Study Of Climate Change Impacts On Regional Crop And Domestic Water Demand

Climate change and water shortage have become global issues, while climate and water resource are closely related. The study of implication of climate change on water resource, however, is limited, probably because the future climate scenarios from General Circulation Models (GCM) can not be applied directly to regional scale. Some transferring technique should be employed to acquire the local climate scenarios, which then could help for impact analysis application. Simultaneously, the forecasting results of water demand in China are always higher than the actual values. Therefore, forecasting ability of water demand model may have some influence on the results of climate change evaluations. Moreover, comparing with social-economical factors, meteorological factors turn out to be weak ones for explaining water demand. So, constructing relations between weak factors and water demand needs further study.Multivariate linear statistical downscaling model was applied to transfer outputs of GCMs to local scale, and water balance method was adopted to analyze the relation between meteorological factors and crop water demand. Downscaling and crop water demand models were coupled to evaluate climate change impacts on wheat and maize water demand in Zhengzhou. Domestic water demand model with weak factors was constructed by modeling meteorological factors against the residual of first calibration. Downscaling and water demand models were coupled to evaluate climate change impacts on domestic water demand in Zhengzhou. Evaluation enriched the study of climate change impacts on water demand.The role of water demand models in evaluation of climate change impacts was analyzed, and water demand model's simulating and forecasting ability for evaluation climate change impacts was explained. What is more, similarities between downscaling and water demand model were presented, which illustrated that interdisciplinary knowledge could be reciprocal. Ability of derived meteorological factors for explaining water demand was also analyzed in this study.Case study shows that wheat and maize water demand have little change under the downscaled future scenarios in Zhengzhou. Climate change has negative impacts on maize water demand, while has complex ones on wheat water demand, which would vary between different scenarios. In general, impacts on wheat water demand are smaller, while relatively larger on maize. On the other hand, increasing temperature has bigger impacts on domestic water demand than rising precipitation has, which then leads to the decreasing trend of water demand.