Example Applications of Erosion Modeling

Court Creek Watershed - Hydrologic Unit 52 [3.6 x 4.6km]

Analysis of soil erosion and deposition by water for different conservation strategies

Land Use legend	C Factor %agriculture (row crops) legend	Soil Detachment: total [1000t] average[t/ay]  legend	Soil Erosion/Deposition: excess[1000t/ay] legend	Comments
bare	N/A	10,500  /  62	77	X
corn	100	5,200  /  31	38	X
60 ft stream buffer	96	4,800  / 28	19	only big streams have buffers
100 ft stream buffer	94	4,600  / 27	19	only big streams have buffers
60ft stream buffer, forest on slopes > 10%	81	2,000  / 12	15	X
current	63	1,300  / 8	4	grains on steep slopes add to erosion - possible error in LU?
model-based, forest/dense grass where A>10	58	200  /  1.2	0.1	almost the same % of agriculture as current, but some are in too small patches

Computed with GRASS5 under LINUX using modified USLE3D and USPED models, and data from USGS and ILGIS.

Land Use Legend

C Factor Legend

Soil Detachment Legend

Net Erosion/Deposition Legend

Comments - the results of the modeling effort indicate that:

1. This area has a very good, conservation oriented land use pattern (e.g. compare current land use with "buffers only" scenario).
2. Soil loss can be further reduced by focusing on headwater areas and areas with concentrated flow (possible gullies, intermittent streams)
3. Rules for conservation areas that include prescription for both distance from stream and slope steepness are good, however they miss headwaters and concentrated flow.
4. Stream buffers based only on a distance from larger streams do not provide sufficient protection - terrain configuration has to be considered.
5. Erosion/deposition modeling (USPED) shows significant deposition in valleys and hollows (more than what is usually observed from the model). High erosion typical for gullies starts to show up in the center of depositional areas only after increasing resolution to 5m and smoothing, which means that at this resolution the erosion from concentrated flow is underestimated and a higher resolution is needed to capture it. Our previous experience suggests 2-3m resolution is sufficient.
6. Modeling the spatial distribution of soil detachment and net erosion/deposition can provide valuable information for science-based extension/enhancement of conservation program rules, particularly if it is coupled with the appropriate field observations.

Up
Hohenfels Example
Camp Shelby extension
Court Creek Pilot Watershed
Court Creek Erosion  Example
Simulation of land use impact on erosion and deposition using SIMWE
Interpolation and simulation of terrain development with hedges