喜马拉雅山脉的地质地貌特征:来自SRTM数字高程模型和降水量数据的约束   总被引：3，自引：1，他引：2       下载免费PDF全文

王猛  刘焰  何延波  魏东 《地质科学》2008,43(3):603-622

利用GTOPO30和SRTM3数字高程(DEM)数据,提取了喜马拉雅山脉(造山带)的数字高程模型并对其进行了地质地貌的初步分析。从SRTM3数字高程数据提取出坡度数据,初步分析了喜马拉雅山脉坡度和高程的特征。数字高程和坡度图清楚地展现了喜马拉雅大型断裂带(构造边界)的空间分布特征。分析了中国气象局下属的西藏、青海、四川和云南4省区气象观测台站55年来的年平均降水量观测数据、喜马拉雅山脉南坡的年平均降水量数据、喜马拉雅DEM和裂变径迹数据,发现喜马拉雅山脉从东至西,年平均降水量逐渐减少,地形起伏逐渐变小,而高程渐次升高,与此同时剥蚀速率降低;从北至南,年平均降水量逐渐增加,地形起伏增大,高程快速降低,而剥蚀速率则急剧升高。这充分说明了喜马拉雅年平均降水量大的地区,地表剥蚀作用相对较强,年平均降水量小的地区,地表剥蚀作用则较弱,即:在喜马拉雅地区,长周期的地表剥蚀过程(可长达数个百万年时间尺度)和短周期(仅仅50年)的降水量观测是耦合的。  相似文献   

顾及DEM误差自相关的坡度计算模型精度分析   总被引：11，自引：1，他引：10  

刘学军  卞璐  卢华兴  朱莹 《测绘学报》2008,37(2):0-249

基于DEM的坡度计算,其误差来源于DEM误差、DEM结构和坡度计算模型。在顾及DEM误差自相关的前提下,对四种DEM坡度计算模型进行了分析和评价。研究表明,三阶不带权差分能给出较高的坡度计算精度;在局部窗口中,格网点数量越多,坡度计算越准确;等权比不等权的坡度计算模型更准确;DEM误差自相关结构形式对坡度计算无影响。进一步的理论分析和试验分析还表明：DEM误差自相关性的存在,不仅能够改善地形分析的精度,也能改善DEM自身精度。  相似文献   

DEM高程基准转换方法及应用     

李月华  孙超 《北京测绘》2021,35(2):217-221

随着数字高程模型(DEM)在电力行业的广泛应用,电力地图需求部门对数字高程模型的要求越来越高。针对在数字高程模型生产中,电力业主方提供的立体模型高程基准不统一的问题,本文提出了基于特征数据的DEM基础转换方法。该方法在进行DEM制作过程中采用先采集特征数据,后转换特征数据高程基准的方式,实现了DEM成果的高程基准的转换,并进行了实验验证。结果表明,通过对比转换前后的DEM成果位置精度,验证了该方法的正确性。  相似文献   

视点相关实时LoD地形模型动态构网算法   总被引：28，自引：2，他引：28  

王源  刘建永  江南  俞高宇 《测绘学报》2003,32(1):47-52

论述了一种视点相关实时LoD地形模型动态构网算法。基于GRID数据，以直角三角形为基本单元，利用二叉树构建地形的层次结构，兼具GRID与不规则三角网（TIN）的优点；并且解决了模型带来的“裂缝”问题。视景体可见区域多分辨率地形生成时，通过地形面片自身复杂程度、地形面片与视点距离以及地形面片与视线间的方向关系三方面确定该面片的绘制分辨率。实验结果表明，该算法在保持地形场景逼真的情况下，极大地提高了绘制速度，满足了实时交互的要求。  相似文献   

基于等高线的DEM生成算法研究和实现   总被引：5，自引：0，他引：5  

刘锦中  马辉 《现代测绘》2004,27(3):34-35,48

数字高程模型是近年来发展起来的为地理信息系统提供空间分析和辅助决策的数据基础。随着科学技术特别是计算机技术的迅速发展，DEM在数据获取方法、数据存储和数据处理速度等方面已经取得突破性进展。通过系统介绍生成DTM过程中等高线的离散化方法，DELAUNAY三角网的特性和基于等高线数据的TIN的建立，以及对产生的问题的一些解决方法。  相似文献   

Land-surface segmentation as a method to create strata for spatial sampling and its potential for digital soil mapping     

