The hydrological correction check dams as a tool for erosion quantification

Abstract

Check dams have as a main purpose to retain sediments and reduce the peak flows in torrential rivers and ravines. The sediments retained upstream of the dams constitute a very valuable information source to quantify soil erosion and transport at basin scale. The aim of this work is to use the accumulated sediments in 425 check dams constructed in the Quipar River (a tributary of the Segura River, SE Spain, with an area of 826 km2). From all the check dams constructed in two periods (1962 and 1996), in 378 it was possible to quantify the volume of retained sediments, amounting to a total of 687.416 tons. Besides, erosion rates were estimated in 195 check dams. Erosion rates show a high variability. Average erosion for the whole basin of the Quipar River is about 4 t ha-1 yr -1, a value similar to that obtained by bathimetric techniques, although much lower than that calculated with USLE. Lithology is the most determinant factor in explaining the erosion rate, in such a manner that check dams withy the highest erosion rates are located on marls, conversely to those on limestones.