Estimating a mathematical formula of soil erosion under the effect of rainfall simulation by digital close range photogrammetry technique

Abstract

A new design of soil erosion and rainfall simulator is presented at this study as an attempt to deduce a mathematical formula of soil surface erosion phenomenon to describe the behavior of the sandy soil under the rainfall simulation, soil deformation such as the gullies and surface eroding rills are monitored by the Digital Close Range Photogrammetry (DCRP) technique that includes capturing digital images by a smart cellphone camera, and a Terrestrial Laser Scanner (TLS) to digitalize the soil surface as a point cloud data to produce Digital Elevation Models (DEM) with an accuracy reaches 0.10mm with the watershed, color relief, 3D surface model. The results show that the mentioned methods give a typical digital surface feature express especially of using geometrical adjustment that controls the orientation of the digital surface. The SIFT technology of the digital imaging feature detection achieves accurate results despite its small cost, 12% if compared to the TLS method. As a result of the statistical observations, a simple mathematical formula was generated through the DCRP technique that describes the sandy soil behavior under a hybrid technique of rainfall simulation as a relation between the eroding rate and the duration through the different gradient slopes.