STATISTICAL DOWNSCALING OF GRACE-DERIVED TERRESTRIAL WATER STORAGE USING SATELLITE AND GLDAS PRODUCTS

抄録

Terrestrial water storage (TWS) at high spatial and temporal resolution is deemed necessary for many hydrological and water resource management applications. Since its launch, Gravity Recovery and Climate Experiment (GRACE) satellite has been providing terrestrial water storage change data at global and regional scales. However, the application of GRACE data for local-scale water resources management has been limited because of its coarse resolution. The purpose of this work is to investigate the feasibility of downscaling GRACE with a statistical method. In this work, empirical regression methods based on the relationship between GRACE and other hydrological fluxes were applied to downscale a 1 degree gridded GRACE product to 0.25 degree. Observed groundwater level data were used to validate the downscaling performance. Results indicated that GRACE TWS had good relationship with storage change obtained by water balance equation. Statistical regression downscaling method can improve GRACE data resolution effectively.