| Popis: |
Construction sites rely on erosion control practices to protect bare slopes and prevent soil loss. The effectiveness of certain erosion controls is often under-evaluated if they are not a part of a product evaluation program. Furthermore, erosion controls in general are not fully understood regarding how their performance can be affected by site specific variables, such as soil variations. This study used large-scale rainfall simulators to evaluate how a commonly used erosion control on construction sites, broadcasted straw mulch, performs on three common soil types in Alabama. The study at the Auburn University, Stormwater Research Facility (AU-SRF) used the industry standard testing method and three different soil types: sand, loam, and clay in accordance with ASTM D6459-19, the standard test method for testing rolled erosion control products’ (RECPs) performance in protecting hillslopes from rainfall-induced erosion. As required by ASTM D6459-19, the rainfall simulators simulated a storm of varying 20 min increments of 2 in./h (5.08 cm/h), 4 in./h (10.16 cm/h), and 6 in./h (15.24 cm/h). A total of nine bare soil tests on the 4:1 test plots was performed with an average total soil loss of 1977 lb (897 kg), 236.2 lb (107 kg), and 114.2 lb (51.8 kg) for sand, loam, and clay, respectively. The average erodibility K-factor for each soil type is calculated to be 0.37 (sand), 0.043 (loam), and 0.013 (clay). Nine straw tests were performed on the 4:1 plots, with an average total soil loss of 44.31 lb (20.1 kg), 6.74 lb (3.1 kg), and 17.13 lb (7.8 kg) for sand, loam, and clay, respectively. Straw testing indicated substantial soil loss reduction with average cover management C-factor values under the revised universal soil loss equation (RUSLE) method of 0.021, 0.047, and 0.193 for sand, loam, and clay applications, respectively. This variation in C-factor across the three soil types indicates that the single C-factor, often reported by product manufacturers, is not adequate to imply performance. |
