Dynamic Change Of Land Use And Its Impact On Ecosystem Service Value In The Three Northern Regions

The dynamic change of land use types can effectively reflect the natural pattern,the process of change and the relationship between the land use types and the human society.At the same time,it is closely related to ecosystem services such as water conservation,climate change and biodiversity.This study adopts the Land Cover data of ESA-CCI-LC(Climate Change Initiative-Land Cover)released by ESA.Six periods of land cover data in 1992,1995,2000,2005,2010 and 2015 were selected as the basic data of the study.Based on IDRISI 18.3 and ArcGIS 10.6 spatial analysis software,the land use intensity analysis method,land use dynamic attitude and CA-Markov model were used to quantitatively analyze the dynamic change of land use types in the three northern regions.With reference to the value of Xie Gaodi equivalent factor method,based on the suitable for three norths area ecosystem service value of the equivalent factor tables,and based on the grid unit in three north area ecosystem service value analysis of time and space differences,through grey correlation coefficient of each land type of the influence degree of the change on ecosystem services.The main research results are as follows:(1)Analysis of spatial-temporal change rules of Land use based on Land Cover data.From the perspective of time,the area change of each land type showed a trend of"five increase and one decrease",that is,the area of Farmland Woodland,Grassland,Water-over land and Urbanland increased,while the area of Bareland decreased.The intensity of area change at different time intervals showed a trend of "slow change-drastic change-obvious change".Among the types,Farmland-Woodland-Grassland interchange frequently.In addition,the intensity of transformation between Farmland and Urbanland is the strongest,and the increase of Urbanland is mainly targeted at Farmland showing a trend of "aggressive" growth.From the perspective of spatial analysis,the land use types in the three northern regions show the characteristics of "unbalanced spatial distribution and significant regional differences".The intensity of land type use is high in the east and central region,but low in the west.The land use rate in the eastern and central regions is high,while the land use rate in the western regions is relatively low.In terms of land use dynamics,there was at least one major land cover change in the three northern regions during 1992-2015,of which the area without land cover change accounted for 90%,the type with one land cover change accounted for about 5%,and the type with more than two land cover changes was less than 5%.The change of land use types in the three northern regions is in a relatively stable state.With the implementation of national policies one after another,the fluctuation of various land types appears in some regions.Therefore,the CA-Markov model is used to simulate and predict the land use change in the three northern regions in 2030,and the simulation results are good.The land use type is still mainly Farmland and Woodland in the east,Grassland in the middle and Bareland in the west.Compared with 2015,the overall layout showed a dynamic change pattern of "three increases and three decreases".The increase rates of Farmland,Woodland and Grassland were 1.17%,0.3%and 1.51%,respectively.The decreasing rates of Water-over land,Urban land and Bareland area were-0.69%,-0.04%and-0.42%,respectively.(2)Based on the value equivalent factor method,the spatial and temporal changes of ecosystem service value were analyzed.From the perspective of the time sequence of the overall ecological service value,the total value of ecological services in the three northern regions showed a fluctuating upward trend from 1992 to 2015.Grassland has the highest ecosystem service value,followed by Woodland.The value of Forestland in each period of time has intermittent changes and shows a trend of increasing year by year.From the comparison of individual ESV,the value of regulation service was the most obvious in each time interval,and its ecological value accounted for 66.6%of the total ESV in the study area,followed by support service,which accounted for 20.2%.The total value of support service and supply service was no more than 10%.It has promoted the value of ecosystem regulation services and support services in the three northern regions.From the perspective of spatial distribution,the ESV generally presents an obvious spatial distribution characteristic of "high in the northeast and low in the southwest".The areas with high value and high value of ecological service value are mainly distributed in the northeast of the three northern regions,while the areas with low value and low value are mainly distributed in the western and central regions.The different service types showed regional differences with the change of community itself and surrounding environment.(3)The impact of land use change on ecosystem service value.Land use change and ecosystem service value were quantitatively analyzed based on grey relational degree.According to the analysis of soil grey correlation data,the correlation degree between ecosystem service value and Grassland type is the highest,with the correlation coefficient of 0.6669,followed by the correlation degree of Farmland and Woodland,with the correlation coefficient of 0.4918 and 0,4634,respectively.In other words,Grassland ecosystem has a greater impact on the total ecosystem service value in the three northern regions.At the same time,the increased fluctuation of Farmland and Woodland area has driven the development of food production and raw material production,and has played an important role in promoting the value-added of ecosystem services.