Abstract
Drought is a natural disaster that mainly affects water resources,
agriculture, and a country’s social and economic development due to its
long-term and frequent occurrence. Therefore, it is important to
characterize and monitor drought and its propagation to minimize the
impact. Precipitation and Terrestrial water storage are popular
hydrological components used frequently to understand the drought
process. However, spatiotemporal assessment of drought propagation over
India based on terrestrial water storage is unexplored. In this study,
the terrestrial water storage anomalies (TWSA) obtained from a Gravity
Recovery and Climate Experiment (GRACE) and Combined Climatological
Deviation Index (CCDI) are used to characterize the drought at different
spatial scales. The changing pattern of TWSA and CCDI is investigated
using the non-parametric Mann-Kendall test and its slope is estimated
using the Theil-Sen slope estimator. TWSA trends unravel that the Ganga
and Indus River Basin have significant negative trends throughout the
year. However, the trends are oscillating for Peninsular basins. The
major river basins Ganga, Indus, Brahmaputra shows decreasing trends for
all seasons; however, Cauvery, Mahanadi, Krishna, and the Godavari show
decreasing trends for winter and Post-monsoon season and increasing
trends for pre-monsoon and monsoon season. It shows that Ganga, Indus,
and Brahmaputra river basins are more prone to drought in the near
future.