Watershed Management: Ugum & Piti-Asan Watersheds Shahram Khosrowpanah Funded by NOAA through Bureau of Statistics and Plans Guam Coastal Management Program (GCMP)
WERI
June 25 04
WERI
Aug 31 04
WERI
Aug 31 04
WERI
Watershed Protection Action ยง ยง ยง
Guam Coastal Nonpoint Pollution Control Section 6217-1990 Requires: Development of a multi-year Watershed Restoration Strategies Watershed assessment and identification of opportunities to reduce nonpoint source pollution for all Guam Watersheds WERI
Environmental Assessment for Non-Point Sources of Pollution for Ugum Watershed
Ugum Watershed Boundary
WERI
Project Goals s
To assess the existing Natural Resources and identify areas within Ugum Watershed that have highest Potential to Contribute Pollution to the Streams and Coastal Areas
WERI
How We Did It? ยง
Gather Physical and Environmental Data of the Ugum Watershed
ยง
Develop a GIS Watershed Management Database
ยง
Site Visitation to Areas with Highest Potential to Generate Pollution (with helicopter)
WERI
Ugum – Digital Elevation Model (DEM)
WERI
Vegetation Layer
Vegetation Distribution VEGETATIO N TYPE
Ravine Forest Savanna Grassland Agriculture Wetland Badland
WERI
COVERAGE AREA (acre)
% OF THE TOTAL WATERSHED AREA
1859 2336
43 54
33 6 96
0.76 0.14 2
Soil Types Layer
WERI
Land Ownership
75% 1.2% used
WERI
Wetlands within Ugum Watershed
WERI
Jeep Trails within the Ugum Watershed
WERI
Site Visitation My Helicopter Crew
WERI
Start of the Journey
WERI
Talofofo & Ugum River joining together
WERI
Farming along Ugum River
WERI
Talofofo Fall
WERI
Bank Erosion
WERI
Bubulao & Ugum River joining together
WERI
Bad Lands & Jeep Trails
WERI
Land Sliding Upper Ugum River
WERI
§
Watershed Protection Problems
Natural occurrence § Badlands § Bank erosion § Earthquake
§
Human activities § Off-Road activities § Farming § Fire
WERI
WERI
WERI
Developing a GIS-based Soil Erosion Model for southern Guam Watershed Dr. Shahram Khosrowpanah Mike Park Dr. Leroy Heitz Dr. Yuming Wen WERI
OBJECTIVES §
Developed a model that: a) estimates the upland erosion, and b) identifies areas of high soil erosion potential within a watershed. – Universal Soil Loss Equation (USLE) – Geographic Information System (GIS)
WERI
R factor K factor LS factor C factor P factor
WERI
For each Grid Cell: A=RxKxLxSxCxP
WERI
WERI
Recommendations s s s s
The Model may be used to simulate all possible scenarios for reducing soil erosion. Land cover (C-factor) needs to be updated for Guam plants. The management plan may implement certain vegetation types such as Vetiver Grass. The public should be informed of the impact of off-road activities and programs to reduce the impacts should be in place.
WERI
Developing a Watershed Management Plan for the Piti-Asan Watershed Dr. Shahram Khosrowpanah Dr. Mark Lander Sydonia Manibusan
WERI
Piti-Asan Watershed
WERI
Natural Erosion Contribution
WERI
Problems associated with construction
WERI
Project Goals ยง
To investigate the dynamic behavior of the Piti-Asan Watershed under different scenarios.
ยง
To identify areas within the Piti-Asan watershed that contribute pollution to the streams and coastal areas.
ยง
To develop management strategies that will prevent damage to the watershed.
WERI
Data Collection
WERI
WERI
WERI
WERI
Piti-Asan High Sediment Contribution Areas
WERI
WERI
Potential Soil Loss within 100m Buffer (tons/acre/year) Site Description
Piti
% Change
Asan
% Change
Existing Condition
4.57
0
5.93
0
Hanjin Development
4.57
0
5.93
0
JHP Development
4.57
0
5.89
-0.67
WERI
Recommendations v
Enforcement of erosion control practices during construction
v
The management plan may implement certain vegetation types such as Vetiver Grass, Hydroseeding
v
Continuation of stream level and flow data collection
v
Slope Stabilization, Silt fencing, Erosion socks, Check Dams
WERI
Silt fencing
Erosion socks
Check dams Existing weir at Masso River
WERI
WERI TECHNICAL REPORTS www.weriguam.org
WERI
WERI
What Is Vetiver Grass Seedlings
Vetiver grass in Nature
WERI
Comparison between Common Savanna Sword Grass and Vetiver grass Root systems Local Sword Grass
WERI
Vetiver Grass