Dynamic Simulation Of Land Use And Evaluation Of Ecosystem Service Value In Longnan City

With the rapid development of new-type urbanization,major changes have taken place in regional land use,and the unreasonable development of land use structure has exacerbated the degradation of the ecological environment.Therefore,simulating future land use change trends and assessing its ecosystem service value(ESV)is of great significance for regional land use.Taking Longnan City as an example,this paper uses remote sensing,geographic information technology and mathematical statistics to study the temporal and spatial characteristics of different land use types from 2009 to 2018 with the help of a single land use dynamic index and land use transfer matrix.On the basis of the correction of the ecosystem service value equivalent of Longnan City,the ecosystem service value of Longnan City is evaluated,and the spatial change characteristics of the ecosystem service value at different scales such as township and 1km ×1km grid are explored,and the ecosystem at the grid scale is explored.The spatial autocorrelation characteristics of service value.The CA-Markov model is used to predict the spatial pattern of land use in 2025 under different development scenarios,explore the characteristics of ecosystem service value changes under different scenarios,and make suggestions for future land use in Longnan City.The results of the study are as follows:(1)From 2009 to 2018,the land use structure of Longnan City remained basically stable,construction land and other land showed an upward development trend,and cultivated land,woodland,grassland,water area and garden land showed a downward development trend.The degree of land use dynamics in 2013-2018 has declined compared with 2009-2013,indicating that the rate of land use change in the study area has decreased.A total of 3684.79hm2 of land in Longnan City participated in the transfer,accounting for 2.24% of the total land area in the study area.The transfer of land use types was mainly construction land,cultivated land and grassland,and the transfer was mainly woodland,cultivated land and garden land.The type transfer flow of construction land has the greatest impact on the stability of the regional land use system.(2)From 2009 to 2018,the value of ecosystem services in Longnan City fell by a total of 166 million yuan,and the decline in ecosystem services value slowed down from 2013 to 2018.The value of ecosystem services such as biodiversity,soil conservation,hydrological regulation,climate regulation,and gas regulation account for 80% of the total value.The average ecosystem service value in the north of Longnan City is higher than that in the south,Anjishan Forest Farm and Dongjiang Township are at a high level,and Liren Town,Longnan Town,Yangcun Town and Jiulianshan Town are at a low level.On the grid scale,from 2009 to 2018,the number of areas with medium and low ecosystem service value increased,and the number of areas with higher ecosystem service value increased.The value of ecosystem services has positive agglomeration and dependence characteristics,and presents a distribution pattern of "western high,middle low".(3)According to the CA-Markov model,under the natural development scenario,from 2018 to2025,the change trend of forest land,water area,construction land and other land will remain unchanged,the cultivated land will change from increase to decrease,and the garden and grassland will change from decrease to increase;The value of ecosystem services dropped by about 1.167 billion yuan,and the proportions of areas with high ecosystem service value,medium areas,and low areas were55.14%,26.64%,and 18.4%,respectively.Under the ecological protection scenario,from 2018 to 2025,the area of forest land and water area will decrease,and the area of arable land and other land will increase.Compared with the natural development scenario,the extent of land use change will be weakened;The value of ecosystem services has dropped by about 217 million yuan.Compared with the natural development scenario,the number of low-value grids in Longnan Town and Dongjiang Township has decreased,and the number of low-value grids in the south has also decreased.Under the coordinated development scenario,from 2018 to 2025,the area of woodland,grassland and waters will decrease,the area of construction land and other land will increase,the area of arable land will change from decrease to increase,and the area of garden land will decrease;the value of ecosystem services will decrease by 951 million yuan.