240 - Soil Erodibility at Bridge Construction Sites

Construction activity-generated sediment released into waterbodies may have adverse impacts on water quality and aquatic habitats. The soil erodibility factor (K) is one of the fundamental parameters affecting soil loss rate. There are several empirical equations for calculating K; however, most of these equations have limitations as they are often based on experiments conducted on soils in specific locations. These equations also do not adequately account for the seasonal variability of K. This study identifies the main factors affecting K and provides a summary of field methods, empirical equations, and models to determine the K factor. The relationship between soil erodibility and other soil loss factors is also discussed. Based on this review, two empirical equations suitable for estimating K at construction sites for U.S. soils are recommended. The study further conducted a comparative analysis, contrasting calculated K values derived from soil parameters collected in the field and those obtained from the SSURGO soil database. The results indicate that, although the recommended equations demonstrate acceptable performance, there are still opportunities for future research.