Chidsanuphong Chartasa. Geo-Informatics for Mae Chan watershed management, Chiang Rai province . Master's Degree(Information Management on Environments and Resources). Mahidol University. : Mahidol University, 2005.
Geo-Informatics for Mae Chan watershed management, Chiang Rai province
Abstract:
The objective of this study is to apply Geo-Informatics including Remote
Sensing (RS), Global Positioning System (GPS), and Geographic Information System
(GIS) integrated with mathematical model in order to calculate seasonal field water
balance, soil erosion, and flood risk area in Mae Chan watershed, Chiang Rai
province.
Field water balance assessment was based on landuse patterns in 2004 and law
of conservation that considered mass balance of rainfall, runoff, evapotranspiration,
and percolation. Soil erosion assessment was based on Universal Soil Loss Equation
(USLE). Flood risk area assessment was based on Potential Surface Analysis (PSA)
that considered rainfall, slope gradient in percent, soil drainage, density of streams,
and density of roads.
Field water balance and water shortage areas that need irrigation for cultivation
in the wet-season were 7,299.50 millimeters and 259.96 square kilometers
respectively. In the dry-season were -179,994.29 millimeters and 1195.08 square
kilometers respectively. Soil erosion was divided into 5 classes: very severe, severe,
moderate, slight, and very slight. In the wet-season, overall soil loss was 1,105,523.36
tones per hectare and areas of very severe, severe, moderate, slight, and very slight
soil loss level were 202.28, 245.59, 297.44, 115.97, and 335.06 square kilometers
respectively. In the dry-season were 369,294.13 tones per hectare and 28.84, 245.78,
234.23, 285.79, and 401.70 square kilometers respectively. Flood risk was divided
into 3 flood risk classes: high, moderate, and low. Areas of high, moderate, and low
flood risk classes in wet-season were 319.73, 130.74, and 224.39 square kilometers
respectively. In dry season were 210.29, 109.52, and 357.20 square kilometers
respectively.
Geo-Informatics and the results of this study are useful information for the Mae
Chan watershed management, Chiang Rai province and associated organizations.