functional linkage of watersheds and streams using landscape networks of reach contributing areas...
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Functional linkage of Functional linkage of watersheds and watersheds and streams using streams using
landscape networks landscape networks of reach contributing of reach contributing
areasareasDavid Theobald, John Norman, David Theobald, John Norman,
Erin Peterson, Silvio FerrazErin Peterson, Silvio FerrazNatural Resource Ecology Lab, Dept of Natural Resource Ecology Lab, Dept of
Recreation & Tourism, Colorado State Recreation & Tourism, Colorado State UniversityUniversity
Fort Collins, CO 80523 USA Fort Collins, CO 80523 USA 26 July 26 July 20052005
Project contextProject context
Challenges of STARMAP (EPA STAR):Challenges of STARMAP (EPA STAR): Addressing science needs Clean Water ActAddressing science needs Clean Water Act Integrate science with states/tribes needsIntegrate science with states/tribes needs
Assisting statisticians to test tenable Assisting statisticians to test tenable hypotheses generated using hypotheses generated using understanding of ecological processesunderstanding of ecological processes
PremisePremise Goal: to find measures that more closely
represent our understanding of how ecological processes are operating
Challenges to develop improved landscape-scale indicators (Fausch et al. 2002; Gergel et al. 2002; Allan 2004) are:- a clearer representation watersheds and their hierarchical relationship;- to incorporate nonlinearities of condition among different watersheds and along a stream segment
Ignoring the spatial heterogeneity and scaling of watersheds has led to somewhat equivocal conclusions regarding general proportions of land use in a watershed as an overall indicator of biological condition.
Landscape Context of Landscape Context of MetricsMetrics1.1. Co-variate(s) at spatial location, site contextCo-variate(s) at spatial location, site context
- E.g., geology, elevation, population density at a point- E.g., geology, elevation, population density at a point
2.2. Co-variate(s) within some distance of a locationCo-variate(s) within some distance of a location- Housing density at multiple scales- Housing density at multiple scales
3.3. Watershed-based variablesWatershed-based variables- Proportion of urbanized area- Proportion of urbanized area
4.4. Spatial relationships between locationsSpatial relationships between locations- Euclidean (as the crow flies) distance between points- Euclidean (as the crow flies) distance between points- Euclidean (as the fish swims) hydrologic network distance - Euclidean (as the fish swims) hydrologic network distance
between pointsbetween points
5.5. Functional interaction between locationsFunctional interaction between locations- Directed process (flow direction), anisotropic, multiple scales- Directed process (flow direction), anisotropic, multiple scales- How to develop spatial weights matrix?- How to develop spatial weights matrix?- Not symmetric, stationary - Not symmetric, stationary violate traditional geostatistical violate traditional geostatistical
assumptions!?assumptions!?
From From watersheds/catchments as watersheds/catchments as hierarchical, overlapping hierarchical, overlapping
regions…regions…River continuum concept (Vannote et al. 1980)
… … to network of to network of catchmentscatchments
Network Dynamics Hypothesis - Benda et al. BioScience 2004
SCALE: Grain
Substrate
Biotic Condition
OverhangingVegetation
Segment
River Network
Network Connectivity
Tributary Size DifferencesNetwork Geometry
Stream Network
ConnectivityFlow Direction Network Configuration
Drainage DensityConfluence Density
Cross Sectional AreaChannel Slope, Bed MaterialsLarge Woody Debris
Biotic Condition, Substrate Type, Overlapping VegetationDetritus, Macrophytes
Microhabitat
Segment Contributing Area
Riparian Vegetation Type & ConditionFloodplain / Valley Floor Width
Localized DisturbancesLand Use/ Land Cover
Landscape
ClimateAtmospheric depositionGeology
TopographySoil Type
Microhabitat
ShadingDetritus Inputs
Riparian Zone
Nested Watersheds
Land UseTopography
Vegetation TypeBasin Shape/Size
COARSE
FINE
Reach
Terrestrial Aquatic
Peterson 2005
Pre-processing segment Pre-processing segment contributing areas (SCAs)contributing areas (SCAs)
Automated delineationAutomated delineation Inputs: Inputs:
stream network (from stream network (from USGS NHD 1:100K)USGS NHD 1:100K)
topography (USGS topography (USGS NED, 30 m)NED, 30 m)
Process:Process: ““Grow” contributing Grow” contributing
area away from area away from segment until ridgelinesegment until ridgeline
Uses WATERSHED Uses WATERSHED commandcommand
“true” catchments
“adjoint”catchments
Segments
Segments are linked to Segments are linked to catchmentscatchments
1 to 1 1 to 1 relationshiprelationship
Properties of Properties of the the watershed watershed can be linked can be linked to network to network for for accumulation accumulation operation operation
““Lumped” or watershed-based Lumped” or watershed-based analysesanalyses % agricultural, % urban (e.g., ATtILA)% agricultural, % urban (e.g., ATtILA)
Average road density (Bolstad and Swank)Average road density (Bolstad and Swank) Dam density (Moyle and Randall 1998)Dam density (Moyle and Randall 1998) Road length w/in riparian zone (Arya 1999)Road length w/in riparian zone (Arya 1999) But ~45% of HUCs are not watershedsBut ~45% of HUCs are not watersheds
EPA. 1997. An ecological assessment of the US Mid-Atlantic Region: A landscape atlas. EPA ATtILA 2002.
