基于无人机倾斜摄影技术的黄土丘陵区典型小流域淤地坝特征信息提取与分析

淤地坝现状特征信息的精准提取对于淤地坝运行现状评估十分重要,全面的淤地坝特征信息可为病险坝除险加固提供重要依据,当前淤地坝特征信息提取尚缺乏科学高效的技术。针对此问题,拟提出基于无人机倾斜摄影技术提取淤地坝运行现状特征的方法,以无人机航拍影像为基础数据,生成三维实景模型和高精度DEM,用于淤地坝数目、位置、剩余库容、有效坝高等重要现状信息的提取和测量,进而分析小流域内淤地坝分布、组成结构、坝体信息、淤积程度、坝控流域面积等特征。将此技术应用于陕西省榆林市子洲县蛇家沟小流域,详细提取1座大型坝和3座中型坝的现状特征信息。经过同野外实测数据对比,提取的淤地坝坝体信息相对误差均＜3.8%。所识别的大型坝剩余库容不足,处于基本淤满状态,且坝顶明显沉降,在极端降水条件下具有极大的漫顶溃坝风险。坝地耕作面积占小流域面积比例仅为2.17%,仍有坝地尚未开垦利用。研究结果可为小流域淤地坝动态监测与科学管理提供新方法和新思路。

Extraction and Analysis of Feature Information of Typical Small Watershed Check Dams in the Loess Plateau Gully Region Based on UAV Tilt Photography Technology

Accurate extraction of the current characteristics of check dam is very important for the evaluation of check dam, and the comprehensive characteristic information of check dam can provide an important basis for the reinforcement of diseased and dangerous dam. However, the current check dam feature information extraction still lacks scientific and efficient technology. To address this problem, the proposed method was based on the unmanned aerial vehicle (UAV) tilt photography technology to extract the characteristics of the current status of check dam operation. UAV aerial images were used as the base data to generat a 3D real scene model and a high-precision DEM for the extraction and measurement of important current information such as the number, location, remaining storage capacity, and effective dam height of the check dam. and then analyze the distribution, composition structure, degree of siltation, dam-controlled watershed area and other characteristics of siltation dams in a small watershed. This technology was applied to the small watershed of Shejiagou in Zizhou County, Yulin City, Shaanxi Province, to extract detailed information on the current status characteristics of one large-scale dam and three mediumsized dams. After comparing with the measured data in the field, the relative error of the check dam body information was less than 3.8%. The identified large dams had insufficient remaining capacity and were in a largely silt-filled state, and the crest has obvious subsidence, which has a significant risk of dam failure under extreme precipitation conditions. The proportion of the dam land cultivated area to the small watershed area was only 2.17%, there was still land uncultivated as farmland. The research reaults can provide a new method and idea for dynamic monitoring and scientific management of check dams in small watersheds.