Abstract:

We used the Poyang lake catchment as study area in this paper.The distributed hydrological model WATLAC was used to explore the catchment hydrological effects in response to climate changes.We used the observed river discharges of five subcatchments to calibrate and validate the hydrological model in simulation period from 2000 to 2008.Results showed that the simulation effects were good.Thereafter,the river discharge,soil evaporation and base flow were used as objective variables of sensitivity analysis to investigate the hydrological response to proposed climate change scenarios.Results showed that the catchment discharge and base flow were sensitive to precipitation changes.The soil evaporation was relatively sensitive to temperature changes.Under the condition of specified precipitation scenarios,these hydrological variables had linear relationship with the temperature changes.Under the condition of specified temperature scenarios,the relationship between the hydrological variables and the precipitation changes was nonlinear.The significant influences of temperature change on the hydrological variables were mainly associated with the increased precipitation.Under the same temperature change scenarios,the increased precipitation had more significant influence on discharge compared with the decreased precipitation.Whereas the decreased precipitation had more significant influence on soil evaporation and base flow than the increased precipitation,which indicated that the precipitation changes played an important role in causing different effects of hydrological variables.We have successfully applied a large scale distributed hydrological model in the Poyang lake catchment.This model was used to study the hydrological effects in response to possible climate changes.More importantly,this study provided a solid scientific basis for regional water resources management and flood regulation