DOCSLIB.ORG

Planning the Fluvial Future: an Intro to Fluvial Hazard Zone Maps and Considerations for Incorporating Geomorphology Into Stream Corridor Planning

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Planning the Fluvial Future: an Intro to Fluvial Hazard Zone Maps and Considerations for Incorporating Geomorphology Into Stream Corridor Planning Planning the Fluvial Future: An Intro to Fluvial Hazard Zone Maps and considerations for Incorporating Geomorphology Into Stream Corridor Planning River Network – Stream Management Planning: 8/5/21 • Kevin Houck and Chris Sturm, CO Water Conservation Board • Michael Blazewicz, Round River Design • Katie Jagt, Watershed Science and Design • Joel Sholtes, University of Colorado, WASH Engineering www.ColoradoFHZ.com TA K E H O M E : • Streams are dynamic, they require space • Streams are corridors, not lines • Fluvial Hazard Zone maps provide a cost effective w a y t o define the space streams may occupy and influence • Identifying fluvial geomorphic processes can help communities plan with land use decisions in their stream corridors. (Fluvial Geomorphology = the study of how moving water shapes the earth) . Flooding is the most frequent severe weather threat and the costliest natural disaster facing the nation. Ninety percent of all natural How do we disasters in the U.S. involve flooding. better capture Nationally, nearly 25% of flood insurance this existing risk claims come from areas outside of the and create a regulatory (100-year floodplain. more complete understanding From 2014 to 2018, policyholders outside of high-risk flood areas filed over 40 percent of of stream- all NFIP flood insurance claims and required related hazards? one-third of federal disaster assistance for flooding. In Colorado, the figure is approximate 51% from the 2013 event alone, and 57% cumulatively, since 1978. Large berm that appears Berms in field to cut-off to have been used in the historic flow paths modeling to “dry up” the land to the south. Alluvial fan The highway, with one undersized crossing - a de-facto dam. • The First Street Foundation Flood Model (i.e., Flood Factor) is a nationwide, probabilistic flood model that shows any location’s risk of flooding from rain, rivers, tides, and storm surge. It builds off decades of peer-reviewed research and forecasts how flood risks will change over time due to changes in the environment. First Street’s data, and other open-source datasets, can serve as important complements to existing sources of flood risk data such as FEMA maps. FEMA maps are designed to set insurance rates and for use by decision-makers, and technical experts—not as communication tools for the general public to understand actual flood risk. This often leaves average Americans navigating the alphabet soup of AE, X, and V zones and having a difficult time understanding how concerned they should be about flood risk. FEMA maps can also create a false sense that flood risk is binary by focusing on whether a property is “inside” or “outside” of a flood zone. Because this designation is binary, it does not provide any indication of risk magnitude for individual properties. This communication challenge is compounded by the fact that FEMA’s maps significantly underestimate risk. As discussed in the section on Fluvial Hazard Zones in this report, FEMA maps assume stationarity in watershed hydrology, channel dimensions and location, and fail to account for a host of dynamic processes inherent in fluvial systems, not to mention they are often outdated. This can lead to substantial consequences for property owners. • ↓Flood Factor map of the South Arkansas River corridor shows a possible inundation flood risk to an area that correlates well with the physical and ecological indicators that were used to define the Active Stream Corridor. Flood Insurance Rate Maps vs. Fluvial Hazard Maps Flood Insurance Rate Maps (FIRM) vs. Fluvial Hazard Zone (FHZ) Maps FEMA Floodplains: FHZ Mapping: Captures Captures Hazards from Hazards from Erosion and Inundation Deposition Fluvial Hazard Zone The Fluvial Hazard Zone (FHZ) is the area a stream has occupied in recent history, may occupy, or may physically influence as it stores and transports water, sediment, and debris. The primary objective of mapping the FHZ is to identify areas vulnerable to fluvial geomorphic hazards, characterize these hazards, and reduce risk to life and property through increased awareness, long-term avoidance, and mitigation. Additional Objectives of Fluvial Hazard Mapping • Increase awareness of natural stream processes. • Support stream planning and management on a watershed scale. • Support long-term restoration of stream function and floodplain connection. • Strategize opportunities for watershed-scale sediment and debris management (FOZ). • Preserve the multitude of benefits provided by open space along stream corridors. How is FHZ mapping completed? • Guidance provided by the Colorado Water Conservation Board (CWCB). • Methods are peer-reviewed and supported by scientific