Assessing Climate Change Impacts on the Performance of Major Water Projects over China

Abstract:

The terrestrial water cycle has been largely altered by water projects in China. Since 1950, half of the world’s large dams over 15 m height have been built in China. The installed hydropower capacity in China was 249 GW in 2012, accounting for about one-fifth of the total installed hydropower capacity of the world. China has also pursued an ambitious effort, the South-North Water Diversion Project, to transfer 44.8 billion m³ of freshwater annually from southern China to the drier north. Climate change is expected to result in changes in land surface hydrology, thus pose a huge challenge to water management. The potential impacts of climate change on the performance of the major water projects are yet to be assessed. We used a land surface hydrological model together with a simple treatment of reservoir operation to assess the impact of hydrological change on the functions of the major water projects under the Intergovernmental Panel on Climate Change (IPCC) climate and socio-economic scenarios. The bias-corrected climate data from global climate models under different Representative Concentration Pathways (RCPs) were used to drive the hydrological model. The operation of 474 major reservoirs was considered with an operating rule to generate maximum possible hydroelectricity and to fulfill water diversion demands. The future socioeconomic conditions, the Shared Socioeconomic Pathways (SSPs), were used to estimate the water requirement and leverage the water diversion. The modeling results suggest that climate change would have negative impacts on hydropower production and water supply reliability in China. This research highlights the need to evaluate the performance change of existing water infrastructures and to develop adaptation strategy in sustainable water management in a changing environment.