Theoretical framework of generalized watershed drought risk evaluation and adaptive strategy based on water resources system

Drought is an extreme event in hydrologic cycle. The occurrences of drought events usually feature determinacy and randomness. With the increasing impact of climate change and anthropogenic activities, drought happens in more areas with higher frequency, and now it threatens the water and ecology security in river basin. Drought is firstly a resource issue, and with its development, it transforms into a disaster issue. From the perspective of the water resources system, the Dongliao River Basin, which has high frequency of drought occurrence, was studied to propose the connotation and the quantitative evaluation method of generalized drought. The driving factors of natural climate variability (NCV), anthropogenic climate change (ACC), underlying condition change and hydraulic engineering regulation (HER) can alter the impacts of drought events. The influencing time of NCV, ACC and HER was decided, respectively, and generalized drought risk maps were drawn. Finally, water emergency dispatch, water demand compression and water diversion were proposed to cope with the generalized drought risk.