studies. • Draws on the current science related to hazard and stream management. • Mapping has been completed through out the Front Range, Denver-Metro area, and state. • For more info and FAQs, visit the website! www.ColoradoFHZ.com Primary FHZ components Active Stream Corridor Fluvial Hazard Buffer Lands subject to channel migration and Erosion-prone land beyond the Active Stream movement, bank erosion, floodplain scour and Corridor that may be susceptible to future slope deposition. It reflects both the past and the future locations where these processes may occur. failures due to toe erosion. The Active Stream Corridor is generally delineated The Fluvial Hazard Buffer is calculated based on using hydraulic, geomorphic, geologic, and biotic hydrologic and geologic characteristics of the stream data. and an analysis of historic valley and terrace erosion throughout the Colorado Piedmont. Primary Benefit: Hazard Reduction Life and Property • Provide more accurate assessments of flood hazards. • Defensible delineations for site development and use in land planning. • Assists in evacuation and emergency planning. • Reduce reliance on channelization, levees, and bank armoring, thus decreasing the need for capital investments. Secondary Benefit: Resilient Infrastructure • Identify at-risk infrastructure and critical facilities within FHZ • Avoid FHZ when repairing and replacing grey infrastructure • Site new infrastructure in less hazardous areas within river corridor • Reduce maintenance and repair costs Secondary Benefits: Wildfire • Provide space for erosion and sediment deposition after a wildfire. • Provide natural fire breaks possibly aiding a community's firefighting response. Photo: Joe Wheaton Planning the Fluvial Future: Incorporate FHZ Concepts into Community Planning • Comprehensive (or master) plan • Local hazard mitigation plans • Pre-disaster recovery plans • Emergency response plans • Emergency response planning • Wildfire planning • Parks and open space plans • Capital improvement plans • Drainage and stormwater; infrastructure/transportation; stream corridor; water resource planning; stream management plans Incentivize Development Outside of FHZ • Development agreements (e.g., density bonuses) • Cluster subdivisions • Transfer of development rights • Conservation easements (e.g., stream corridor easement) • Land acquisition Consider • FHZ overlay zoning Incorporation into • Comprehensive recovery ordinances Regulatory • Community rating system (CRS) Mechanisms • Development application submittal requirements • Post-disaster moratorium Enhance Local Administration & Procedures • Development application submittal requirements • Post-disaster moratorium Aftermath of 2013 flood in Jamestown, CO. Source - Michael Rieger, FEMA Promote Actions to Mitigate Hazards • No Adverse Impact Standards • Identify critical areas • Provide opportunities for relocation or buyouts Create Opportunities to Inform Community • Provide the FHZ as an information layer on NFIP maps • Incorporate FHZ’s into utility connections and septic permit reviews • Encourage the purchase of flood insurance in the FHZ • Incorporate fluvial hazard information onto community websites • Incorporate fluvial processes and hazards into school education • Partner with local watershed organizations Defining Stream Corridors in Fluvial Hazard Mapping Energy Flow and Dissipation Sediment Continuity ) 2 Stream Power and W Geomorphic post Response to Floods / W pre Unit Stream Power StreamUnit Power (W/m Distance (km) The Active Stream Corridor (ASC) is land that has been or may be shaped by erosion and deposition under a range of conditions in the prevailing The Active Stream Corridor (ASC) flow and sediment regimes (i.e., the contemporary geomorphic floodplain). Dominant processes within this corridor include channel incision, widening, avulsion, lateral and downstream migration, aggradation, and braiding. These processes manifest over a range of time and space. The geographical extent of the riverscape is defined by the boundaries of the ASC. ← Conceptual Fluvial Hazards Map of the South Arkansas Corridor. These draft maps were developed for planning purposes only and were delineated with topographic information developed from 2011 LiDAR. The Fluvial Hazard Zone consists of two primary components: the Active Stream Corridor (described above) and the Fluvial Hazard Buffer. The Fluvial Hazard Buffer accounts for erosion prone land located beyond the Active Stream Corridor, such as hillslopes and terraces, that may be susceptible to slope failure as a result of toe erosion caused by fluvial scour. It is a buffer applied to the outer boundary of the ASC. Avulsion Hazard Zones are used to mark the area a stream may occupy and impact due to a wholesale shift in channel position on the valley floor as further defined and detailed in the Colorado
Load more

Recommended publications
  • Seasonal Flooding Affects Habitat and Landscape Dynamics of a Gravel
