In recent years,with the acceleration of the process of regional integration and the deepening of the degree of openness and collaboration between neighboring countries,land use/cover situation and ecological risk in geopolitical and economic junctions area of many countries have changed significantly,and have gradually became a hotspot area of current LUCC and ecological risk research,strengthen research on LUCC and ecological risk in such area was of great significance both in theory and practice.Therefore,this article take Golden Quadrangle Region in the border of China,Myanmar,Thailand and Laos as an example,rely on technical support from GIS,RS and FRAGSTATS,by construction models of center of gravity measurement,transition matrix,landscape index,ecological risk index,and gray prediction,analyzd the pattern situation,change characteristics,landscape pattern and drive mechanism of land use/cover in the study area,assessed the ecological risk situation and spatial-temporal evolution of the study area,predicted future land use/cover change and ecological risk in the study area and proposed ways and guidelines to promote the rational use of land resource and reduce ecological risk in the study area.The main research conclusions were as follows:(1)The land use/cover in the study area was mainly constituted by forest land,cultivated land and shrubs and there were certain national difference.With time going on,the area of cultivated land and construction land have expanded rapidly,while the transfer of forest land,shrubland and other land types has begun to appear.There were similarities and differences in the structural composition and change between four country sections.From 2000 to 2018,the spatial distribution of the center of mass and the change trajectory of each land type in the study area have changed significantly,and the inter-class conversions have also been significant.In the past 18 years,the main type of land use change in the study area have undergone a transition from shrubs and cultivated to forest to forest and shrub to cultivated.During the past 18 years,the land use/cover conversion process in the study area continued to deteriorate and the range of change has increased.The macro-ecological status of land use/cover has continued to deteriorate and has shown certain regional and national difference.(2)From 2000 to 2018,the rate of land use/cover change in the study area slowed down significantly and there were certain national difference.Over time,thedifference between the four countries have increased.During the study period,the spatial change activity of forest,shrubland and cultivated land distribution area were all significantly higher than those of other land types.With the evolution of time,the magnitude and difference of the spatial change activity in each area decreased,and there were certain country differences.From 2000 to 2018,the degree of land use in the study area continued to increase,and the section in China and Thailand were significantly higher than those in Laos and Myanmar;Over the past 18 years,the balance and homogeneity of the spatial distribution of land use in the study area have continued to increase,of which the Thailand segment was the highest and the Laos segment was relatively low;From the two types of patch type and landscape level,there were some spatial and temporal difference in the landscape pattern index and dynamic trend between patches of various land use/cover types in the whole region and four country sections,further comparison found that the national variation of the degree of variation of each landscape pattern index at different scales was significant.The driving force system that affect the spatial-temporal change of land use/cover was intricate and complex,overall,can be divided into different levels such as natural driving and human activities,factors such as altitude,slope,administrative center,traffic roads,geopolitical constraint and subject-driven have significant effect on the distribution pattern and change of land use/cover in the study area.(3)With the evolution of time,the landscape ecological risk index of the whole region has been continuously expanded and the increase rate has been improved,while the national difference in ERI change between the four countries have been significant.With time going on,the ecological risk level in the study area has been continuously improved.The change in the ERI of 259 grid units were mainly based on the overall promotion,and the spatial distribution of various grid unit was different.As time goes on,the area proportion,transformation trend and spatial distribution of each ecological risk level area in the study area have different characteristics.In the past 18 years,the ERI of each grid unit in the study area has a large spatial positive correlation,and showed a certain spatial distribution "convergence" trend,during the study period,the proportion of land area of LL(low-low)agglomerated grid cells continued to be the largest but its dominance declined,with the evolution of time,the agglomeration situation of the spatial distribution of ERI in the study area has weakened as a whole.In 2018,the ecological risk level of the main distribution area of all land use types in the study area were relatively high and the country differencewas significant,with the Thailand segment overall being the highest and the Laos segment being relatively low.Over time,the proportion of the area of different ecological risk levels in the main distribution areas of various land use types have fluctuated significantly,and there were certain national difference.(4)In 2027,the land cover of the study area will continue to be dominated by forest,cultivated and shrub,but the dominance of the three land type will be weakened;From 2018 to 2027,the increase in the area of cultivated and building land will be significantly higher than that of other land types,and the transfer of forest will be more significant.The national difference of the composition and change of land use/cover in the study area from 2018 to 2027 will also continue to be significant.From 2018 to 2027,the ecological risk situation of the whole region and the four country sections will be all worsened,but the change will be different,by 2027,the ERI in the southern part of the study area will be the highest,followed by the western part,while the northern and eastern sections of China and Laos will be relatively low.From 2018 to 2027,the ERI of all grid units in the study area will be improved as a whole,based on the variation and spatial distribution,can be divided into four categories: ecological risk reduction,small increase,medium increase and large increase.(5)To promote the rational use of land resource and the reduction of ecological risk in the study area,should on the basis of adherence to the principles of national differentiation,multi-agent participation,similarity and difference,dynamics and gradual,mutual benefit,livelihood and sustainability,adopt reasonable planning,give priority to ecology,strengthen coordination and cross-border cooperation,optimize layout,moderate regulation,"take" "replenish" combination,adapt to local conditions,industrial upgrading,economic transformation,multi-party participation,remove geographical constraints,distinguish between levels and improve mechanisms,early warning and other paths. |