黄土丘陵区小流域景观格局与生态恢复措施和地形因子耦合关系研究

Coupling Relationships of Terrain Factors With Landscape Pattern and Ecological Restoration Measures in Small Watershed in Loess Hilly-Gully Region

选择地处典型黄土丘陵区的彭阳县高建堡流域为对象,按生态恢复措施将高建堡流域划分成8种景观类型,在Arc GIS 10.0软件的支持下,应用空间叠加和地形分析等空间分析方法,结合流域地貌特征,应用DEM数据结合地形图、遥感影像按梁峁顶部、梁峁坡、沟坡和沟底划分高程梯度带,结合坡度及坡向等地形因子对景观现状数据进行分析处理,对流域景观类型的空间分布格局进行分析。结果表明:地形因子是影响流域生态恢复的一个重要因素,高建堡流域生态恢复景观空间分布与地形因子显著相关,垂直分布特征明显。海拔由低到高景观类型的分布表现为沟底防冲林→经果林→退耕还林(草)→荒山自然封育→水平梯田→鱼鳞坑整地→荒山造林的顺序;各景观组分的空间分布受坡度的影响很大,分布比例均呈先逐渐增大后逐渐减小趋势;坡向由阴坡转向阳坡的过程中,退耕还林(草)、水平梯田和荒山造林景观的分布比例减小,荒山自然封育和经果林的分布比例增加,鱼鳞坑及沟底防冲林景观基本不受坡向影响。

Gaojianpu Watershed in Pengyang County,a typical loess hilly region,was selected as subject of study. The watershed was divided into 8 types of landscapes in the light of the ecological restoration measures adopted therein. With the aid of Arc GIS 10. 0 software,data of the status quo of landscape were processed and spatial distribution of landscape types in the watershed analyzed with spatial analysis methods,like spatial overlay,terrain analysis etc.,by taking into account landform features of the watershed,delineation of elevational gradient zones by＂ridge＂,＂hill＂,＂slope＂and＂gully＂,based on DEM topographical maps and remote sensing images of the watershed and topographical factors,like slope,aspect,etc.. Results show that topographical elements are important factors affecting watershed ecological restoration,and spatial distribution of restored ecological landscapes in the watershed is closely related to topographical factors of the watershed and characterized by obvious vertical distribution. With rising elevation,landscape type changes,following an order of gully forest,economic fruit forest,grain-for-green grassland,enclosure for natural restoration,contour terrace fields,piezoglypts,and barren slope for afforestation; spatial distribution of landscape components is much affected by slope,with distribution ratio gradually increasing first and then decreasing; with aspect turning from shady aspect to sunny slope,grain-for-green grassland,contour terrace fields and barren slope for afforestation decreases in distribution ratio,while enclosure of barren hills for natural restoration,and economic fruit forest increases,and piezoglypts and gully forest landscape were not affected.