    Seasonal flooding affects habitat and landscape dynamics of a gravel-bed river floodplain Katelyn P. Driscoll1,2,5 and F. Richard Hauer1,3,4,6 1Systems Ecology Graduate Program, University of Montana, Missoula, Montana 59812 USA 2Rocky Mountain Research Station, Albuquerque, New Mexico 87102 USA 3Flathead Lake Biological Station, University of Montana, Polson, Montana 59806 USA 4Montana Institute on Ecosystems, University of Montana, Missoula, Montana 59812 USA Abstract: Floodplains are comprised of aquatic and terrestrial habitats that are reshaped frequently by hydrologic processes that operate at multiple spatial and temporal scales. It is well established that hydrologic and geomorphic dynamics are the primary drivers of habitat change in river floodplains over extended time periods. However, the effect of fluctuating discharge on floodplain habitat structure during seasonal flooding is less well understood. We collected ultra-high resolution digital multispectral imagery of a gravel-bed river floodplain in western Montana on 6 dates during a typical seasonal flood pulse and used it to quantify changes in habitat abundance and diversity as- sociated with annual flooding. We observed significant changes in areal abundance of many habitat types, such as riffles, runs, shallow shorelines, and overbank flow. However, the relative abundance of some habitats, such as back- waters, springbrooks, pools, and ponds, changed very little. We also examined habitat transition patterns through- out the flood pulse. Few habitat transitions occurred in the main channel, which was dominated by riffle and run habitat. In contrast, in the near-channel, scoured habitats of the floodplain were dominated by cobble bars at low flows but transitioned to isolated flood channels at moderate discharge.
    [Show full text]
  • Natural Character, Riverscape & Visual Amenity Assessments
    Natural Character, Riverscape & Visual Amenity Assessments Clutha/Mata-Au Water Quantity Plan Change – Stage 1 Prepared for Otago Regional Council 15 October 2018 Document Quality Assurance Bibliographic reference for citation: Boffa Miskell Limited 2018. Natural Character, Riverscape & Visual Amenity Assessments: Clutha/Mata-Au Water Quantity Plan Change- Stage 1. Report prepared by Boffa Miskell Limited for Otago Regional Council. Prepared by: Bron Faulkner Senior Principal/ Landscape Architect Boffa Miskell Limited Sue McManaway Landscape Architect Landwriters Reviewed by: Yvonne Pfluger Senior Principal / Landscape Planner Boffa Miskell Limited Status: Final Revision / version: B Issue date: 15 October 2018 Use and Reliance This report has been prepared by Boffa Miskell Limited on the specific instructions of our Client. It is solely for our Client’s use for the purpose for which it is intended in accordance with the agreed scope of work. Boffa Miskell does not accept any liability or responsibility in relation to the use of this report contrary to the above, or to any person other than the Client. Any use or reliance by a third party is at that party's own risk. Where information has been supplied by the Client or obtained from other external sources, it has been assumed that it is accurate, without independent verification, unless otherwise indicated. No liability or responsibility is accepted by Boffa Miskell Limited for any errors or omissions to the extent that they arise from inaccurate information provided by the Client or
    [Show full text]
  • On the Quantitative.Invent01·Y of the Riverscape' ,I
    WATER RESOURCES RESEARCH AUGUST 1968 _ On the Quantitative .Invent01·y of the Riverscape' LPNA B. LEOPOLD AND MAURA O'BRIEN MARCHAND U. S. Geological Survey W""hinglon, D. C.IIO!!42 ,I Ab8tract. In the vicinity of Berkeley. California, 24 minor "alleys were described in terms of factors chosen to represent aspects of the river landscape. A total of 28 factors were evalu­ ated at eaeh site. Some were directly measurable. others were estimated, but each obsen'atioll was assigned to ODe of five categories for tha.t factor. Each factor for each site was then expressed as a uniqueness ratio, which depended on the number of sites being in Ute same category. The uniqueness ratio is believed to represent one way the scarcity of a given river­ &CRpe can be ranked quantitatively without bias based 011 notions of good or bad, and without assigning monetary value. GENERAL STATEMENT differently. depending upon individual back­ ground, interest, desires, and thus one's objec­ On property we grow pigs or peanulll. On tives. we grow suburbs or sunJlowers. On land­ The present paper presents a tcntntiye nod pe we grow feelings or frustrations. The modest attempt to record the presence or ab­ 'ty of a landscape may be an asset to sence of chosen factors that contribute to iety, or it may be a 'scarlet letter' that should aesthetic worth. Observations were made in a . d us of wbat we have thrown away. All restricted range of exnmples in one locality, empts to preserve the environment must ne- Alameda and Contra Costa count.ics near San ily rewesent a compromise between the Francisco Bay.
