GSDD, A Catchment-Scale Global Streamflow Drought Database based on Observed Daily Discharge

Aparna Raut , Poulomi Ganguli

Streamflow droughts increasingly threaten global water security, hydropower production, and freshwater ecosystems. Understanding observed streamflow drought characteristics is key to water supply management, energy and food production. However, global drought datasets primarily rely on meteorological indicators (e.g., precipitation and evapotranspiration), while a few offers grid-based hydrological drought datasets. All these datasets are in monthly temporal resolution. The streamflow droughts and associated characteristics at finer temporal resolutions, using observed discharge series, are currently lacking at a global scale, making it challenging to capture the full spectrum of drought characteristics and their impacts. We introduce the Global Streamflow Drought Database v1 (GSDD-v1), a comprehensive global inventory of streamflow droughts. The database comprises drought characteristics of 2,998 regulated and unregulated catchments, representing 29 IPCC climate regions, covering the past seven decades (1950-2024). Our global dataset includes event-based drought onset and termination times and accumulated deficit volume, which is relevant for reservoir planning and agricultural operations. GSDD-v1 provides a key starting point for basin-scale drought risk assessment, offering valuable resources for climate-resilient water management, and is publicly available at https://doi.org/10.5281/zenodo.17950907 (Raut and Ganguli, 2025b).