新疆20世纪80年代末以来耕地与建设用地扩张分析

Expansion of both cultivated and construction land in Xinjiang since the late 1980s

基于20世纪80年代末、2000年、2005年、2010年、2015年5期中国土地利用数据集(NLUD)中的新疆部分,以耕地与建设用地(城乡、工矿、居民用地)为对象,从土地利用动态数据中提取其扩张图斑,分析了近30 a来新疆耕地与建设用地扩张的时空特征。结果表明:(1)南北疆耕地及建设用地扩张具有明显的时空差异。持续增长、南快北缓、重心南移是新疆耕地扩张呈现的总体特征;提速增长、南缓北快、城市扩张为主是建设用地扩张的基本特征。南北疆耕地面积差距逐渐缩小,建设用地面积差异加大。(2)对比近30 a来不同绿洲区内耕地与建设用地的扩张数量及趋势,可将耕地的扩张模式归纳为双峰型、减速型及阶段增长型,将建设用地的扩张模式归纳为指数增长型、双峰型、缓降型及缓降陡增型。(3)各绿洲区耕地及建设用的扩张特征十分显著。北疆耕地除阿勒泰绿洲区依然保持加速扩张外,其余绿洲区耕地扩张规模均出现下降,而北疆各绿洲区建设用地均呈持续加速扩张趋势,其中天山北坡城市扩张尤为突出;南疆各绿洲区耕地扩张均呈加速态势,建设用地扩张规模相对较小。

Based on land use datasets available since the late 1980 s till 2015 of Xinjiang（one component of the Chinese National Land Use Datasets,NLUD）,aiming at examining the expansion of both cultivated and construction land,this paper extracted its patches from the dynamic land use datasets and analyzed their different patterns and characteristics at different spatial scales over the past 35 years. The results show as follows：（1）The spatial and temporal pattern disparities between Northern and Southern Xinjiang were obvious. Continual increase,the southern Xinjiang expanding faster than the Northern,the southwestward moving of the gravity center were the main characteristics of the expansion of the cultivated land in Xinjiang. The accelerated increase,the Northern Xinjiang growing faster than the Southern,urban sprawl as the principal cause were the characteristics of construction land expansion. Moreover,it had been found that the cultivated land area gap between the Southern and Northern Xinjiang was gradually narrowing,whereas the construction land area gap between them was enlarging.（2）After comparing the quantity and the trend differences of cultivated and construction land expansion between10 oasis units at 4 stages,the expansion mode of construction land was grouped into three categories namely the exponential type,the bimodal type,and the phased exploration type;the cultivated land expansion mode was grouped into four categories,namely the exponential rising type,the bimodal type,the gentle falling-steep rising type,and the deceleration type.（3）The discrepanciesin terms of the characteristic of both cultivated and construction land expansion type in different oasis units were significant. For the northern oasis units,apart from the Altay region,all other oasis units of Northern Xinjiang had a declining trend with regard to the cultivated land expansion area. However,the construction land of all oasis units in Northern Xinjiang was under a continuously accelerated expansion,especially the Mt. Tianshan oasis unit. For the southern oasis units,the cultivated land showed a vast expansion scale,while the construction land occupied a relatively small increment scale. This paper made an overall review of the expansion characteristics of both cultivated and construction land of Xinjiang since the 1980 s which can provide a useful reference for the development and management of the land resources in the future.