共查询到19条相似文献，搜索用时 406 毫秒
1.
不同比例尺水系修正DEM的流域河网提取对比 总被引：1，自引：0，他引：1
选取三门峡至小浪底区间小流域为研究对象,以1∶5万和1∶25万两种尺度的数字化水系分别修正DEM,在此基础上运用ArcGIS水文分析模块(ArcHydro Tools)进行流域河网提取。研究表明,基于水系修正的DEM和ArcGIS水文分析模块提取的流域河网精度较高,1∶5万水系修正DEM得到的河网更接近自然水系;通过对两种水系修正DEM生成的河网套合差计算发现,二者河网吻合程度较好,在DEM数据精度较高或者地形起伏较大的地区,如果没有更高精度的水系数据,1∶25万水系可取代1∶5万水系用于修正DEM。 相似文献
2.
由于DEM数据不包括河流、湖泊(水库)及流域边界和堤坝等信息,因此常规仅依靠DEM提取水系的方法不能反映平坦区域及受人类影响强烈区域水系的真实特征。该文建立了融合DEM、河流、湖泊水库、流域边界和堤坝等多源数字信息的流域水系提取方法,对多源信息进行栅格化,采用所提出的高程-距离函数对DEM进行校正,使得提取的数字水系与实际水系精确拟合。将该方法应用于山区太湖西苕溪流域老石坎水库及其上游集水区和平原丘陵分布区的淮河史灌河蒋家集站、梅山、鲇鱼山水库区间流域,提取的河网结构与地图信息拟合较好。 相似文献
3.
基于DEM的数字流域特征提取研究进展 总被引：9，自引：0，他引：9
数字高程模型(DEM)是地表形态高程属性的数字化表达,利用流域DEM数据构建数字水系模型并提取流域水文特征,是分布式水文过程模拟的重要基础。DEM中闭合洼地和平坦区域的处理、流向的确定以及DEM分辨率的大小都直接影响着流域水系特征提取的质量与效率。针对当前基于DEM提取河网与流域特征的诸多问题,阐述了DEM数据提取流域水系特征的原理,回顾了数字水系模型与流域特征提取方法,评述了洼地和平地的处理方法及水流方向的确定方法的研究进展,介绍了当前基于不同DEM数据类型的提取方法研究,探讨了DEM尺度和分辨率对提取流域特征的影响,总结了平缓区域数字水系和河网提取的研究进展。 相似文献
4.
基于DEM的复杂地形流域特征提取 总被引：21，自引：2，他引：19
利用流域数字高程模型(DEM)构建数字水系模型并提取流域水系特征是分布式水文过程模拟的重要前提。提出了面向分布式水文过程模拟和流域特征提取的数字水系模型,并针对现有方法对复杂地形DEM中含有的平地、洼地及其嵌套情形的处理不足,提出了栅格水流分类、填洼分类与归并及有效填平处理、河谷平地的出流代价法构建栅格流向和流序等新的处理方法,并在开发的软件系统得到实现。使用该方法创建的黄土岭流域数字水系模型和提取的水系等流域特征结果表明:本文方法可有效应对复杂地形流域的处理,提取的流域水系特征与实际自然水系比较吻合,能够有效地消除现有方法在地形平坦区域容易产生的平行河道、奇异河道、河道变形等不足。 相似文献
5.
大尺度分布式水文模型数字流域 提取方法研究 总被引：11，自引：1，他引：10
构建大尺度分布式水文模型是当前大气水文模型耦合研究的一项重要内容。本文介绍一 种根据1km DEM 生成更大网格尺度DEM 数据, 同时可以保持流域河网信息并减缓高程、坡度 等地貌参数信息量衰减速度的有效方法———ZB算法。利用该方法和常规的网格平均法生成黄河 唐乃亥以上流域的5km、10km、15km 和20km 两套DEM 数据, 分别提取高程、坡度、地形指数、河 网密度、主河道长度、流域面积等流域特征参数, 并与1km DEM 提取的上述参数进行比较, 对两 种方法作出评价。结果显示, 随着网格尺度的增大, ZB 算法获得的DEM 数据可以保持河网的连 续性, 提取出合理的流域范围, 减缓地形信息量的衰减速度。该方法满足构建大尺度分布式水文 模型提取数字流域的需要。 相似文献
6.
