Spatial Pattern Of Land Use And Scenario Simulation In Mountain Hill Area

Land use/land cover change is the result of the interaction between human and nature.It is the most intuitive signal to represent the impact of human activities on the natural ecosystem of the Earth's land surface.The land use pattern is a very complex and comprehensive system,which is not only subject to natural The influence of factors is influenced by socio-economic factors at the same time.With the continuous improvement of the level of economic development,land use changes and forecasting simulation have become a research hotspot in the academic circles of various countries.The land use simulation model provides an effective means to understand the influencing factors of land use spatial pattern and to understand the regional land use change.Especially in hilly terrain with complex terrain,land use is fragmented and fragmentation is severe.Research on land use spatial patterns and future land use scenarios in mountainous and hilly regions will enable policymakers to understand and understand land use in mountainous and hilly regions.The pattern change process is conducive to the optimal utilization of the spatial pattern of land use in the region.At the same time,timely and effective adjustment of regional land use is of great significance for the rational and efficient use of limited land resources.Qijiang District is located in the transitional zone between the southeastern edge of the Sichuan Basin and the Yunnan-Guizhou Plateau.It is a typical hilly area.This article takes Qijiang District as an example.Based on the data of land use and utilization in 2015,the paper studied the spatial pattern of land use in the Qijiang District using ArcGIS.This paper analyzes the spatial difference of land use intensity in the Qijiang District and the distribution characteristics of gradients of different elements in the vertical and horizontal directions.The article uses Logistic binary regression model to analyze the relationship between spatial patterns of land use and natural,economic and social factors.This paper uses the Dyna-CLUE model and the improved AutoLogistic model to simulate land use in 2015 based on the current data of land use in 2010,and to verify the Kappa coefficient.Based on the data of land use in 2015,the article predicts the land use in 2020.This paper sets up two scenario scenarios,the natural scenario and the planning constraint scenario,and analyzes the land use in the planning scenario from the quantitative and spatial aspects to predict the land use characteristics of the Qijiang District in 2020.The results of the study are as follows.(1)The land use in Qijiang District is dominated by cultivated land and forest land.The degree of land use is overall low,and there are significant differences in the vertical gradients and horizontal gradients between different regions within and between different regions.The land use status of the Minjiang River area is mainly cultivated land and forest land.The spatial characteristics of land use degree are characterized by low height from north to south,low height from east to west,low height from center to high,and overall low land use.Topography has an important influence on land use in the region.With the increase of topographic gradient,the degree of land use is gradually reduced.Urban construction land and water areas have absolute superiority in topographically favorable terrain conditions.Cultivated land,gardens,and rural settlements Land use gradient dominates the median terrain gradient,and forest land and unused land occupy absolute advantages in high terrain.The degree of land use is highly affected by cultivated land,and the cultivated land and woodland are in a state of competition.The distance from the town center is most obvious for the degree of land use.The distance to the nearest water source is generally no more than 2 km.This has important reference value for future land remediation and construction of water conservancy facilities in mountainous and hilly areas.(2)Eliminating the collinearity factor and adding spatial autocorrelation factor improved the Logistic model's ability to explain land use distribution.Topographic relief,slope,industrial organization,population density,and urbanization rate are factors that have a significant impact on land distribution.In terms of the relationship between spatial patterns of land use and influencing factors,the ROC values of Logistic model regression results are all greater than 0.8,and the logistic regression results have better explanatory power.With the addition of spatial autocorrelation factor,except for urban construction land,the ROC values of other land types have increased to varying degrees,indicating that the addition of autocorrelation factors improves the goodness of fit of land use types as a whole.This helps to increase the accuracy of the model.The binary logistic regression results show that,among the natural factors,the contribution of terrain conditions to the distribution of land types is greater than the regional conditions.Among the economic factors,the industrial structure has a greater impact on the regional land use,and the contribution of the industrial structure is the largest in all kinds of impact factors.Among social factors,the urbanization rate and population density have a greater impact on the distribution of localities,and the urbanization rate is relatively significant.It can be seen that among the factors affecting the distribution of land types,the influence of economic and social factors is greater,and the topography conditions occupy the dominant position in natural factors.(3)The Dyna-CLUE model can effectively perform regional land use scenario simulation.The simulation results show that the loss of cultivated land in the area is more serious and needs attention from land managers.Using the Dyna-CLUE model to simulate the land use in Yongjiang district in 2020,there are similarities and differences in land use in the Minjiang District under natural growth scenarios and planning constraints.The same point is that the cultivated land,gardens,rural residential areas and unused land all show a downward trend,in which the largest reduction in arable land is the largest.In addition,construction land and water areas in forest lands,towns,and cities show increasing trends,among which construction land and forest lands have increased significantly.The difference is that under the natural growth scenario,the degree of change in various localities is relatively small,the largest reduction in arable land,and the largest increase in industrial and mining construction land in urban areas.Under the planning constraint scenario,the changes in various localities are larger,the cultivated land is substantially reduced,the forest land is significantly increased,the scale of urban construction land increases is reduced,and the expansion of urban construction land is controlled to a certain degree.The geographical transformation of the study area presents the characteristics of large concentration and small dispersion,and the change focus area is around the town.In the early stage of land conversion,the land used for construction was converted into cultivated land.In the later period,the land was mainly converted to cultivated land,and the cultivated land was transferred to urban construction land.In the two scenarios,the cultivated land in the study area continued to decrease.Under the planning constraint scenario,a large amount of cultivated land with poor topographic conditions within the ecological red line was converted into forest land.The protection and effective supplementation of cultivated land will be an important topic for future land managers in the study area.