Mitigation of surface runoff and erosion impacts on catchment by stone hedgerows

Abstract

This paper presents the results of a study on the influence of hedgerows on the process of the surface runoff in the experimental catchment Verneřice 1, Ústí n. L. region, the Czech Republic. The influence of hedgerows on the surface runoff was simulated using the KINFIL rainfall-runoff model. The model parameters were assessed from the field measurements of the soil hydraulic parameters, in particular the saturated hydraulic conductivity and sorptivity. The catchment area is characterised by stone hedgerows constructed by land users throughout the past centuries, using stones collected from the adjacent agricultural fields. Presently, the hydraulic properties of these hedgerows reflect the characteristics of the mixture of stones, deposited soil, and vegetation litter, and they are more permeable than soil on the areas between them. Due to this fact, the permeability of the hedgerows produces a higher infiltration and a lower surface runoff. Therefore, the overland flow vulnerability and impact of water erosion decrease if they are situated in parallel to the contour lines system. The model was applied for two scenarios in the catchment – with and without hedgerows – to assess their effects on extreme rainfalls with a short duration. The surface runoff caused by extreme rainfall was simulated in order to show how hedgerows can mitigate the resultant flood and erosion. This paper provides relevant hydrological data and summarises the influence of man-made hedgerows on the overland flow control, i.e. on long and steep slopes surface runoff.