Forecast of seasonal water availability in Central Asia with near-real time GRACE water storage anomalies

Abstract

Abstract Water availability during summer in Central Asia is controlled by the snow melt in the surrounding mountains. Reliable forecasts of river discharge during this period are essential for the management of water resources. This study tests the predictive power of GRACE gravity-based water storage anomalies in a linear regression framework for two large catchments. The results show substantial improvements of the forecasts in the larger Amudarya catchment compared to forecasts using just climate, snow cover, and discharge data. In this catchment, GRACE water storage anomalies even provide the largest share of explained variance. This leads to the conclusion that GRACE data can improve the forecast of seasonal water availability for large basins in Central Asia. The GRACE-FO mission launched in May 2018 opens up the possibility of operational forecasts utilizing upcoming near-real time products from satellite gravimetry for Central Asia and similar environments.