中文摘要：

无人机低空摄影测量技术是继遥感和三维激光扫面之后，在三维空间数据领域中又一个可用于大面积、高精度和快速获取三维点云数据的技术方法。随着摄影测量算法的改进和商品化发展，目前该项新技术在国内外广泛应用于各个领域，在地质灾害防治领域的应用也处于不断尝试阶段。结合利用无人机低空摄影测量技术调查甘肃黑方台地区黄土滑坡实例，在简要介绍低空摄影测量的基本原理和数据获取方法的基础上，阐述了该技术在区域黄土滑坡调查（面积为36km^2）和单体黄土滑坡调查方面的应用效果。结果表明：在区域滑坡调查方面，可以很好地认识其空间分布规律和发育特征；在单体滑坡方面，通过滑坡前后两期低空摄影测量数据分析，很好地认识滑坡的滑前变形迹象和成灾过程。由此可见，低空摄影测量技术在地质灾害防治领域具有广阔应用前景和一定科研价值。

英文摘要：

The new technology of UAVs low-altitude photogrammetry is a new three-dimensional space technology after radar remote sensing and 3D laser scanning. This technology has many advantages in the aspect of acquiring 3D point cloud data, such as large area operation, high-accuracy and capturing 3D geographical information quickly. With the algorithm improvement and commercialization development of low-altitude photogrammetry, this new technology is widely used in various fields in foreign countries. This new technology shows a tendency of rapid development in China, especially in the field of surveying and mapping, but in the geological and geotechnical engineering field is at a tentative stage. Based on briefly introducing the new technology of the basic principle and 3D data acquisition method, combined with an example about loess landslide investigation at Heifangtai tableland in Gansu Province, this paper described the application effect of the new technology in the regional landslide investigation and individual landslide investigation. The results showed as follows： ①We could greatly understand the regional spatial distribution of loess landslide in the regional landslide investigation. ②We learned the development characteristics and disaster process of the landslide by means of analyzing pre-sliding and post-sliding low-altitude photogrammetry datum in individual landslide investigation. Thus, UAVs low-altitude photogrammetry technology has broad prospects and research value in the field of geotechnical engineering and geological engineering application.