Relationship between soil erodibility and shear wave velocity: A feasibility study

Abstract

Soil erosion seriously threatens environmental sustainability, affecting water quality and quantity, urban infrastructure, soil fertility and productivity, and forestry. Several empirical- and physical-based models have been developed to estimate soil erosion. Soil erodibility is one of the key factors used in these models for the assessment of soil erosion. It accounts for soil characteristics and properties effect on the erosion process. This study attempts to establish a relationship between soil erodibility (K) and shear wave velocity (Vs) in order to simplify the evaluation of K factor by omitting laboratory investigations. For this purpose, site along the Sungai Langat was considered as a case study and soil samples were collected from chosen points. According to the Tew equation, K factor depends on the basic soil properties, including particle size distribution, soil structure and texture, soil permeability, and organic matter content. The soil parameters used to estimate K factor were determined in the laboratory. Spectral-analysis-of-surface-wave (SASW) method was implemented to determine the Vs of soil. The results were plotted against K factor to determine the correlation of soil properties and Vs with K factor. It was found that sand was negatively correlated with K factor with a coefficient of determination (R2) value of 0.76. Clay was found to be positively correlated with K factor with an R2 value of 0.74. The relation between Vs and positive values of K factor produced an R2 of 0.304 through linear regression. This study provide the basis for future research with larger data points and variety in soil type and texture.