DOCSLIB.ORG

Deriving Drainage Networks and Catchment Boundaries: a New Methodology Combining Digital Elevation Data and Environmental Characteristics

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Deriving Drainage Networks and Catchment Boundaries: a New Methodology Combining Digital Elevation Data and Environmental Characteristics Geomorphology 53 (2003) 281–298 www.elsevier.com/locate/geomorph Deriving drainage networks and catchment boundaries: a new methodology combining digital elevation data and environmental characteristics Ju¨rgen V. Vogta,*, Roberto Colomboa, Francesca Bertolob a EC Joint Research Center, Institute for Environment and Sustainability, Via Enrico Fermi, s/n, 21020 Ispra, Varese, Italy b 21100 Varese, Italy Received 8 May 2002; received in revised form 2 October 2002; accepted 4 October 2002 Abstract Digital data on the position and characteristics of river networks and catchments are important for the analysis of pressures and impacts on water resources. GIS tools allow for the combined analysis of digital elevation data and environmental parameters in order to derive this kind of information. This article presents a new approach making use of medium-resolution digital elevation data (250-m grid cell size) and information on climate, vegetation cover, terrain morphology, soils and lithology to derive river networks and catchments over extended areas. In general, methods to extract channel networks at small scale use a constant threshold for the critical contributing area, independent of widely varying landscape conditions. As a consequence, the resulting drainage network does not reflect the natural variability in drainage density. To overcome this limitation, a classification of the landscape is proposed. The various data available are analysed in an integrated approach in order to characterise the terrain with respect to its ability to develop lower or higher drainage densities, resulting in five landscape types. For each landscape type, the slope–area relationship is then derived and the critical contributing area is determined. In the subsequent channel extraction, a dedicated critical contributing area threshold is used for each landscape type. The described methodology has been developed and tested for the territory of Italy. Results have been validated comparing the derived data with river and catchment data sets from other sources and at varying scales. Good agreement both in terms of river superimposition and drainage density could be demonstrated. D 2002 Elsevier Science B.V. All rights reserved. Keywords: Drainage network extraction; Catchment delineation; Drainage density; Landscape characterisation; Digital elevation data 1. Introduction * Corresponding author. European Commission, DG Joint Research Centre, Institute for Environment and Sustainability From its source, water is transported along networks (IES), TP 262, Via Enrico Fermi, s/n, 21020 Ispra, Varese Italy. of rivers, canals and lakes to the sea. Such networks of Tel.: +39-0332-78-5481; fax: +39-0332-78-9803. E-mail addresses: [email protected] (J.V. Vogt), drainage channels and associated drainage basins form [email protected] (R. Colombo), [email protected] complex functional entities not only for hydrological (F. Bertolo). processes but also for geomorphological processes at 0169-555X/02/$ - see front matter D 2002 Elsevier Science B.V. All rights reserved. doi:10.1016/S0169-555X(02)00319-7 282 J.V. Vogt et al. / Geomorphology 53 (2003) 281–298 large. Human pressures on water resources have con- study for Italy, a country that includes areas with large stantly increased over the last decades. Population differences in their morpho-climatical characteristics. growth, intensified agriculture, industrialisation and Results have been validated by comparing the derived recreational activities are among the primary drivers data with river and catchment data sets from other for such pressures, and climatic extremes such as sources and at varying scales. droughts can aggravate these problems (EEA, 1998; In Section 2, we briefly review standard method- Vogt and Somma, 2000). ologies to derive drainage networks from digital Monitoring systems for water quality and quantity elevation data as well as the results of investigations exist in all European countries. The level of detail of into the relationship between environmental factors the collected information does, however, vary to a and drainage density. Section 3 describes the imple- large degree. Information on the relationship between mented methodology, with special emphasis on the the state of the water bodies and environmentally landscape characterisation. In Section 4, the results relevant variables (e.g., land use, soil types, popula- are presented, and in Section 5, the main conclusions tion density) is often lacking or not available. Still, are drawn. such information is necessary for a more holistic analysis and for the analysis of cause–effect relation- ships between policies and environmental pressures. 