Water Resources Study for Strategic Flood Risk Management in Ping-Nan and Chao Phraya River Basin

Abstract

Thailand has experienced water logging for the last few years. Severe floods occurred in various watersheds with return periods at 15 to 20 years, and it tends to have more frequency due to the influence of global climate change causing more swings in seasonal and rainfall intensity, flooded agricultural areas and people's houses. Even a little rain may cause severe problems for certain city areas, which creates large infrastructure problems for the city and huge economic losses, agricultural products, production and traffic system. Study areas are structured by Nays2DFlood software for the basis on simulating the two-dimension flood flow. This study explored the potential simulation for 2 scenarios; (1) present condition, and (2) blocked retention areas/or monkey cheek. The results show that it was the flood boundaries from the model were close to the flooded areas from GISTDA, some areas were flooded by heavy rain at GISTDA satellite imagery. The comparison of the flood depth from the model with fielded survey. It was found that the flood depth from the model was close to the fielded data. There are differences of the flooded depth of approximately 0.3 to 1.5 meters. For blocked retention areas/or monkey cheek scenario, it was found that overall flooded depth, is increased 0.60 meter. Results from this study can use to estimate flooded risk area, guideline for adaptation planning for water and agriculture management for flood risk management of Ping, Nan and Chao Phraya River basins.