Landslide Mitigation - Semi-quantitative Approaches for Landslide Assessment and Prediction - page 239

8.3.8 Geo-textile Method for Landslide Mitigation
(A Bio-engineering Approach)
Among many other methods applied for soil erosion control and slope stabilization,
bio-engineering approach is one of the best choices. Gray and Leiser ( 1982 ) and
Howell et al. ( 2006 ) established bio-engineering methods to protect soil erosion and
slope instability. Collison ( 1993 ) assessed the role of vegetation cover on slope
stability. Bio-engineering is the utilization of vegetation may be alone or in com-
bination with geotechnical structure, for the protection of slopes by reducing and
controlling factors that cause instability. In the Shivkhola watershed, massive
landslide area with steep slope at Lower Paglajhora (not approachable, below the
Hill Cart Road, Fig. 8.13 ) should be brought immediately under the geo-textiles
method (mainly the jute nets) with an integrated scheme of introduction and
maintenance of the grass and fern seedlings at the opening of the net at regular
interval so that at maturity the entire slope becomes covered with vegetation thatch.
Another section of Paglajhora (Fig. 8.14 ) that faced massive landslide phenomena
on May, 2011 should also be brought under this geo-textile mechanism. The
introduced vegetation will get the nutrient from the decomposed jute net and grow
to its maximum soon to offer optimum protection of slope. Jute geotextiles are the
most effective among all types of geotextiles-both natural and man-made (Thomson
and Ingold 1986). Additionally, hygroscopic nature of jute yarns in the Jute
geotextile cause them to swell by around 20 % when wet. This situation will
promote to reduce the velocity of sub-surface water as well as entrapment of soil
particles. Before netting the slope, a fertilizer is to be spread on the slope in order to
Fig. 8.13 Landslip at
Paglajhora