Utilization of RADASAT Data and Digital Elevation Model to Assess Flood Damage for Rice Production in Chi River Basin Flood, Thailand

摘要

Rice production is the most important agricultural activity in Thailand. Flooding due to seasonal climatic monsoon conditions destroys substantial amount of the rice crop. To assess flood damage, RADARSAT data was integrated with digital elevation model (DEM) in order to extract water depth information for purpose of determining "non-damaged" and "damaged" paddy areas. The results were visually compared with ASTER VNIR acquired during the harvesting season to confirm the type of damages in the flood affected areas. The knowledge of the elongation ability of the rice varieties grown in 2001 within flood affected areas of Chi-river basin was used to estimate the rice production in the damaged paddy areas. It was estimated that 48% of total area of paddies field were "non-damaged". The total rice crop which could have been obtained in the flood-affected areas during the 2001 season after the flood event was estimated to be 45 x 10~3 metric tones. In order to improve the rice production in flood affected areas of Chi-river basin, we recommend planting of the appropriate varieties of rice crop suitable for the type of flood damages based on its elongation ability.