2. Deriving drainage networks from digital A Pan-European spatial database of rivers and catch- elevation data ments and their characteristics, therefore, is important for the analysis of these processes and for the mon- The extraction of drainage networks and catchment itoring and sustainable management of our water boundaries from digital elevation models (DEMs) has resources. The scales for presenting such information received considerable attention in recent years. A over extended areas such as Europe should preferably variety of algorithms has been reported in the liter- range from 1:250,000 to 1:1,000,000, and data should ature and the most pertinent problems have been be sufficiently accurate to support the mentioned highlighted. These are related to the treatment of flat applications (Vogt et al., 1999). areas and to the location of the channel heads. In the With a total surface of about 11.2 million km2, the following, we briefly summarise the main findings Pan-European area (from the Mediterranean to north- and discuss the relation between drainage density and ern Scandinavia and from the Atlantic to the Urals) environmental factors. comprises a large variety of landscape types, and the sheer extent of the area calls for the development of 2.1. Pre-processing digital elevation data efficient and reliable methods to derive the required information. To this end, a methodology has been Standard techniques of DEM preparation include developed which allows for the derivation of drainage pit filling, stream burning and the calculation of flow networks and associated catchments from digital ele- direction and flow accumulation grids. vation data and other environmental parameters in an During pit filling, local sinks are assumed to be automatic and repeatable way. artefacts, resulting from DEM generation. They are This paper presents the methodology which is filled up to the level of the lowest grid cell on the rim sensitive to different natural drainage density patterns of the sink with a defined flow direction. As a as a function of five landscape types that account for consequence, also natural sinks (e.g., in karstic land- spatial variations in hydrologic controls such as cli- scapes) are filled up and the technique often results in mate, vegetation cover, relief, soils and lithology. For extended areas of flat terrain. Common approaches are each landscape type, a suitable critical contributing based on the techniques described by Jenson and area is derived by analysing the relationship between Domingue (1988), O’Callaghan and Mark (1984), local slope and contributing area. Using this spatially Fairfield and Leymarie (1991) and Martz and Gar- varying threshold in the derivation of channel heads brecht (1998). results in a naturally varying drainage density. The From the pit-filled DEM, a flow direction grid is methodology has been developed and tested in a case calculated. In the simplest case, flow direction J.V. Vogt et al. / Geomorphology 53 (2003) 281–298 283 between neighbouring grid cells is described by a 2.2. Selecting a critical contributing area single direction according to the steepest downward slope in a 3 3 neighbourhood (O’Callaghan and One of the most critical issues in deriving drain- Â Mark, 1984). Such a description is well adapted for age networks from DEMs is the location of the zones of convergent flow and along well-defined channel head. Many channel initiation models valleys. For overland flow analysis, however, a par- describe the head location as the result of competing titioning of the flow into multiple directions may be sediment transport processes. The prevalence of one better (Freeman, 1991; Quinn et al., 1991; Desmet or another process depends to a large extent on the and Govers, 1996). A particular case of multiple flow amount of water available and, as a consequence, on dispersion was proposed by Tarboton (1997) in which the size of the area contributing water