An official website of the united states government. Rainfall erosivity is a term that is used to describe. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. Among these factors, soil erodibility factor k is one of the key factors that required for soil erosion determination andor prediction across the world 10 and was.
While erodibility is an intrinsic material property resulting from characteristics, such as grain size and degree of cementation, erosivity depends upon hydraulic factors including discharge and channel curvature. Reasonable and prudent practices for stabilization rapps. Finetextured soils that are high in clay have low k values about 0. The samples of soil scope of the study the study focused on the characterization of erodibility using soil strength and stressstrain indices for soils in anambra state in southeastern nigeria and was limited to three sites in the state namely awka, agulu nanka and nnewi. This form provides notice to epa that you, the project operator identified in section i of this form, are certifying that construction activity at the project site identified in section ii, will take place during a period when the rainfall erosivity factor is less than five 40 cfr 122. This soil erodibility factor is a measure of the inherent erodibility of a given soil under the standard condition of the unit usle plot maintained in continuous fallow. Pdf rainfall erosivity and erodibility of inceptisols in the. Method factsheet rusle revised universal soil loss. Estimation of rainfall erosivity using 5 to 60minute fixedinterval rainfall data from china s. Given a constant discharge, the product of erodibility and erosivity varies with. Soil erosion modeling using rusle and gis on cameron highlands, malaysia for hydropower development soo huey teh a 30 ects credit units master. Pdf the rainfall erosivity r and soil erodibility k factors of the universal soil loss equation usle were determined on two sites in the. For a given soil conditions one storm can be compared quantitatively with another and a numerical scale of the values of erosivity can be developed. Erosivity and erodibility in encyclopedia of environmental management.
Erosivity and erodibility 981 erosion by water erosion. This guidance document provides an overview of soil erodibility and directions on how to assess erodibility for completion of appendix a. Rusle k values california state water resources control. Thus, erosivity of precipitation events is a function of their intensity and duration, and of the mass, diameter, and velocity of the raindrops. Soil erodibility is an estimate of the ability of soils to resist erosion based on the physical characteristics of each soil. The particular site is located on a soil survey map, and the erodibility of the soilmapping unit at the site is identified and entered into the rusle2 program. To facilitate these calculations, climate data files.
One of the key site characteristics is the erodibility of the soil. The rainfall erosivity factor calculator can be used to help determine if your small construction site qualifies for stormwater discharge waivers. Erosivity of precipitation as percent of total annual jan feb mar apr may jun jul aug sep oct nov dec soil erodibility soils differ in their susceptibility to erosion erodibility depending on natural and human factors. Erosivity is used around the world for assessing and predicting rates of soil erosion on agricultural lands. Generally, the quantity of erosion yield is dependent upon the ability of rain to detach the soil particles i. Difference between erosivity and erodibility soil erosion. A direct link to the materials for this video can be. In lake county, the soil erodibility of mountainous terrain is moderately low to very low, particularly in portions of the county north of clear lake. Erosivity definition and meaning collins english dictionary. To facilitate the soil loss calculations, a city database file is developed. Assessing changes in wind erosion climatic erosivity in china.
Results also show that the study area has high rainfall erosivity hence making it very susceptible to erosion. Estimating the usle soil erodibility factor in sicily, south. How to calculate rainfall erosivity factor using qgis. Tamk, university of applied sciences department of environmental engineering tampere, june 2011 tampere university of applied sciences department of environmental engineering ii. Soil erosion modeling using gis and rusle on the eurajoki watershed finland gossa wordofa thesis supervisor. In this article we will discuss about erosivity and soil erodibility. Once provided with this set of data, t he rusle model links erosion factors influencing soil erodibility k factor, erosivity r facto r, land cover and management c factor, slope length l fact or and slope s factor. Pdf rainfall erosivity is the capability of rainfall to cause soil loss from hillslopes by water. Panos panagos, pasquale borrelli, jonathan spinoni, cristiano ballabio, katrin meusburger, santiago begueria, andreas klik, silas michaelides, saso petan, michaela hrabalikova, preben olsen, juha aalto, monika lakatos, anna rymszewicz, alexandru dumitrescu, melita percec tadic, nazzareno diodato, julia kostalova, svetla rousseva, kazimierz banasik, christine alewell 2016, monthly. Over 10 million scientific documents at your fingertips. Erosion prediction revised universal soil loss equation. Prediction of soil erosion in pansoon subbasin, malaysia.
