Analysis on landscape pattern in Yanhe River valley | 延河流域土地利用景观格局分析

chinois. 查清延河流域土地利用/覆盖格局，为该区域土地资源合理利用、改善水土保持措施提供理论依据。利用ENVI 4.0软件对2006年延河流域遥感图像进行处理，结合野外考察，在ArcGis 9.0平台下获得延河流域土地利用现状分布图；从景观格局的角度，根据国标2007《土地利用现状分类》的二级分类体系，将研究区土地利用现状划分为住宅用地（城镇住宅用地、农村宅基地）、耕地（水浇地、旱地）、园地（果园）、林地（有林地、灌木林地）、草地（天然牧草地、其他草地）、水域及水利设施用地（内陆滩地、湖泊水面、水库水面、河流水面）和其他土地（裸地、沙地、沼泽地、设施农用地）共7个大类17个二级类，分析了土地利用的数量结构和景观形态结构特征。延河流域土地利用类型中旱地的面积比最大，约为37%，其次是天然牧草地、裸地和有林地，分别为22.17%，23.6%和14.4%，其他类型面积均较小；旱地、有林地、天然牧草地和裸地频率比相对于其他土地利用方式较高；所有土地利用类型中，沼泽地平均面积指数最大，其次是裸地和天然牧草地；旱地、有林地、天然牧草地、裸地等图斑形状简单且各形状的图斑数呈正态分布；耕地为主要的土地利用方式，耕地、林地、草地和水域及水利设施用地的优势度较大。延河流域土地资源开发的重点是开展土地整理和规模经营，减少土地利用地块数量，降低形状指数，增加水域、人工草地和林地等生态用地面积，提高土地利用集约度和促进土地利用的多样化、均匀化；今后土地利用结构调整的方向是：增加生态系统稳定性和提高生态系统服务功能的经济价值。

anglais. The landscape pattern in Yanhe River valley was identified to provide some scientific information for reasonable land use and for improving soil and water conservation. Using ENVI 4.0 to process the digital RS image in 2006 of Yanhe River valley, land use map was obtained with ArcGis 9.0 integrating with field investigation. According to the system of land use classification in 2007, 7 classes including adobe land (urban abode land, rural abode land), farm land (irrigated land, dry land), garden (orchard), woodland (forest land, shrub land), grass land (natural pasture, other woodland), water and water project land(inland interval, lake, reservoir, river) and other land (nudation, desert, marsh and agricultual facilities land) were determined. The structural characteristics of land use quantity and landscape structure were analyzed in this study. The area of dry land is the largest of all land use types in Yanhe River valley, about 37%, followed by natural pasture, nudation and forest land respectively 22.17%, 23.6% and 14.4%, and other land use is small. The frequency ratio of dry land, natural pasture and nudation are bigger than others. The even area of marsh is the largest; nudation and natural pasture are next. The diversity indices of all land use are small. The block shapes of dry land, forest land, natural pasture and nudation are simple and the number of block is of normal distribution. Farmland is prevalent, and the dominance indices of farmland, woodland, grassland and water and water project land are larger than others. Land onsolidation and scale operation are important in developing land resources in Yanhe River valley, and the decreasing quantities of land use block, depressing shape index, and increasing the area of water and water project land, artificial grassland and artificial woodland can enhance diversity, homogenizing land use, and improve the stability of ecosystem.