to a given flow dispersion is reduced by dividing the flow point. between a maximum of two neighbouring downslope Based on this concept, a common approach for grid cells. extracting drainage networks from a DEM is to From the flow direction grid, a flow accumulation consider a grid cell as being part of a channel if its grid can be calculated and from this grid drainage contributing area is larger than a defined contributing networks can be extracted. While most algorithms area threshold (O’Callaghan and Mark, 1984). The produce comparable networks in terrain with sufficient underlying hypothesis states that channel heads are relief, major differences occur in areas with relatively located in zones where fluvial transport becomes flat terrain. Special attention, therefore, has to be paid dominant over diffusive transport, corresponding to to modelling the flow of water in (almost) flat
Load more

Recommended publications
  • Inland Waterways: Romantic Notion Or Means to Kick-Start World Economy? by Karel Vereycken
    Inland Waterways: Romantic Notion or Means To Kick-Start World Economy? by Karel Vereycken PARIS, Sept. 24—Some 300 enthusiasts of 14 nations, dominated most of the sessions—starts from the dan- among them, the USA, France, Belgium, Netherlands, gerous illusion of a post-industrial society, centered Germany, China, Serbia, Canada, Italy, and Sweden), on a leisure- and service-based economy. For this gathered in Toulouse Sept. 16-19, for the 26th World vision, the future of inland waterways comes down to Canals Conference (WCC2013). The event was orga- a hypothetical potential income from tourism. Many nized by the city of Toulouse and the Communes of the reports and studies indicate in great detail how for- Canal des Deux Mers under the aegis of Inland Water- merly industrial city centers can become recreational ways International (IWI). locations where people can be entertained and make Political officials, mariners, public and private indi- money. viduals, specialists and amateurs, all came to share a Radically opposing this Romanticism, historians single passion—to promote, develop, live, and preserve demonstrated the crucial role played by canals in orga- the world heritage of waterways, be they constructed by nizing the harmonic development of territories and the man and nature, or by nature alone. birth of great nations. Several Chinese researchers, no- For Toulouse, a major city whose image is strongly tably Xingming Zhong of the University of Qingdao, connected with rugby and the space industry, it was an and Wang Yi of the Chinese Cultural Heritage Acad- occasion to remind the world about the existence of the emy showed how the Grand Canal, a nearly 1,800-km- Canal du Midi, built between 1666 and 1685 by Pierre- long canal connecting the five major rivers in China, Paul Riquet under Jean-Baptiste Colbert, the French Fi- whose construction started as early as 600 B.C., played nance Minister for Louis XIV.
    [Show full text]
  • Nitrogen Flows from European Regional Watersheds to Coastal
    Chapter Nitrogen fl ows from European regional watersheds 1 3 to coastal marine waters Lead author: G i l l e s B i l l e n Contributing authors: Marie Silvestre , Bruna Grizzetti , Adrian Leip , Josette Garnier , M a r e n Vo s s , R o b e r t H o w a r t h , F a y ç a l B o u r a o u i , A h t i L e p i s t ö , P i r k k o K o r t e l a i n e n , P e n n y J o h n e s , C h r i s C u r t i s , C h r i s t o p h H u m b o r g , E r i k S m e d b e r g , Øyvind Kaste , Raja Ganeshram , Arthur Beusen and Christiane Lancelot Executive summary Nature of the problem • Most regional watersheds in Europe constitute managed human territories importing large amounts of new reactive nitrogen. • As a consequence, groundwater, surface freshwater and coastal seawater are undergoing severe nitrogen contamination and/or eutrophi- cation problems. Approaches • A comprehensive evaluation of net anthropogenic inputs of reactive nitrogen (NANI) through atmospheric deposition, crop N fi xation, fertiliser use and import of food and feed has been carried out for all European watersheds. A database on N, P and Si fl uxes delivered at the basin outlets has been assembled. • A number of modelling approaches based on either statistical regression analysis or mechanistic description of the processes involved in nitrogen transfer and transformations have been developed for relating N inputs to watersheds to outputs into coastal marine ecosystems.
