基于三维激光扫描的坡沟系统侵蚀产沙过程研究  

Investigation of Erosion Processes on the Slope-Gully System Using 3D Laser Scanning

作　　者：李朋飞 张晓晨 党旭 胡晋飞 姚顽强[1] 郝铭揆 LI Pengfei;ZHANG Xiaochen;DANG Xu;HU Jinfei;YAO Wanqiang;HAO Mingkui(College of Gomatics,Xi′an University of Science and Technology,Xi′an 710054,China)

机构地区：[1]西安科技大学测绘科学与技术学院,西安710054

出　　处：《水土保持研究》2023年第2期13-21,共9页Research of Soil and Water Conservation

基　　金：国家自然科学基金项目(41977059;41807063);陕西省自然科学基础研究计划(2022JQ-259)。

摘　　要：为了探究野外自然坡沟系统土壤侵蚀过程,研究于黄土丘陵沟壑区典型流域辛店沟内自然坡面开展5场放水冲刷试验,利用地面三维激光扫描技术(Terrestrial laser scanning, TLS)获取高精度地形信息,并采用DEM of difference(DoD)地形变化监测方法计算产沙量,利用实测产沙量评估TLS的监测精度,并探讨了坡沟系统侵蚀/沉积的变化特征。结果表明:(1)累积场次中,DoD不确定性(即level of detection, LoD)平均值(范围)为16.5 mm(16.2~16.8 mm)。单场次中,LoD值平均值为16.4 mm(16.2~16.6 mm);(2)累积场次中,梁峁坡、沟谷坡、坡沟系统TLS扫描所得产沙量相对误差的平均值(范围)为52.63%(26.06%~106.98%),56.68%(30.26%~75.49%)和56.28%(33.37%~73.28%),与实测数据显著相关(R2>0.9,p<0.05)。单场次TLS扫描相对误差波动范围更大且平均值高于累积场次,其值分别为83.70%(4.08%~190.40%),91.41%(0.95%~225.09%)和87.58%(4.09%~215.55%),与实测值非显著相关(R2<0.57,p>0.05),表明TLS更适合于坡沟系统累积场次侵蚀产沙监测,而单场次监测精度较差;(3)随冲刷次数的增加,梁峁坡、沟谷坡和坡沟系统侵蚀产沙均呈增长趋势,但沟谷坡和坡沟系统沉积量快速增长后趋于平稳。(4)梁峁坡侵蚀区域主要位于梁峁坡上中部,沉积主要分布于梁峁坡中下方,沟谷坡大部分区域侵蚀剧烈,沉积主要分布于沟底,梁峁坡和沟谷坡侵蚀区占地形变化区域的比例均高于79%。结果可为黄土高原土壤侵蚀监测与机理研究提供参考。In order to explore the soil erosion process of in-situ slope-gully systems, five runoff scouring experiments were undertaken on a slope-gully system plot established on a natural slope of a small catchment(i.e. Xindiangou Catchment) in the hilly-gully region of Loess Plateau, while the terrestrial laser scanning(TLS) was employed to acquire the ultra-high resolution terrain information of the slope-gully system. The digital elevation model(DEM) of difference(DoD) algorithm was used to derive the sediment yield of the plot. The accuracy of the derived sediment yield was then assessed by using the measured sediment yield. The spatial pattern of erosion-deposition within the slope-gully system was also investigated based on the DoD results. The results showed that:(1) DoD uncertainty(i. e. level of detection, LoD) ranged between 16.2 mm and 16.8 mm(average value is 16.5 mm) for a cumulative erosion monitoring, while LoD ranged between 16.2 mm and 16.6 mm with an average value of 16.4 mm for the consecutive erosion monitoring;(2) TLS-derived and measured cumulative sediment yields were highly correlated(R~2>0.9, p<0.05), and the mean(minimum-maximum) relative errors of TLS-derived values for the hillslope, the gully slope and the whole of the slope-gully system were found to be 52.63%(26.06%~106.98%), 56.68%(30.26%~75.49%) and 56.28%(33.37%~73.28%), respectively;no significant relation(R~2<0.57, p>0.05) was found between TLS-derived and measured consecutive sediment yield, and the mean(minimum-maximum) relative errors of TLS-derived values were 83.70%(4.08%~190.40%), 91.41%(0.95%~225.09%) and 87.58%(4.09%~215.55%), which demonstrated that TLS was more suitable for a monitoring of cumulative sediment yield rather than consecutive sediment yield in the slope-gully system;(3) the amounts of erosion and sediment yield on hillslope, gully slope and slope-gully system increased with the progress of runoff scouring, while depositions on gully slope and the whole of the slope-gully system stabilized after a rapid increase i

关 键 词：侵蚀产沙 三维激光扫描 时空分布 坡沟系统 黄土高原 

分 类 号：P237[天文地球—摄影测量与遥感]