Author(s): Theerapol Charoensuk; Apimook Mooktaree; Sathit Chantip; Ticha Lolupiman; Watin Thanathanphon; Narongrit Luangdilok; Piyamarn Sisomphon
Linked Author(s):
Keywords: Flash Flood Potential Index (FFPI); PERSIANN-CCS; WRF-ROMS; Antecedent Moisture Content (AMC); Southern Part of Thailand
Abstract: Southern part of Thailand is vulnerable for flash flood. The long ridge of western mountains lying from North to South is receiving high intensity of rainfall especially during northeast monsoon. Due to its high slope area and highly saturated soil during the monsoon season the flood can occur in a short period of time so called “flash flood”. Excessive rainfall with high intensity and saturated soil moisture are the main factors causing this flash flood. But it is difficult to get direct measurement of soil moisture or even to estimate the soil moisture content from rainfall amount because the rain gauge station is poorly distributed or rarely available on the upstream mountain area. Therefore, in this study an attempt has been made to incorporate a real time global high - resolution satellite precipitation data from PERSIANN-CCS (4km x 4km) in the estimation of soil moisture. The bias correction has been studied and applied to the satellite rainfall PERSIANN -CCS to reduce the spatial and temporal uncertainties of the satellite rainfall product. The state of soil moisture condition has been identified using Antecedent Moisture Content (AMC) based on 5 days accumulated rainfall. The Flash Flood Potential Index or FFPI has been developed to provide information of flash flood risk area. In combination with hourly rainfall forecast computed from WRF-ROMS the flash flood risk area can be predicted. The approach has been tested and evaluated its performance. The results are confirmed with more accurate flash flood warning area during heavy rainfall event.
Year: 2020