Ecological security assessment of Chaohu Lake Basin of China in the context of River Chief System reform

In the face of the increasingly severe water environment, establishing an effective water environment management mechanism is a major concern of governments around the world. The River Chief System attempts to match water environment management to the performance of the main leaders of the local party and government and represents an institutional innovation to solve the problem of river and lake management in China. However, there is still a lack of systematic research on the performance of the River Chief System and how to promote its overall effectiveness. This paper took Chaohu Lake Basin, with a concentrated and complicated water environment, as the research object and divided it into eastern and western halves. The water ecological security before and after the implementation of the River Chief System was comprehensively evaluated, and the obstacles to ecological security were diagnosed. The implementation effect of the River Chief System and the weak links of the corresponding river chiefs’ work performance were analyzed. The results show the following: (1) Since the implementation of the River Chief System in 2013, the overall water ecological security of Chaohu Lake Basin has been raised from the lower limit to the upper limit of the generally healthy category, initially reflecting the effect of the River Chief System. (2) For the eastern half of the lake, the threat to water ecological security mainly comes from the development of industry. Industrial water use intensity is the primary obstacle to the ecological security of the eastern half of the lake in recent years. (3) For the western half of the lake, the threat to water ecological security mainly comes from the process of urbanization. The wetland area, urban domestic water use intensity, and artificial afforestation area are the main factors hindering the ecological security of the western half of the lake. The above analysis results can be used as the basis for future work to improve the performance of the relevant river chiefs in Chaohu Lake Basin.