Study on Water Resources Efficiency with the Regional Water Resources Carrying Capacity into Consideration

Most of the existing studies on regional water resources efficiency only consider the total regional water use while ignoring the regional endowment. Therefore, it is essential to introduce the water resources carrying capacity into the study. Given that data envelopment analysis(DEA) cannot compare the time series of a single decision-making unit, we employ the DEA-window analysis to study China's water resources efficiency during 2005–2012 with the regional carrying capacity being considered, and analyze the spatiotemporal evolution. The study shows that such efficiency has increased from 0.71 in 2005 to 0.79 in 2012. High water resources efficiency is observed in Liaoning, Tibet, Yunnan, Beijing, Tianjin, Shanghai, Jiangsu, Zhejiang, Guangdong and Sichuan,where the output levels and utilization ratios of water resources are positively correlated. Low water resources efficiency is observed in Henan, Shaanxi, Gansu, Ningxia and Xinjiang which feature high-level utilization and low carrying capacity of water resources. As for regional water resources efficiency, eastern and southern coastal regions rank first, followed by Northeast China and northern coastal regions, southwest and northwest regions of China and lastly the middle reaches of the Yellow and Yangtze Rivers. Therefore, policy-makers should not only accord the regional development with carrying capacity, but also enhance cross-regional industrial cooperation for coordinated development.