    [Show full text]
  • Coastal Recovery Unit Implementation Plan for Bull Trout (Salvelinus Confluentus)
    U.S. Fish & Wildlife Service Coastal Recovery Unit Implementation Plan for Bull Trout (Salvelinus confluentus) Top left: Clackamas bull trout reintroduction, Clackamas River, Oregon. David Herasimtschuk, Freshwaters Illustrated; Top, right: Glines Canyon Dam removal, Elwha River, Washington. John Gussman, Doubleclick Productions; Center: South Fork Skagit River and Skagit Bay, Washington. City of Seattle; Bottom: Riverscape surveys, East Fork Quinault River, Washington. National Park Service, Olympic National Park Coastal Recovery Unit Implementation Plan for Bull Trout (Salvelinus confluentus) September 2015 Prepared by U.S. Fish and Wildlife Service Washington Fish and Wildlife Office Lacey, Washington and Oregon Fish and Wildlife Office Portland, Oregon Table of Contents Introduction ................................................................................................................................. A-1 Current Status of Bull Trout in the Coastal Recovery Unit ........................................................ A-6 Factors Affecting Bull Trout in the Coastal Recovery Unit ....................................................... A-8 Ongoing Coastal Recovery Unit Conservation Measures (Summary) ..................................... A-33 Research, Monitoring, and Evaluation ..................................................................................... A-38 Recovery Measures Narrative ................................................................................................... A-39 Implementation Schedule for
    [Show full text]
  • WATS 5150 – Fluvial Geomorphology WEEK 5: Habitat Suitability Models
    Instream Geomorphic Units I. Intro → Geomorphic Units & Process-Form Associations II. Classification & Field Identification III. Your Book (River Styles) I. Sculpted, Erosional Bedrock & Boulder GUs II. Mid-Channel, Depositional GUs III. Bank-Attached, Depositional GUs IV. Sculpted, Erosional Fine-Grained GUs V. Unit & Compound GUs VI. Forced GUs IV. Continuum of GUs V. Fluvial Taxonomy GUs (Topographically Defined) I. Tier 1 – Stage II. Tier 2 – Shape / Form III. Tier 3 – Attributed VI. GUT (Geomorphic Unit Toolkit) Reminder… • In fluvial, we found over 100 different terms to describe geomorphic units, of which 68 were actually distinctive… • This is based on same units as above, but with some clarifications • Done with your Book’s Authors • The legend should include a) margins, b) geomorphic units, and c) structural elements From: Wheaton et al. (2015) – Geomorphology; DOI: 10.1016/j.geomorph.2015.07.010 Taxonomy for Mapping Fluvial Landforms • Four Tiers • Stage Height • Shape / Form • Morphology • Roughness/Vegetation • Over 100 fluvial geomorphic units found in literature, of which 68 are distinctive (3b) • Clearer, topographically based definitions From: https://riverscapes.github.io/pyGUT/ Wheaton et al. (2015) DOI: 10.1016/j.geomorph.2015.07.010 Williams et al. (2020) DOI: 10.1016/j.scitotenv.2020.136817 Instream Geomorphic Units I. Intro → Geomorphic Units & Process-Form Associations II. Classification & Field Identification III. Your Book (River Styles) I. Sculpted, Erosional Bedrock & Boulder GUs II. Mid-Channel, Depositional GUs III. Bank-Attached, Depositional GUs IV. Sculpted, Erosional Fine-Grained GUs V. Unit & Compound GUs VI. Forced GUs IV. Continuum of GUs V. Fluvial Taxonomy GUs (Topographically Defined) I.
