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Web-based Tools for Soil Erosion Assessment and Management. Bernie Engel, Larry Theller, Indrajeet Chaubey engelb@purdue.edu. Outline. Watershed delineation L-THIA L-THIA LID SEDSPEC Flow and load duration curves. L-THIA: Long-Term Hydrologic Impact Assessment Begins with a delineation….
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Web-based Tools for Soil Erosion Assessment and Management Bernie Engel, Larry Theller, Indrajeet Chaubey engelb@purdue.edu Purdue University is an Equal Opportunity/Equal Access institution.
Outline • Watershed delineation • L-THIA • L-THIA LID • SEDSPEC • Flow and load duration curves Purdue University is an Equal Opportunity/Equal Access institution.
L-THIA: Long-Term Hydrologic Impact AssessmentBegins with a delineation… Purdue University is an Equal Opportunity/Equal Access institution.
https://engineering.purdue.edu/~lthia/ Click any state
Streaming data layers over • Google Maps™ display. Current Interface
Improved Interface • GLRI project with Michigan State Institute of Water Research will connect an improved L-THIA interface to their Digital Watershed.
Water layers are toggled on, watersheds are toggled off. Water is NHD High Resolution stream lines Enter: town, Zip, or street address and click Search button
Streaming data layers include High Impact Target layers, impaired streams from Michigan State Institute for Water Resources, and HUC layers from EPA WATERS WMS streaming data services.
Water features show up over “satellite” images and in urban areas.
This is the scenario’s proposed development area This is a good delineation point. Click “delineate” button then click here.
Watershed (HUC8,10,12) info Landuse and soil breakdown Option to view this watershed over Google Maps. Multiple online models with data populated from this delineated area
Click pushpin to see toolbar. Then choose from several actions. Pour Point
L-THIALong-Term Hydrologic Impact Assessment • Based on the rainfall – land cover – runoff analysis method already used in many communities • Input: Land Use Pattern(s) + Soils Pattern • Process: Daily Runoff and Pollutant Loading Calculations (30 years) • Output: Average Annual Runoff and NPS loads for Specific Land Use Patterns
Background Layers Pour Point Set the layers for edit session, then move to map editor
Landuse and Soil are automatically entered into spreadsheet Purdue University is an Equal Opportunity/Equal Access institution.
L-THIA Model Long-Term Hydrologic Impact Assessment Average annual runoff NPS pollution An overview / screening model User friendly tool Does not require detailed data input Identifies need for more detailed modeling Provides "What-If" alternatives evaluation scenarios
Tabular and Graphic results Purdue University is an Equal Opportunity/Equal Access institution.
Web-based Low Impact Development Decision Support and Planning Tool Bernie Engel, Larry Theller, IndrajeetChaubey, James Hunter Purdue University
Low-Impact Development (LID) An approach to land development to mimic the pre-development site hydrology to: • Reduce volume of runoff • Decentralize runoff, diffusing flows into smaller retention/detention areas • Improve water quality • Encourage groundwater infiltration
Minimization Reduce imperviousness Soil Compaction LID Major Components 1. Conservation (Watershed and Site Level) 2. Minimization (Watershed and Site Level) 3. Integrated Management Practices (Site Level) • Conservation • Forest/Woods • Infiltrable Soils • Storage, Detention & Filtration • Rain gardens • Drainage swales • Green roofs • Porous Pavement https://engineering.purdue.edu/mapserve/LTHIA7/lthianew/lidIntro.htm
L-THIA LID Basic Application: Target preliminary goals at the watershed and site level • Reduce imperviousness • Conserve infiltratable soils • Conserve functional / sensitive landscape • Minimize land disturbances • Anticipate need for other LID practices to reduce NPS and stormwater volume
Purdue University is an Equal Opportunity/Equal Access institution.
L-THIA LID: Lot Level Screening Tool Application: Target preliminary goals by adjusting lot level features • Site Design & Development preparation • Narrowing impervious areas (sidewalks, driveways, roads) • Natural resource preservation • Heavy equipment use compaction • Permeable paving materials • Vegetative roof systems • Bioretention cells • Vegetated swales /Filter strips • Rain barrels • Disconnect impervious areas
Using web-based tools to delineate and capture watershed, land use, and soils data for L-THIA input
Assumption For Max. Development Scenario • 983 Acres: Commercial / Mixed Residential • Most Agriculture 55% B Soils, 45% C Soils • Current CN = 78 • Post –Developed w/o LID CN = 84 • Post – Developed w/ LID CN 76-82
Using L-THIA LID Basic – Reducing Impervious Surface by 10% Reduces runoff by 23%
Using L-THIA LID Lot Level • Reduce street width from 26ft. to 18ft. • Rain barrels for Residential • Green Roofs for Commercial • Bioretention/Raingardens Reduces Post-developed runoff by 46% Purdue University is an Equal Opportunity/Equal Access institution.
Summary • L-THIA LID is a screening tool to evaluate the benefits of LID practices • L-THIA LID provides an easy to use interface • Will enable decision makers to formulate watershed management plans to meet goals • Along with other tools, allows stakeholders to understand impacts of water quantity and quality resulting from land use change • https://engineering.purdue.edu/~lthia/
SEDSPEC Purdue University is an Equal Opportunity/Equal Access institution.
SEDSPEC Introduction • SedSpec assists in analyzing runoff and erosion problems • Provides information about runoff and erosion control structures • Provides peak runoff estimation using • Rational method • TR55
What you can do using SEDSPEC • Peak Runoff Estimation • Preliminary erosion control structures design and selection • Channels (Grass Lined, Riprap Lined, Concrete Lined, Open) • Culvert • Sediment Basin • Level Terraces • Storm Water Detention Basin • Runoff Diversion • Low Water Crossing
SEDSPEC model main page: design channels based on landuse and soil conditions of the watershed
SEDSPEC design result for channels based on landuse and soil conditions of the watershed
Flow and Load Duration Curves Purdue University is an Equal Opportunity/Equal Access institution.
Use: For analyzing water quality concentration and load variability for • development of TMDLs and watershed management plans • Water Quality Data: Federal, State, watershed practitioners, etc • Water Quality Standard: EPA, local stakeholders • LDC Estimation = Stream flow *water quality target *conversion factor Load Duration Curves (LDC)
Web-Based Flow Duration and Load Duration Curve Tool https://engineering.purdue.edu/~ldc
Enter / Upload Flow and WQ Data for LDC 100 cfs Flood Conditions FDC LDC WQ Target (0.10 ppm) Target Concentration FDC, LDC and Target Concentration (2002-2007) for USGS Gauge 04180000, Cedar Creek, IN