Quantitative monitoring of gravity erosion using a novel 3D surface measuring technique: validation and case study
Quantitative monitoring of gravity erosion using a novel 3D surface measuring technique: validation and case study
复制标题
DOI：
10.1007/s11069-014-1405-z
复制
发表时间：
2014
期刊：
影响因子：
3.7
通讯作者：
Xiangzhou Xu;Hongwu Zhang;Wen-long Wang;Chao Zhao;Q. Yan
中科院分区：
文献类型：
--
作者：
Xiangzhou Xu;Hongwu Zhang;Wen-long Wang;Chao Zhao;Q. Yan
重力侵蚀是山区特别是中国黄土高原最显著的自然灾害之一。然而，由于重力侵蚀通常是随机发生的，而且它与水力侵蚀相结合，所以破坏质量的测量是非常困难的。在这里，我们提出了一种新的测试技术，可以定量测量黄土陡坡上的时变重力侵蚀。本实验室自行研制了一种结构光三维表面测量仪--轮廓仪。在模拟降雨条件下监测陡坡起伏的动态变化，并利用计算机视频技术记录坡体变形过程。利用激光打标技术，将平面图形矢量化地转换为三维图形，从而精确计算出目标表面的形状。通过比较侵蚀前后某一时刻的坡面几何形状，可以得到坡面重力侵蚀量和坡面径流侵蚀量等多种侵蚀数据。通过一系列的标定试验，结果表明，该方法精度较高，足以用于坡面侵蚀机理的研究。随后，利用该装置对120多个降雨模拟事件进行了测试，进一步证实了该装置的可行性和可靠性。
Gravity erosion is one of the most remarkable natural hazards in mountainous regions, especially on the Loess Plateau of China. Nevertheless, the measurement of failure mass is very difficult because gravity erosion usually occurs randomly and it combines with hydraulic erosion. Here, we present a novel testing technique that could quantitatively measure time-variable gravity erosion on the steep loess slopes. A structured-light 3D surface measuring apparatus, the Topography Meter, was designed and manufactured in our laboratory. Dynamic variation of the steep slope relief was monitored under rainfall simulation, and the slope deforming process was recorded by a computer video technology. With the help of laser marking, plane figures were vectorially transformed into 3D graphs, thus the shape of target surface was accurately computed. By comparing the slope geometries in the moments before and after the erosion incident on the snapshot images at a particular time, we could obtain the volume of gravity erosion and many other erosion data, including the volume of slide mass and the amount of soil loss eroded by overland flow. A series of calibration tests were conducted and the results showed that the accuracy of this technique was high and sufficient for exploring the mechanism of slope erosion. More than 120 rainfall simulation events were subsequently tested with the apparatus, further confirming its feasibility and reliability.