Understanding the precipitation and temperature variability under changing climate in a Himalayan sub-basin
Abstract
The water tower snow-capped Himalayas, source to the Ganges riparian countries, are in the verge of depleting as the warming of the earth's surface gets increased. Precipitation and temperature variability are indispensable for understanding the hydrologic processes under the changing climate. By the end of 21st century, the precipitation in the Himalayas is likely to increase by 4-25% whereas the temperature is likely to increase by at least 0.30C even though the global warming is kept below 1.5OC. In this study, we aim to understand the climatic variability in projecting the future climate in a Himalayan sub basin of Nepal. Five COordinated Regional Climate Downscaling EXperiment- South Asia (CORDEX-SA) regional climate model (RCM) experiments have been used to analyze the precipitation and temperature variability within the basin. The climate models were bias corrected using quantile mapping method. Precipitation and temperature variability in the basin were analyzed for different future time frames namely, near future (2021-2040), mid future (2041-2070), and far future (2071-2099). The climate projection analysis indicated a significant increase in precipitation and temperature in the future. Annual precipitation was projected to change from +1.5 to +20% for five CMs under RCP4.5 with average annual increase of +10% while under RCP8.5 the same is projected to increase by +8.3 to +21% with an average increment of +14.8% by the end of the century. Similarly, the maximum temperature is expected to have variability ranging from -0.1 to +5.7OC under RCP4.5 with an average temperature rise of +0.8 OC. Under the RCP8.5 scenario the Himalayan temperature is found to increase by +1.9 OC (+0.8 to +2.8). The minimum temperature in the basin is found to have more susceptibility under the climate change scenario with an average rise of +1.4 and +2.7 OC under RCP4.5 and RCP8.5 scenarios. The rise in the minimum temperature leads to a fact that the snow caps of the Himalayas are in the state of melt. The results of this research would be helpful to practitioners, researchers and decision/policymakers to regulate the issues of water availability in the future.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2020
- Bibcode:
- 2020AGUFMOS0460014A
- Keywords:
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- 3305 Climate change and variability;
- ATMOSPHERIC PROCESSES;
- 4321 Climate impact;
- NATURAL HAZARDS;
- 4215 Climate and interannual variability;
- OCEANOGRAPHY: GENERAL;
- 4513 Decadal ocean variability;
- OCEANOGRAPHY: PHYSICAL