Web-based GIS Application of the WEPP Model Dennis C. Flanagan Research Agricultural Engineer USDA - Agricultural Research Service National Soil Erosion Research Laboratory West Lafayette, Indiana, USA
Outline of Presentation Background Advantages/Disadvantages of Existing WEPP Interfaces WEPP Web-Based GIS Software Example Application Status of new Great Lakes WEPP interface for forested watersheds Summary 2
Background WEPP Model (1985-present) Water Erosion Prediction Project Public release of validated hillslope and watershed model (1995) Model Interface Development DOS interface 1992-1995 Windows interface 1997-2000 GeoWEPP ArcView/ArcGIS extensions 1999-2008 Web-browser interfaces 2001-present 3
Windows Interface Hillslope Profiles Profile depicted graphically in 2-D or 3-D. Graphic image hot and allows viewing & editing of underlying parameters. Can copy, cut, paste, & delete soil or mgmt. regions. Erosion & deposition rates shown in shades of red & green in center profile layer. 4
Windows Interface - Watershed Background image can be used, such as a scanned photo. Project can be scaled to known landmarks on image. Graphic is hot and allows viewing/editing of underlying input parameters. Top view of erosion & deposition in shades of red & green can show trouble areas needing treatment. 5
Windows Interfaces Advantages Easy to use, especially for simple field situations. Can access full functionality of WEPP model for hillslope and watershed simulations. Best tool for building unique input sets and populating databases. Disadvantages Takes time to learn and understand all options and procedures. User must fully describe or select the slope, soil, management and climate being used for the unique site. For complex watershed simulations with many elements, can be difficult to represent. 6
GeoWEPP Interface Requires ESRI Arcview or ArcGIS and Spatial Analyst software Can access commonly available U.S. databases of USGS 30-m or 10-m resolution DEM data, DRG data, land use data, etc. User can also import and use their own more detailed data. Utilizes TOPAZ Topographic Analysis software (Garbrecht and Martz, 1997), ArcView 3.x or ArcGIS 9.x, Spatial Analyst, custom software for I/O to WEPP simulations, CLIGEN model, and WEPP model. 7
GeoWEPP ArcView Flowpath Output 8
GeoWEPP Interface Advantages Easy to use for someone already familiar with ArcView / ArcGIS or other GIS software Allows use of either commonly available or user s own elevation data Best tool for an experienced GIS user to apply WEPP to watersheds Disadvantages For novice GIS users, takes time to learn and understand options and procedures User must manage and find data, and use correct projections and data preparations Requires a substantial investment in software (ArcGIS & Spatial Analyst - $4000). 9
Web-browser Interfaces Advantages Very easy to access and use, just need a basic computer with an internet connection and Web-browser. No installation or set-up time. All inputs selected from existing databases through picklists, or from simple screen entries. Best tool for running WEPP simulations from existing databases. Makes model and database maintenance and management much simpler single distribution point. Disadvantages Limited in ability to fully describe inputs for a particular site. Cannot (yet) modify existing databases. Can make the model too easy to use (if user just selects default inputs, and does not carefully choose best available option) 10
Existing Web-browser Interfaces for WEPP ARS Basic Hillslope Profile Hillslope Profile with Filter Strip at Bottom Strip Cropping Worksheet Watershed GIS Interface (this presentation) Forest Service Cross Drain WEPP: Road Disturbed WEPP WEPP FuME (Fuel Management) ERMiT (Erosion Risk Management Tool) Others Iowa Daily Erosion Project 11
ARS WEPP Web Browser Interfaces http://milford.nserl.purdue.edu/ 12
WEPP Web Watershed GIS Interface Client Web Browser (Internet Explorer, Firefox, Chrome, etc.) Server MapServer - Web GIS (Univ. of Minnesota) TOPAZ topographic analysis tool (Garbrecht and Martz, 1997) TopazPrep custom software to prepare DEM inputs for TOPAZ processing, handle output from TOPAZ, and prepare and send maps to MapServer. WeppPrep custom software to take data from TOPAZ runs and create slope inputs for WEPP. Also to prepare all other input files for WEPP. Run WEPP, process output files, and prepare and send soil loss maps to MapServer. CLIGEN generator to create climate inputs for WEPP. WEPP erosion model for flowpath and watershed simulations. 13
Client PC User s (Client) Web Browser (Internet Explorer, Firefox, Chrome, etc.) Server Hardware Web Server (Apache 2.0) Mapserver (Web GIS) (1) [HTML, Javascript, Map config. files] TOPAZ Maps TopazPrep (2) extract DEM data, reformat [PHP, C++] TOPAZ (3) channel delineation [FORTRAN] NED, Land use, soils, roads, rivers, layers TOPAZ (3) watershed delineation [FORTRAN] TOPAZ generated data Erosion Maps WeppPrep (4) extract land use, soils, climate, generate WEPP inputs, run model, produce maps [PHP, C++] WEPP (6) [FORTRAN] TerraServer Web Services (Orthophotos, DRGs) remote data CLIGEN (5) [FORTRAN] WEPP generated data 14
