3. Methodology
3.1 Data sources
3.1.1 Multi-temporal satellite data used in this study included Landsat TM acquired in January-February 1990 and January and March 2001 and SPOT HRV in December 2006 and January-February 2007.
3.1.2 Rainfall data within the study area over the year of 1990, 2001 and 2007 were collected by Dept of Meteorology.
3.1.3 Geological map 1:250,000 scale generated by Department of Mineral Resources.
3.1.4 Soil series map 1:50,000 scale was prepared by Land Development Department.
3.1.5 Topographic maps 1:50,000 scale, 20m contour interval, produced by Royal Thai survey Department were used for DEM generation.