Multiscale Estimates of Soil Erodibility’ Variation Under Conditions of High Soil Cover Heterogeneity in the Northern Forest-Steppe of the Central Russian Upland

Abstract

One of the important scopes in erosion science is the study of soil erodibility, i. e. its ability to resist the destructing action of water flow and raindrops. The values of soil erodibility are used in erosion models and make it possible to calculate the rate of soil matter loss/accumulation. The purpose of this study was to assess the soil erodibility and variation of this indicator in different scale areas in the northern forest-steppe of the Central Russian Upland. It has been established that the calculated indicator of soil erodibility (K-factor) is depended mainly by the content of organic matter. The average K-factor values of unwashed grey forest soils are more than one and a half times higher than those of unwashed chernozems. With an increase in the degree of erosion, the values of the K-factor also increase, for example, in the series: non-, weakly, medium- and strongly eroded chernozems with the following average values: 38, 42, 44, 57 kg h/(MJ mm), respectively. It has been found that grey forest soils are much more liable to risk of degradation from erosion than chernozems, other things being equal, due to their greater erodibility and lower thickness of the humus layer. The use of various methods of K-factor interpolation had little effect on changes in the average soil erosion rates calculated by the WaTEM/SEDEM model, even under conditions of high soil cover contrast. With a change in the scale level of soil erosion estimates (transition from a medium to a large scale, or from a large to a medium scale), the deviation of calculated average soil erosion rates was less than 15%.