Introducing Normalized Surface-adjusted Precipitation Index (NSPI) for regional drought assessment.

Drought is a natural event, but its frequency and severity are increasingly influenced by human activity and climate change. In the current Anthropocene era, human-induced changes to the hydrological cycle combined with natural climate variability are reshaping how droughts develop and persist. Droughts often result from complex interactions between atmospheric conditions and land surface processes, which affect how water and energy move through the environment.