LTHIA – 2007 -2008 Upgrades and Training. Bernard A. Engel Tong Zhai Larry Theller Agricultural and Biological Department Purdue University In conjunction with POLIS Center, IUPUI and Indiana Dept. Environmental Management. Contents. Basic concepts New data layers
Bernard A. Engel
Agricultural and Biological Department
In conjunction with
POLIS Center, IUPUI and
Indiana Dept. Environmental Management
We break soils into 4 hydrologic conditions, which are used to estimate runoff volume.
We break landuse into 8 basic types, which are used to estimate chemistry.
LTHIA isolates the flowshed to estimate the runoff, so it calculates runoff for the -shed.
rainfall to runoff ratio for different surfaces
Working with 10 meter DEMS means we can not use watersheds larger than 10 digit.
So, if the user clicks on the mouth of the Wabash or the Tippecanoe River, they get the first upstream 10 Digit watershed.
All contiguous 10 Digit watersheds are supported.
DEM is only used to calculate flowshed
DEM is not used for erosion – or runoff
Runoff is based on surface type – not slope
won’t account for frozen ground
30 year average rainfall
Chemistry is based on landuse averages
Outlet Point Selection Using Aerials, roads, or streams
Run Watershed Delineation
To get contributing area
Watershed Delineation Result
Reflect Land Use Change Using Online Digitizing
Runoff and NPS Output/Impact Evaluation
Choose to click a point, input X and Y, or select a 14 – digit watershed
For Example,Add Low Density Residential, Commercial, and High Density Residential Areas
Present Land Use Data
After Change Land Use Data
Application Buttons forHydrological Model Operation
Multiple scenarios – offer multiple development options. User constructs scenario by online digitizing.
Can display pre-and post calibration and also land-use change scenarios.