    [Show full text]
  • Determining Flow Directions in River Channel Networks Using Planform Morphology and Topology
    Earth Surf. Dynam. Discuss., https://doi.org/10.5194/esurf-2019-19 Manuscript under review for journal Earth Surf. Dynam. Discussion started: 23 May 2019 c Author(s) 2019. CC BY 4.0 License. Determining flow directions in river channel networks using planform morphology and topology Jon Schwenk1*, Anastasia Piliouras1, Joel C. Rowland1 5 1Los Alamos National Laboratory, Earth and Environmental Sciences Division Correspondence to: Jon Schwenk ([email protected]) Abstract. The abundance of global, remotely-sensed surface water observations has paved the way toward characterizing and modeling how water moves across the Earth’s surface through complex channel networks. In 10 particular, deltas and braided river channel networks may contain thousands of links that route water, sediment, and nutrients across landscapes. In order to model flows through channel networks and characterize network structure, the direction of flow for each link within the network must be known. In this work, we propose a rapid, automatic, and objective method to identify flow directions for all links of a channel network using only remotely-sensed imagery and knowledge of the network’s inlet and outlet locations. We designed a suite of direction-predicting 15 algorithms (DPAs), each of which exploits a particular morphologic characteristic of the channel network to provide a prediction of a link’s flow direction. DPAs were chained together to create “recipes”, or algorithms that set all the flow directions of a channel network. Separate recipes were built for deltas and braided rivers and applied to seven delta and two braided river channel networks. Across all nine channel networks, the recipes’ predicted flow directions agreed with expert judgement for 97% of all tested links, and most disagreements were attributed to 20 unusual channel network topologies that can easily be accounted for by pre-seeding critical links with known flow directions.
    [Show full text]
  • INSTITUTIONALISING the PICTURESQUE: the Discourse of the New Zealand Institute of Landscape Architects
    INSTITUTIONALISING THE PICTURESQUE: The discourse of the New Zealand Institute of Landscape Architects A thesis submitted in fulfilment of the requirements for the degree of Doctor of Philosophy in Landscape Architecture at Lincoln University by Jacky Bowring Lincoln University 1997 To Dorothy and Ella iii Abstract of a thesis submitted in fulfIlment of the requirements for the degree of Doctor of Philosophy in Landscape Architecture INSTITUTIONALISING THE PICTURESQUE: The discourse of the New Zealand Institute of Landscape Architects by Jacky Bowring Despite its origins in England two hundred years ago, the picturesque continues to influence landscape architectural practice in late twentieth-century New Zealand. The evidence for this is derived from a close reading of the published discourse of the New Zealand Institute of Landscape Architects, particularly the now defunct professional journal, The Landscape. Through conceptualising the picturesque as a language, a model is developed which provides a framework for recording the survey results. The way in which the picturesque persists as naturalised conventions in the discourse is expressed as four landscape myths. Through extending the metaphor of language, pidgins and creoles provide an analogy for the introduction and development of the picturesque in New Zealand. Some implications for theory, practice and education follow. Keywords picturesque, New Zealand, landscape architecture, myth, language, natural, discourse iv Preface The motivation for this thesis was the way in which the New Zealand landscape reflects the various influences that have shaped it. In the context of landscape architecture the specific focus is the designed landscape, and particularly the perpetuation of design conventions. Through my own education at Lincoln College (now Lincoln University) I became aware of how aspects of the teaching of landscape architecture were based on uncritically presented design 'truths'.
