地缘经济背景下泰国及其毗邻国家边境农业扩张与集约化抵边特征

自泰国总理差猜1988年提出“变印支战场为市场”倡议以来,泰国与毗邻国家（缅、老和柬）的地缘关系由政治阻隔转向经济合作,并在其边境（尤其是口岸）引发不同程度的土地覆被/利用变化。利用美国国际开发署SERVIR-Mekong项目土地覆被产品,基于GIS空间分析对泰缅、泰老和泰柬边境地带（国界线两侧20 km缓冲区）1988、1998、2008、2018年的土地覆被现状及其时空变化、以及因农业扩张与集约化引起森林变化的抵边/离边、趋同/趋异特征进行了定量研究与国别对比。结果表明：① 森林、耕地和果园是3条边境主要土地覆被类型,土地占比超过96%,其中森林因农业扩张与集约化而持续减少。② 农业扩张与集约化引起的森林转换时空特征显著,即泰缅、泰老边境于1998—2008年在湄索（泰）-妙瓦底（缅）口岸、汶干（泰）-北汕（老）口岸附近及“金三角”地区较为剧烈,泰柬边境则在1988—1998年内于卡普曾（泰）-奥斯玛（柬）口岸周边较为突出,土地占比超七成。③ 边境地区农业扩张与集约化引起的森林变化具有明显的抵边/离边、趋同/趋异特征。农业扩张所致森林变化在泰老边境由同向变化转为反向趋异,在泰缅边境两侧由强抵边转为在缅一侧抵边更为明显,在泰柬边境主要表现为先抵边后离边再抵边。集约化生产所致森林变化在泰老边境表现为泰国一侧抵边更强,在泰缅缅甸一侧为离边到抵边,在泰柬边境两侧主要为反向抵边。④ 边境森林变化的抵边/离边、趋同/趋异特征分析表明,泰国对老挝的影响最大,柬埔寨次之,缅甸最次。本研究可为从地理学空间视角研究边境土地利用与地缘经济关系交叉互动提供启发。

Border-prone Characteristics of Agricultural Expansion and Intensification in the Borders of Thailand and its Neighboring Countries (Cambodia,Laos and Myanmar) Under the Context of Geo-Economy

Since the implementation of the initiative of"Turning the Battlefields into Marketplaces"by Thai Prime Minister Chatichai Choonhavan in 1988,the relation between Thailand and its neighboring countries(including Cambodia,Laos and Myanmar)has shifted from political isolation to economic cooperation,which leads to varying degrees of land cover/use changes in the border areas(particularly the border crossings).With the land cover data products gathered from the US Agency for International Development’s SERVIR-Mekong project,the status of land cover types and their spatial and temporal changes were quantitatively analyzed and compared between different countries using GIS-based spatial analysis,followed by the characteristics analyses of bordering and off-bordering,convergence and divergence of forest cover dynamics due to agricultural expansion(increased cropland)and cash-crops intensification(increased orchard or plantation)within the 20-km buffer areas of Thailand-Myanmar,Thailand-Laos,and Thailand-Cambodia borders in 1988,1998,2008,and2018.The results show that:(1)Forests,cropland,and orchards(including plantations)were the main types of land cover in the border areas of Thailand,Myanmar,Laos,and Cambodia in the past decades,accounting for over 96%.An overall decrease of forests was also seen because of agricultural expansion and intensive production of commercial crops.(2)The forests conversion had obvious spatial and temporal features.Extensive forest transformations occurred in the neighborhood area of the border crossings of Mae Sot(Thailand)-Myawady(Myanmar)and Bueng Kan(Thailand)-Paksan(Laos)as well as the"Golden Triangle"area among Thailand,Myanmar,and Laos during 1998-2008.Similar transitions were also observed in the neighborhood area of the border crossings of Kap Choeng(Thailand)-Osmach(Cambodia)from 1988 to 1998,accounting for more than 70%.(3)Agricultural expansion and cash-crops intensification showed obvious characteristics of bordering and off-bordering,convergence and divergence in the border areas.Specifically,the forest changes caused by agricultural expansion has changed from the same to opposite direction showing divergence in the Thai-Lao border,from bilateral stronger bordering to unilateral bordering in the Myanmar side along the ThaiBurmese border,and from bordering to off-bordering and back to bordering in the Thai-Cambodian border.The forest changes caused by intensive production showed stronger bordering in the Thai-side of Thai-Lao border,from off-bordering to bordering in the Burmese side of Thai-Myanmar border,and bilateral opposite bordering of Thai-Cambodian border.(4)Bordering characteristics analysis of forest change indicated that Thailand had the greatest geo-influence on Laos,followed by Cambodia and Myanmar.Our study contributes to further investigating the cross-interaction between border land use and geo-economic relations from the perspective of spatial difference in Geography.