Author(s): M. L. Kavvas; Su-Hyung Jang; Z. Q. Chen; K. Ishida; A. Ercan; M. Z. M. Amin; A. J. Shaaban
Linked Author(s): Mohd Zaki bin Mat Amin
Keywords: Climate Change; WEHY-HCM; RegHCM-PM; Watersheds; Change in flow
Abstract: In order to assess the impact of climate change on the water balances and flooding conditions at 11 selected watersheds of Peninsular Malaysia (PM) the calibrated and validated, process-based distributed watershed environmental hydrology-hydro-climate model WEHY-HCM for each watershed utilized the 2010-2100 hydroclimate data from 15 dynamically downscaled GCM (ECHAM5, CCSM3 and MRI GCMs) projections (by means of the regional hydro-climate model of Peninsular Malaysia (Reg HCM-PM) ) and thedynamically downscaled 1970-2000 historical control runs from 3GCMs as its input at the scale of Peninsular Malaysia at6km grid resolution and hourly intervals, and then downscaled these climate inputs further to hillslope scale (~0.5sqkm) over each selected watershed at hourly intervals. The downscaled space-time precipitation water was then routed through the surfaces and subsurface, and the stream channel network of these watersheds. Evapotranspiration from these watersheds was also computed simultaneously in time and space by WEHY-HCM. Ensemble averages of the annual mean flows of the15 dynamically downscaled projections show increasing trends for the 11 selected watersheds, especially in the second half of the 21 st century. According to the statistical tests that were performed, the impact of the expected climate change in the 21 st century on monthly mean flows is statistically significant for all of the 11 selected watersheds. The flood frequency analysis by means of the annual peak flows during early (2010-2040), mid (2040-2070) and end of 21st (2070-2100) century was carried out at the 11 selected watersheds. In general, the annual peak flows for various return periods increase towards the end of the 21 st century for the selected watersheds.
Year: 2014