Hydrological drought measurement using GRACE terrestrial water storage anomaly

Hydrological drought is a global issue that many countries face. In this paper, we present a new hydrological index (SGI) based on the Gravity Recovery and Climate Experiment (GRACE) product. For comparison, we compare it with the documented drought in July 2010 and calculate the correlation coefficient between it and the standardized precipitation index (SPI). The result shows the new index can reflect spatiotemporal distribution of dryness and wetness, and it has good agreement with SPI in different time scales, and the new index can be used in the hydrological drought measurement in the global scale.