Future changes in extreme temperature events using the statistical downscaling model (SDSM) in the trans-boundary region of the Jhelum river basin

Abstract

a b s t r a c tIn the 21st century, climate change is considered to be one of the greatest environmental threats to the world, and the changes in climate extremes are estimated to have greater negative impacts on human society and the natural environment than the changes in mean climate. This study presents the projections of future changes in extreme temperature events under A2 and B2 SRES scenarios using the statistical downscaling model (SDSM) in the trans-boundary region of the Jhelum River basin. This area is located in Pakistan and India. In order to get realistic results, bias correction was also applied to downscale the daily maximum and minimum temperature values before calculating 8 intensity and 4 frequency indices. Validation (1991)(1992)(1993)(1994)(1995)(1996)(1997)(1998)(1999)(2000) showed great reliability of SDSM in ascertaining changes for the periods 2011-2040, 2041-2070 and 2071-2099, relative to 1961-1990.The intensity of the highest and the lowest night time temperatures is simulated to be higher than the highest and lowest day time temperatures. In contrast, the intensity of high night time temperature (hot nights) is projected to be lower than high day time temperature (hot days). The number of hot days and hot nights is predicted to increase, and by contrast, the frequency of cold days and cold night is predicted to decrease in all three future periods. Almost all the seasons will witness warming effects in the basin. However, these effects are much more serious in spring (hot days and nights) and in winter (cold and frosty days).On the whole in the Jhelum basin, the intensity and frequency of warm temperature extremes are likely to be higher and the intensity and frequency of cold temperature extremes to be lower in the future.& 2014 Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/3.0/).

Potential Impacts of Climate Change on Water Resources in the Kunhar River Basin, Pakistan

“…In both seasons, the negative changes at Naran (ranging from 40%-73%) were greatly higher than Gari Habibullah, (ranging from 6% to 28%) under both A2 and B2. Mahmood and Babel [43] conducted a study about extreme temperature events in the Jhelum River basin under A2 and B2, and they found that the intensity of cold days and cold nights will increase in the future. The reduction in flow (as indicated by the results of this study) is likely to be the case due to more accumulation of snowfall that would result from the increased intensity of cold days and cold nights in winter (based on the projections of Mahmood and Babel that indicate that precipitation will increase in winter and decrease in spring) [1].…”

“…However, Q 95 was predicted to decrease by 18%-99% in the future in the basin. This might be due to the increase in the intensity of cold days and cold nights (mentioned by Mahmood and Babel [43]) which may cause precipitation as snow accumulation in winter (low flow season).…”

“…Water 2016, 8,23 cold days and cold nights (mentioned by Mahmood and Babel [43]) which may cause precipitation as snow accumulation in winter (low flow season).…”

Assessment of Climate and Land Use Change Projections and their Impacts on Flooding

“…resolutions (100-500 km) reduce their applicability where regional scales are concerned [5]. Regional/local scales require high resolution to adequately represent complex topographical features when the environmental and hydrological impacts of climate change are to be examined [5].…”

“…Regional/local scales require high resolution to adequately represent complex topographical features when the environmental and hydrological impacts of climate change are to be examined [5]. In the last two decades, the statistical and dynamic downscaling models have been developed with the main aim of downscaling temporal and spatial outputs of GCMS at regional (50x50 km) and local (0-50 km) levels [6][7].…”