Impacts of climate change on the availability of water resources and water resources planning

The application of climate change research results in the planning of water resources development and management is facing the challenges caused by the uncertainties. Taking the upstream watershed in Hanjiang basin as an example, the SWAT model was used to simulate the monthly averaging runoff and the amounts of ecological water demands in streams were estimated under the current and future situations, considering the impact of climate change in order to evaluate the available water resources for local users and the transportation project. The results show that the exploitation and utilization of the surface water resources of the Han River basin is rational and moderate utilization at a sustainable level for now and in near future. It was also found that there are obvious uncertainties in the evaluation of the availability of surface water resources because the impacts of climate change on the key variables that should be calculated in the method, such as ecological water demands and the high flow during flooding season are not considered. In order to use the climate change researching results in the design of water engineering and the planning of water resources development and management, the modelling and predicting reliability of related elements of climate and the response of the factors influencing the runoff generation and the related planning components to the climate change should be comprehensively evaluated.