L. Drăguţ  A. Dornik 《International journal of geographical information science》2016,30(7):1359-1376

Sampling efforts are constrained by limited availability of resources. Therefore, methods to reduce the number of samples, while still achieving reasonable accuracy are needed. Land-surface segmentation (LSS) has proven a powerful technique to partition digital elevation models (DEMs) and their derivatives into relatively homogeneous areas, which can be further employed as support in soil sampling. Though topography is one of the main soil forming factors, a robust assessment of the potential of this technique to digital soil mapping (DSM) is still missing. In this study, we aimed at evaluating the potential of LSS in stratifying a landscape into relatively homogeneous areas, which can be used as strata for guiding the selection of sampling points in DSM. The experiments were carried out in two study areas where soil samples were available. Land-surface derivatives were derived from DEMs and segmented with a tool based on the multiresolution segmentation algorithm, into objects considered as homogeneous soil-landscape divisions. Thus, one sample was randomly selected within each segment from the existing sample data, based on which predictions of soil classes/sub-orders and properties, i.e. soil texture and A-horizon thickness, were made. Results were compared with predictions based on simple random sampling (SRS) and conditioned Latin hypercube (cLHS). The segmentation-based sampling (SBS) scheme performed better than SRS and cLHS schemes in predicting the A-horizon thickness, soil texture fractions and soil classes, showing a high potential of LSS in stratifying a landscape for the purposes of DSM. The novelty of this study is in the way strata are constructed, rather than in the sampling design itself. Further research is needed to demonstrate the value of a SBS design for practical use. The analyses presented here further highlight the importance of considering locally adaptive techniques in optimization of sampling schemes and predictions of soil properties.  相似文献   

Topographic monitoring of a middle estuary mudflat, Humber estuary, UK – Anthropogenic impacts and natural variation     

Suzanne J. Boyes  James H. Allen 《Marine pollution bulletin》2007,55(10-12):543

Annual topographic surveys were carried out at the Saltend mudflat (Humber estuary, UK) between 1998 and 2006. These surveys formed part of an ongoing monitoring programme to examine the potential effects on the mudflat topography of the construction and operation of a waste water treatment works (WwTW) development by Yorkshire Water. Of particular concern was the potential disruption to the sedimentological regime within the special protection area (SPA) and candidate special area of conservation (cSAC) which could affect the invertebrate communities and ornithological functioning of the site. In addition to the development of the WwTW located to the extreme north-west of the site, a port extension removing 10 ha of the Saltend intertidal mudflat (outside the SPA but immediately south east of the WwTW) also occurred between 1999 and 2006. Minimal change was noted across the site following the construction and operation of the WwTW between 1998 and 2000. However, the construction of the bund in closer proximity to the SPA and cSAC masked any potential impact the WwTW could have had across the site after 2000. Profiles and contour mapping indicate that significant mudflat accretion occurred in the immediate area of the bund, with a general increase recorded across the western section of the site since 2000. In contrast the alternations to channel planform and subsequent rapid accretion of the mudflat to the east of the jetty, being a significant distance from the developments, are attributed to natural cyclical changes.  相似文献   

地形RSG模型的动态构网算法   总被引：13，自引：1，他引：13  

陈刚  夏青  万刚 《测绘学报》2002,31(1):44-48

论述了一种基于规则格网地形模型的动态构网算法。通过定义模型中顶点间的约束关系以及顶点误差的继承方法，利用四叉树构建出顶点的层次结构，有效解决了不同分辨率网络间接边的裂缝问题，实现在模型误差控制下的多分辨网络的实时正确构网。实验证明，该方法对于实时控制地形模型的细节层次，增强地形模型的绘制效率是非常有效的。  相似文献   

GPS应用于垂直位移监测的方案设计及数据处理方法     

莫乃鹤  李向新 《国土资源信息化》2007,(2):28-30

本文主要研究了GPS变形监测中垂直位移的问题。通过对误差分析,建立GPS大地高高差平差模型,以便提高GPS变形监测在垂直位移方向上的精度。从而真正的达到GPS三维监测。  相似文献   

青藏高原及其邻近地区近30年气候变暖与海拔高度的关系   总被引：51，自引：10，他引：41  

刘晓东  侯萍 《高原气象》1998,17(3):245-249

利用青藏高原及其邻近地区１６５个站１９６１～１９９０年月平均地面气温资料,分析了气候变暖与海拔高度的关系。结果表明：近３０年青藏高原及其相邻地区的地面气候变暖与海拔高度有关,变暖的幅度一般随海拔高度升高而增大,海拔高度在５００ｍ以下,５００～１５００,１５００～２５００,２５００～３５００及３５００ｍ以上等不同高度范围内台站下平均的平均温度的增温率分别为０．０,０．１１,０．１２,０．１９和０．２  相似文献