Because the mechanics behind erosion depend upon the competence and coherence of the material, erodability is treated in different ways depending on the type of. This paper investigates the predictability of the soil erodibility factor k in the revised universal soil loss equation from soil clay content c, the naperian logarithm of the geometric mean particle size d g and organic matter content om, using a global dataset compiled from published studies. Erodibility of agricultural soils, with examples in lake. Rainfall erosivity is an index that describes the power of rainfall to cause soil erosion. Calculating erodibility index the erodibility index ei. Fact sheet for determining construction rainfall erosivity waiver requirements. The soil erodibility factor kfactor is a quantitative description of the inherent erodibility of a particular soil. States rangelands are found in the rusle manual and the computer program. R rainfallrunoff erosivity factor k soil erodibility factor l slope length factor s slope steepness factor c covermanagement factor p support practice factor see the agriculture handbook no. Soil erodibility k factor values are selected from soil survey information available in field offices of the usdanatural resources conservation service nrcs. Soil erodibility soil erodibility k is the intrinsic susceptibility of a soil to erosion by runoff and raindrop impact.
Soil erodibility and processes of water erosion on hillslope. A high erodability implies that the same amount of work exerted by the erosion processes leads to a larger removal of material. Estimation of rainfall erosivity using 5 to 60minute. Erodability or erodibility is the inherent yielding or nonresistance of soils and rocks to erosion. Unified soil classification void ratio plasticity index. Erodibility of agricultural soils, with examples in lake and. Effect of land use types and slope on soil erodibility factor. Scientists are certain that changes in climate and land use will affect the erodibility of soils and regoliths and also the erosivity of rainstorms. Rusle2 data files supplied with the program or can be obtained from readily available.
The rainfall erosivity factor r is defined as the average annual sum of. In the universal soil loss equation, soil erodibility factor k is one of the effective factors on soil loss. Construction rainfall erosivity waiver fact sheet pdf 12 pp, 3 mb. Characterization of erodibility using soil strength and. Enhancing rusle to include runoffdriven phenomena 75 from measured daily values or daily values developed using a stochastic climate generator. The purpose of this study is to assess rainfall erosivity in europe in the form of the rusle rfactor, based on the best available datasets. The soil erodibility factor, k for the area is greater than 0.
In contrast, erosivity values in rusle are based on analysis of data from over 1,000 weather stations. The rainfall erosivity formula is an equation that researchers created and use to calculate the r factor of a location. Data have been collected from 1541 precipitation stations in all european union eu member states and switzerland, with temporal resolutions of 5 to 60 min. The following soil properties were used to determine the appropriate soil erosion category for nearly all soil types in iowa.
This guidance document is divided into a quick reference guide for ease of use by field personnel followed by supporting technical information. Soil where x 1 is % silt multiplied by 100 % clay, x 2 is % or ganic matter, x 3 is the soil structure code used in the u. Reasonable and prudent practices for stabilization rapps of. Erosivity is the term used to describe the potential of raindrop impact, runoff from snowmelt, or water applied with an irrigation system rainstorm to detach and erode soil. Instead of this, in keeping with the desire for a general conservation planning model, rusle2 developers assumed that only monthly normal precipitation and erosivity values were. Ei 30 is the most commonly used rainfall erosivity index, where e is the total kinetic energy per unit area during a precipitation event mjha 1 and i 30 is its peak 30min intensity mmha. Rainfall erosivity and erodibility of inceptisols in the. As a result, erosion is directly proportional to these two factors, and erodibility is the amount of soil loss divided by rainfall erosivity index.
One key parameter for modelling soil erosion is the soil erodibility, expressed as the kfactor in the widely used soil erosion. Rusle2 also uses values for the bimonthly distribution of the erosivity. Here, soils with low erodibility ratings are more resistant to the erosive effects of water. Applications of the usle the usle was developed initially as a tool to assist soil conservationists in farm planning. Erosivity can be defined as the potential ability of the rain to cause erosion. The greatest obstacle to soil erosion modelling at larger spatial scales is the lack of data on soil characteristics. To facilitate these calculations, climate data files have been developed called a city code for climatically homogeneous areas. R rainfall erosivity factor, expressed by an average erosion index. Relationship between soil erodibility, rainfall erosivity. Modern definitions of rainfall erosivity began with the development of the universal soil loss equation usle, where rainfall characteristics were statistically related to soil loss from thousands of plotyears of natural rainfall and runoff data. Conceptually, rainfall erosivity is the capacity of rain to produce erosion, whereas soil erodibility is the susceptibility of the soil to be eroded.
