Evaluation of ecohydrological regime and its driving forces in the Dongting Lake, China

Study region: The Dongting Lake (DTL) wetland, China. Study focus: At present, there are few studies on ecohydrological assessments based on the collaborative study of flow and water level. The focus of this study is to use ecologically meaningful indicators (Environmental Flow Components method and Range of Variability Approach method) to evaluate the dynamic process of flow and water level components, whose changes have a negative impact on the DTL wetland ecosystem. In addition, we quantitatively expressed the ecological response process of flow and water level under changing environments, and proposed to use the underlying surface parameters to further clarify the impact of human activities and climate change (evaporation and rainfall) on runoff in different time periods. New hydrological insights for the region: After the construction of the Three Gorges Dam, the components of environmental flow in DTL were reduced and the overall change of the flow and water level of the DTL was 37% and 36%, respectively, The results of the wetland ecological response coincided with the trend of habitat fragmentation and miniaturization of fish individuals in DTL. The underlying surface parameters show that the weight of the impact of climate change on runoff is increasing, and the contribution rate of driving forces (human activities, evaporation, and rainfall) to runoff are 49.32%, 20.88%, and 29.80% respectively, and to water levels are 60.00%, 21.3%, and 18.7%, respectively.