Climate Change Impact on Probable Maximum Precipitation in Chenar-Rahdar River Basin

摘要

In this paper, future climate change impact on Probable Maximum Precipitation (PMP) in Chenar-Rahdar river basin, southern Iran, was investigated. For this purpose, two Global Circulation Models (HadCM3 and CGCM3) were implemented under A2 emission scenario utilizing three statistical downscaling methods; namely Change Factor (CF), Statistical DownScaling Model (SDSM), and Long Ashton Research Station Weather Generator (LARS-WG). Precipitations over the basin were downscaled to 24-hr rainfalls for the future period of 2011-2040 (2020's) utilizing the models. Then, statistical approaches were undertaken to estimate the extreme rainfall in different return periods and PMP for the base (1971-2000) and the future periods. Comparison of the future to the base extreme rainfalls and PMP for Chenar-Rahdar river basin showed increases of up to 18.2% and 27.3%, respectively by different models. This finding suggests the need for careful evaluation of the impact of climate change on hydraulic structures design and their life expectancy in watersheds.