    [Show full text]
  • European Coasts of Bohemia the Danube–Oder–Elbe Canal Attracted a Great Deal of Attention Throughout the Twentieth Century
    Jiří Janáč Jiří European Coasts of Bohemia The Danube–Oder–Elbe Canal attracted a great deal of attention throughout the twentieth century. Its promo- ters defined it as a tool for integrating a divided Europe. Negotiating the Danube-Oder-Elbe Canal in Although the canal was situated almost exclusively on Czech territory, it promised to create an integrated wa- a Troubled Twentieth Century Jiří Janáč terway system across the Continent that would link Black Sea ports to Atlantic markets. In return, the landlocked European Coasts of Bohemia Czechoslovakian state would have its own connections to the sea. Today, the canal is an important building block of the European Agreement on Main Inland Waterways. This book explains the crucial role that experts played in aligning national and transnational interests and in- frastructure developments. It builds on recent inves- tigations into the hidden integration of Europe as an outcome of transnational networking, system-building, and infrastructure development. The book analyzes the emergence of a transnational waterway expert network that continued to push for the development of the ca- nal despite unfavorable political circumstances. The book shows how the experts adapted themselves to various political developments, such as the break-up of the Austrian–Hungarian Empire, the rise of the Third Reich, and integration into the Soviet Bloc, while still managing to keep the Canal project on the map. This book provides a fascinating story of the experts who confronted and contributed to different and often con- flicting geopolitical visions of Europe. The canal was never completed, yet what is more re- markable is the fact that the canal remained on various agendas and attracted vast resources throughout the twentieth century.
    [Show full text]
  • River Basins 2017
    International Conference RIVER BASINS 2017 International Conference RIVER BASINS 2017 Transboundary Management of Pollutants Editors: O. Zoboli, M. Zessner, S. Fuchs Vienna, 2017 Institute for Water Quality, Resource and Waste Management TU Wien Karlsplatz 13/226 1040 Vienna, Austria In cooperation with International Conference RIVER BASINS 2017 Table of contents 1. Oral presentations ........................................................................................................................... 3 Session 1: Monitoring .......................................................................................................................... 4 A monitoring network platform for automated data assessment and its long-term application as surveillance system for transboundary water pollution ................................................................. 5 Ship-borne measurements of enzymatic GLUC activity on large water bodies: A rapid screening tool to localize point sources of potential microbial pollution ....................................................... 7 The impact of the Sava river pollution on biomarkers response in the liver and gills of three cyprinid species ............................................................................................................................... 8 Session 2: Monitoring and Modelling................................................................................................ 10 Multidimensional monitoring of microbial faecal pollution reveals dominance of human contamination
    [Show full text]
  • On the Way to the Fluvial Anthroposphere—Current Limitations and Perspectives of Multidisciplinary Research
    water Review On the Way to the Fluvial Anthroposphere—Current Limitations and Perspectives of Multidisciplinary Research Lukas Werther 1 , Natascha Mehler 1,2, Gerrit Jasper Schenk 3 and Christoph Zielhofer 4,* 1 Institute of Prehistoric and Medieval Archaeology, Department of Medieval Archaeology, Tübingen University, 72070 Tübingen, Germany; [email protected] (L.W.); [email protected] (N.M.) 2 Institute for Northern Studies, University of the Highlands and Islands, Kirkwall, Orkney KW15 1FL, UK 3 Institute of History, History of the Middle Ages, Technical University of Darmstadt, 64293 Darmstadt, Germany; [email protected] 4 Institute of Geography, Leipzig University, 04103 Leipzig, Germany * Correspondence: [email protected]; Tel.: +49-341-97-32965 Abstract: Floodplains represent a global hotspot of sensitive socioenvironmental changes and early human forcing mechanisms. In this review, we focus on the environmental conditions of preindustrial floodplains in Central Europe and the fluvial societies that operated there. Due to their high land-use capacity and the simultaneous necessity of land reclamation and risk minimisation, societies have radically restructured the Central European floodplains. According to the current scientific consensus, up to 95% of Central European floodplains have been extensively restructured or destroyed. There- fore, question arises as to whether or when it is justified to understand Central European floodplains as a ‘Fluvial Anthroposphere’. The case studies available to date show that human-induced impacts on floodplain morphologies and environments and the formation of specific fluvial societies reveal fundamental changes in the medieval and preindustrial modern periods. We aim to contribute to Citation: Werther, L.; Mehler, N.; disentangling the questions of when and why humans became a significant controlling factor in Schenk, G.J.; Zielhofer, C.