    [Show full text]
  • Springbrook Nutrient Dynamics
    University of Montana ScholarWorks at University of Montana Graduate Student Theses, Dissertations, & Professional Papers Graduate School 2012 Spatial Drivers of Ecosystem Structure and Function in a Floodplain Riverscape: Springbrook Nutrient Dynamics Samantha Kate Caldwell The University of Montana Follow this and additional works at: https://scholarworks.umt.edu/etd Let us know how access to this document benefits ou.y Recommended Citation Caldwell, Samantha Kate, "Spatial Drivers of Ecosystem Structure and Function in a Floodplain Riverscape: Springbrook Nutrient Dynamics" (2012). Graduate Student Theses, Dissertations, & Professional Papers. 902. https://scholarworks.umt.edu/etd/902 This Thesis is brought to you for free and open access by the Graduate School at ScholarWorks at University of Montana. It has been accepted for inclusion in Graduate Student Theses, Dissertations, & Professional Papers by an authorized administrator of ScholarWorks at University of Montana. For more information, please contact [email protected]. SPATIAL DRIVERS OF ECOSYSTEM STRUCTURE AND FUNCTION IN A FLOODPLAIN RIVERSCAPE: SPRINGBROOK NUTRIENT DYNAMICS By SAMANTHA KATE CALDWELL Bachelor of Science, Environmental Biology & Ecology, Appalachian State University, Boone, NC, 2008 Thesis presented in partial fulfillment of the requirements for the degree of Master of Science in Systems Ecology The University of Montana Missoula, MT May 2012 Approved by: Sandy Ross, Associate Dean of The Graduate School Graduate School Dr. H. Maurice Valett, Chair Division of Biological Sciences Dr. Jack Stanford Division of Biological Sciences Dr. Bonnie Ellis Division of Biological Sciences Dr. Solomon Dobrowski Department of Forest Management Caldwell, Samantha K., M.S., Spring 2012 Systems Ecology Spatial drivers of ecosystem structure and function in a floodplain riverscape: springbrook nutrient dynamics Chairperson: Dr.
    [Show full text]
  • Braided River Management: from Assessment of River Behaviour to Improved Sustainable Development
    BR_C12.qxd 08/06/2006 16:29 Page 257 Braided river management: from assessment of river behaviour to improved sustainable development HERVÉ PIÉGAY*, GORDON GRANT†, FUTOSHI NAKAMURA‡ and NOEL TRUSTRUM§ *UMR 5600—CNRS, 18 rue Chevreul, 69362 Lyon, cedex 07, France (Email: [email protected]) †USDA Forest Service, Corvallis, USA ‡University of Hokkaido, Japan §Institute of Geological and Natural Sciences, Lower Hatt, New Zealand ABSTRACT Braided rivers change their geometry so rapidly, thereby modifying their boundaries and flood- plains, that key management questions are difficult to resolve. This paper discusses aspects of braided channel evolution, considers management issues and problems posed by this evolution, and develops these ideas using several contrasting case studies drawn from around the world. In some cases, management is designed to reduce braiding activity because of economic considerations, a desire to reduce hazards, and an absence of ecological constraints. In other parts of the world, the eco- logical benefits of braided rivers are prompting scientists and managers to develop strategies to preserve and, in some cases, to restore them. Management strategies that have been proposed for controlling braided rivers include protecting the developed floodplain by engineered structures, mining gravel from braided channels, regulat- ing sediment from contributing tributaries, and afforesting the catchment. Conversely, braiding and its attendant benefits can be promoted by removing channel vegetation, increasing coarse sediment supply, promoting bank erosion, mitigating ecological disruption, and improving planning and devel- opment. These different examples show that there is no unique solution to managing braided rivers, but that management depends on the stage of geomorphological evolution of the river, ecological dynamics and concerns, and human needs and safety.
    [Show full text]
  • Open Source Riverscapes: Analyzing the Corridor of the Naryn River in Kyrgyzstan Based on Open Access Data
    remote sensing Article Open Source Riverscapes: Analyzing the Corridor of the Naryn River in Kyrgyzstan Based on Open Access Data Florian Betz * , Magdalena Lauermann and Bernd Cyffka Catholic University Eichstaett-Ingolstadt, Applied Physical Geography, 85072 Eichstaett, Germany; [email protected] (M.L.); bernd.cyff[email protected] (B.C.) * Correspondence: fl[email protected]; Tel.: +49-8421-9323106 Received: 8 July 2020; Accepted: 5 August 2020; Published: 6 August 2020 Abstract: In fluvial geomorphology as well as in freshwater ecology, rivers are commonly seen as nested hierarchical systems functioning over a range of spatial and temporal scales. Thus, for a comprehensive assessment, information on various scales is required. Over the past decade, remote sensing-based approaches have become increasingly popular in river science to increase the spatial scale of analysis. However, data-scarce areas have been widely ignored so far, even if most remaining free flowing rivers are located in such areas. In this study, we suggest an approach for river corridor mapping based on open access data only, in order to foster large-scale analysis of river systems in data-scarce areas. We take the more than 600 km long Naryn River in Kyrgyzstan as an example, and demonstrate the potential of the SRTM-1 elevation model and Landsat OLI imagery in the automated mapping of various riverscape parameters, like the riparian zone extent, distribution of riparian vegetation, active channel width and confinement, as well as stream power. For each parameter, a rigor validation is performed to evaluate the performance of the applied datasets. The results demonstrate that our approach to riverscape mapping is capable of providing sufficiently accurate results for reach-averaged parameters, and is thus well-suited to large-scale river corridor assessment in data-scarce regions.