LiDAR技术能够提供高分辨率DEM数据,可用于准确提取流域水系网络信息。研究中针对LiDAR系统提供的高精度DEM数据中存在的噪声,提出采用各向异性扩散滤波算法进行噪声平滑,与常用的DEM滤波算法比较,该方法既能有效去除噪声,同时又能保留高梯度的地形信息。在DEM噪声去除的基础上,采用基于局部地形曲面几何分析的Peuker&Douglas算法初步提取水系网络原型,进一步利用改进的基于坡面流物理模拟分析的加权D8算法提取水系网络,构建了基于LiDAR数据水系网络提取的技术流程。通过鹤壁市某小流域的LiDAR数据水系网络提取试验证明了该方法准确提取水系网络的有效性。 相似文献
7.
基于不同DEM数据源的数字河网提取对比分析——以韩江流域为例 总被引：4，自引：1，他引：3
基于HYDRO1K、SRTM3和ASTER GDEM三种DEM数据,利用BTOPMC地形子模型提取韩江流域河网,并作对比分析。结果表明:①SRTM3提取的河网精度最高,HYDRO1K相对最低。②DEM的垂直精度对提取的河网精度起控制作用。ASTER GDEM的水平分辨率较高,但垂直精度不如SRTM3,因而提取的河网精度不如SRTM3。③HYDRO1K提取大尺度流域河网具有一定的精度,但在地势平坦区域的效果较差,HY-DRO1K不宜用来提取小尺度流域河网。④由DEM提取的数字河网精度与当地的地面坡度以及处理DEM的填洼算法有关。 相似文献
8.
流域特征的精确提取对深入研究流域水文过程和水资源管理至关重要。利用DEM数据进行数字流域特征分析,尤其在难以进入、地形复杂的无资料山区,可高效精准地提取、统计和研究地貌和水系特征。基于Arc GIS实验平台,利用DEM数据,从流域产汇流形成以及洪水调蓄角度对那陵格勒河山谷段进行流域特征提取。结论如下:1)流域地貌特征表明产汇流面较大,地面侵蚀过程较强,重力侵蚀过程较弱。2)流域水系为狭长形弯曲河道,主河道比降小。实际沟谷网络密度为1.71~2.32 km/km2。3)流域地貌特征使子流域的沟谷集水面广量大且速度快,易形成大的径流汇入主河道;但流域水系特征可降低主河道汇流速度,延长汇流时间,有利调蓄,洪峰不易集中。 相似文献
9.
10.
随着信息化技术的快速发展,基于DEM产品提取水系等数据已经变得不再困难,但是,目前无论在水系自动提取方面还是自动分级方面,都存在很多需要改进之处。论文分析了自动提取河网水系与流域边界,以及河网水系分级的研究进展,在此基础上总结了当前存在的问题：（1）水系自动提取中的洼地处理、平地区域流向处理等;（2）河网水系自动分级方法中的参数单一,准确性较差,并且缺少水系实体之间的互相关联关系等问题。在此基础上,提出了基于地理特征建立水系分级模型以解决分级问题的构想。 相似文献
11.
1 Introduction Automated extraction of drainage features from DEMs is an effective alternative to the tedious manual mapping from topographic maps. The derived hydrologic characteristics include stream-channel networks, delineation of catchment boundaries, catchment area, catchment length, stream-channel long profiles and stream order etc. Other important characteristics of river catchments, such as the stream-channel density, stream-channel bifurcation ratios, stream-channel order, number… 相似文献
12.
Hydrologic data derived from digital elevation models (DEM) has been regarded as an effective method in the spatial analysis of geographical information systems (GIS). However, both DEM resolution and terrain complexity has impacts on the accuracy of hydrologic derivatives. In this study, a multi-resolution and multi-relief comparative approach was used as a major methodology to investigate the accuracy of hydrologic data derived from DEMs. The experiment reveals that DEM terrain representation error affects the accuracy of DEM hydrological derivatives (drainage networks and watershed etc.). Coarser DEM resolutions can usually cause worse results. However, uncertain result commonly exists in this calculation. The derivative errors can be found closely related with DEM vertical resolution and terrain roughness. DEM vertical resolution can be found closely related with the accuracy of DEM hydrological derivatives, especially in the smooth plain area. If the mean slope is less than 4 degrees, the derived hydrologic data are usually unreliable. This result may be helpful in estimating the accuracy of the hydrologic derivatives and determining the DEM resolution that is appropriate to the accuracy requirement of a particular user. By applying a threshold value to subset the cells of a higher accumulation flow, a stream network of a specific network density can be extracted. Some very important geomorphologic characteristics, e.g., shallow and deep gullies, can be separately extracted by means of adjusting the threshold value. However, such a flow accumulationbased processing method can not correctly derive those streams that pass through the working area because it is hard to accumulate enough flow direction values to express the stream channels at the stream's entrance area. Consequently, errors will definitely occur at the stream’s entrance area. In addition, erroneous derivatives can also be found in deriving some particular rivers, e.g., perched (hanging up) rivers, anastomosing rivers and braided rivers. Therefore, more work should be done to develop and perfect the algorithms. 相似文献
13.