Assessing changes in wind erosion climatic erosivity in. Effect of land use types and slope on soil erodibility. The quick reference guide located in the following section is provided as a sixstep tool to evaluate slope, erosivity. Thus, rainfallerosivity and soilerodibility terms were added to the zingg and.
Method factsheet rusle revised universal soil loss equation. It is dependent on the physical characteristics of rainfall, which include raindrop size, drop size distribution, kinetic energy, terminal velocity etc. The result shows that 66% 7433 ha of the pansoon subbasin is classified. Rainfall erosivity is the capability of rainfall to cause soil loss from hillslopes by water. The amount of erosion will, therefore, depend upon the combination of the power of the rain to cause erosion and the ability of the soil to withstand erosion. This factor also correlated with the siltfine sand soil population. The usda natural resource conservation service is the primary user of rusle. One of the important variables used in the design of grassed waterways is the soil erodibility category.
For a particular soil, the soil erodibility factor is the rate of. By multiplying these factors, the me an relative soil loss in tons per hectare per year is calculated. Thus, the soil erosion is the function of both erosivity and erodibility. Erosion sensitive lands are those less resistant to erosive factors, and their soil. Land use map was used to produce coverage and management practice factor. It is defined as the potential ability of rain to cause the erosion. At the smallest scale, erosion begins by one of two processes. Rusle k values california state water resources control board. Pdf isolating erosivity and erodibility components in erosion by. Values used by rusle2 for average monthly temperatures and precipitation are available in. Relationship between soil erodibility, rainfall erosivity and. Rusle applications on arizona rangelands christopher jones1 introduction the revised universal soil loss equation rusle is a standardized soil erosion prediction equation that can be used for many land use situations. So we will explain what rainfall erosivity factor is, why and when you need to calculate rainfall erosivity factor.
While rusle has been used before in europe, rusle2015 improves the quality of estimation. When rainfall erosivity exceeds the soil erodibility, soil erosion occurs. Erodibility of agricultural soils, with examples in lake and mendocino counties anthony toby ogeen, uc cooperative extension assistant soil resource specialist, department of land, air, and water resources, uc davis. Wanga a school of geography, beijing normal university, key laboratory of environmental change and natural disaster, ministry of education, beijing, china b usdaars, southwest watershed research center, united states. Bryan soil erosion laboratory, faculty of forestry, uni. Erosivity r factor values for locations where a particular user will apply rusle are in a database file in the rusle computer program. You may need a pdf reader to view some of the files on this page. It is a function of the physical characteristics of the rainfall. K soil erodibility factor for specific soil horizon. Determining and mapping soil erodibility factor case.
Erosion sensitive lands are those less resistant to. Soil erodibility k is the intrinsic susceptibility of a soil to erosion by runoff and. Before we proceed, its important for us to mention a few points about rainfall erosivity factor. Erodibility definition and meaning collins english. Firstly, the research on soil erodibility is mainly focused on farmland. The results indicate that mean annual climatic erosivity was 2166 at 292 stations and 237471 at 6 stations, with the spatial distribution highly in accordance with wind speed r2 0. Rainfall erosivity and erodibility of inceptisols in the southwest colombian andes volume 32 issue 1 m. This article is a simplified guide on how to calculate rainfall erosivity factor using qgis. A term connected to erosivity is erodibility as both are functions of erosion.
Secondly, soil erodibility in different areas cannot be compared sufficiently. Soil erodibility and processes of water erosion on hillslope rorke b. Erosion prediction revised universal soil loss equation rusle the revised universal soil loss equation rusle is an easily and widely used computer program that estimates rates of soil erosion caused by rainfall and associated overland flow. These same factor values are retained in the rusle. Historically, the terms erosivity and erodibility were originally associated with the r and k factors in the universal soil loss equation usle, a r k l s c p 1. Erodibility is influenced by many factors, some of which vary during the year and or vary with soil management. Conceptually, rainfall erosivity is the capacity of rain to produce erosion where as soil erodibility is the susceptibility of the soil to be eroded. K soil erodibility factor provided gis map of k factor for the state or.
Predictability and uncertainty of the soil erodibility factor. The musgrave equation was the first to include a rainfall erosivity factor in the process of soil. Estimating the usle soil erodibility factor in sicily, south italy article in applied engineering in agriculture 282. Erosivity is a measure of the potential ability of soil, regolith, or other. They studied various properties of raindrop in various parts of the world to create this equation. Erodibility is defined as the vulnerability or susceptibility of the soil to erosion. Thus, erosion is a function of the erosivity of the rain and the erodibility of the soil.