Universal Soil Loss Equation
The Universal Soil Loss Equation (USLE) is a widely used mathematical model that describes soil erosion processes.[1]
Erosion models play critical roles in soil and
The USLE was developed in the U.S., based on soil erosion data collected beginning in the 1930s by the U.S. Department of Agriculture (
Overview of erosion models
The two primary types of erosion models are process-based models and
Description of USLE
The USLE was developed from erosion plot and rainfall simulator experiments. The USLE is composed of six factors to predict the long-term average annual soil loss (A). The equation includes the
The USLE has another concept of experimental importance, the unit plot concept. The unit plot is defined as the standard plot condition to determine the soil's
A simpler method to predict K was presented by Wischmeier et al.
Over the last few decades, various techniques have emerged to compute the five RUSLE factors.[8] However, determining the P factor has proven to be challenging as there is usually a lack of geospatial information on the specific soil conservation practices in a given region. Thus, to estimate the P factor value in the RUSLE formula, a combination of land use type and slope gradient is often used, where a lower value indicates more effective control of soil erosion.[9]
The practice of creating field boundaries, such as stone walls, hedgerows, earth banks, and lynchets, was effective in preventing or reducing soil erosion in pre-industrial agriculture.[10] Recently a novel P-factor model for Europe has been developed from the data retrieved during a statistical survey that recorded the occurrence of stone walls and grass margins in EU countries. While this is one of the first efforts to incorporate cultural landscape features into a soil erosion model on a continental scale, the authors of the study pointed out several limitations, such as the small number of surveyed points and the chosen interpolation technique.[11] It has been demonstrated that landscape archaeology has the potential to fill this gap in the data about soil conservation practices using a GIS-based tool called Historic Landscape Characterisation[12] (HLC). Starting from the assumptions that the construction of field boundaries has always represented an effective method to limit soil erosion and that the efficiency of any conservation measures to mitigate soil erosion increases with the increasing of the slope, a new P factor equation has been developed integrating the HLC within the RUSLE model. In a recent study, modelling landscape archaeological data in a soil loss estimation equation enables deeper reflection on how historic strategies for soil management might relate to current environmental and climate conditions.[13]
See also
- Certified Professional in Erosion and Sediment Control (CPESC)
- Erosion control
- WEPP (Water Erosion Prediction Project), a physically based erosion simulation model
References
- ISBN 9789251034064.
- ^ National Resources Conservation Service, U.S. Department of Agriculture. Washington, DC. 61 FR 27998 "Technical Assistance." 1996-06-04.
- ^ Wischmeier, W.H. and D.D. Smith. 1978. "Predicting Rainfall Erosion Losses: A Guide to Conservation Planning." Agriculture Handbook No. 537. USDA/Science and Education Administration, US. Govt. Printing Office, Washington, DC. 58pp.
- ^ Wischmeier, W. H., and D. D. Smith, 1960. "A universal soil-loss equation to guide conservation farm planning." Trans. Int. Congr. Soil Sci., 7th, p. 418-425.
- ^ United States Department of Agriculture - Agricultural Research Service. 2014. "Revised Universal Soil Loss Equation (RUSLE) - Welcome to RUSLE 1 and RUSLE 2".
- ^ Lane, L.J., E.D. Shirley, and V.P. Singh. 1988. "Modeling erosion on hillslopes." p.287-308. In: M.G. Anderson (ed.) "Modeling Geomorphological Systems." John Wiley, Publ., NY.
- ISSN 1941-3300
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