Soil Movement in West Virginia Watersheds

1
Soil Movement in West VirginiaWatersheds

• A GIS
• Assessment

Greg Hamons Dr. Michael Strager Dr. Jingxin Wang
2
A little about me.

• Native West Virginian
• Pocahontas County
• B.S. in Forest Resource Management
• Seeking M.S. Forestry
• Very interested in Forestry and GIS Analysis!

3
Issue

• Sedimentation
• Soil movement can cause lots of damage especially
  when its moving into water resources.
• Pollution of streams, Raise flood levels, Raise
  stream temperatures, Degrade site/stream quality
  and Productivity, and reduce navigational
  abilities.
• Sediment created from Silvicultural Operations is
  the issue at hand.

4
Project Description

• Problems
• Soil Movement, specifically sedimentation, is
  very detrimental to streams and forested sites.
• Pollution to Water Resources
• Site Degradation-Both Environmentally and
  Aesthetically
• Habitat and Productivity Loss-Both Onsite and
  Downstream
• Assess Best Management Practices (BMP)
  Functionality
• GOAL FIND SIGNIFICANT SOIL MOVEMENT CONTRIBUTORS
  and IDENTIFY DIFFERENCES BETWEEN WATERSHEDS

5
Project Study Area

• Two Watersheds located in Tucker County, WV
• Both Similar in
• Geologic and
• Physical Makeup.
• Slopes
• Elevations
• Land-cover
• etc

6
(No Transcript)
7
Project Description

• Study designed to evaluate soil movement and its
  relation to logging.
• Two Watersheds (Control and Treatment)
• Silt-fence Installed around all Streams
• Material Removed Once a Year
• Extensive Mapping Procedures
• Classification/Regression Trees to Model and/or
  Predict Sedimentation

8
(No Transcript)
9
Silt-fence Installation
10
(No Transcript)
11
(No Transcript)
12
Data Collection and Recording
13
Total Oven-Dry Material
Burn sub-samples, calculate average percent
mineral (Mostly Organic)
Manually separate predominantly mineral from
predominantly organic
Place in water (Mostly Mineral)
Apply average percent to predominantly organic
fraction weight
Oven Dry and Burn
Pour off and discard
Mineral associated with predominantly organic
fraction
Mineral associated with predominantly mineral
fraction
Total Sediment
14
Methods

• Use GIS to identify Landscape elements in each
  watershed that contribute to soil movement. (i.e.
  Disturbance, Moisture, Slope, Soil Types, etc)
• Calculations Derived From Digital Elevation Map
• Slope, Aspect, Flow Direction, Flow Accumulation,
  Moisture Index, Distance Grids (from road, from
  stream, etc.), Soils, Land-cover, etc Many
  Variables!
• Analysis Performed Using Various Extensions of
  the ESRI ArcMap 9.1 GIS program. As well as the
  newly developed 3-Meter DEM and Aerial
  Photography from the WV GIS Tech-center.
• Statistical Method-Classification Trees
• R Statistical Package

15
Inputs ---
Tools ---
Output Grids ---
16
Sediment a function of

• Sediment Reaching Silt-fence
• F (Slope, Distance From Silt-fence, Distance From
  Disturbance, Distance From Slope Breaks,
  Moisture, Aspect, Accumulation, Soil Type,
  Vegetation, Land-use, )
• Very Dynamic Subject

17
(No Transcript)
18
(No Transcript)
19
(No Transcript)
20
Ecological Land Units (ELU)Moisture Index

• This index assumes that the relative moisture in
  a particular area (in this case a grid cell)
  primarily depends on two factors
• How much water is flowing into the area and how
  fast the water can flow out of the area.
• Ln (catchment area 1) / (slope 1)
• The created index is a relative one so the
  numbers dont represent any type of units.
• Higher Positive Numbers are Wetter
• Lower Negative Numbers are Drier
• Strager (2006)

21
(No Transcript)
22
(No Transcript)
23
(No Transcript)
24
(No Transcript)
25
(No Transcript)
26
(No Transcript)
27
Analyses Performed

• Also
• Classification Tree Modeling Technique
• Statistical Analyses (S-plus and R Statistics
  Systems)
• Future Analyses
• Stream Loading-Sediment
• Refining of Classification Tree Modeling
• Key to possibly modeling the soil movement or
  sedimentation

28
Results

• According to the Statistical Modeling R
• Slope is the most important variable
• 21.58º
• Followed by
• Moisture- 3.62 (Range -4.3 7.6)
• Aspect- 141º
• Combined Grids Using Raster Calculator
• Model Refinement to Include more Variables Coming
  Soon!

29
(No Transcript)
30
Conclusions

• 3-Meter DEM much higher accuracy!
• 14800 scale aerial photography gives great
  visual representation!
• Leads to more thorough analysis.
• Detailed 3-D Representation.
• Hydrology Tools Very Influential
• Upon Completion of Analyses
• Identify Contributors to Soil Movement
• Order there level of Importance
• Assess current Best Management Practices (BMP)
• Model/Predict Soil Loss

31
Thank You

• Any Questions?

32
References

• (Grayson et al. 1992 Mitasova 1996 Moore, I.
  D. et al. 1988 Boer et al. 1996, OLoughlin
  1986, Parker 1982)
• Strager 2006