Water storage and vegetation changes in response to the 2009/10 drought over North China

Drought frequently occurs in North China and is one of the most damaging disasters in this region, and drought also brings considerable challenges the world-famous South-to-North Water Diversion (SNWD) project. However, it is difficult to identify the drought-induced water deficit at a regional scale. Gravity Recovery and Climate Experiment (GRACE) satellites monitor temporal variations in the Earth's gravitational potential and provide quality data sets for water storage analysis. In this study, we quantify the water deficit over North China by focusing on a recent drought event, the 2009/10 drought, and identifying its onset, persistence, and recovery. The results indicate that GRACE can successfully capture temporal variations in total water storage (TWS). TWS shows a declining trend, reaching a low point during the 2009/10 drought with a water storage deficit of up to 25 km(3) (similar to 22 mm). Groundwater storage shows a similar pattern, with a trend of -6.97 mm/yr. Together with the water deficit, vegetation growth is substantially restricted, as indicated by a reduction in the leaf area index. The amount of water transferred by the SNWD project may ease the water crises in North China.