准格尔丘陵沟壑区五分地沟流域土地覆盖分析

摘要

This article mainly assessed the size and spatial patterns of land cover/vegetation in the Wufendi watershed in the Zhunger Hill and Gully Region, Inner Mongolia, and examined the changes of major land cover/vegetation categories that had accompanied eco-reclamation over the past 20 years.To produce the land cover/vegetation maps of 1987 and 2000 at fine scale, high spatial resolution remote sensing data, including colour-infrared aerial photography ( CIAR), and IKONOS data with 1 mpixel size were selected as source images, and suitable land cover/vegetation classification systems were presented respectively. In addition, in order to reflect the land cover/vegetation before restoration, a land use map of 1979 produced based on field survey was digitised and co-registered with the land cover maps of 1987 and 2000 in a geographic information system (GIS). The results indicated the land cover/vegetation in 2002 was in a high degree mosaic of farmland, grassland, plantation of trees and shrubs, and grassland planted with spare shrub. The changes of major land covers between 1979 and 2002 were significant, with major increase of types and area of anthropogenic land covers,landscape heterogeneity has also enhanced. Based on the comparison among different remote sensing dada and the high heterogeneity of land covers, it is necessary to use high spatial resolution remote sensing data to map the land cover/vegetation at fine scale in this region.%以准格尔丘陵沟壑区五分地沟流域为研究区,应用彩红外航片和IKONOS卫星影像,绘制了1987、2002年土地覆盖/植被类型图,并数字化基于地面土地利用调查绘制的1979年土地利用图.利用景观格局指数,评价了研究区土地覆盖/植被空间格局现状及土地覆盖类型动态变化;并以ETM+数据为信息源,绘制了2002年土地覆盖/植被类型图.研究表明:2002年研究区土地覆盖/植被呈现出一个耕地、草地、人工乔木林和人工灌木林以及种植稀疏灌木的草地高度镶嵌的景观格局特征;20年内土地覆盖类型发生了显著的变化,景观异质性增强.基于研究区景观的高度破碎化,绘制小流域精细尺度土地覆盖图,高空间分辨率遥感数据十分必要.