Comprehensive Benefit Evaluation And Analysis Of Water Ecosystem In Xiangjiang River Basin

In recent years,the ecosystem has gradually deteriorated with the rapid development of the economy.How to balance the relationship between economic development and ecological environment and coordinate the distribution of interests between various regions in the basin has become an urgent problem to be solved.This paper quantifies the benefits of the water ecosystem in the Xiangjiang River in Hunan Province using functional value method and equivalent factor method,in order to estimate the comprehensive benefit of the water ecosystem in Xiangjiang River Basin and the main results were obtained as following:(1)Estimation of the comprehensive benefit of the water ecosystem in Xiangjiang River Basin.Based on the functional value method,the comprehensive benefits of water ecosystems in 2005,2010 and 2015 were estimated to be 352.615 billion yuan,356.075 billion yuan and380.825 billion yuan,respectively,in terms of ecological benefits,economic benifits and social benefits,Based on the equivalent factor method,the comprehensive benefits of the water ecosystem in Xiangjiang River Basin in 2005,2010 and 2015 were estimated to be 42.635 billion yuan,59.634 billion yuan and 51.246 billion yuan,respectively.(2)Comparison of assessment methods for comprehensive benefit of the water ecosystems in Xiangjiang River Basin.The functional valuemethod and the equivalent factor method were compared in terms of the principle of the method,classification system,data requirements,calculation process and results.Owing to the subjective nature of the equivalent factor method,the functional value classification system are lack of representativeness,the calculated results are lack of regionality and the differences of ecosystem benefits under different conditions are not considered.Therefore,the comprehensive benefits of the water ecosystem in Xiangjiang River Basin were finally determined using the functional value method.(3)Analysis of comprehensive benefit of the water ecosystem in Xiangjiang River Basin.Taking the Xiangjiang River as the research object,the overall change,spatio-temporal patterns,trade-off and synergy relationship of the comprehensive benefits at different administrative scale were analyzed.The results showed that the ecological benefit accounted for 79%~90% of the comprehensive benefits in Xiangjiang River Basin.The comprehensive benefits of the water ecosystem services in Xiangjiang River Basin increased by 28.210 billion yuan from 2005 to2015,of which the economic and social benefits increased while the ecological benefits decreased.In terms of time,the ecosystem service change index was used to analyze the service benefits and the differences in Xiangjiang River Basin.In the service benefit analysis,the aesthetic landscape has the largest growth rate;in the eight-city benefit analysis,Zhuzhou City's water ecosystem benefit increased the most,and Yueyang City's water ecosystem benefit decreased.In terms of space,the ecosystem benefits are in a pattern of high north and south,and low in the middle,which is basically consistent with the spatial distribution of the water surface area.The interrelationship between the water ecosystem services in the Xiangjiang River from 2005 to 2015 was mainly a synergistic relationship.all of which were positively correlated,but the significant correlations at 2005,2010 and 2015 have differences.