Representative Hillslopes from a DEM z l WEPP topography determined by averaging flowpaths within a subcatchment to a single representative hillslope. Executes WEPP watershed, includes channel routing Single soil loss, sediment yield, runoff values represent each subcatchment Best suited for predicting off-site water quality 15
Flowpaths from a DEM Determined using TOPAZ model Interactions and weighting No Channel Routing Numerous WEPP Runs (One for each flowpath). Soil loss displayed by grid cell Best suited for targeting hillslope erosion mitigation practices 16
DATABASE REQUIREMENTS & STATUS Soils 1995 SOILS-5, can associate WEPP soil files to SSURGO IDs or custom soil map ids. US Soils-5 included with WEPP install. Climate 2600+ CLIGEN stations, included with WEPP install. Can import NOAA 15 minute and daily data using WEPP Windows. Can also use now use PRISM data as part of WEPP GIS climate input. Management base tillage operations from RUSLE1. Forest related datasets. Can associate USGS National Landcover Data or custom land use grid IDs to WEPP managements. Plant Major crops in US. Basic rangeland and forest. Topography WEPP GIS automatically develops slope inputs to WEPP model based on DEM. Other Orthophotos, Digital Raster graphs, other GIS layers used as optional information to locate area of interest. 17
WEPP Web-GIS Main Screen 18
State Map 19
State Map Zoom to County 20
Zoom into Area of Interest 21
Delineate Channel Network 22
Delineate Watershed Boundary and Subcatchments 23
Setup WEPP Model Simulation & Run 24
Spatial Soil Loss Results from Flowpath Method Corn-Soybean Rotation, Fall Moldboard Plow system, T = 4 tonnes/ha 25
Subcatchment Sediment Loss Results from Hillslope Method Corn-Soybean Rotation, Fall Moldboard Plow system, T = 4 tonnes/ha 26
Results from Flowpath Method with Revised Management Corn-Soybean Rotation, No-till system, T = 4 tonnes/ha 27
Results from Hillslope Method with Revised Management Corn-Soybean Rotation, No-till system, T = 4 tonnes/ha 28
Text Output Summarizing Simulation Results For Representative Hillslope Profiles (Subcatchments) For Channels in Hillslope Procedure Flowpath Results by Mapped Subcatchments 29
Current grant project on Web-based GIS WEPP system for Great Lakes forested watersheds Funding from U.S. Army Corps of Engineers to USDA- Forest Service, RMRS (Bill Elliot, David Hall). Sub-contract to Washington State University (Joan Wu, Shuhui Dun) Sub-contract to USDA-ARS NSERL (Dennis Flanagan, Jim Frankenberger) Project was initiated in late summer 2009 Title of proposal: Developing an Online GIS-Based Tool to Predict Soil Erosion from Forested Watersheds 30
Project Objectives 1) to replicate the ARS online site on a public server, to incorporate templates for Great Lakes forest soils, vegetation, and climate 2) to identify an appropriate data set and conduct a model performance assessment in or near the Great Lakes Basin 3) to present the tool at appropriate workshops within the basin in the second year of the proposed project. 31
Project Status Server purchased and running at WSU in fall 2009. System software installed. Existing ARS modeling software installed. Addition of Great Lakes basin databases is nearly complete (complete by 7/1/2010) FS developing & testing new forest mgmt files FS evaluating WEPP v2010, and determining how to best parameterize the new winter routines for forests where the litter layer and snow cover often limit soil freezing. 32
Main View of new Interface 33
Land Use Data Layer incorporated 34
Work plans By October 2010, have the new forest files incorporated into the interface, then work on testing and debugging. Evaluate other options than MapServer, such as use of Google Earth technology. By June 2011, demonstrate new interface, and begin training May be able to leverage the grant funding to enhance the interface. One of the Forest Service Regions (Montana and N. Idaho) is interested in expanding the coverage of the interface to include their forests. 35
Summary WEPP Model is available for prediction of runoff, soil loss, and sediment yield from small watersheds. Existing ARS Web-based WEPP GIS system is available for use (mainly as a prototype), and allows rapid assessment of erosion potential at any location within the United States. Development of slope inputs from DEMs is impartial and may be a more consistent procedure than in-field estimates. Spatial results from flow-path procedure can easily identify areas that may need to be targeted for erosion control treatment or remediation. New Web GIS WEPP interface is targeted towards forested watersheds in the Great Lakes region, and should be available by late 2011 36
Acknowledgements Jim Frankenberger Computer Specialist, USDA-ARS NSERL (all ARS interface design & programming) Tom Cochrane Assistant Professor, University of Canterbury, Christchurch, New Zealand (simulation pre/post processing logic) Bill Elliot Research Engineer, USDA-Forest Service, Rocky Mountain Research Station, Moscow, ID (FS WEPP applications & interfaces) David Hall Computer Programmer, USDA-Forest Service (FS web-based interface programmer) Joan Wu Professor, Biosystems Engineering, Washington State University Shuhui Dun Post-doctoral Research Associate, WSU (main programmer, new Great Lakes WEPP interface) U.S. Army Corps of Engineers Chicago Office (grant funding) 37
Questions? 38