    [Show full text]
  • Ecological Simplification: Human Influences on Riverscape Complexity
    BioScience Advance Access published September 9, 2015 Overview Articles Ecological Simplification: Human Influences on Riverscape Complexity MARC PEIPOCH, MARIO BRAUNS, F. RICHARD HAUER, MARKUS WEITERE, AND H. MAURICE VALETT The rationale of most restoration strategies is that with reconstruction of natural habitats comes biodiversity, and ecosystem functioning and services will follow suit. Uncertainty and frequent failure in restoration outcomes, however, are recurrent and likely related to the complexity of Downloaded from ecosystem properties. Here, we propose ecological simplification as the general mechanism by which human impacts have modified cross-scale relationships among landscape complexity, integrity, and niche diversity in ecosystems. To manage and reverse the negative effects of ecological simplification, the interplay between research and management must quantify the large-scale complexity of reference to restore simplified systems and to link these measures to niche diversity quantified at finer scales. Because of their historical interaction with human societies, we use riverine floodplains as model ecosystems to review the causes and consequences of simplification and to discuss how contemporary restoration can minimize the effects of simplification on biodiversity, functioning, and services of riverine floodplains. http://bioscience.oxfordjournals.org/ Keywords: ecological simplification, complexity, niche diversity, restoration, floodplains n their natural state, landscapes exhibit two distinct The concept of complexity
    [Show full text]
  • Stream Hierarchy Defines Riverscape Genetics of a North American Desert
    Molecular Ecology (2013) 22, 956–971 doi: 10.1111/mec.12156 Stream hierarchy defines riverscape genetics of a North American desert fish 1 MATTHEW W. HOPKEN,* MARLIS R. DOUGLAS†‡ and MICHAEL E. DOUGLAS†‡ *Graduate Degree Program in Ecology and Department of Fish, Wildlife and Conservation Biology, Colorado State University, Fort Collins, CO 80523, USA, †Illinois Natural History Survey, Prairie Research Institute, University of Illinois, Urbana- Champaign, IL 61820, USA, ‡Department of Biological Sciences, University of Arkansas, Fayetteville, AR 72701, USA Abstract Global climate change is apparent within the Arctic and the south-western deserts of North America, with record drought in the latter reflected within 640 000 km2 of the Colorado River Basin. To discern the manner by which natural and anthropogenic drivers have compressed Basin-wide fish biodiversity, and to establish a baseline for future climate effects, the Stream Hierarchy Model (SHM) was employed to juxtapose fluvial topography against molecular diversities of 1092 Bluehead Sucker (Catostomus discobolus). MtDNA revealed three geomorphically defined evolutionarily significant units (ESUs): Bonneville Basin, upper Little Colorado River and the remaining Colora- do River Basin. Microsatellite analyses (16 loci) reinforced distinctiveness of the Bonneville Basin and upper Little Colorado River, but subdivided the Colorado River Basin into seven management units (MUs). One represents a cline of three admixed gene pools comprising the mainstem and its lower-gradient tributaries. Six others are not only distinct genetically but also demographically (i.e. migrants/generation <9.7%). Two of these (i.e. Grand Canyon and Canyon de Chelly) are defined by geomorphol- ogy, two others (i.e. Fremont-Muddy and San Raphael rivers) are isolated by sharp declivities as they drop precipitously from the west slope into the mainstem Colorado/ Green rivers, another represents an isolated impoundment (i.e.
    [Show full text]