Study On Land Use Change Trajectory And Regulation In The Agricultural And Pastoral Area Of Fragile Grassland Belt

The northern foothills of the Yin Mountains in Inner Mongolia are the most ecologically fragile areas in the farming-pastoral ecotone in northern China.Due to the transitional natural features and excessive human activities,this area has become a fragile grassland farming-pastoral ecotone with serious ecological environment problems such as land impoverishment and grassland degradation.Its ecological nature is characterized by fragility,instability,and irreversibility,and the rationality of its land use will directly affect the stability of the grassland ecological environment.Conducting research on the trajectory of land use change in the fragile grassland farming-pastoral ecotone is of great significance for understanding the human land use process and regional ecological environment protection,and realizing the sustainable use of land resources.This paper takes the farming-pastoral ecotone composed of five contiguous townships in the southern part of Siziwang Banner,Inner Mongolia,where the ecological environment is relatively fragile,as the research area.Based on GIS technology and by interpreting eight remote sensing images from 1987,1992,1997,2002,2007,2012,2017,and 2022,the paper obtained land use data in the research area.Using the method of geographic information graphs and the geographic detector model,the paper analyzed the trajectory of land use change and its driving mechanisms in the research area over 35 years(1987-2022),and proposed measures for regulating the sustainable use of land based on this analysis.The main research conclusions are as follows:(1)In 2022,the three major land use types in the research area are cropland,grassland,and shrubland,which together account for 90.22% of the total land area.They form a spatial pattern of cropland-grassland-cropland or cropland-shrubland-cropland,and croplands are less concentrated in large areas.Over the 35-year period,although cropland has shown a decreasing trend,it still has the largest proportion of land use;grassland is the second largest land use type,and shrubland has the third largest proportion.Other land use types have fluctuated to varying degrees,among which industrial and mining storage land,although it has a small proportion,has shown a continuous upward trend over the past 35 years.(2)The stage changes in land use in the research area over the 35-year period mainly involve the mutual conversion of cropland-grassland,cropland-shrubland,grassland-cropland,and grassland-shrubland.From 1987 to 1997,the changes in land use were not significant.With the continuous implementation of the national project of returning farmland to forest and grassland,grassland and shrubland areas began to show a mutually exchanged growth trend from 1997,with the main sources of increase being cropland and grassland.From 1987 to 2022,shrubland became the land use type with the largest increase.(3)Over a period of 35 years,the main patterns of land use change in the study area can be classified into six types,in descending order of area: sustained stability,early stability,sustained change,mid-term change,late stability,and mid-term stability.The sustained stability type is dominated by long-term stable cropland and grassland.The early stability type is dominated by the pattern of "cropland-cropland-cropland-cropland-shrubland-shrubland-shrubland-shrubland".The sustained change type is dominated by the pattern of "cropland-cropland-cropland-grassland-grassland-shrubland-shrubland-shrubland".The mid-term change type is characterized by the pattern of "cropland-cropland-cropland-cropland-cropland-shrubland-cropland-cropland".The late stability type is dominated by the pattern of "cropland-cropland-cropland-shrubland-shrubland-shrubland-shrubland-shrubland".The mid-term stability type is dominated by the pattern of "shrubland-shrubland-cropland-cropland-cropland-cropland-cropland-shrubland".(4)During the 35-year study period,the driving factors with the highest contribution rates in each period were artificial shrubland,artificial shrubland,artificial shrubland,elevation,annual precipitation,annual average temperature,and annual average temperature,respectively.The impact of land use change was more prominent when seven factors including annual average temperature,annual precipitation,per capita GDP,distance to residential areas,distance to transportation roads,artificial shrubland,and elevation interacted with each other.Therefore,effective implementation and continuous promotion of relevant national land use policies are crucial for the formation of a reasonable land use structure in the fragile grassland areas with a mixed agricultural and pastoral economy under specific natural conditions.(5)Combining the trends,trajectories,and driving factors of land use change in the study area,the area was divided into six types of land use regulation zones:sustained cropland use zone,sustained grassland use zone,sustained residential land use zone,ecological protection zone for returning farmland to forests and grasslands,sustained water use zone,and other land use zones.Targeted regulatory measures were proposed based on the natural conditions and ecological environmental problems faced by each area.