A study on DEM-derived primary topographic attributes for hydrologic applications: Sensitivity to elevation data resolution 总被引：1，自引：0，他引：1
Primary topographic attributes play a critical role in determining watershed hydrologic characteristics for water resources modeling with raster-based digital elevation models (DEM). The effects of DEM resolution on a set of important topographic derivatives are examined in this study, including slope, upslope contributing area, flow length and watershed area. The focus of the study is on how sensitive each of the attributes is to the resolution uncertainty by considering the effects of overall terrain gradient and bias from resampling. Two case study watersheds of different gradient patterns are used with their 10 m USGS DEMs. A series of DEMs up to 200 m grid size are produced from the base DEMs using three commonly used resampling methods. All the terrain variables tested vary with the grid size change. It is found that slope angles decrease and contributing area values increase constantly as DEMs are aggregated progressively to coarser resolutions. No systematic trend is observed for corresponding changes of flow path and watershed area. The analysis also suggests that gradient profile of the watershed presents an important factor for the examined sensitivities to DEM resolution. 相似文献
14.
DEM提取黄土高原地面坡度的不确定性 总被引：72，自引：0，他引：72
选择陕北黄土高原6个典型地貌类型区为试验样区,采用野外实测及高精度的1:1万比例尺DEM为基准数据,研究栅格分辨率及地形粗糙度对DEM所提取地面平均坡度精度的影响。结果显示,对于1:1万比例尺DEM,5 m是保证该地区地形描述精度的理想分辨率尺度;多要素逐步回归模拟的方法进一步揭示了DEM所提取的地面平均坡度误差E与栅格分辨率X以及地形起伏的代表性因子-沟壑密度S之间存在的量化关系为E = (0.0015S2+0.031S-0.0325)X-0.0045S2-0.155S+0.1625,该结果也为确定适用的DEM分辨率提供了理论依据。 相似文献
15.
不同分辨率DEM提取地面坡度的不确定性模拟:以在黄土高原的试验为例 总被引：1，自引：0，他引：1
Slope is one of the crucial terrain variables in spatial analysis and land use planning,especially in the Loess Plateau area of China which is suffering from serious soil erosion. DEM based slope extracting method has been widely accepted and applied in practice. However slope accuracy derived from this method usually does not match with its popularity. A quantitative simulation to slope data uncertainty is important not only theoretically but also necessarily to applications. This paper focuses on how resolution and terrain complexity impact on the accuracy of mean slope extracted from DEMs of different resolutions in the Loess Plateau of China. Six typical geomorphologic areas are selected as test areas, representing different terrain types from smooth to rough. Their DEMs are produced from digitizing contours of 1:10,000 scale topographic maps. Field survey results show that 5 m should be the most suitable grid size for representing slope in the Loess Plateau area. Comparative and math-simulation methodology was employed for data processing and analysis. A linear correlativity between mean slope and DEM resolution was found at all test areas,but their regression coefficients related closely with the terrain complexity of the test areas. If taking stream channel density to represent terrain complexity, mean slope error could be regressed against DEM resolution (X) and stream channel density (S) at 8 resolution levels and expressed as (0.0015S2+0.031S-0.0325)X-0.0045S2-0.155S+0.1625, with a R2 value of over 0.98. Practical tests also show an effective result of this model in applications. The new development methodology applied in this study should be helpful to similar researches in spatial data uncertainty investigation. 相似文献
16.
