祖厉河流域1:50000与1:250000比例尺DEM信息容量的比较  

Comparison of DEMs at Different Scales in the Zuli River Basin

作　　者：刘慧明[1] 许宝泉[1] 李凤民[1] 阎天成[2] 孙国钧[1] 

机构地区：[1]兰州大学干旱与草地生态教育部重点实验室,甘肃兰州730000 [2]甘肃省水利厅农村水利处,甘肃兰州730000

出　　处：《干旱区研究》2007年第1期131-134,共4页Arid Zone Research

基　　金：国家重点基础研究发展规划项目(G2000018603)

摘　　要：以甘肃省祖厉河流域为实验样区,以1∶50 000 DEM为基准,运用比较分析与数理统计的方法,研究该区域1∶250 000 DEM描述地表形态的精度特征。基本技术平台为ArcGIS 8.3软件。研究结果表明,利用1∶250 000DEM所提取的流域各级河网、地面坡度、地面坡向3种因子与基于1∶50 000 DEM所提取的各因子相比较,均存在不同程度的信息损失,1∶50 000 DEM能较好地模拟真实的地面信息。研究成果为半干旱区集水农业工程的规划和水土保持等应用标准的制定提供了理论依据。Located in the west Loess Plateau, the Zuli River is a first-level tributary of the Yellow River, and the area of its drainage basin （ 35°18 - 36° 34＇ N, 104°12-105° 33＇ E, 1 419.40 m a. s. 1. in average and 2 853.10 m in maximum） is 10 635 km^2. In this paper, a series of experiments were carried out to investigate the accuracy of topographic variables derived using DEMs at scale of 1 ： 250 000 by comparing with that at scale of 1：50 000. The Zuli River Basin in central Gansu Province is taken as a test area, and ArcGIS 8.3 is used as a main working platform. The results reveal that some information is lost in deriving the topographic variables （such as the drainage nets, slopes and aspect） in a drainage basin using DEMs at scale of 1：250 000 compared with that at scale of 1 ： 50 000. DENIs can be used to factually simulate the surface information at scale of 1 ： 50 000. The study results can be used to guide the error rectification and the accuracy evaluation of DENIs in practical applications. They are important for the planning and management of the rain-catching agriculture and water and soil conservation in the semiarid areas. A series of experiments were made to investigate the accuracy of tofograpic variables derived from DENIS of 1 ： 250 000 scaled DEM by means of a careful comparison with 1 ： 50 000 scaled DEM of the same area. Taking Zuli watershed in the centre of Gansu province as a test area and ArcGIS 8.3 as a main working platform, the results show different errors can be found in all three topographic variables, such as slope gradient, aspect of surface and the net of river. The results of study can be used to guide the error-rectifying and the accuracy evaluating of the DEMs in practical applications. They are important for the planning and management of the rain-harvesting agriculture in the semi-arid loess plateau area.

关 键 词：数字高程模型 比例尺 地形因子 精度 甘肃 

分 类 号：P28[天文地球—地图制图学与地理信息工程]