跨图幅任意区域DEM裁剪功能的实现   总被引：1，自引：0，他引：1  

钱海忠  武芳等 《测绘学院学报》2002,19(2):128-130

随着计算机技术和图形图像技术的发展，3维地形模型的研究越来越受到重视，为了实现GIS中3维地形的无级缩放和无缝漫游，任意区域的DEM裁剪是一个必须解决的问题，文中通过举例详细论述了任意区域DEM裁剪功能实现的思想和过程。  相似文献   

一种消除坡度分级图中“马赛克现象”的方法     

宋国民  张锦明 《测绘工程》2002,11(1):52-54

介绍了基于数字高程模型进行坡度分析的一般方法，分析了坡度分级图中出现的“马赛克现象”的原因，本文尝试利用数字高程模型内插的思路制作坡度分级图，较好的消除了“马赛克现象”；同时提出了一种坡度分级数据边界线的提取方法。  相似文献   

DOM与DEM数据的管理和三维可视化   总被引：6，自引：0，他引：6  

蒋欣  陈鹰 《测绘科学》2002,27(3):40-43

为了统一管理数字正射影像 (DOM)和数字高程模型 (DEM)数据 ,提出建立一个实用系统 ,该系统基于数据库技术统一管理海量的 DOM和 DEM数据。为了达到充分利用 DOM和 DEM数据的目的 ,在该系统中实现了DOM和 DEM数据叠加二维浏览、自动生成等高线、生成三维景观图、数字正射影像地形图、三维景观地形图等功能  相似文献   

基于DEM的地质岩层体积求取方法的研究     

李晓印  刘爱利 《新疆地质》2004,22(1):101-103

地质岩层体积的求取一直是困扰地质学界的一难题．在对基于DEM的地质岩层体积求取方法进行说明的基础上．通过在陕西省长武县进行地质钻探和建立DEM．获得该地区各系岩层深度数据等基础数据及DEM．然后用GIS软件ARCVIEW中的三维分析模块．快速求取出本地区各系岩层体积，并对该方法的精度及注意的问题进行讨论．  相似文献   

Assessment of C-band SRTM DEM in a dense equatorial forest zone     

Bernard Bourgine  Nicolas Baghdadi 《Comptes Rendus Geoscience》2005,337(14):1225-1234

A Digital Elevation Model issued from the SRTM mission was assessed on a study area located in a dense equatorial forest setting in French Guiana. The SRTM DEM defined on a 90-m grid was compared to three check sources: (1) airborne laser altimeter data, (2) an accurate heliborne DEM, and (3) spot heights. The paper also includes a comparison with a radargrammetric RADARSAT DEM. The results show that the accuracy of the SRTM DEM is about 10 m (standard deviation of errors). For a given slope aspect, the absolute value and the standard deviation of elevation errors increase almost linearly with the slope value. The slope aspect has a major influence on the sign of the elevation error: elevations are underestimated for slope facing SRTM signal (foreslopes, northwest), and conversely in the opposite direction (backslopes, southeast). Maximum errors are observed along these two directions. To cite this article: B. Bourgine, N. Baghdadi, C. R. Geoscience 337 (2005).  相似文献   

The Identification of Debris Torrent Basins Using Morphometric Measures Derived within a Gis   总被引：1，自引：0，他引：1  

David Rowbotham  Fes De Scally  John Louis 《Geografiska Annaler: Series A, Physical Geography》2005,87(4):527-537

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Tectonic forcing of longitudinal valleys in the Himalaya: morphological analysis of the Ladakh Batholith, North India     