TANGGuoan ZHAOMudan LITianwen LIUYongmei ZHANGTing 《地理学报(英文版)》2003,13(4):387-394
Slope is one of the crucial terrain variables in spatial analysis and land use planning, especially in the Loess Plateau area of China which is suffering from serious soil erosion. DEM based slope extracting method has been widely accepted and applied in practice. However slope accuracy derived from this method usually does not match with its popularity. A quantitative simulation to slope data uncertainty is important not only theoretically but also necessarily to applications. This paper focuses on how resolution and terrain complexity impact on the accuracy of mean slope extracted from DEMs of different resolutions in the Loess Plateau of China. Six typical geomorphologic areas are selected as test areas, representing different terrain types from smooth to rough. Their DEMs are produced from digitizing contours of 1:10,000 scale topographic maps. Field survey results show that 5 m should be the most suitable grid size for representing slope in the Loess Plateau area. Comparative and math-simulation methodology was employed for data processing and analysis. A linear correlativity between mean slope and DEM resolution was found at all test areas, but their regression coefficients related closely with the terrain complexity of the test areas. If taking stream channel density to represent terrain complexity, mean slope error could be regressed against DEM resolution (X) and stream channel density (S) at 8 resolution levels and expressed as(0.0015S2 0.031S-0.0325)X-0.0045S2-0.155S 0.1625, with a R2 value of over 0.98. Practical tests also show an effective result of this model in applications. The new development methodology applied in this study should be helpful to similar researches in spatial data uncertainty investigation. 相似文献
17.
Slope is one of the crucial terrain variables in spatial analysis and land use planning, especially in the Loess Plateau area of China which is suffering from serious soil erosion. DEM based slope extracting method has been widely accepted and applied in practice. However slope accuracy derived from this method usually does not match with its popularity. A quantitative simulation to slope data uncertainty is important not only theoretically but also necessarily to applications. This paper focuses on how resolution and terrain complexity impact on the accuracy of mean slope extracted from DEMs of different resolutions in the Loess Plateau of China. Six typical geomorphologic areas are selected as test areas, representing different terrain types from smooth to rough. Their DEMs are produced from digitizing contours of 1:10,000 scale topographic maps. Field survey results show that 5 m should be the most suitable grid size for representing slope in the Loess Plateau area. Comparative and math-simulation methodology was employed for data processing and analysis. A linear correlativity between mean slope and DEM resolution was found at all test areas, but their regression coefficients related closely with the terrain complexity of the test areas. If taking stream channel density to represent terrain complexity, mean slope error could be regressed against DEM resolution (X) and stream channel density (S) at 8 resolution levels and expressed as (0.0015S2+0.031S-0.0325)X-0.0045S2-0.155S+0.1625, with a R2 value of over 0.98. Practical tests also show an effective result of this model in applications. The new development methodology applied in this study should be helpful to similar researches in spatial data uncertainty investigation. 相似文献
18.
The fractal characteristics of drainage in the ten kongduis of the upper Yellow River were obtained using the box counting dimension, and the evolution stages of the watershed topography were defined by different ranges of the fractal dimensions of river networks (Dg). The results show that the fractal scaleless range of the Maobula River is 20–370 m based on a combination of artificial judgment, correlation coefficient test and fitting error. Other kongduis show good fractal characteristics in this fractal scaleless range as well. The box counting dimension can be used as a quantitative index of watershed topography fractal characteristics. The fractal dimension of stream networks is independent of the threshold contributing area used for extracting the drainage networks from the DEM. The values of Dg in the upper ten kongduis are in the range of 1.08?1.14. Both the runoff yield and the sediment yield are positively and linearly related with Dg. The positive relation between the sediment yield and Dg reflects the effect of landform features on sediment yield in the young and/or mature stages of landform evolution of the study area. By revising the critical value of Dg, the value of Dg of the basin in the young evolution stage is less than 1.06, while it is more than 1.06 for the basin in mature or old evolution stage. The upper ten kongduis are in the mature stage of landform evolution. 相似文献
19.
黄土高原典型小流域道路特征及影响因素 总被引：5，自引：1，他引：4
通过GPS野外实测黄土高原纸坊沟小流域的道路特征,在GIS空间分析等方法支持下研究了流域内各级道路的分布规律。研究表明:黄土高原道路可分为4级,2级以下的土路是小流域的代表路型。各级别道路总长度都随级别增大而增加且累计总长度与道路级别线性相关,道路平均长度和密度则随级别增大而减小。道路网系和流域水系在结构规律上具有一定的相似性。不同级别道路分布范围受地形特征影响不同。爬坡道路坡度与地表坡度之间存在线性回归关系,且次级道路分布受主路控制;典型爬坡路在大于25°坡度范围内多呈"之"字形弯曲,随坡度的减小道路弯曲跨度和与等高线夹角增大。研究结果有助于定量模拟黄土高原地区道路分布特征,并为土壤侵蚀模型中道路影响因子的确定提供参考。 相似文献