三峡地区土地利用/土地覆被变化及其驱动力分析

Land-Use/Cover Change Process and Driving Force Analysis in Three Gorges Area

三峡地区是生态环境的脆弱地区,这与其特殊的自然地理环境息息相关。从土地利用/土地覆被的角度出发,利用RS和GIS技术,阐明了20世纪最后10年库区土地利用/土地覆被变化在数量、结构、类型和空间分布上的特点,并进一步分析了库区土地利用/土地覆被变化的驱动力,得出以下结论:(1)10年间除建设用地和草地面积增加外,其他土地利用类型都呈现出不同程度衰减;(2)建设用地以高速增长,增幅达21528.09hm2;(3)耕地减少的幅度较大,达18399.29hm2,主要转变为建设用地;且减少的耕地多为位置相对优越,产量较高的优质良田;(4)林地面积总趋势是减少,主要转变为草地、旱地和建设用地,其中有林地减少的幅度较大,达7411.93hm2;(5)草地的面积总体增加,主要源自于林地和旱地的变化;(6)库区土地利用/土地覆被的空间格局分为3个主导因子变化区域:耕地-城镇型、林灌-耕地型和复合型;(7)库区土地利用/土地覆被变化的驱动力主要为:经济因素、人口压力、宏观政策及三峡工程4个方面,这4个方面不是孤立的,而是互相影响、互相制约的,共同影响库区的土地利用/土地覆被类型。

The eco-environment is sensitive and fragile in Three Gorges Area (TGA), which is closely influenced by the special natural environment of the area. The society and economy greatly developed in the last decade of the 20th century. However,the heavy activities of human beings aggravated the burden of the eco-environment, which can be characterized by the land deterioration, soil erosion and the increase frequency of natural hazards (debris flow and landslide) etc. This paper focused on the LUCC, and explained the quantities, inner structure, types and spatial distribution features of the dynamic changes in TGA in ten years. Furthermore, the driving forces of the LUCC were analyzed in detail. The conclusions were: (1) all the land-use types were decreased more or less except cultivated land and grassland;(2) the construction land area was increased by 21 528.09 hm^2 in ten years;(3) the cultivated land area was decreased by 18 399.29 hm^2, which changed mainly into construction land and had the high quality with the plain location;(4) the woodland area was decreased, which changed mainly into grassland, arid land and construction land, and the area of the forest land was decreased by 7 411.93 hm^2; (5) the area of the grassland was increased, which came mainly from the conversion of the woodland and the arid land; (6) the spatial distribution pattern can be divided into three-types—cultivated land to cities and rural residence,Woodland to cultivated land and complex type; (7) the driving force of the LUCC in TGA were the economic development, the pressure of the increase of population, adjustment of the macro policy and the construction of the three gorges project.