基于无人机技术的藏东南帕隆4号冰川表面高程和运动速度变化研究

应用无人机技术,采用后差分测量（post processed kinematic,PPK）方法替代传统控制点的方法,对藏东南帕隆4号冰川消融区进行了航测,获得了2017—2018年3期高精度正射影像（DOM）、数字表面模型（DSM）和三维点云数据;分析了该冰川航测区内表面高程变化、运动速度空间差异和冰川微地貌特征等. 结果表明:PPK测量技术应用效果良好,无人机产品水平和垂直精度分别约为0.11和0.17 m;帕隆4号冰川消融区表面高程变化量呈现随海拔升高而降低的空间分布规律,冰川冰体整体减薄4.06 m;冰川表面运动速度随海拔升高而增大,呈现冰川中流线区域略快于两侧的空间分布特征;冰川表面地貌特征随海拔由高到低呈现趋于“平滑”的变化规律. 此外,还探究了无人机技术在冰川变化研究中的潜力,为未来利用无人机开展更大范围冰川变化的研究提供了有益经验. 

Changes in surface elevation and velocity of Parlung No.4 glacier in southeastern Tibetan Plateau: monitoring by UAV technology

High-precision glacier change data is helpful for quantitative analysis of ice amount change and glacier dynamic movement change. Glacier monitoring by unmanned aerial vehicle (UAV) technology has the advantages of wide coverage, flexible observation time and high precision to overcome defects associated with traditional methods. UAV with PPK (Post Processed Kinematic) measurement technology was used to replace traditional control point (GCP) method to obtain three-phase high-precision DOM, DSM and three-dimensional point cloud data of Parlung No.4 glacier in the southeastern Tibetan Plateau from 2017 to 2018. Glacier surface elevation change, spatial difference of surface velocity and glacier microtopography characteristics were investigated. The horizontal and vertical precision of UAV products were found to be 0.11 and 0.17 m respectively. The decrease value of surface elevation difference of Parlung No.4 glacier showed a spatial distribution rule that decreased with elevation, glacier ice body was found to have thinned by 4.06 m. The surface velocity of glacier was found to increase with elevation, with the central streamline part of glacier slightly faster than the two sides. The landform characteristics of glacier surface tended to be “smooth” with elevation from high to low. The present work provides useful experience for future larger scale studies.