Soil loss and its possible consequences at a flatland watershed. Case of study: El Pescado Creek, Central-Eastern Argentina

Abstract

Among the models available to assess water erosion, the Universal Soil Loss Equation (USLE) is one of the most widely used. It is based on five factors, including rainfall, topography, soil, land-use and conservation practices. Due to the relevance of soil characteristics for most productive activities, modelling soil erosion is essential for studies that pursue territorial planning. The aim of this work was to determine the current soil loss in the flatland watershed of El Pescado Creek, in the Pampean region of Argentina, and to compare it with past and future scenarios. This research could be a useful contribution for policy makers in the design of future management strategies, especially considering the limited existence of previous studies regarding soil loss in the area. This lack of earlier information, and the fact that this watershed is undergoing an intense land-use change process, brings the novelty to this research. The land-use change process involves a substitution from grassland to urbanization, but in a large scale from grassland to horticulture and also to greenhouse horticulture in some specific areas. We estimated an increase in soil loss from the past scenario (1985) -mean of 0.85 Mg ha−1 y−1 to the current one -mean of 1.52 Mg ha− 1 y−1, with a trend that seems to continue towards the future scenario (2050) -mean of 3.07 Mg ha−1 y−1, this future scenario was established according to local land-use estimations and global projections. In order to contribute to the sustainability of the watershed as a system, we believe that territorial planning must be immediately included in the agenda of local policy makers, mostly regulating the transition towards agriculture and urbanized areas, which might be changing the patterns of natural landscape.