Study On The Change Of Land Use And Ecosystem Service Value In Aksu City

To understand the ecological service value and land use structure characteristics of Aksu City during the 30 years,this paper discussed the pattern evolution characteristics of land use change and ecosystem service value of Aksu in larger time scale.It showed a reliable basis for the land space planning,social and economic development and ecological civilization construction in the later period of Aksu City,and provided a reference for the relevant evaluation and analysis of the region.Taking Aksu City as the research object,this paper used supervised classification to interpret the Landsat series remote sensing image data of Aksu City in 1990,2000,2010 and 2019.By using the methods of land use transfer matrix,fluctuation potential map,standard deviation ellipse,center of gravity transfer and kernel density analysis,discussed the land use structure,spatial and temporal characteristics,change rule and aggregation degree.The ecosystem service value was estimated by using the land use data and the equivalent coefficient of ecosystem service value.Spatial and temporal distribution characteristics of ESV were analyzed based on grid scale,gradient and urban-rural gradient.Using hot spot analysis,sensitivity analysis and so on,the spatial and temporal characteristics was further explored.Correlation analysis were used to analyze the correlation degree between them.Some suggestions and measures were put forward for the local government.The main conclusions are as follows:(1)From 1990 to 2019,the areas of construction land,cultivated land and forest land in Aksu city had been increasing the areas of grass land and water area had been decreasing,and the unused land area showed a fluctuating trend of first increasing and then decreasing.The largest net land use change rate was grass land,and the smallest was unused land.The cultivated land,construction land and forest land are mainly transferred in,and the area showed an increasing trend.The spatial distribution of the overall change of land use in Aksu city showed the trend of first diffusion and then concentration.In general,the center of land use change moved from northeast to southwest,and then to Southeast.The results of kernel density analysis showed that the density value increases gradually,and the distribution of the change area tends to be centralized.Socio economic factors and policy factors are the key driving factors of land use change in Aksu City.(2)From 1990 to 2019,the ecosystem service value of Aksu City has a trend of first decreasing and then increasing.The ESV of cultivated land and forest land is increasing trend,the ESV of grass land and water area decreased,the ESV of unused land fluctuated during this period.The ESV of hydrological regulation function,aesthetic landscape function and waste treatment function showed a decreasing trend,the ESV of other single function is increasing.In space,the ecosystem service value of Aksu city increases gradually in the East and North,and decreases gradually in both sides of the Aksu River Basin.The low value areas were mainly distributed in the central urban area and rural residential areas.When the slope grade is between 0-2°,ESV accounts for a large proportion.Along the urban-rural gradient,The northern region was high value distribution.The ESV value in the southern region shows a trend of increasing gradually from the city center to the township.(3)The contribution rate of cultivated land and forest land was high in the study period.There was also a strong correlation between land use and ecological service value.In the future development planning,we should realize the reasonable layout of land use,ecological protection and coordinated development of social economy.