The Optimization Of Land Use Spatial Pattern In Jiangchuan District Based On CLUE-S Model And Ecological Sensitivity Analysis

Land is the basis for human survival and development.Land use refers to the purpose of human development of land resources.Although the development of land resources promotes regional economic development,it also brings many ecological and environmental problems.Taking Jiangchuan District as the research object,this paper optimizes the spatial pattern of land use under the goal of ensuring food security and ecological security.This provides a reference for Jiangchuan District to rationally optimize land resources,formulate overall plans for land use,land development and utilization,and development of ecological environment governance and protection policies.Based on the analysis of spatial patterns and changes of land use in Jiangchuan District from 2006 to 2016,this paper discusses the relationship between land use types and driving forces.From the four aspects of soil erosion sensitivity assessment,biodiversity sensitivity assessment,water environment sensitivity assessment,and geological disaster sensitivity assessment,comprehensive ecological sensitivity assessment was conducted and partitioned in Jiangchuan District Based on the land use data of Jiangchuan District in 2006,the CLUE-S model is used to simulate the land use pattern in 2016,which is compared with the current land use data in 2016.It shows that the simulation is applicable to the simulation of land use patterns in Jiangchuan District.Based on this,the CLUE-S model is used to simulate the spatial pattern of land use in Jiangchuan District in 2025.Using the natural development conditions and ecological sensitivity zoning results in Jiangchuan District,two scenarios for natural development and land ecological optimization were set,to complete the optimal allocation of land use spatial pattern in Jiangchuan District in 2025.The main research results are as follows:(1)The main features of land use change in Jiangchuan District from 2006 to 2016 are the reduction of large areas of cultivated land and the significant increase in construction land.This shows that during the 11 years,Jiangchuan District was in a period of rapid urban expansion.In the future,the contradiction between cultivated land and construction land will persist for a certain period of time.(2)The optimal spatial scale of land use spatial pattern change evaluation in Jiangchuan District is 90m×90m.Comparing the results of binary logistic regression and ROC on the six spatial scales of 30mx30m,60m×60m,90m×90m,120mx 120m,150m×150m and 180m×180m,the results show that the driving force factor has the best explanatory power for forest land,cultivated land,grassland,water areas,unused land and construction land at the 90mx90m scale.The ROC test values of logistic regression equations for land use types are 0.850,0.794,0.781,0.998,0.795,and 0.914,respectively.The ROC values are all greater than 0.7.It shows that the simulation accuracy is better and the selected driving force factor is effective.(3)Selecting five secondary indicators of soil erosion intensity,land use type,vegetation coverage,distance from water source and disaster susceptibility,and constructing an ecological sensitivity evaluation index system suitable for Jiangchuan District.The ecological sensitivity of Jiangchuan District was mainly moderate Most of the above are sensitive,with an area of 57,111.37 hm2,accounting for 70.91%of the total area of Jiangchuan District.According to the results of ecological sensitivity assessment,Jiangchuan District is divided into highly sensitive areas,moderately sensitive areas,low sensitive areas and non-sensitive areas.(4)Based on the land use data of 2006,the results of land use spatial simulation in Jiangchuan District in 2016 were simulated based on the CLUE-S model,and verified with the current land use data in 2016.The simulation results show that the correct grid number accounts for the total grid number.The 81.59%and Kappa coefficient are 0.7791.The CLUE-S model can better predict the spatial pattern of land use in Jiangchuan District on the 90m×90m spatial scale.It can provide some reference for future land use planning in Jiangchuan District.(5)Set two scenarios of natural development and land ecological optimization,and simulate and optimize the spatial pattern of land use in Jiangchuan District in 2025.The two scenarios set the same land use demand,land use transfer files,and two different priority allocation areas:Scenario 1,The two major lakes of Xingyun Lake and Fuxian Lake are regional restricted areas,while other areas are preferentially deployed,and Scenario 2 is highly sensitive,for the area restricted area,other areas are prioritized.Scenario 2 has more than one scenario as a driving force factor,and eco-sensitivity division as an ecological driving force factor.The CLUE-S model was used to simulate the spatial pattern of land use under the two scenarios.The results show that the land use patterns of Jiangchuan District in 2025 have both common features and differences under the two scenarios.Under both scenarios,the original forest land,cultivated land,unused land,and construction land patterns were effectively protected,but new forest lands,Grassland and other spatial distribution patterns are different.Comparing the distribution of land use types in different sensitivity areas under the two scenarios of 2025 and 2016,it shows that the spatial pattern of land use in Scenario 2 is generally superior to the natural development scenario and the current situation of land use in 2016.The results of the study suggest that the land ecological optimization scenario is more reasonable and that it can not only maintain a significant reduction in cultivated area,but also take into account the needs of ecological protection and urban development.