基于遥感的祖厉河流域土地分类及其分布空间分析

以陇西黄土高原的祖厉河流域为研究区，利用1993和2007年两期TM影像数据对研究区土地利用类型进行分类，在此基础上结合数字高程模型(Digital Elevation Model,DEM)、多年平均降水量的空间分布数据，利用地理信息系统(GIS)空间分析方法，重点分析坡耕地、林地和草地的气候特征空间与地形特征空间，研究得出：①14 a内研究区大约有 214.82 km²坡耕地被治理，但2007年仍有145.08 km²处于临界坡度以上。②林地大致分布在降水量386~517 mm之间，14 a内人工林地有所增多。③在人为活动的干扰下，草地的覆盖度普遍降低。植被的恢复和重建是流域治理的切入点，该项研究目的为退耕还林还草提供科学支撑，服务于建立祖厉河流域生态系统的良性循环。

Land Classification Based on Remote Sensing Data and Analysis of Spatial Distribution in Zuli River Basin

Taking the Zuli River basin in Loess Plateau of Longxi as the study area,the land classification was carried on using Landasat TM7 data in 1993 and 2007 respectively.The land use types were combined with topographical data from DEM and the spatial distribution data of multi-annual mean precipitation.The distribution spaces of terrain and climate for farmland,forest land and grassland were obtained. The conclusion can be drawn from the approach:① the area about 214.82 km² of farmland is controlled in 14 years,and about 145.08 km² of farmland should be converted into grassland and forestland in 2007,because it is located at above the threshold of slope(18.2°); ②forest land is distributed the area where precipitation is between 386 mm and 517 mm,and planted forest is increasing in 14 years; ③coverage of grass has generally been reduced due to the human activities.To mediate the soil erosion and water loss in this primarily hilly loess area,the vegetation’s restoration and reconstruction is very important.The objective of this research will provide the scientific support for returning farmland to forestland or grassland,which will contribute to build the positive cycle of the ecosystem in Zuli River basin.