Example: Human Urban Example: Human Urban IndexIndex
LocalLocal
AccumulatedAccumulated
AccumulatedAccumulated
Generating RCAsGenerating RCAs1.) Filled DEM 2.) Flow Direction
Generating RCAsGenerating RCAs 3.) Stream Reaches 4.) RCAs (Yellow)
Landscape NetworkLandscape NetworkLandscape network features and associated relationships table
From graph theory perspective, reaches are nodes, confluences are edges
Landscape networks with Landscape networks with PythonPython
Need to represent relationships between featuresNeed to represent relationships between features Using graph theory, networksUsing graph theory, networks Retain tie to geometry of featuresRetain tie to geometry of features Flow relationships table (like NHD, but flow-Flow relationships table (like NHD, but flow-
sorted!)sorted!) Implementation in ArcGISImplementation in ArcGIS
Geometric Networks (ESRI – complicated, slow)Geometric Networks (ESRI – complicated, slow) Landscape Networks: Open, simple, fastLandscape Networks: Open, simple, fast
Began with VBA (1.5 years), moved to Python (2 Began with VBA (1.5 years), moved to Python (2 months)months)
Working on integration with PySal (Python Spatial Working on integration with PySal (Python Spatial Library)Library)
USGSNHD,NED
FLoWS v1 tools for FLoWS v1 tools for ArcGIS v9.0…ArcGIS v9.0…
Will migrate to Will migrate to v9.1v9.1
Next stepsNext steps
Attach additional datasets to SCA Attach additional datasets to SCA databasedatabase Land cover (urban, ag, “natural”)Land cover (urban, ag, “natural”) Historical, current, future housing densityHistorical, current, future housing density Road densityRoad density
From segments to geomorphological From segments to geomorphological reaches, gradientreaches, gradient
Project/tool website: Project/tool website: www.nrel.colostate.edu/projects/starmapwww.nrel.colostate.edu/projects/starmap Email: Email: [email protected]@nrel.colostate.edu
Thanks!Thanks! Comments? Questions?Comments? Questions? Funding/Disclaimer: The work reported Funding/Disclaimer: The work reported
here was developed under the STAR here was developed under the STAR Research Assistance Agreement CR-Research Assistance Agreement CR-829095 awarded by the U.S. 829095 awarded by the U.S. Environmental Protection Agency (EPA) Environmental Protection Agency (EPA) to Colorado State University. This to Colorado State University. This presentation has not been formally presentation has not been formally reviewed by EPA. The views expressed reviewed by EPA. The views expressed here are solely those of the presenter here are solely those of the presenter and STARMAP, the Program (s)he and STARMAP, the Program (s)he represents. EPA does not endorse any represents. EPA does not endorse any products or commercial services products or commercial services mentioned in this presentation.mentioned in this presentation.
FLoWS: FLoWS: www.nrel.colostate.edu/pwww.nrel.colostate.edu/projects/starmaprojects/starmap
[email protected]@nrel.colostate.edu
CR - 829095