Construction and application of the ecological benefit assessment model for the follow-up development of the Three Gorges Reservoir Area in Chongqing, China

Understanding ecological benefits is one of the key questions related to the stability and sustainable development of the Three Gorges Reservoir Area (TGRA). However, ecological benefits assessment in the TGRA in Chongqing has not been quantified and assessed effectively. This study constructed the assessment system of ecological benefits for the follow-up development of the TGRA in Chongqing, on three aspects of society, economy and environment, based on the regional characteristics and development status of the Chongqing section of the TGRA. By using entropy technology and a grey model to revise the indicators weight value determined by traditional analytic hierarchy process, an ecological benefit assessment model is constructed based on fuzzy mathematics. Afterwards, the ecological benefits of the Chongqing section in the TGRA from 2009 to 2015 are comprehensively evaluated. The results include the following. (1) The ecological benefits of the east of the middle area of TGRA are higher than that of the upper area. The spatial distribution of the ecological benefits shows a gradual decreasing trend from northeast to southwest. (2) The ecological benefit level of the Chongqing section in the TGRA is in poor to good condition, and there are no bad or excellent assessment levels. (3) From 2009 to 2015, the number of counties with a good assessment level increased from 1 to 5, the number of counties with moderate assessment level increased from 12 to 15, while the number of counties with poor assessment level decreased from 9 to 2. (4) The ecological benefits of 16 counties show an increasing trend, while the other six counties show a decreasing trend in the Chongqing section in the TGRA from 2009 to 2015. There are 19 counties, including six counties with decreasing ecological benefits and 13 of 16 counties with increasing ecological benefits, which are not coordinated in the development of environment, social and economic benefits. These findings indicate that the ecological benefits of the Chongqing section of the TGRA are improving year by year, while unstable factors exist at the same time. To ensure the steady improvement of ecological benefits in the Chongqing section of the TGRA, the follow-up development of the reservoir area needs to further adjust the development mode of the society, economy and environment.