The Coordination Relationship Between Land Use Change And Ecological Service Value Change—Case Study In Ili River VallE(y)in Xinjiang

Land use change is a major driver of global change,which changes the capacity of ecological services provision by affecting ecosystem patterns and processes,and ultimately leads to changes in the value of regional ecological services.Quantifying the impact of land use change on the value of regional ecological services can help optimize the allocation of land resources,provide a comprehensive understanding of environmental change trends and promote the sustainable development of regional land resources and ecological environment.This paper takes the Ili River Vall Ey in Xinjiang as the research area,based on the theory of geography,ecology and land system science,adopting“3S”technology,combining quantitative and qualitative methods,on-site investigations and related experiments and carries the following research:First,I use remote sensing images from 1990,2000,2010,and 2018 to extract land use change information in the study area during multiple periods,and quantitatively analyze land use changes in the Ili River Vall Ey from the two dimensions of“time”and“space”.The magnitude,speed,direction,structure and spatial characteristics of the changes reveal the spatiotemporal evolution process,characteristics,and trends of land use changes in the Ili River Vall Ey from 1990 to 2018.Secondly,the Logistic regression model is adopted to evaluate the impact of 17 driving factors on different types of land.These driving factors are selected from the four aspects of natural environment,social economy,technological development,and policy systems.Thirdly,I use the food price revision and biomass revision methods to measure the ecological service values of different land types and the value of individual ecological service functions at different time periods.Based on the 28-year land use data and the ecological service value coefficients,the ecological environment effects of land use changes in the Ili River Vall Ey during 28 years can be evaluated.Fourthly,I measure the coupling degree of land use change and ecosystem service function change in the Ili River Vall Ey,and delineate the development type of coupling coordination degree.Finally,suggestions for the sustainable and coordinated development of land use and ecological environment in the Ili River Vall Ey are proposed.The main conclusions of the thesis are:(1)The major land use changes in the Ili River Vall Ey from 1990 to 2018 were grassland,cultivated land,and construction land.The change process of different land types showed different trajectories according to the external influences and their conditions.From the perspective of quantitative changes,the grassland area of the Ili River Vall Ey has changed the most in 28 years,reaching 173288.01 hm~2,followed by168692.73 hm~2 of cultivated land,24471.41 hm~2 of woodland,16016.84 hm~2 of construction land,7453.96 hm~2 of other lands,and 5025.91 hm~2 of water area.Specifically,the proportions of cultivated land,construction land,and water areas show an increasing trend,while the proportions of forest land,grassland,and other land are decreasing.In terms of spatial changes,the increased arable land is mainly distributed in Qapqal County and Yining County,mainly from grassland,and the decreased arable land is mainly distributed in Yining City and Khorgas and other areas,and the arable land is mainly converted to construction land.In the remaining counties and cities,arable land is also decreasing,and it is mainly converted to urban construction land.The reduction in forest area was mainly distributed in Gongliu County,Xinyuan County,and Zhaosu County,and the forest land was mainly converted to construction land and water areas.The largest decrease in grassland was in Qapqal County,which was mainly converted to cultivated land.The largest increase in construction land was in Yining City,Yining County and Khorgas City.The areas where the water area has increased are mainly in Nilka County and Gongliu County(two reservoirs have been established),and the increased water area comes from grassland.Other land changes are mainly converted to construction land and cultivated land,and the main reduction is in Huocheng County,Tekes County,and Zhaosu County.(2)In this paper,six dependent variables of cropland,forest land,grassland,construction land,watershed and other land,and 17 representative independent variables in four categories,such as natural environment,socio-economic,scientific and technological development and policy system,are selected.Each variable is first standardized by SPSS software,and then factor analysis is conducted to form principal components F1 and F2.After that,a logistic regression model is applied to establish the relationships between the principal components and the standardized dependent variables(arable land,woodland,grassland,construction land,water area,other lands)to analyze the driving mechanisms of land use changes in the Ili River Vall Ey from 1990-2018.The results show that the changes of cultivated land in 28 years are mainly affected by socio-economic and policy factors.Forest land changes are mainly affected by technological development and policy factors.Grassland changes are mainly affected by socio-economic,policy factors and natural factors.Construction land is affected by socio-economic factors and policy factors.The water area is affected by natural factors,technological development,and policy factors.The other land is mainly affected by the technological development and the natural environment.(3)The total value of ecological services in the Ili River Vall Ey from 1990 to 2018shows a trend of“decrease-increase-decrease”,and the overall trend is to decrease.The total value of ecological services in the Ili River Vall Ey dropped from 323.66×10~8yuan in 1990 to 320.28×10~8yuan in 2000,increased to 320.39×10~8 yuan during2000-2010,and then decreased to 319.65×10~8yuan in 2018.The total value of ecological services decreased by 1.27%during 1990-2018.Among the ecological service values of each land type,the ecological service value of grassland is the largest and the construction land is the smallest,and the change of ecological service value is mainly influenced by the change of the area of grassland and forest land.The relationship between them shows a negative correlation.In terms of the individual values of ecological service functions,the contribution rate in descending order is:soil formation and protection>waste treatment>biodiversity protection>water conservation>climate regulation>gas regulation>food production>raw materials>entertainment culture.(4)From the perspective of the spatial distribution of ecological service value in the Ili River Vall Ey from 1990 to 2018,the spatial distribution of ecological service value in the Ili River Vall Ey is stable.The ecological service value of the eastern,northern,and southern mountainous areas of the Ili River Vall Ey is greater than that of the central and western regions.Regarding spatial distribution,the value of ecological services is mainly distributed in Nilka County,Tekes County,Zhaosu County,and Xinyuan County.In terms of the spatial change of ecological service value,the largest change is in Qapqal County,followed by Yining City,Yining County,and Khorgas City.The change in ecological service value of Qapqal County is mainly due to the conversion of grassland and woodland to cultivated land and construction land,while changes in Yining City,Yining County,and Khorgas are caused by the conversion of cultivated land and grassland to construction land.(5)The coupling degree between the land use change index and the ecological service value index in the Ili River Vall Ey is above 0.9 during 1990 to 2018,and the two periods of 1990-2000 and 2010-2018 are relatively close to 1,indicating that land use change and the ecological services are highly coordinated.The degree of coupling and coordination between land use change and ecological service value has changed significantly during 1990 to 2018.From 1990 to 2010,it experienced intermediate coupling to good coupling development,and from 2010 to 2018 it returned to intermediate coupling development.The two development models have shifted from the original lagging type of land use change to the synchronization of the two.From the perspective of the comprehensive evaluation index T,it has been fluctuating between0.479 and 0.499 from 1990 to 2018,and the overall evaluation index is relatively low.From 1990 to 2000,the land use change index of the Ili River Vall Ey grew from 0.228to 0.319,indicating that with the socio-economic development and policy changes,the land use change in the Ili River Vall Ey was obvious.Then it dropped to 0.131 from2000 to 2010,indicating that the rate of land use change had slowed down.Finally,it grew to 0.417 from 2010 to 2018,indicating that land use changes during this period showed an intensified trend.During 1990-2018,the ecological service value index of the Ili River Vall Ey experienced the process of“rising-declining-rising”,which indicates that the ecological service value is also changing with land use change.The trends of both changes are basically the same,indicating that the ecological environment has been well protected,and the coordinated development of land use change and ecological environment has been basically realized.