Mitigating Climate Change Impacts for Optimizing Water Productivity

In ecologically fragile areas with arid climate, such as the Heihe River Basin in Northwest China, sustainable social and economic development depends largely on the availability and sustainable uses of water resource. However, under the influence of the rapidly changing climate and human activities, the Heihe River Basin undergoes serious water shortage and water productivity decline. In this chapter we adopted a semi-distributed conceptual hydrological model (SWAT – Soil Water Assessment Tool) coupled with a glacier melting algorithm to investigate the sensitivity of streamflow to climatic and glacial changes in the upstream of the Heihe River Basin. The glacier mass balance was calculated at daily time-step using a distributed temperature-index melting and accumulation algorithm embedded in the SWAT model. Specifically, the model was calibrated and validated using daily streamflow data measured at Yingluoxia Hydrological Station and decadal ice volume changes derived from survey maps and remote sensing images between 1960 and 2010. This study highlights the effects of glacier melting on streamflow and their future changes in the mountainous watersheds. Further, we used improved CGE model to analyze the difference and change between different industries in middle stream of the Heihe River Basin. Simulation results indicate that industrial transformation and development of water-saving industries will also improve water productivity. Lastly, we put forward some strategies on how to mitigate climate change impacts for optimizing water productivity from three perspectives: (1) scientific research needed by scientists, (2) management and institution formulation needed by governments, and (3) water resource optimal allocation by the manager at all administrative levels.