Evaluation of Erosion Intensity and Dynamics Using Terrestrial Laser Scanning

Abstract

A new method of instrumental measurement of the intensity of rill and linear erosion on slopes by the method of terrestrial laser scanning is proposed. This method was tested on four plots in 2012–2016 with the use of Trimble™ GX, Trimble™ VX, and Trimble™ TX8 laser scanners. The terrestrial laser scanning is characterized by a high precision and rapidity, which could not be previously achieved by other devices. It has a number of advantages: registration of various types of erosion of temporary water streams; measurements from a distance without the disturbance of the studied surface and providing the safety of works; and calculations of morphometric parameters of slope using a high-precision digital model of topography. The given examples show that this approach may be applied to assess the denudation-accumulative balance of the moved soil material on slopes, to determine the dynamics of amount of deposits on different parts of a slope as a result of different kinds of surface runoff, and to identify spatial regularities of the formation of the network of rills and gullies. In addition, laser scanning makes it possible to perform an integral assessment of the combined impact of the entire combination of exogenous processes developed on slopes and affecting the soil cover. The observations on test plots showed a rather great role of autumn rains in the total soil loss from erosion. The data obtained were used as the basis for the elaboration of practical recommendations concerning the survey organization and monitoring of erosion with the use of laser scanning.