QUANTITATIVE MEASUREMENT OF SOIL EROSION FROM TLS AND UAV DATA

Abstract. Soil erosion is a major issue concerning crop land degradation. Understanding these complex erosion processes is necessary for effective soil conservation. Herein, high resolution modelling of relief changes caused by run-off from precipitation events is an essential research matter. For non-invasive field measurements the combination of unmanned airborne vehicle (UAV) image data and terrestrial laser scanning (TLS) may be especially suitable. The study's objective is to measure high precision digital terrain models (DTM) of the soil surface at two selected research areas with the extent of at least 500 square meters. The used UAV is integrated with GPS and inertial measurement unit (IMU). Furthermore, an active stabilizing camera mount equipped with a customary compact camera is implemented. For multi-temporal comparison of measured soil surfaces and for aligning UAV and TLS data a stable local reference system consisting of signalized points is defined by total station measurements. Two different software packages are applied for DTM generation from UAV images and compared to the corresponding DTM captured by TLS. Differences between the point clouds are minimal six millimeters and generally within TLS accuracy range. First multi-temporal comparisons are made and illustrate interesting surface changes.