The contribution of the root network of vegetation to slope stability

Mary Carmelle V. Bautista, MEP


Landslips and mass movement of soil is often the result of heavy, continuous rains.  This phenomenon is prevalent in areas where vegetation which protects the underlying soil is almost depleted.  The mere absence of vegetative cover exposes and weakens these slopes by allowing rainwater and the forces of gravity to work on these unstable areas.  As a response to the need to protect these slopes, several slope protection methods have been introduced and constructed in erosion prone areas.  However, meta analysis of researches have shown that vegetation can contribute to the surface protection of these slopes in two ways: providing cover against the infiltration of water and possessing roots which form an interlocking network in the subsurface of the soil, thereby reducing the chances of slope slips and movements.  Awareness and dedication to the preservation of the environment is the key to understanding the beneficial effects brought by the presence of vegetation on mountainous slopes.  The researcher recommended 1) the adoption of bio-engineering approach as a cost effective and reliable way of slope protection; 2) proper selection of plant species to be used in the bio-engineering approach; and 3) further study on the beneficial effects of the root system of vegetation on the stability of exposed soil slopes.

Source: UB Research Journal, Vol. XXXI, No. 2, July – December 2007