Evaluation of the spatial characteristics of slope erosion using field electrical resistivity measurements

Abstract

Slope erosion due to rainfall, being a complex and serious problem worldwide, is related to natural hazards and the environment. However, scientific evaluations of slope stability are lacking, and research on the spatial characteristics of slope erosion is scarce. As such, in this study, we constructed a method of evaluating the spatial characteristics of slope erosion that we combined with electrical measurements; subsequently, we conducted an in situ model test. We observed a step-type growth trend in the change in resistivity, which was divided into different degrees of erosion using the K-means clustering method. Moreover, we selected excavated slopes with supporting structures and landfill slopes without supporting structures to evaluate the spatial characteristics of engineered slopes after several months; finally, we applied the proposed evaluation method. We used seasonal and trend decomposition using loess to remove the noise and randomness in the resistivity data, and determined the change in resistivity based on the threshold calculated through probability density statistics. We categorized the erosion of slopes into different states and identified a spatial step-type growth trend in slope erosion, which was in good agreement with the spatial distribution characteristics of cracks on the slope. We observed serious erosion at the bottom and shallow parts of both slopes, which showed a high risk of local collapse according to the spatial characteristics of slope erosion and our slope stability analysis.