元阳哈尼梯田及周边土地利用格局的时空变化分析

SPATIO TEMPORAL CHANGES OF LAND USE IN YUANYANG COUNTY

以哈尼梯田所在之元阳县为例,应用遥感和GIS方法,首次对该区域1974年、1992年和2000年3个时期的土地利用变化及其特点进行了分析。结果表明:(1)从1974年至2000年,元阳县土地利用结构变化不大,均以有林地和灌木林为主,二者始终占元阳县总面积的50%以上。其次为水田和旱地,分别占元阳县总面积的15%和20%左右,其他土地利用类型如园地和未利用地所占比例较小。(2)土地利用总体来说,有林地、水田、旱地和未利用地呈现减少趋势;灌木林、荒草地和园地呈增长趋势。(3)从1974年到2000年这27年间不同土地利用类型的相互转化比较复杂,主要发生在有林地、灌木林和荒草地及水田和旱地之间,最显著的演变过程有旱地—水田、旱地—荒草地、灌木林—有林地、有林地—灌木林、灌木林—园地、灌木林—未利用地。(4)政策和经济因素可能是造成元阳县土地利用变化的主要原因。

Based on Remote Sensing and GIS, this paper studies the land use change of yuanyang county during 1974 to 2000. The results are shown as follows： 1 ） in three periods, forest land are main types of land use, which occupied 50% of total area of yuanyang, area of water-arable land and dry-arable land relatively is 15% and 20%, and other land use types only occupies 30% of total area, which showed land use structure changed little during 1974 - 2000. It also shows that at time scale within 30 years, the macrostructure of land use of a watershed doesn＇t change greatly; 2） generally speaking, during 27 years between 1974 and 2000, the area of forest land, water-arable land, dry-arable land and unused land have been decreasing, Results also show that the ar- ea of woodland and garden land increased. 3 ） During these periods, intertransitions between different types of land use are very complex, mainly occurring among woodland, waste grassland and water-arable land. The most notable transition occurred between dry-arable land to water-arable land, dry-arable land to waste grassland and so on; 4） The main reasons of land use change in yuanyang are probably policies and economic development.