Hydraulic factors and erodibility on the edafoclimatic gradient Ebro Depression-Pyrennes

Abstract

The soils of 5 test areas along a transect between the Inner Ebro Basin and the Central Pyrenees have been studied, in order to detect possible gradients in soil erodibility and hydraulic properties. All studied soils show similar values of erodibility, with a slight trend to decrease from the Ebro Basin to the Pyrenees. In all areas, except the one in the Inner Ebro Depression, the soil stoniness reduces considerably the erodibility of the soils. Soil hydraulic conditions show a bigger variability inside the test areas than along the transect. Strongly eroded areas show very low values of available water. In addition, the soils of all test areas show very low water conductivities under unsaturated conditions. This leads to a high runoff, resulting in soil erosion and in incomplete filling of the soil water storing capacity. Soil physical data of the studied areas show that the soil hydraulic conditions will degrade with time. This leads to unfavorable conditions for restoring vegetation after land use change.