Estimation of soil losses due to water erosion in the Dagua River Basin, Colombia

Abstract

The Dagua river basin, in Colombia, is the most important source of water for the Valle del Cauca ecosystem, however, due to poor agricultural practices, it has been affected by water erosion. This study aimed at estimating soil erosion in the Dagua river basin, using the universal soil loss equation (USLE). The results show that most of the area presents erosivities that are between 1000-5000 MJ.mm.ha-1, corresponding to low and very low categories. On the other hand, erodibility ranged from 0.143 to 0.842 t. ha.h. MJ-1 mm-1 ha-1, which is framed in the categories from weak to extremely erodable, where the low to medium category predominates. Regarding soil losses due to erosion, it was found that more than 20% of each of the municipalities of Dagua, Restrepo, La Cumbre, and Vijes, showed high and very high erosion, particularly in the areas with bare soils and crops such as pineapple, contribute strongly, sometimes reaching over 1000 t ha-1 yr-1. Therefore, it is important to promote practices such as contour or contour planting, integrated crop cover management, land uses that integrate trees, and in more critical cases to consider ecological restoration processes.