Abstract: Three-dimensional scanning with LiDAR has been widely used in geological surveys. The LiDAR with high accuracy is promoting geoscience quantification. And it will be much more convenient, efficient and useful when combining it with the Unmanned Aerial Vehicle (UAV). This study focuses on UAV-based Laser Scanning (UAVLS)geological field mapping, taking two examples to present advantages of the UAVLS in contrast with other mapping methods. For its usage in active fault mapping, we scanned the Nanpo village site on the Zhangxian segment of the West Qinling north-edge fault. It effectively removed the effects of buildings and vegetation, and uncovered the fault trace. We measured vertical offset of 1.3m on the terrace T₁ at the Zhang river. Moreover, we also scanned landslide features at the geological hazard observatory of Lanzhou University in the loess area. The scanning data can help understand how micro-topography affects activation of loess landslides. The UAVLS is time saving in the field, only spending about half an hour to scan each site. The amount of average points per meter is about 600, which can offer topography data with resolution of centimeter. The results of this study show that the UAVLS is expected to become a common, efficient and economic mapping tool.

Key words: Unmanned Aerial Vehicle(UAV), LiDAR, Active fault, Landslide, High resolution

摘要： 激光雷达（Light Detection and Ranging，LiDAR）三维地形测绘技术已广泛应用于地质调查和地球科学研究中，其高精度特性推动了地球科学定量化发展；将其与无人飞行器集成为低空扫描系统，使其更加省时、便捷、高效，拓宽了LiDAR在野外调查的用途。将无人机载LiDAR测绘系统应用于野外地质调查，以2个实例展示了该系统LiDAR的优势与潜在使用前景。在活断层探测应用中，利用该系统对西秦岭北缘断裂漳县段南坡村研究点进行了扫描，有效地消除了地物和植被的影响，验证了断层展布位置，并获取了漳河T₁阶地的抬升量约为1.3m。另外，还对兰州大学黄土地质灾害观测试验站进行了扫描，为进一步分析微地貌对浅层黄土滑坡的影响提供了高分辨率地形数据。以上2个例子，扫描时间均较短，在0.5h左右，而且扫描得到的点云数据平均每m²约为600个点，分辨率可达到cm级别。试验结果表明，无人机载LiDAR三维扫描有望成为1种常规、高效和经济的测绘手段。

关键词: 无人机, LiDAR, 活动断层, 滑坡, 高分辨率