Soil erodibility and its estimation for agricultural soils in China

Abstract

Soil erodibility (the K factor in the Universal Soil Loss Equation, USLE) is an important index to measure soil susceptibility to water erosion, and an essential parameter needed for soil erosion prediction. To evaluate the appropriateness of the nomograph and other methods for estimating the K factor for the USLE and to develop a relationship for soil erodibility estimation for Chinese soils, a set of soil erodibility values was calculated using soil loss data from natural runoff plots at 13 sites in eastern China. The definition of soil erodibility in relation to the USLE was strictly followed. Comparing these measured values to those estimated using the nomograph method, the method adopted for the EPIC model and the formula of Shirazi and Boersma, we found that all these estimated soil erodibility values were considerably higher than the measured soil erodibility for these sites in eastern China. Soil erodibility for these Chinese sites is typically in the range from 0.007 to 0.02 t h (MJ mm)À1 and consistently lower in comparison to the measured K values from the USLE database for the conterminous United States. Strong linear relationship between the estimated and measured K values were used to develop empirical formulas for soil erodibility estimation from soil survey data for sites in eastern China. r

Optimizing hotspot areas for ecological planning and management based on biodiversity and ecosystem services

“…where SC stands for the amount of soil conservation (t/(ha·yr)) ; SEp and SEa denote the potential and actual soil erosion rates; R is rainfall erosivity factor (MJ·mm/ (ha·h·yr)), and was computed using monthly average rainfall with an empirical equation (Wisch-meier and Smith, 1978;Fu et al, 2011); K is the soil erodibility factor (t·ha·h/(ha·MJ·mm)) and was calculated using the modified equation based on the Erosion/Productivity Impact Calculator (EPIC) model (Zhang et al, 2008) so as to be consistent with the practical situation of China (Li et al, 2011); LS is the dimensionless topographic factor, and was calculated based on the methods developed by Hickey and Van Remortel (Hickey, 2000;Van Remortel et al, 2001) with the help of an Arc Macro Language (AML) script in ArcGIS; C is dimensionless vegetation cover factor, and was estimated by the method using the form of NDVI (Li et al, 2011); P is the dimensionless conservation practice factor. As to P factor, the slope-based Wener method (Lufafa et al, 2003) was applied to calculate.…”

National assessment of soil erosion and its spatial patterns in china

“…The erosion-productivity impact calculator (EPIC; Williams et al 1983) was employed to calculate K using the soil clay, silt, sand, Ecosystem Health and Sustainability and organic carbon content. The study conducted by Zhang et al (2008) was used for subsequent revisions.…”

Prioritization of Soil Erosion Vulnerable Areas Using Multi-Criteria Analysis Methods

“…Susceptibility of these soil types to erosion, denoted as a K factor (Fig. 3), based on soil texture (content of silt, sand, and clay fraction) and organic carbon content in the surface soil layers (0-30 cm) is estimated using the equation given in the EPIC model [14]. The third parameter used for assessing the vulnerability to erosion was a topographic parameter -mean watershed slope and its values are displayed in Table 1.…”