Research On The Temporal And Spatial Changes Of Ecosystem Service Functions In Shiyang River Basin Based On InVEST Model

Since 2000,valuation of ecosystem services has attracted more and more attention.Shiyang River basin,many ecological environment problems have caused by the uniquely geographical location and unreasonable human activities,becoming a typical area of ecological degradation.In the paper,taking Shiyang River basin as research object and using GIS technology and methods to explore the scientific and reasonable ecosystem services valuation in Shiyang river basin,the key services of water supply,soil conservation,carbon storage,food supply and so on were valuated by them.Based on the spatial distribution characteristics and dynamic changes of services,ecosystem services were reasonably divided into five sections to provide important basis for ecological protection and programming in Shiyang River basin,also provide scientific reference for other watershed research.Main conclusions are as follows:(1)In the paper,the open source InVEST model was selected to evaluate results of ecosystem services in Shiyang river basin,the rationality and scientificity of the results confirm the strong applicability of InVEST model in the region.(2)The spatial distribution of ecosystem services in Shiyang river basin were different: water conservation,biodiversity,carbon storage had a similar spatial distribution pattern,decreasing from southwest to northeast,and high value along the river and around the river;The high value area distribution of water purification was more fragmentary;Food supply service was mainly distributed in the midstream.(3)There were some regular changes among ecosystem services in Shiyang river basin: during the decade,when water supply has been decreased first and then increased,soil conservation has been decreased after the increase,Water purification,corbon storage,biodiversity have been improved year by year.(4)From the perspective of landuse on ecosystem services,grassland accounted for the largest proportion in water conservation and soil conservation,all over 44%;21% of Water purification and 41% carbon storage from grassland,second to farmland;In addition,about 92% of the food supply comes from farmland.(5)Ecosystem comprehensive service in Shiyang river basin were divided into four ecological function areas,ecological conservation areas of qilian,ecological function areas of agriculture,ecological function areas of hexi corridor oasis,ecological function areas of desert.