ASSESSING FLOOD HAZARD MAPPING OF CHAO PHRAYA RIVER BASIN USING RAINFALL-RUNOFF-INUNDATION (RRI) MODEL WITH VARIOUS RETURN PERIODS ON THE BASIN

Abstract

The Chao Phraya River Basin is an important basin that occupies an important position in central Thailand. This basin is an important strategic point that affects the economy, travel, and lifestyle of Thai people. But this area has been suffering from floods for a long time, such as the severe flood in 2011, which causes a waste of opportunity in terms of the economy and the development of the country. This study performed flood hazard simulations in the Chao Phraya River Basin by using the rainfall-runoff-inundation (RRI) model, which is a two-dimensional distributed hydrological model that can simulate the river runoff and inundation depth. Then, the maximum flood inundation maps can be produced by using geoprocessing models (ArcGIS). The rainfall gauge data was analyzed with various return periods to perform the different scenarios at 50, 100, and 200 years return periods. The results from this study could be further used to estimate the economic loss leading to the development of flood risk management planning in the Chao Phraya River Basin.