THE UTILIZATION USING OF REMOTE SENSING TECHNOLOGY FOR STUDY ON RIVER BANK EROSION AND DEPOSITION OF CHAO PHRAYA RIVER AND PASAK RIVER IN PHRA NAKHON SU AYUTTHAYA PROVINCE

Abstract

The objective of this study on the river bank erosion and deposition of Chao Phraya river and Pasak river in Phranakhon Si Ayutthaya province in last 20 years. By using the remote sensing technology and satellite images of the rivers during 2000, 2010, and 2020 to find the boundary to the river bank erosion and deposition area by Modified Normalized Difference Water Index (MNDWI).The study indicates that during 2000–2010, there are 116 eroded spots or 0.515 km2 along the rivers and the erosion rates are 0.005 km2 per year. The most erosion area is located in Bang Sai district. During 2010–2020, there are 12 eroded spots or 0.050 km2/year along the rivers and the erosion rates are 0.005 km2 per year. The most erosion area is located in Bang Pa-in district. During 2000-2010 there are 32 deposited spots or 0.094 km2 along the rivers and the deposition rates are 0.009 km2 per year. The most deposited area is located in Bang Pa-in district. Although, there are 119 deposited spots or 0.767 km2 along the rivers and the deposition rates are 0.077 km2 per year. The most deposited area is located in Bang Sai District. In Comparatively, the bank erosion raised in 2010–2020 while the deposition raised in the period of 2000–2010. The validation of the erosion and deposition is 81.08 percentages.