The impact of the farming practice of remodelling hillslope topography on badland morphology and soil erosion processes

Abstract

Badland landforms, created in Plio–Pleistocene clay landscapes of the Basilicata region of southern Italy, form marginal features in a semi-arid landscape dominated by the widespread cultivation of subsidised cereals. These badland features are high relative relief forms exhibiting a high drainage density and steep slopes, with slope angles typically in excess of 35°. Economic incentives to increase agricultural productivity have resulted in the practice of remodelling these marginal areas using heavy earth-moving equipment. Remodelling the badland features creates longer slopes at lower angles, which can be cultivated using conventional farm machinery. These changes in hillslope morphology have altered the degree to which soil erosion processes operating in these areas are spatially coupled. In the badland areas, erosion and deposition are strongly localised with minimal sediment delivery to ephemeral or perennial channel systems. The economically-driven change in land use from visually striking badland areas to newly remodelled fields for agricultural use results in an increase in the coupling of drainage networks and a net increase in soil erosion.