Authors: Miroslav Dumbrovský and Veronika Sobotková
Abstract: In the Czech Republic, soil erosion is a significant degradation process that threatens more than half the area of the arable land currently. The paper deals with the problem with ephemeral gully erosion. Ephemeral gully erosion is a serious problem in many cultivated fields in the Czech Republic. Ephemeral gullies are flow areas formed of deep rills in the path of concentrated runoff during the corn-growing season after conventional tillage operations. Erosion deprives the agricultural soils of the most fertile part (humus horizon), makes degradation of physical, chemical and biological soil properties, and reduces the thickness of the soil and humus content in the soil. The main purpose of this paper is to provide information about a suitable method for field assessment of ephemeral gully erosion with such a special kind of direct measurement procedures. Universal Soil Loss Equation often underestimates erosion in agricultural fields because it does not account for the loss of soil from ephemeral gullies. To properly assess the rate of ephemeral gully erosion in agricultural areas, it is necessary to determine precisely the volume of ephemeral gullies in the field by using direct methods. Recently, there has not been a suitable method for identifying and predicting the occurrence of erosion runoff from ephemeral gullies in the Czech Republic. This research used a special new method to quantify ephemeral gully losses in arable land. For analysis, when calculating ephemeral gully volumes, a new cross section method was developed. At the Institute of Landscape Water Management, Brno University of Technology, a device called an “ephemeral gully bridge” was designed and constructed, which allows the measuring of the soil surface cross section and quantifies the volume of ephemeral gullies. In the South Moravia Region of the Czech Republic, 63 cross sections of erosion rills were measured using the special kind of the soil erosion bridge directly in the field. Using this method, it is possible to calculate the volume of soil loss in different parts of a hillside on the plot after concreted intensive rain.
Keywords: soil erosion; rill and gully erosion; soil loss; ephemeral gully bridge