S. S. R. Jamieson  H. D. Sinclair  L. A. Kirstein  R. S. Purves   《Geomorphology》2004,58(1-4):49-65

Longitudinal valleys form first order topographic features in many mountain belts. They are commonly located along faults that separate tectonic zones with varying uplift histories. The Indus Valley of Ladakh, northern India, runs northwestwards following the boundary between the relatively undeformed Ladakh Batholith to the north–east and the folded and thrusted Zanskar mountains to the south–west. In this region the Shyok Valley, on the northern side of the batholith, approximately parallels the course of the Indus. This study investigates geomorphic variations in transverse catchments that drain the Ladakh Batholith, into the Indus and Shyok rivers. The batholith has been divided into three zones based on varying structural characteristics of its northeastern and southwestern boundaries. Morphometric analysis of 62 catchments that drain into the Indus and Shyok valleys was carried out using three digital datasets, and supported by field observations. Morphometric asymmetry is evident in the central zone where the Shyok valley is considered tectonically inactive, but the Indus Valley is bound by the northeastwardly thrusting Indus Molasse and the batholith. In this zone the catchments that drain into the Indus Valley are more numerous, shorter, thinner and have lower hypsometric integrals than those that drain into the Shyok. By linking these observations with the regional geology and thermochronological data it is proposed that high sediment discharge from the deformed Indus Molasse Indus Valley has progressively raised base levels in the Indus Valley and resulted in sediment blanketing of the opposing tectonically quiescent catchments that drain southwestwards off the batholith. The Indus Molasse thrust front has propagated at least 36 km towards the Ladakh Batholith over the last 20 Ma. Hence it is proposed that this long term asymmetric structural deformation and exhumation has forced the Indus longitudinal valley laterally into the Ladakh Batholith resulting in the morphometric asymmetry of its transverse catchments.  相似文献   

Simulation of astronomical solar radiation over Yellow River Basin based on DEM     

QIU Xinfa  ZENG Yan  LIU Changming  WU Xianfeng 《地理学报》2004,14(1):63-69

Based on the developed distributed model for calculating astronomical solar radiation (ASR), monthly ASR with a resolution of 1 km×1 km for the rugged terrains of Yellow River Basin was calculated, with DEM data as the general characterization of terrain. This model gives an all-sided consideration on factors that influence the ASR. Results suggest that (1) Annual ASR has a progressive decrease trend from south to north; (2) the magnitude order of seasonal ASR is: summer>spring>autumn>winter; (3) topographical factors have robust effect on the spatial distribution of ASR, particularly in winter when a lower sun elevation angle exists; (4) the ASR of slopes with a sunny exposure is generally 2 or 3 times that of slopes with a shading exposure and the extreme difference of ASR for different terrains is over 10 times in January; (5) the spatial differences of ASR are relatively small in summer when a higher sun elevation angle exists and the extreme difference of ASR for different terrains is only 16% in July; and (6) the sequence of topographical influence strength is: winter>autumn>spring>summer.  相似文献   

基于DEM的岷山构造带构造地貌初步研究   总被引：5，自引：2，他引：5  

张会平  杨农  张岳桥  孟晖 《国土资源遥感》2004,15(4):54-58

以地理信息系统(GIS)为平台,结合构造地貌研究,利用矢量地形数据,构建了岷山构造带数字高程模型(DEM),初步对岷山构造带,特别是岷山断裂带构造地貌特征进行了分析。研究表明,将DEM与GIS技术结合,辅以遥感图像解译和详细野外地质调查,能够直观地进行坡度、坡向以及地形起伏度和高程的统计分析等研究,在构造地貌研究中具有良好的应用前景。  相似文献   

不同精度DEM流域地形特征提取分析及坡度误差控制研究   总被引：1，自引：0，他引：1  

秦福来  王晓燕  窦培谦  王丽华 《国土资源遥感》2005,(4):56-59

以北京密云水库牤牛河流域为试验区,对该流域4种精度DEM提取的流域地形值进行分析,并基于此对不同精度DEM所提取的坡度值进行了误差量化控制,运用曲线回归方法,建立了坡度损失拟合方程系.试验证明,该方法对坡度误差控制较好,具有较大的应用价值.  相似文献