Effects of Danjiangkou Reservoir on hydrological regimes in the middle and lower reaches of Hanjiang River GUO Wen2xian1 , XIA Zi2qiang1 , WANG Qian2 (1. State Key Laboratory of Hydrology2Water Resources and Hydraulic Engineering , Hohai University , Nanjing 210098 , China ; 2. Yellow River Estuary Management Bureau , Dongying 257091 , China) Abstract : Based on the mean daily flows at Xiangyang h