Deciphering Flash Droughts in India: Trends, Dynamics, and Prediction Insights

Droughts are among the most severe hydro-meteorological hazards. IPCC (2022) reports that the global area affected by droughts is expected to increase in the context of climate change. Their impact on the agriculture, economy, and ecosystems of a region is significant. Flash droughts represent a particularly challenging phenomenon characterized by their rapid onset. They are primarily driven by a sudden increase in evapotranspiration coupled with significant deficits in precipitation. The duration of flash droughts is relatively shorter as compared to traditional droughts. They are difficult to predict and often lack adequate mitigation measures. High-resolution indices such as the pentad-scale (5-day) SPEI (Standardized Precipitation Evapotranspiration Index) have emerged as essential tools to detect and evaluate the flash droughts.

The present study investigates the flash droughts across India during the period 1979 to 2020. It utilizes the IMDAA dataset (0.12°×0.12°) to develop a pentad-scale SPEI dataset throughout India. The analysis reveals that northern and central states, including Punjab, Haryana, Madhya Pradesh, and eastern Maharashtra, experience comparatively prolonged and severe flash droughts. The spatial evaluation of drought progression is also conducted across multiple agro-climatic zones. We assessed the predictability of flash droughts at a lead time of 7, 14, and 21 days utilizing data-driven frameworks such as LSTM, Transformers, and Informers. The temporal evaluation of prediction performance is done across both monthly and seasonal scales. The findings of the study underscore the need for improving the prediction performance of flash droughts, particularly across regions with high elevation variability. This approach aims to strengthen the nation’s resilience to flash droughts in the face of a changing climate.