Spatio-Temporal Dynamics of Droughts in India Using the RRV Index: Historical and Future Perspectives

The climate change brings increasingly serious challenges for society, one of which is the increase in extreme events. Extremes such as droughts have led to substantial impacts on the livelihood of humans and animals. Understanding the spatial extent of drought-prone regions is important for its assessment and effective management. The Reliability–Resilience–Vulnerability (RRV) integrated index map approach gives a fair idea about the drought-prone regions. This study conducted an extensive RRV analysis of droughts, using the drought properties duration and severity. These properties were assessed using the Standardised Precipitation Index (SPI-3). The investigation is conducted across India, with precipitation data collected at a spatial resolution of 0.25°, utilising a dataset spanning 200 years (1901–2100). Historical data for 121 years (1901–2021) collected from the India Meteorological Department, and data for the future period (2022–2100) were collected from the NEX-GDDP, ACCESS CM_2 climate model for the SSP585 scenario. The analysis is carried out for five periods 1901–1940 (1st), 1941–1980 (2nd), 1981–2021 (3rd), 2022–2060 (4th), and 2061–2100 (5th). The spatial distribution of drought properties, namely duration and severity at the 50th, 70th, and 90th percentile levels, revealed the places with significant and prolonged drought conditions. From the integrated RRV index map, an increase in drought severity was observed until the 4th period, followed by a decline in the 5th period. Noticeable changes are observed in the distribution of the spatial extent of the map, indicating areas prone to drought (integrated RRV map) in India for the 2nd and 3rd periods compared to the 1st period. The results indicate a shift in drought-prone areas from traditionally arid and semi-arid regions to more humid regions. The time series analysis of percentage area of India under drought shows that there is a substantial increase up to the 4th period and then decreases in the 5th period. These findings can assist decision-makers and government bodies identify areas requiring urgent attention for drought management, enabling them to develop region-specific action plans.