The objective of this project was to use GIS based modeling to find land most susceptible to erosion along the Fennimore Fork, a tributary of the Blue River which drains directly into the lower Wisconsin River.

1. Soil Conservation on the Lower Wisconsin
Riverway:
GIS Modeling to Determine Prospective CRP
Candidates Based on Soil Erosion Susceptibility
in the Fennimore Fork Watershed

2. The Fennimore Fork
Watershed exhibits
characteristics that make
it prone to soil erosion
 Highly variable
topography
 Farming throughout
region
 Soil loss as threat to
soil quality (Govers et
al., 2004)
http://www.nrcs.usda.gov/news/images/erosion.jpg

3. Study Area:
Fennimore Fork
Watershed
• Fennimore Fork Watershed is a
subwatershed within one of
eighteen watersheds draining into
the Lower Wisconsin Riverway

4. • Agriculture is the economic
mainstay of the region
• The Conservation Reserve
Program (CRP) is a
nationwide, voluntary
program that works in part
to enhance the environment
by reducing sedimentation
in streams and lakes

5. • Use GIS modeling
(WetSpa) to find land
most susceptible to
erosion in the Fennimore
Fork Watershed of Grant
County
• Provide results to CRP to
determine which land
should be targeted for
enrollment in the
program.
http://www.vub.ac.be/WetSpa/

6.  Process-based
 GIS based hydrologic model
 Watershed/catchment scale
 Simulate hydrograph (flood), water
balance
 Hydrological attributes over watershed

7.  WetSpa can provide:
• Spatial distribution of runoff velocity
• Spatial distribution of runoff volume
 Define areas with high runoff velocity and
volume as highly susceptible to soil
erosion
• Velocity is calculated over entire time period
• Volume is calculated for specific storm events

8. LAND 30 Meter
Layers SOIL DEM
USE Resolution
PARAMETERS DERIVED FROM
+ CLIMATE INPUTS
EACH LAYER ABOVE
WETSPA

9. PERMATERS DERIVED FROM
EACH LAYER
Soil Land Use Topography
Flow Direction
Conductivity Root Depth Stream Link
Fill Sink
Residual Moisture Manning’s Coefficient Mask
Flow Length
Porosity Vegetated Fraction Stream Order
Stream Network
Pore distribution Interception Capacity Slope of land/river
Subwatershed
Index Leaf Area Index Stream width
Hydraulic Radius
Wilting point
Field Capacity

10. Simulates basic hydrologic process in each cell
Yongbo Liu, Ping Wang

11. LAND
SOIL USE DEM
PARAMETERS DERIVED
FROM EACH LAYER CLIMATE INPUTS
ABOVE
WETSPA
 Precipitation,
Temperature, Potential
Evapotranspiration
 Vary Temporally, Not Spatially

12. Parameterize with DEM, WISCLand, and soils layer
Yongbo Liu, Ping Wang

13.  Quartile classification:
• Four classes with even
distribution
 Bottom left corner
chunk is the town of
Fennimore
(impervious area)
High
 Dark red considered
Low
highest

14. High Velocity Farmland
Farmland with high velocity

15. Farmland with High Runoff
High Velocity Volume in 11
Storm Events
Intersect
Farmland
susceptible to
erosion

19.  The red areas show
up as high velocity
and volume in all
eleven storm events
 Therefore, these
areas, while taking
into account land
ownership parcels,
should be considered
for enrollment in CRP

20. POTENTIAL ERROR FUTURE RESEARCH
 Bad news: Climate data not within  Run comparison of our
study site results to soil classes most
Good news: Within 5 miles susceptible to erosion to find
 No model is perfect even more conclusive
 6-8 year difference in data from
today
results
 30 meter raster pixel size – not  Assign addresses to land
very precise with most susceptible areas
TROUBLE ENCOUNTERED
 Our first time using this
model so roadblocks required
help from more experienced
users – even a fix from the
creator of the model

21. A special thank you to Ping Wang for all of her help,
A-Xing Zhu for the guidance and
WetSpa Model Author: Yongbo Liu

22.  Classification based results
 Calibration gives more accurate numeric
results, not the objective of this study