Analysis of Areas at Risk of Landslides by Applying Geospatial Technology Together with the Highest Daily Rainfall Data in 30 Years in the Northern Thailand

Abstract

          The purpose of this research was to study the major factors in the occurrence of landslides. and analyze the occurrence of landslides The boundary of 9 northern provinces of Thailand is a collection of factors used to analyze landslide risk areas from 25 data sets in order to select factors used to analyze landslide risk areas. Data overlaying techniques are also used. Geographic information system, ArcGIS program, study results, 10 factors used for analysis In order of more or fewer factors influencing landslides, namely the highest rainfall in the past 30 years (1981 - 2010) of the Meteorological Department), area slope (Slope), use land use (Landuse), the elevation of a site (m), fault distance (DF), distance from the water source (m), soil drainage, distance from road (m), type of rock and direction of rainwater When analyzing 5 levels of landslide risk areas, it was found that the lowest risk area had an area of 22,571.677 square kilometers. Representing 24.092 percent, located in Mae Hong Son, and Chiang Mai, respectively, low-risk areas with an area of 28,242.155 square kilometers. Representing 30.144 percent, located in Chiang Mai, and Lampang, respectively, medium-risk areas with an area of 20,924.511 square kilometers. Representing 22.334 percent, located in Chiang Mai, and Chiang Rai, respectively, high-risk areas with an area of 15,952.100 square kilometers. Representing 17.026 percent, located in Chiang Mai, and Chiang Rai, respectively, the highest risk area with an area of 6,000.558 square kilometers. representing 6.405 percent in Chiang Mai Chiang Dao District, Chai Prakan, Wiang Haeng, Doi Saket, Chiang Rai, Mae Fah Luang, Mae Chan, Mae Suai and Nan, Chalerm Prakiat District, Chiang Klang, Pua respectively.