Author(s): Sawitree Rojpratak; Chaitawatch Sudprasert; Thannob Aribarg; Seree Supharatid
Keywords: Extreme precipitation indices; ETCCDI; Multi-Model ensemble (MME); CMIP5
Abstract: Various climate extreme events in Thailand such as more recurrent and more intense floods, droughts, tropical storms, and extreme rainfall events pose increasing threats to environment, water resources, and agricultural production. To assess the occurrence and impacts of extreme climate events, we have inves tigated the changes of indices characterizing extreme precipitation across the country. Eleven extreme precipitation indices (SWMR, NEMR, SDII, R10mm, R20mm, R95p, R99p, Rx1day, Rx5day, CDD, and CWD were calculated from the station data, then comparisons and projections were made with CMIP5 models. The SWMR displays higher values in the southern and eastern regions than in the northern, northeastern, and central regions, implying high potential flood and drought hazard areas similar to the distributions of precipitation intensity extreme indices. Most GCMs display similar spatial distribution pattern of high intensity of extreme precipitation indices to observations while there is a much greater variety of results between models and observations for the frequency indices. The multi-model ensemble (MME) projects increases in most precipitation extreme indices, indicating stronger precipitation events across the regions notably in the west, central, and south. Overall, the west, central, south, and the northeast of Thailand may encounter with high flood and drought hazards, respectively from extreme climate by the end of 21th century.