The hydrology drought normally refers to the water shortage phenomenon caused by the long-term payment imbalance between surface water and underground water, which can greatly impacts the development of regional agriculture, ecology, society and economy. Compared with other agricultural and climate drought, the hydrology drought has more complicated characteristics and therefore the results it causes will be more severe. Yangtze River catchment is one of the most developed areas in China. Therefore, learning and evaluating the time and space characteristics of the hydrology drought has a significant referring meaning to deepen the understanding of the water recycle structure of Yangtze River catchment and to strengthen the catchment water sources management.

Funded by the Major State Basic Research Development Program of China (973 Program) and National Natural Science Fund of China, Zhang Qi team reconstructed the water reserve sequence of Yangtze River catchment and expanded it from 1979 to 2012 on the basis of GRACE gravity satellite. The team evaluated the hydrology drought events of Yangtze River catchment by using the date sequence and based on which estimated the recovering time of drought events according to eCDF. The research shows that there are 29 droughts in the Yangtze River catchment from 1979 to 2012, with an average time of 7.5 months, and an average water deficit of 146mm. Years since 2000 belong to the period with few water reserve in Yangtze River catchment, which is mainly caused by the decreasing of catchment rainfall, high temperature and human activities.

The research makes use of GRACE gravity satellite and the ground station data and studies on the water reserve changes of large river catchment. The research methods are of great reference value to evaluate large catchment hydrology drought and to predict and prevent floods and droughts. The research result is published in the mainstream journal of hydrometeorology “Journal of Hydrometeorology (IF3.645)”.