Abstract

Erosive processes on sloped grounds lead, on the one hand, to the infringement of the soil cover, and on the other hand, to the contamination of other environmental compartments with the products of surface runoff and the washout of soil. It is necessary to have reliable mathematical models for forecasting the processes of erosion at the catchment scale. From these positions the Russian-German project “Erosion” in the bilateral program “Volga-Rhine” has been developed and was realized.

One of the results of joint German and Russian group of scientists was the modelling system IWAN (Integrated Winter Erosion and Nutrient Load Model). This model allows the prediction of soil erosion during spring snow melting which was identified by catchment monitoring to be the major trigger for erosion. Application and calibration of the model was conducted with monitoring data from 2003 to 2005 for the catchment of the small river Lubazhikha (18.8 km2), located approximately 100 km south of Moscow. The dominant soil type is a gray forest soils. 53% of the area of the Lubazhikha catchment is used agriculturally.

The modelled annual water balance and the amount of runoff during individual snowmelt events for the period 2003 to 2005 match the measurements. Due to the realistic spatial distribution of erosion areas and their individual connectivity to the main stream channel, the simulated net erosion of the catchment is close to the measured loads. The error of sediment loads varies between 10 and 30%.

 

Keywords: Modelling, soil erosion, forecasting of water erosion, mathematical modeling