Geomorphological Features and Drainage Patterns in Earthquake Area, Mae Pung and Mae Lao Sub-Watershed, Chiang Rai Province

Abstract

The Geomorphological Features and drainage patterns in Mae Pung and Mae Lao Sub-Watershed, Chiang Rai Province after 6.3 magnitude earthquake on May 5, 2014 were analysed by geomorphological theory using Geographic Information System (GIS) software-Arc GIS 9.3. According to the result, it was found that the terrain sloped down from northwest to southeast. The geological structure including sandstone, limestone, shale and mudstone aligned in the horizontal plane with low slope. It covered with alluvial sediment, gravel, sand, silt and clay. Moreover, the medium dendritic drainage pattern and the medium to fine dendritic drainage pattern existed in the areas allowing water can freely without bearing. The main rivers in this areas consisted of Mae Lao, Mae Khao, Rong Than and Mae Pon. In addition, the areas with small fault segment, which is a part of the Northern Phayao fault zone were demonstrated that they were rectangular drainage pattern in the direction of faults and the first order stream. Finally, the impact of the earthquake did not affect the drainage patterns in this area.