Soil Loss Risk Analysis for Construction Activities

Abstract

Construction-related ground-disturbing activities leave exposed land susceptible to soil loss and increase the risk of polluting adjacent waterbodies with sediment-laden discharge. State and federal regulations require stormwater pollution prevention plans to be implemented during construction to mitigate the impact of stormwater runoff. Areas prone to soil loss can be identified early in site planning using soil loss modeling. Identification of these critical areas could influence the design and placement of erosion and sediment control practices. The Revised Universal Soil Loss Equation (RUSLE) can be applied to estimate the soil loss on construction sites in tonnes per Ha per year (tons/acre/year) by considering factors of rainfall erosivity, soil erodibility, length of slope, erosion control, and sediment control. This study integrates geographic information system (GIS) with RUSLE to create soil loss models for residential, commercial, and highway construction scenarios in the contiguous U.S.A. These three construction types were modeled in various locations throughout the country to assess erosive risk. Soil loss outputs were categorized into five risk tiers ranging from very low to very high. Southeastern states had the highest estimated soil loss during residential, commercial, and highway construction, reaching rates of 1,464, 706, and 1,302 tonnes per Ha per year (653, 315, and 581 tons/acre/year), respectively. This study provides a customizable model for any site-specific slope-length factor outside of the three construction scenarios modeled. Integration of GIS provides a unique opportunity to apply RUSLE across a larger landscape. The presented macro-scale data can be used for the design of erosion and sediment control practices.

Efficacy of Undisturbed Vegetated Buffers in Capturing Suspended Sediment

“…Using data obtained by Kazaz et al, a soil loss risk analysis for Nebraska was completed to determine which portions of the state are more at risk of erosion because of different soil and rainfall rates and require more intensive erosion and sediment controls ( 23 ). National geographic information system maps of soil erosion risk show that there is considerable variation in Nebraska of the factors that models use to determine erosion rates.…”

“…National geographic information system maps of soil erosion risk show that there is considerable variation in Nebraska of the factors that models use to determine erosion rates. Rainfall erosivity factors can range from 31 to 182 hundreds of ft tons acre -1 year -1 in h -1 (69 to 406 hundreds of m tonnes ha -1 year -1 in h -1 ) ( 23 ). Figure 1 shows the amount of soil loss because of erosion on a 1-acre (0.4-ha) site with an LS-factor of 1.0 and no cover or erosion control factors to demonstrate relative erosion risk owing soil and rainfall.…”

“…Models such as the Universal Soil Loss Equation (USLE) and the Revised Universal Soil Loss Equation (RUSLE) are tools designers and regulators often use to predict soil loss resulting from rill and interrill erosion ( 22 ). These models account for soil properties, rainfall energy based on location, topography, and any erosion or sediment controls, such as vegetation cover or sediment barriers installed ( 22 , 23 ). Rainfall erosivity, referred to as the R-factor, is based on location, with the largest values being in areas that experience the heaviest rainfall.…”

“…Vegetation on a site dramatically reduces the cover factor by securing the soil with roots and surface biomass. The support practice factor, or P-factor, represents the efficiency of any sediment control practices, usually considered 1.0 on bare construction sites, causing no change in the soil loss predicted ( 23 ).…”

Large-Scale Performance Evaluation of Various Woven Silt Fence Installations under Nebraska Highway Conditions

“…Sediment barrier designs are typically based on rules of thumb, with little scientific research being used in the design of most standard practices [10]. Some sediment barrier testing has been conducted to improve silt fence designs and implementations and increase the body of knowledge on the state of practice [9][10][11][12][13][14][15][16][17][18][19]. Past testing efforts can be divided into three general testing methods: (1) small-scale testing (typically in flumes), (2) the field monitoring of installations on active construction projects, and (3) large-scale testing that subjects entire installations to controlled conditions.…”