    [Show full text]
  • Pleistocene Glaciations of Czechia
    Provided for non-commercial research and educational use only. Not for reproduction, distribution or commercial use. This chapter was originally published in the book Developments in Quaternary Science, Vol.15, published by Elsevier, and the attached copy is provided by Elsevier for the author's benefit and for the benefit of the author's institution, for non- commercial research and educational use including without limitation use in instruction at your institution, sending it to specific colleagues who know you, and providing a copy to your institution’s administrator. All other uses, reproduction and distribution, including without limitation commercial reprints, selling or licensing copies or access, or posting on open internet sites, your personal or institution’s website or repository, are prohibited. For exceptions, permission may be sought for such use through Elsevier's permissions site at: http://www.elsevier.com/locate/permissionusematerial From: Daniel Nývlt, Zbyněk Engel and Jaroslav Tyráček, Pleistocene Glaciations of Czechia. In J. Ehlers, P.L. Gibbard and P.D. Hughes, editors: Developments in Quaternary Science, Vol. 15, Amsterdam, The Netherlands, 2011, pp. 37-46. ISBN: 978-0-444-53447-7 © Copyright 2011 Elsevier B.V. Elsevier. Author's personal copy Chapter 4 Pleistocene Glaciations of Czechia { Daniel Ny´vlt1,*, Zbyneˇ k Engel2 and Jaroslav Tyra´cˇek3, 1Czech Geological Survey, Brno branch, Leitnerova 22, 658 69 Brno, Czech Republic 2Department of Physical Geography and Geoecology, Faculty of Science, Charles University in Prague, Albertov 6, 128 43 Praha 2, Czech Republic 3Czech Geological Survey, Kla´rov 3, 118 21 Praha, Czech Republic *Correspondence and requests for materials should be addressed to Daniel Ny´vlt.
    [Show full text]
  • Settling Waterscapes in Europe. the Archaeology of Neolithic and Bronze Age Pile-Dwellings
    New perspectives on archaeological landscapes in the south-western German alpine foreland — first results of the BeLaVi Westallgäu project 11 Martin Mainberger1, Tilman Baum2, Renate Ebersbach3, Philipp Gleich4, Ralf Hesse3, Angelika Kleinmann5, Ursula Maier3, Josef Merkt5, Sebastian Million3, Oliver Nelle3, Elisabeth Stephan3, Helmut Schlichtherle3, Richard Vogt3, Lucia Wick2 Introduction 1 – UWARC, Fachbetrieb für Unterwasserarchäologie und Forschungstauchen, Staufen im Annually laminated lake sediments contain an amazing wealth of evi- Breisgau, Germany dence on activities of prehistoric communities. If it is possible to link 2 – IPNA, University of Basel, their palaeoenvironmental, palaeoeconomic, and palaeoclimatic informa- Switzerland 3 – Landesamt für Denkmalpflege im tion precisely to waterlogged archaeological evidence, prehistoric human Regierungspräsidium Stuttgart, presence can be detected in a resolution and on a spatial scale far be- Germany yond conventional lake dwelling research. The successful methodological 4 – Ur- und Frühgeschichtliche und Provinzialrömische Archäologie, combination of on-site and off-site approaches in the same microregion Departement was one of the core outcomes of a research project carried out between Altertumswissenschaften, University of Basel, Switzerland 2008 and 2010, which focused on Degersee, a small lake in southwest 5 – Herbertingen, Germany Germany, in the hinterland of Lake Constance (Mainberger et al. 2015b)*. In the same years it became evident that small lakes in the Swiss Plateau provided comparable datasets of high-resolution data covering several thousand years of postglacial human-environmental interaction (Tinner et al. 2006). Based upon those studies, the trinational project ‘Beyond Lake Settlements: Studying Neolithic environmental changes and human impact at small lakes in Switzerland, Germany and Austria’ (BeLaVi) aims to develop a bigger and at the same time more detailed picture of the northern pre-alpine prehistoric landscapes and their transformation by humans†.
