Evaluation Of Ecosystem Services Value In The Upper Reaches Of The Yongding River Based On The InVEST Model

The Yongding River Basin is the confluence area of the three functions of water conservation,wind and sand fixation,and soil and water conservation in the Beijing-Tianjin-Hebei urban agglomeration.At present,the Yongding River in Zhangjiakou City has problems such as lack of water resources,deterioration of the water environment,and imperfect ecological compensation mechanisms.How to strengthen water ecosystem management has become an important challenge facing the region.Quantitative evaluation of various service functions of the water ecosystem is helpful to comprehensively understand the value of water resources and to formulate ecological compensation standards scientifically and reasonably.This article takes the upper reaches of the Yongding River in Zhangjiakou City as the research object.According to the lack of spatial data in Zhangjiakou,referring to the value classification method,based on water supply not only has its own price,but also generates great value.Therefore,this paper innovatively divides the value of water ecosystem services into water supply value and other incidental values.Other additional values include the value of 9 types of ecosystem services such as hydropower generation,aquatic product production value,soil conservation,river sediment transport,and carbon and oxygen release.The evaluation of water supply service functions uses the InVEST model to simulate water production,which more intuitively and fully shows the spatial characteristics of water supply in the area.Other value-added methods are classified and evaluated by a variety of methods,such as the model method,the market value method in the alternative technology method,the opportunity cost method,and the equivalent factor method.On this basis,according to the compensation range and theoretical compensation value of the river basin,the actual ecological compensation standards for each district and county in the research area were determined.This paper attempts to provide theoretical support and scientific basis for objectively measuring the service efficiency of aquatic ecosystems in the area by evaluating the value of aquatic ecosystems services in the upper reaches of the Yongding River in Zhangjiakou City.Through the above studies,the following conclusions are mainly drawn:(1)This paper comprehensively uses the InVEST model and market value method to comprehensively evaluate the water supply in the research area,and expresses the water supply situation in the area intuitively by means of space and money.For areas where spatial data is difficult to obtain,to evaluate soil and water conservation and biodiversity values,the equivalent factor method can be widely used.Adopting the apportionment method has great practical significance for many areas without a classification of aquatic ecotourism.Therefore,adopting the above-mentioned assessment methods has improved the scientificity of the method,and has certain reference significance for areas where basic data is relatively lacking.(2)The value of aquatic ecosystem services in the Zhangjiakou area of the upper reaches of the Yongding River was evaluated,with a total value of ￥5.514 billion.The ecological value and economic benefit of the unit area are ￥35 million and ￥23 million,respectively,and the ecological value is far higher than the economic value.(3)The order of the value of various aquatic ecological service functions is: leisure and entertainment> water supply> soil conservation> biodiversity> flood storage>aquatic product production> carbon and oxygen release> hydropower generation> water quality purification> river sediment transport.(4)According to the results of the ecological compensation standard,the total ecological compensation in the upper reaches of the Yongding River is ￥2.337 billion,and the actual compensation amount of each district and county is Chongli District> Yu County> Shangyi County> Zhuolu County> Huailai County> Qiaodong Districts and Qiaoxi Districts> Yangyuan County> Xuanhua County> Xiahuayuan District> Huai’an County> Wanquan County.It can be seen that the Chongli District and Yuxian need to increase the compensation,which is the key compensation object of this research area.Xiahuayuan District,Xuanhua District,Huai’an County,and Wanquan District have the lowest.These indicate that the ecological damage in those areas are relatively serious,and there are less need for ecological compensation.