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| DEM提取黄土高原地面坡度的不确定性 | |
| 引用本文： | 汤国安,赵牡丹,李天文,刘咏梅,谢元礼.DEM提取黄土高原地面坡度的不确定性[J].地理学报,2003,58(6):824-830. |
| 作者姓名： | 汤国安 赵牡丹 李天文 刘咏梅 谢元礼 |
| 作者单位： | 1. 西北大学城市与资源学系,西安,710069;西北大学大陆动力学教育部重点实验室,西安,710069 2. 西北大学城市与资源学系,西安,710069;中国科学院水利部西北水土保持研究所,陕西,杨凌,712000 3. 西北大学城市与资源学系,西安,710069 |
| 基金项目： | 国家自然科学基金(40271089)，国家高技术研究发展计划课题(2001AA130023)，测绘遥感信息工程国家重点实验室高级访问学者基金 ~~ |
| 摘 要： | 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，5m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一沟壑密度S之间存在的量化关系为E=(0．0015S^2 0．031S-0．0325) X-0．0045S^2-0．155S 0．1625，该结果也为确定适用的DEM分辨率提供了理论依据。 |
| 关 键 词： | 数字高程模型 DEM 黄土高原 地面坡度 分辨率 数据不确定性 基准数据 |
| 收稿时间： | 2003-07-19 |
| 修稿时间： | 2003年7月19日 |
Modeling Slope Uncertainty Derived from DEMs in Loess Plateau |
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| TANG Guoan,ZHAO Mudan,LI Tianwen,LIU Yongmei,XIE Yuanli.Modeling Slope Uncertainty Derived from DEMs in Loess Plateau[J].Acta Geographica Sinica,2003,58(6):824-830. | |
| Authors: | TANG Guoan ZHAO Mudan LI Tianwen LIU Yongmei XIE Yuanli |
| Institution: | 1. Department of Urban and Resource Science, Northwest University, Xi'an 710069, China; 2. The Key Open Laboratory of Continental Dynamics, Ministry of Education, Northwest University, Xi'an 710069, China; 3. Institute of Soil and Water Conservation, CAS and Ministry of Water Resources, Yangling 712100, China |
| Abstract: | Slope is one of crucial terrain variables in spatial analysis and land use planning, especially in the Loess Plateau area of China where rugged terrains enhance serious soil erosion. DEM based on slope extracting method has been widely accepted and applied in practice. However slope accuracy derived from this method usually does not match with their 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 the accuracy of mean slope extracted from DEMs of different resolutions in the Loess Plateau. 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 1:10000 scale topographical maps. Field survey results show that 5 m should be the most suitable grid size for representing slope in loess 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 were closely related with the terrain complexity of the test areas. If stream channel density was taken to represent terrain complexity, mean slope error could be regressed against DEM resolution (X) and stream channel density (S) at 8 resolution levels could be expressed as (0.0015S 2 + 0.031S-0.0325)X-0.0045S 2 -0.155S+ 0.1625, with a R 2 value of over 0.98. Practical tests also show an effective result of this model in applications. |
| Keywords: | Loess Plateau DEM slope resolution uncertainty |
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