Slope Stabilization with Vegetation, La Paz

The stability of slopes is governed by the load, which is the driving force that causes failure, and the resistance, which is the strength of the soil-root system. The weight of trees growing on a slope adds to the load but the roots of trees may serve as a soil reinforcement and increase the resistance. Vegetation may influence slope stability indirectly through its effect on the soil moisture regime. Vegetation intercepts rainfall and draws water from the soil via evapotranspiration. This reduces soil moisture and pore pressure, increases the shear strength of the soil, and increases the resistance. Vegetation roots tend to increase soil permeability and increase infiltration and soil moisture, while the organic layer associated with vegetative cover tends to retard infiltration. We stabilized 650 squared meters (sqm) in the CA-7 highway near Marcala, La Paz.