Error assessment in the Universal Soil Loss Equation.
Estimated average tolerable soil loss and conservation practice factor (P) values for Ratnagiri district are 9.45 t/ha/yr (for moderately deep soil) and 0.21, respectively.
Use and misuse of the Universal Soil Loss Equation.
Erosion increases with slope steepness, but in contrast to the L factor for the effects of slope length, RUSLE makes no differentiation between rill and interrill erosion in the S factor that computes the effect of slope steepness on soil loss.Slope shape is a variation of slope steepness along the slope. Slope steepness and position along the slope interact to greatly affect erosion. Soil loss is greatest for convex slopes that are steep near the end of the slope length where runoff rate is greatest and least for concave slopes where the steep section is at upper end of the slope where runoff rate is least.The LS factor is a measure of sediment production. Deposition can occur on concave slopes where transport capacity of the runoff is reduced as the slope flattens. This deposition and its effect on sediment yield from the slope is considered in the supporting practices P factor.C factor: The C factor for the effects of cover-management, along with the P factor, is one of the most important factors in RUSLE because it represents the effect of land use on erosion. It is the single factor most easily changed and is the factor most often considered in developing a conservation plan. For example, the C factor describes the effects of differences between vegetation communities, tillage systems, and addition of mulches.
This mixture of effects illustrates that K is empirical. It is not a soil property, but is defined by RUSLE definitions. The definition for K, and for all RUSLE factors as well, must be carefully observed to achieve accurate results. For example, using K to account for reduced soil loss from incorporation of manure is not proper and produces incorrect results.
Soil loss estimation by field measurements in the …
RUSLE is a "lumped" process-type model based on the analysis of a large mass of experimental data and equations based on fundamental erosion processes where experimental data are inadequate to define RUSLE factor values. Rather than explicitly representing the fundamental processes of detachment, deposition, and transport by rainfall and runoff, RUSLE represents the effects of these processes on soil loss.
Watershed delineation and soil loss estimation of ..
Supporting practices typically affect erosion by redirecting runoff around the slope so that it has less erosivity or slowing down the runoff to cause deposition such as concave slopes or barriers like vegetative strips and terraces. The major factors considered in estimating a P factor value include runoff rate as a function of location, soil, and management practice; erosivity and transport capacity of the runoff as affected by slope steepness and hydraulic roughness of the surface; and sediment size and density.
system based soil loss and sediment estimation in gerdi ..
Version 1.04 included major improvements in the C factor for rangelands and no-till cropland. RUSLE1.05 improved the handling of residue for crops that senesced, the computation of the effects of mechanical disturbance on rangelands, and the effect of row grade on soil loss in low rainfall areas.
The comparison between universal soil loss equation …
New features in version 1.06 include computation of deposition on concave slopes, in terrace channels, and in sediment basins as a function of sediment characteristics; computation of deposition in terrace channels as a function of the incoming sediment load and the transport capacity in the terrace channel; computation of b values for the effectiveness of ground cover based on land use, slope steepness and length, and the ratio of rill to inter-rill erodibility; computation of the slope length factor from an estimate of the ratio of rill to inter-rill erosion, slope steepness, and land use; and improved computation of the effectiveness of ground cover on steep slopes at construction sites. The current 1.06b version also contains a calculation change for the soil moisture (SM) sub-factor of the cover-management (C) factor.
estimation of soil loss and identification of critical area for ..
NumberOCOrganic carbonOMOrganic matterPConservation practice factorRRainfall erosivity factorRSRemote sensingSSlope steepness factorSCSSoil Conservation ServiceSOISurvey of IndiaSPAWSoil-Plant-Air-WaterSRTMSatellite Radar Topography MissionTTonneUSDAUnited States Department of AgricultureUSLEUniversal soil loss equationviz.