Reconstruction of historical soil surfaces and estimation of soil erosion rates with mound measurements and UAV photogrammetry in Mediterranean olive groves

Abstract

Soil water erosion is one of the most important environmental problems for the sustainability of Mediterranean olive groves on hillsides. Governments and public agencies recognize the need to control this process in order to improve soil conservation, especially in vulnerable areas. In the present study, a simple, inexpensive method using Structure-from-motion (SfM) and Unmanned Aerial Vehicle (UAV) technology was applied to quantify the soil loss rates provoked by water erosion and tillage in mountain olive groves, according to a reconstruction of their historical surface features. Specifically, the main study aims were: i) to quantify the historical soil loss in olive groves, by analysing residual tree mounds; ii) to consider how soil relief and management can influence the erosion process; iii) to determine the degree to which the proposed method achieves the above aims.