Eco-Efficiency Assessment of Water Systems in China

With the transformation of water conservancy from traditional to eco-hydraulic aiming at sustainable development, the study on eco-efficiency of the water system has attracted a great deal of attention. This study aims to develop a methodology for evaluating the eco-efficiency of water systems of 31 administrative regions in China. Considering the multiple attributes of water systems and a piecewise linear technological frontier, the Rough Set Theory (RST) and Data Envelopment Analysis model (DEA) are combined to analyze the eco-efficiency of water systems. An input-and-output index system is established based on RST. The eco-efficiency for the water system of 31 administrative regions in China is calculated by DEA, and the characteristics of its spatial differences are discussed. The results show that there is a significant difference in the eco-efficiency of water systems: (1) On the whole, the efficiency value of north China is slightly higher than the south; (2) In the eight sub-regions of China, the north coastal area gains the highest efficiency score and the middle reaches of the Yangtze River obtains the lowest value; (3) There are 11 out of 31 regions at the best practice frontier. The spatial difference in eco-efficiency of the water system is a common phenomenon, which reflects the direct or indirect influence by economical, political, legislative, historical, cultural factors and other social development. Based on the above findings, some suggestions are made to improve the eco-efficiency of the water systems in China.