Gis application for landslide risk area assessment in yom watershed, Thailand

The landslide risk area assessment in Yom watershed was manipulated using the potential surface analysis (PSA) approach. The parameters utilized in this study were including average maximum daily rainfall in 30 years return period, slope, geology, soil drainage, and vegetation cover. They were transformed into raster format for the analysis approach at the scale of 1:50,000. The descending weighting and rating score was employed for the overlay analysis. It was found that the critical or high risk area of landslide was covered the area of 3,419.59 square kilometers or 13.58% of the whole watershed area. It was apparently identified mostly in three main provinces including Phrae, Sukhothai, and Phayao respectively.