DEM提取黄土高原地面坡度的不确定性
收稿日期: 2003-07-19
修回日期: 2003-09-03
网络出版日期: 2003-11-25
基金资助
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
Modeling Slope Uncertainty Derived from DEMs in Loess Plateau
Received date: 2003-07-19
Revised date: 2003-09-03
Online published: 2003-11-25
Supported by
National Nature Science Foundation of China, No.40271089; National High Technique Research Development Project, No.2001AA130023; Senior Visiting Scholar Project of National Laboratory for Information Engineering in Survey, Mapping and Remote Sensing
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。
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 . DOI: 10.11821/xb200306004
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 (0.0015S2 + 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.
Key words： Loess Plateau; DEM; slope; resolution; uncertainty
[1] Tang Guoan. A Research on the Accuracy of Digital Elevation Models. Beijing and New York: Science Press, 2000.
[2] Ahmadzadeh M R, Petrou M. Error statistics for slope and aspect when derived from interpolated data. IEEE Transactions on Geoscience and Remote Sensing, 2001, 39(9): 1823-1833.
[3] Tang Guoan, Yang Qinke, Zhang Yong et al. Research on accuracy of slope derived from DEMs of different map scales, Bulletin of Soil and Water Conservation, 2001, 21(1): 53-56.
[汤国安, 杨勤科, 张勇 等. 不同比例尺DEM提取地面坡度的精度研究. 水土保持通报, 2001, 21(1): 53-56.]
[4] Bolstad P V, Stowe T. An evaluation of DEM accuracy - elevation, slope, and aspect. Photogrammetric Engineering and Remote Sensing, 1994, 60(11): 1327-1332.
[5] Giles P, Franklin S E. Comparison of derivation topographic surfaces of a DEM generated from stereoscopic SPOT images with field measurements. Photogrammetric Engineering and Remote Sensing, 1996, 62(10): 1165-1171.
[6] Chang K, Tsai B. The effect of DEM resolution on slope and aspect mapping. Cartography and Geographic Information Systems, 1991, 18(1): 69-77.
[7] Carter J. The effect of data precision on the calculation of slope and aspect using gridded DEMs. Cartographica, 1992, 29(1): 22-34.
[8] Gao J. Resolution and accuracy of terrain representation by grid DEMs at a micro-scale. Int. J. Geographical Information Science, 1997, 11(2): 199-212.
[9] Tang Guoan, Chen Nan et al. A comparison on digital terrain models of different scales in loess hilly and gully area. Bulleten of Soil and Water Conservation, 2001, 21(2): 34-36.
[汤国安, 陈楠 等. 黄土丘陵沟壑区1:1万及1:5万比例尺DEM地形信息容量对比. 水土保持通报, 2001, 21(2): 34-36.]
[10] Holmes K W, Chadwick O A, Kyriakidis P C. Error in a USGS 30-meter digital elevation model and its impact on terrain modelling. Journal of Hydrology, 2000, 233(1-4): 154-173.
[11] Florinsky I V. Accuracy of local topographic variables derived from digital elevation model. International Journal of Geographical Information Science, 1998, 12(1): 47-61.
[12] Walker J P, Willgoose G R. On the effect of digital elevation model accuracy on hydrology and geomorphology. Water Resources Research, 1999, 35(7): 2259-2268.
[13] Thompson J A, Bell J C, Butler C A. Digital elevation model resolution: effects on terrain attribute calculation and quantitative soil-landscape modelling. Geoderma, 2001, 100(1-2): 67-89.
[14] Giles P T, Franklin S E. An automated approach to the classification of the slope units using digital data. Geomorphology, 1998, 21(3-4): 251-264.
[15] Wang G X, Gertner G, Parysow P et al. Spatial prediction and uncertainty assessment of topographic factor for revised universal soil loss equation using digital elevation models, ISPRS Journal of Photogrammetry and Remote Sensing, 2001, 56(1): 65-80.
[16] Burrough P A. Principles of Geographical Information Systems for Land Resources Assessment. New York: Oxford University Press, 1986.
[17] John P Wilson, John C Gallant. Terrain Analysis: Principles and Applications. New York: Wiley Press, 2001.
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