Soil Erosion Equation (USLE) factors (R, K, L, S and P), Soil Erodibility
Factor (K) is one of the most important and key factors which determines soil
particles resistance to be detachment by water erosion (rainfall and/or runoff)
forces. In fact, K factor is the rate of soil loss per rainfall erosion index
unit and affected by 6 parameters including soil primary particles (silt, sand
and clay), organic matter content and also permeability and structure of soil.
The USLE nomograph is one of the most rapid and common methods for calculating
K factor based on mentioned parameters. In this study, 38 samples of surface
soil (0 - 15 cm) were collected from Yamchi watershed and the percentage of
silt, sand, clay and organic matter content were determined in soil laboratory. Also textures of soil
samples were determined to choice soil permeability and structure class codes
based on United States Department of Agriculture (USDA) published information.
Using USLE nomograph equation, K factor was calculated for each soil sample and
based on kriging interpolation method, soil erodibility factor (K) map was
constructed for entire study area which average soil erodibility factor and
average standard error of interpolated map were 0.442 and 0.0076 t·ha·h·ha-1·Mj-1·mm-1,
 Panagos, P., Meusburger, K., Alewell, C. and Montanarella, L. (2012) Soil Erodibility Estimation Using LUCAS Point Survey Data of Europe. Environmental Modeling & Software, 30,143-145. http://dx.doi.org/10.1016/j.envsoft.2011.11.002
 Bagarello, V., Di Stefano, C., Ferro, V., Giordano, G., Iovino, M. and Pampalone, V. (2012) Estimating the USLE the Soil Erodibility Factor in Sicily, South Italy. Applied Engineering in Agriculture, 28, 199-206. http://dx.doi.org/10.13031/2013.41347
 Manyiwa, T. and Dikinya, O. (2013) Using Universal Soil Loss Equation and Soil Erodibility Factor to Assess Soil Erosion in Tshesebe Village, Northeast Botswana. African Journal of Agricultural Research, 8, 4170-4178.
 Pimentel, D., Harvey, C., Resosudarmo, P., Sinclair, K., Kurz, D., McNair, M., Crist,S., Shpritz, L., Fitton, L., Saffouri, R. and Blair, R. (1995) Environmental and Economic Costs of Soil Erosion and Conservation Benefits. Science, 267, 1117-1123.
 Pazhouhesh, M., Gorji, M., Taheri, S.M. and Keshavarzi, A. (2011) Determination of Soil Erodibility Factor Using Fuzzy Rule Base System. International Journal of Environmental Sciences, 1, 1874-1883.
 Wischmeier, W.H. and Smith, D.D. (1978) Predicting Rainfall Erosion Losses: A Guide to Conservation Planning. USDA Agriculture Handbook No. 537, USDA, Washington DC.
 Vaezi, A.R., Bahrami, H.A., Sadeghi, S.H.R. and Mahdian, M.H. (2010) Spatial Variability of Soil Erodibility Factor (K) of the USLEin North West of Iran. Journal of Agricultural Science and Technology, 12, 241-252.
 Auerswald, K., Fiener, P., Martin, W. and Elhaus, D. (2014) Use and Misuse of the K Factor Equation in Soil Erosion Modeling: An Alternative Equation for Determining USLE Nomograph Soil Erodibility Values. Catena, 118, 220-225.
 Wang, G., Gertner, G., Liu, X. and Anderson, A. (2001) Ncertainty Assessment of Soil Erodibility Factor for Revised Nniversal Soil Loss Equation. Catena, 46, 1-14. http://dx.doi.org/10.1016/S0341-8162(01)00158-8
 Zhang, Z.G., Fan, B.E., Bai, W.J. and Jiao, J.Y. (2007) Soil Anti-Erodibility of Plant Communities on the Removal Lands in Hilly-Gully Region of the Loess Plateau. Science Soil Water Conserve, 5, 7-13.
 Tejada, M. and Gonzalez, J.L. (2006) The Relationships Between Erodibility and Erosion in a Soil Treated with Two Organic Amendments. Soil and Tillage Research, 91, 186-198. http://dx.doi.org/10.1016/j.still.2005.12.003
 Renard, K., Foster, G., Weesies, G., McCool, D. and Yoder, D. (1997) Predicting Soil Erosion by Water: A Guide to Conservation Planning with the Revised Universal Soil Loss Equation (RUSLE). US Department of Agriculture, Agriculture Handbook No.703USDA, USDA, Washington DC.
 Wischmeier, W.H., Johnson, C.B. and Cross, B.V. (1971) A Soil ErodibilityNomograph for Farmland and Construction Sites. Journal of Soil and Water Conservation, 26, 189-193.
 Tran, L.T., Ridgley, M.A. and Duckstein, L. (2002) Application of Fuzzy Logic Based on the Revised Universal Soil Loss Equation. Catena, 47, 203-226. http://dx.doi.org/10.1016/S0341-8162(01)00183-7
 Bahrami, H.A., Vaghei, H.G., Vaghei, B.G., Tahmasbipour, N. and Taliey-Tabari, F. (2005) A New Method for Determining the Soil Erodibility FactorBased on Fuzzy Systems. Journal of Agricultural Science and Technology, 7, 115-123.
 Perez-Rodriguez, R., Marques, M.J. and Bienes, R. (2007) Spatial Variability of the Soil Erodibility Parameters and Their Relation with the Soil Map at Subgroup Level. Science of the Total Environment, 378, 166-173. http://dx.doi.org/10.1016/j.scitotenv.2007.01.044
 USDA (1983) National Soil Survey Handbook. No. 430. US Department of Agriculture, USDA, Washington DC.
 Smith, J.L., Halvorson, J.J. and Papendick, R.I. (1993) Using Multiple-Variable Indicator Kriging for Evaluating Soil Quality. Soil Science Society of America Journal, 57, 743-749. http://dx.doi.org/10.2136/sssaj1993.03615995005700030020x
 Bonilla, C.A. and Johnson, O.I. (2012) Soil Erodibility Mapping and Its Correlation with Soil Properties in Central Chile. Geoderma, 189-190, 116-123. http://dx.doi.org/10.1016/j.geoderma.2012.05.005