Seasonal Drought Index Predictability for Historical and Future periods Using Worldclim over the Southern Plain of Himalayan Tarai
Abstract
Drought episodes around Himalaya are unavoidable due to rapidly increasing atmospheric temperatures and uncertainties in rainfall patterns. A tropical region like the Tarai region of Nepal, located in the foothills of the Central Himalaya, is viewed as a countrys food granary with a contribution of over 50% to the entire nation's agricultural production. However, studies on spatiotemporal occurrence of drought in these regions under the projected climate conditions remain almost unexplored and limited. In this study, we used the ensemble of nine climate models of the Coupled Model Intercomparison Project Phase 6 (CMIP6) under two shared socioeconomic pathways: SSP245 (an intermediate development pathway) and SSP585 (a high development pathway), to assess anticipated drought conditions until 2060 AD. We used the openly accessed bias-corrected gridded data from the Worldclim to compare drought events under future climate scenarios with respect to the historical period (1989-2018). We divided the entire Tarai region of Nepal Himalaya into Eastern, Central, and Western region, and computed Thornthwaite Moisture Index (TMI) to evaluate soil moisture conditions on a seasonal scale. In both scenarios, we found a significant increase in the amount of precipitation and temperature for the entire Tarai region. However, the winter and spring seasons are yet projected to suffer the deficiency of precipitation and rise in temperature in future compared to the autumn season. We report that the Eastern Tarai is projected to have the highest percentage decrease of winter precipitation. In addition, the highest and lowest temperatures were recorded in the Western Tarai for the spring and winter seasons, respectively. Similarly, the lowest moisture index (MI) is recorded and projected for the Eastern Tarai for the winter season under both scenarios. In contrast, the Western Tarai is projected with the lowest MI in autumn and spring seasons. However, the relative decrease in MI was highest in the Central Tarai of Nepal during the spring season under the SSP245 and the Eastern Tarai during the winter season under the SSP585. This spatiotemporal analysis of the MI will be instrumental to address needs of the irrigational facility, choice, and rotation of crops under the changing climate scenarios.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2021
- Bibcode:
- 2021AGUFM.H45M1328S