长江科学院院报 ›› 2019, Vol. 36 ›› Issue (9): 155-160.DOI: 10.11988/ckyyb.20180236

• 信息技术应用 • 上一篇    下一篇

基于LiDAR的青藏高原山坡小流域地形提取方法

吴鹏飞1,柳林2,乔骁1,周杰3,刘金涛1,4,李晓鹏5,韩小乐1   

  1. 1.河海大学 水文水资源学院,南京 210098;
    2.水利部海河水利委员会 水文局,天津 300170;
    3.南京水利科学研究院水工水力学研究所,南京 210029; 4.河海大学 水文水资源与水利工程科学国家重点实验室,南京 210098;
    5.中国科学院南京土壤研究所 土壤物理与盐渍土研究室,南京 210008
  • 收稿日期:2018-03-13 修回日期:2018-06-04 出版日期:2019-09-01 发布日期:2019-09-12
  • 通讯作者: 刘金涛(1977-),男,河北唐山人,教授,博士,主要从事流域水文相似与模拟研究。E-mail:jtliu@hhu.edu.cn
  • 作者简介:吴鹏飞(1994-),男,江苏如东人,硕士研究生,主要从事流域水文相似与模拟研究。E-mail:18351936707@163.com
  • 基金资助:
    国家自然科学基金项目(91647108,91747203);西藏自治区科技项目(2015XZ01432)

Terrain Extraction of Small Hillside Watershed on Qinghai-Tibet Plateau Based on LiDAR

WU Peng-fei1, LIU Lin2, QIAO Xiao1, ZHOU Jie3, LIU Jin-tao1,4, LI Xiao-peng5, HAN Xiao-le1   

  1. 1.College of Hydrology and Water Resources, Hohai University, Nanjing 210098, China;
    2.Hydrology Bureau of Haihe River Water Conservancy Commission, Ministry of Water Resources, Tianjin 300170, China;
    3.Hydraulic Engineering Department, Nanjing Hydraulic Research Institute, Nanjing 210029, China;
    4.State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing 210098, China;
    5.Department of Soil Physics and Saline Soils, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China
  • Received:2018-03-13 Revised:2018-06-04 Online:2019-09-01 Published:2019-09-12

摘要: 数字高程模型(DEM)的精度和分辨率影响着地形分析的结果,这种影响在高原、高山地带尤为明显。以拉萨河夺底沟小流域一处山坡为研究对象,选取典型剖面对比3种DEM数据对实际地形的还原效果。分析表明:SRTM和ASTER GDEM地形数据在青藏高原高山区存在高估山谷谷底高程、漏失地形要素的现象,使用LiDAR技术获取的DEM则可以准确反映实际地形。针对8种分辨率(1,2,5,10,15,20,25,30 m)的LiDAR DEM,使用局部方差均值分析坡度、平面曲率、剖面曲率等地形属性,发现低分辨率DEM在高山地区会遗失大量地形信息,造成地形平坦化和山坡微地形改变。为避免高山地区地形特征失真,给出了坡度和曲率研究适用的最小分辨率阈值:在坡度研究中使用的DEM分辨率应<5 m,曲率研究的最优分辨率为1 m。研究表明在青藏高原高山区,使用LiDAR技术提取高分辨率DEM具有远大的应用前景。

关键词: 山坡地形, LiDAR, 数字高程模型, 青藏高原, 分辨率

Abstract: The accuracy and resolution of the Digital Elevation Model (DEM) affect the results of terrain analysis, and such effect is particularly evident in plateau and high mountains. With a hillside slope in the Duodigou watershed which is a sub-basin of the Lhasa River Basin as study object, we examined the abilities of three types of DEM data in reflecting the real terrain of typical profiles. As the analysis shows, in the high mountains of the Qinghai-Tibet Plateau, the SRTM and ASTER GDEM data have overestimated the elevation of the bottom of the valley and lost terrain features, while the DEM obtained using LiDAR (Light Detection And Ranging) technology can accurately reflect the actual terrain. We elaborated the terrain features, inclusive of slope gradient, plane curvatures and profile curvatures, of LiDAR DEMs of eight resolutions (1 m, 2 m, 5 m, 10 m, 15 m, 20 m, 25 m, 30 m) by means of local variance. We found that DEMs of low resolutions have lost much topographical information in high mountains, causing attenuations of the terrain and changes in the microtopography of hillsides. In order to avoid the distortion in high mountain areas, we further gave the minimum resolution for studies of slopes or curvatures. The resolution of DEMs used in slope studies should be higher than 5 m, and the optimal resolution for curvature studies is 1 m. The study has shown that the use of LiDAR technology to extract high-resolution DEMs has a promising application prospect in high mountains of the Qinghai-Tibet Plateau.

Key words: terrain of hillside, LiDAR, Digital Elevation Model, the Qinghai-Tibet Plateau, resolution

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