乌裕尔河流域土地利用变化及驱动力分析

An Analysis of Land Use Change and the Driving Force in Wuyuer River Basin

土地利用变化是影响土壤侵蚀、社会经济发展等的重要因素。根据1985、1995和2000年3期土地利用TM遥感数据,运用地理信息空间分析及土地利用转移矩阵和动态度等方法,研究了乌裕尔河流域3个时期的土地利用变化特征及其驱动因素。研究发现:流域内土地利用以耕地为主,3个时期耕地分别占到总土地利用面积的66%、67%和70%左右;林草地面积则呈现逐年下降的趋势,所占面积比例由1985年的17.6%下降到2000年的13.9%,而建设用地、水域以及沼泽地面积变化不大。耕地占用林地、草地和沼泽地成为这3种土地利用类型面积减少的主要原因。近年来,土地利用变化速度加快,1995-2000年土地利用变化速度相对剧烈,1985-1995年耕地和林地年均变化速度分别为0.21%、-0.56%,而1995-2000年年均变化速度为0.64%、-2.65%。研究表明,自然环境因素决定该流域的土地利用空间分布格局,而土地政策的变化及人口的增加等人类活动很大程度上影响了土地利用变化的方向和速度。该研究可为流域土壤侵蚀产沙变化及水土保持提供借鉴,对于指导该区乃至整个东北黑土区土地资源合理利用具有指导意义。

Land use is one of the major factors determining soil erosion and social and economic developments. Based on three years＂ TM-derived land use data with resolution of 30 meter, the land use changes of the Wuyuer River Basin in Northeastern China as well as their driving forces were studied with the help of spatial analysis tool in ArcC-IS software and Markov conversion matric analysis, and some meaningful results were obtained. During 1980-2000, cultivated lands dominated the land use types, with land use percent ages ca. 66% in 1985, 67% 1995 and 70% in 2000, respectively. However, forest- and grass-land areas presented a decreasing trend, and the land use percentages decreased from 17.6% in 1985 to 13.9% in 2000, resulting from their translations to cultivated lands. In contrast, the area percentage of construction land, water body and wetland changed little during 1985--2000. With the economic development and increasing population, the changing rate of land use increased. The changing rate of Iand use during 1995-2000 was faster than that during 1985--1995, with mean annual changing rates of cultivated lands and forest land were 0. 21% and 0. 560/oo during 1985 1995 and 0. 64% and --2. 65% during 1995--2000, respectively. Natural factors determine the spatial pat-tern of land use types, while human activities changed the land use directions and land use changing rates. This study can help explain the changes of soil erosion and sediment yield in this basin, direct soil conservation, guide the rational use of the land resources for this basin and even for the whole black soil region, Northeastern China.