    [Show full text]
  • Watershed Management in European Policies
    Proceedings of the European Regional Workshop on Watershed Management PART 2 WATERSHED MANAGEMENT IN EUROPEAN POLICIES Proceedings of the European Regional Workshop on Watershed Management CHAPTER 3 OVERVIEW ON ACHIEVEMENTS AND PERSPECTIVES OF THE EUROPEAN FORESTRY COMMISSION/FAO WORKING PARTY Josef Krecˇek President, FAO/EFC Executive Committee Working Party on the Management of Mountain Watersheds HISTORICAL FACTS In 1952, the EFC/FAO Working Party on Torrent Control and Protection from Avalanches held its first session in Nice, France. This group originated at the European Forestry Commission (EFC) of FAO, and its main task was to solve the technical aspects of natural disasters (control of torrent floods, landslides and avalanches) using both civil engineering and forestry practices. In the 1960s, the tasks of the working party were extended to mountain agriculture, tourism, and social and economic problems in mountain areas. To reflect a new situation, the official name of the group was changed to the Working Party on Torrent Control, Protection from Avalanches and Watershed Management. In the 1970s, environmental problems and their impact on society became the highlighted item of the group, changing its title to the present Working Party on the Management of Mountain Watersheds. The group started to be more open to an interdisciplinary approach. In the 1980s and 1990s, the working party also addressed the transfer of knowledge to developing countries in Africa, Asia and Latin America. In 1998, the theme of the twenty-first session of the working party, held in Marienbad, Czech Republic, was integrated management of mountain watersheds, discussing a modern watershed concept using procedure of both the environmental impact assessment (EIA) and strategic environmental assessment (SEA).
    [Show full text]
  • In Brief About Water in the Czech Republic
    In brief about WATER in the Czech Republic Ministry of Agriculture of the Czech Republic Similar publications issued by the Těšnov 17, 110 00 Praha 1 Ministry of Agriculture can be www.eagri.cz found on the website www.eagri.cz English section Publications Contacts Department of Water Management Water management. L Department of Water Management: +420 221 812 790 L Section of Water Management: +420 221 812 769 L Department of State Administration of Water Management and River Basin: +420 221 812 486 - Unit for the State Administration of Wanter Management: +420 221 812 319 - Unit for the River Basin: +420 221 812 426 L Department of Water Management Policy and Flood Prevention Measures: +420 221 812 329 - Unit for the Water Management Policy: +420 221 812 831 - Unit for the Flood Prevention Measures: +420 221 812 432 L Department of Water Supply and Sewerage: +420 221 812 183 - Unit for the Water Supply and Sewerage: +420 221 812 314 - Unit for the Technical Operations Management: +420 221 813 036 L Department of Water in the Landscape and Repair of Flood Damages: +420 221 812 086 - Unit for the Flood Damage Remediation and Oher Measures in the Water Management: +420 221 812 437 - Unit for the Water in the Landscape and Budget: +420 221 813 048 Dear Readers, The Ministry of Agriculture prepared for you a brief publication System WATER www.voda.gov.cz, or through contact with the with key facts about water management in the Czech listed specialized departments in the area of water management. Republic. You will find basic hydrological data, information on watercourse administration, interesting facts about floods and I will be happy if we manage through this booklet arouse flood control measures, water supply and sewerage systems, your interest and enrich your knowledge about water and reports on international cooperation in the field of water and management of this irreplaceable asset which is extremely many other facts related to water management.
