Web-based GIS Application of the WEPP Model

Dennis C. FlanaganResearch Agricultural Engineer

USDA - Agricultural Research ServiceNational Soil Erosion Research LaboratoryWest Lafayette, Indiana, USA

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Outline of Presentation

BackgroundAdvantages/Disadvantages of Existing WEPP InterfacesWEPP Web-Based GIS SoftwareExample ApplicationStatus of new Great Lakes WEPP interface for forested watershedsSummary

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Background

WEPP Model (1985-present)Water Erosion Prediction Project

Public release of validated hillslope and watershed model (1995)Model Interface Development

DOS interface – 1992-1995Windows interface – 1997-2000GeoWEPP – ArcView/ArcGIS extensions –1999-2008Web-browser interfaces – 2001-present

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Windows Interface – Hillslope ProfilesProfile 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.

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Windows Interface - WatershedBackground 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.

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Windows Interfaces

AdvantagesEasy 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.

DisadvantagesTakes 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.

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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.

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GeoWEPP ArcView – Flowpath Output

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GeoWEPP InterfaceAdvantages

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

DisadvantagesFor novice GIS users, takes time to learn and understand

options and proceduresUser must manage and find data, and use correct projections

and data preparationsRequires a substantial investment in software (ArcGIS &

Spatial Analyst - $4000).

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Web-browser Interfaces

AdvantagesVery 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.

DisadvantagesLimited 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)

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Existing Web-browser Interfaces for WEPPARS

Basic Hillslope ProfileHillslope Profile with Filter Strip at BottomStrip Cropping WorksheetWatershed GIS Interface (this presentation)

Forest ServiceCross DrainWEPP: RoadDisturbed WEPPWEPP FuME (Fuel Management)ERMiT (Erosion Risk Management Tool)

OthersIowa Daily Erosion Project

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ARS WEPP Web Browser Interfaces

http://milford.nserl.purdue.edu/

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WEPP Web Watershed GIS InterfaceClient

Web Browser (Internet Explorer, Firefox, Chrome, etc.)

ServerMapServer - 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.

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Mapserver (Web GIS) (1)[HTML, Javascript, Map config. files]

User’s (Client) Web Browser (Internet Explorer, Firefox, Chrome, etc.)

Web Server – (Apache 2.0)

Client PC

Server Hardware

TOPAZ Maps

TerraServer Web Services(Orthophotos, DRGs)

remote data

Erosion Maps

TopazPrep (2)– extract DEM data,reformat [PHP, C++]

TOPAZ (3)– channel

delineation[FORTRAN]

TOPAZ (3)– watershed delineation

[FORTRAN]NED, Land use,

soils, roads, rivers,layers

WeppPrep (4)– extract land use, soils, climate, generate WEPP inputs, run model,

produce maps [PHP, C++]

WEPP (6)[FORTRAN]

WEPPgenerated data

TOPAZ generated data

CLIGEN (5)[FORTRAN]

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Representative Hillslopes from a DEM

z

lWEPP 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

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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

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DATABASE REQUIREMENTS & STATUSSoils – 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.

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WEPP Web-GIS Main Screen

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State Map

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State Map – Zoom to County

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Zoom into Area of Interest

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Delineate Channel Network

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Delineate Watershed Boundary and Subcatchments

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Setup WEPP Model Simulation & Run

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Spatial Soil Loss Results from Flowpath Method

Corn-Soybean Rotation, Fall Moldboard Plow system, T = 4 tonnes/ha

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Subcatchment Sediment Loss Results from Hillslope Method

Corn-Soybean Rotation, Fall Moldboard Plow system, T = 4 tonnes/ha

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Results from Flowpath Method with Revised Management

Corn-Soybean Rotation, No-till system, T = 4 tonnes/ha

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Results from Hillslope Method with Revised Management

Corn-Soybean Rotation, No-till system, T = 4 tonnes/ha

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Text Output Summarizing Simulation Results

For Representative Hillslope Profiles (Subcatchments)

For Channels in Hillslope Procedure

Flowpath Results by Mapped

Subcatchments

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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”

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.

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Project StatusServer 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 filesFS 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.

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Main View of new Interface

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Land Use Data Layer incorporated

Work plansBy 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.

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SummaryWEPP 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

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AcknowledgementsJim 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 UniversityShuhui Dun – Post-doctoral Research Associate, WSU (main programmer, new Great Lakes WEPP interface)U.S. Army Corps of Engineers – Chicago Office (grant funding)

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Questions?