matoušková Milada 35 Szałkiewicz Ewelina 55 Mazurkiewicz-Boroń Grażyna 41 Szarek-Gwiazda Ewa 41 Melun Gabriel 42 Szoszkiewicz Krzysztof 32 Mikuś Paweł 12, 14, 28, 30, 36, 42, 59, 65, 69, 72, 73 Szwed Małgorzata 40 Miyake Yo 33 Trenc Neven 49 Moir Hamish 23, 43 Trizna Milan 34 Mouton Ans 57 Uziębło Aldona K. 56 Nachlik Elżbieta 43 van Puijenbroek Peter 47 Nadachowski Jan 39 van Rheede Henk 50, 50 Nikolaidis Anastasios 17 Vandenwalle Francois 44 Nohara Seiichi 33 Vaudor Lise 48, 54 Oglęcki Paweł 28, 36, 59, 73, 78 Vennman Tommy 56 Okruszko Tomasz 9, 12 Vermeersch Sophie 57 Ó Brian Rossa 15 Vezza Paolo 47 Parussatti Sandro 49 Vivier Anne 41 Peress Josée 44 Vouvalidis Konstatinos 17 Perfect Charles 24 Wagner Maciej 12 Peyret Hugues 44 Waloch Piotr 22 Piégay Hervé 10, 16, 48, 54 Walusiak Edward 42, 72 Pires Miguel Dionisio 50, 50 Wasilewicz Michał 46 Plesiński Karol 36, 45 Wiejaczka Łukasz 33 Poławski Łukasz 13, 46 Wilkes Martin 20 Popek Zbigniew 46 Wilk-Woźniak Elżbieta 41 Poyatos Jose M. 21 Willby Nigel 24 Proto Matteo 51 Wolak Andrzej 58 Quick Ina 34 Wolter Christian 58 Raczkiewicz Tomasz 26 Wyrębek Maciej 55 Radecki-Pawlik Artur 12, 18, 28, 32, 36, 46, 59, 73, 76, 78 Wyżga Bartłomiej 12, 14, 18, 28, 36, 42, 45, 59, 60, 6 5 , 6 7 , Radecki-Pawlik Bartosz 32 69, 72, 73, 76, 78 Reyjol Yorick 42 Zając Katarzyna 60 Rinaldi Massimo 10, 16, 47 Zając Tadeusz 60 Riquier Jérémie 48 Zalewska-Gałosz Joanna 61 Roset Nicolas 49 Zalewski Jacek 25 Rosskopf Carmen Maria 52 Zarzycki Wojciech 56 Ruiz-Villanueva Virginia 11 Zawiejska Joanna 28, 42, 59, 60, 62, 72, 73, 76, 78 Ruman Stanislav 34 Zen Simone 51 Rusnák Miloš 34 Zolezzi Guido 51 Sabolić Marija 49 Zwolińska Iwona 13 Sadot Michael 49

* Numbers in normal font refer to conference abstracts, those in italics to field trip guide. 84 notes