Worldwide seasonal drought forecasts with local relevance

Worldwide drought frequencies and intensities are changing, and many countries and river basins are confronted with the impacts of severe droughts leading to food insecurity and drinking water shortage.  Hydrological drought forecasts with long lead-times can be of great value to help reduce societal impacts, especially when they include local sector-specific information.

To provide high-resolution hydrological forecasts with sufficient local detail we enable the automized implementation of high-resolution basin scale hydrological models anywhere in the world instead of implementing one often lower resolution global hydrological model. The underlying distributed hydrological model – wflow_sbm – relies on so-called pedo-transfer functions that translate input base maps such as land use, digital elevation model, river network and soil type to estimate model parameter values. Herewith the model requires little calibration and can be easily implemented for additional river basins. So far, hydrological models have been included for the Paraná, Lempa,  Vardar, Rhine and Niger river basins and drought forecasts are set-up using the ECMWF seasonal forecasts (SEAS5). All has been integrated in the operational forecasting platform Delft-FEWS that facilitates the data handling, hydrological model simulations and statistical analysis.

The forecasting platform facilitates research analysis and developments on amongst others (1) spatial explicit drought forecasting skill, (2) the value of different meteorological and hydrological drought indicators such as the Standardized Precipitation Index (SPI), Standardized Precipitation and Evaporation Index (SPEI), discharge anomalies, soil moisture deficit (SMDI) and evaporation deficit indices (ETDI) and (3) the development of dedicated indicators for specific user groups defined based on their needs.