    [Show full text]
  • Water Supply and Sewerage Systems in the Czech Republic
    Water Supply and Sewerage Systems in the Czech Republic September 2001 Contents 1. Basic information about water conditions in the Czech Republic . 3 2. Selected information of water balance for managing water in the Czech Republic in the year 2000 . 4 3. Public water supply and sewerage systems . 6 4. Water supply and sewerage charges . 11 5. State of treatment of waste water from the aspect of Directive 91/271/EHS concerning the treatment of municipal waste water and its implementation in the Czech Republic . 12 6. State support for improvement in the level of water management infrastructure . 13 7. Legislation . 15 8. PDWSSSTU . 16 9. Preparation for accession of Czech Republic to the European Union . 17 10. SOVAK – basic information . 18 2 1. Basic information about water conditions in the Czech Republic The Czech Republic has a total area of 78,866 km2 and lies between two neighbouring mountain ranges – the Czech Highlands and the Carpathians, which have greatly differing geological ages and characters. The hilly terrain is distinguished by significant differences in elevation (1602 metres above sea level for the peak of the mountain SnûÏka and 115 metres above sea level for the valley of the river Elbe at the state border). Highlands and lowlands are represen- ted on a relatively small territory; most of the territory has a height above sea level of 200-600 metres. The long-term average for annual preci- pitation varies greatly in the Czech Republic depending on the height above sea level and the relief. The driest area in North-West Bohemia has an average annual total of just 450 mm, whereas the greatest average is on the ridges of the Jizerské mountains with 1700 mm.
    [Show full text]
  • Negotiating the Danube-Oder- Elbe Canal in a Troubled Twentieth Century
    European coasts of Bohemia : negotiating the Danube-Oder- Elbe Canal in a troubled twentieth century Citation for published version (APA): Janac, J. (2012). European coasts of Bohemia : negotiating the Danube-Oder-Elbe Canal in a troubled twentieth century. Amsterdam University Press. https://doi.org/10.6100/IR748489 DOI: 10.6100/IR748489 Document status and date: Published: 01/01/2012 Document Version: Publisher’s PDF, also known as Version of Record (includes final page, issue and volume numbers) Please check the document version of this publication: • A submitted manuscript is the version of the article upon submission and before peer-review. There can be important differences between the submitted version and the official published version of record. People interested in the research are advised to contact the author for the final version of the publication, or visit the DOI to the publisher's website. • The final author version and the galley proof are versions of the publication after peer review. • The final published version features the final layout of the paper including the volume, issue and page numbers. Link to publication General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal.
    [Show full text]
  • Supplementary Material To
    European Nitrogen Assessment Chapter 13: Nitrogen flows from European regional watersheds to coastal marine waters Supplementary Material: Datasets on watersheds Author: Billen, G In order to establish a budget of nitrogen delivery from European watersheds to European marine coastal zones, a data base of N delivery at the outlet of European watersheds has been assembled owing to the collective efforts of all participants to the NinE-ENA. The data have been organised according to the CCM River and Catchment Database from the European Commission (JRC, 2007 and Vogt et al., 2007). The European watersheds have been grouped according to the marine coastal zones where they are discharging, as indicated in Fig. 13.1 of ENA chapter 13. They include 5872 individual catchments, most of them representing very small rivers. The major ones, with an area larger then 10 000 km², represent 67% of the total European coast watershed area. The data base includes recent data on total N, P and Si fluxes. Typically, average values of annual fluxes observed between 1995 and 2005 are registered. When only inorganic nitrogen data were available, total nitrogen has been estimated using the relationship between TN and DIN discussed by Durand et al. (2011, ENA Chapter 6). Documented watersheds in the NinE data base cover 69 % of the total European watershed area. The material consists of a set of GIS shape files describing the contours of the European watersheds and their sea outlets (CCM 21, JRC, 2007). Attributes of the watersheds include: Watershed identifier (WSO_ID) Watershed names (NAME) Maximum river Strahler’ streamorder (STRAHLER) Watershed area (AREA_KM2) Coastal zone to which it discharges (COAST_CODE) Indication whether or not the basin outlet is in EU27 (EXUT_EU) An associated dbf file provides the information about nutrient fluxes, NANI (Net Anthropogenic Nitrogen Inputs) and Autotrophy and Heterotrophy.
    [Show full text]