Introduction - Semi-quantitative Approaches for Landslide Assessment and Prediction - page 48

with Space Application Centre (SAC), Ahmedabad in 1:50,000 scale. They used
IRS LISS-II and PAN data and integrated different thematic maps giving weigh-
tages and ranks in a GIS environment. Lee and Pradhan ( 2006 ) introduced landslide
hazard and risk mapping on Penang Island, Malaysia using Geographic Information
System and Remote Sensing Data. Barbieri and Cambuli ( 2009 ) presented statis-
tical method in landslide susceptibility mapping in 18th World IMACS/MODSIM
Congress, Australia. An integrated approach for landslide susceptibility mapping
using Remote Sensing and GIS was produced by Sarkar and Kanungo ( 2004 ),
Shari

kia (2007) Pande et al. ( 2008 ), and Nithya and Prasanna ( 2010 ). Recently,
Remote Sensing and GIS based Analytical Hierarchy Approach is one of the most
popular and widely applied decision support system and has been used to syn-
thesize various judgement comparisons to derive priorities among the criteria
responsible for landslide and to prepare landslide susceptibility map (Saaty 1990 ,
1994 ; Saaty and Vargas 2001 ; Yang et al. 2006).

1.12 Study on Landslide Management

Given the rapid demographic expansion found in much of the region, it simply
won ' t be possible to set aside all vulnerable slopes for protection; therefore, some
strategies of slope stability on steep lands are required. Reforestation and improved
road drainage (e.g. Bergin et al. 1995 ; Siddle et al. 1985; Royster 1979; Cruz and
Reyes 2000; IADB 1999), have received considerable attention but there is still a
need to identify agricultural practices that reduce vulnerability to slope failure.
A soil conservation survey conducted in Honduras, Nicaragua, and Guatemala in
the wake of Hurricane Mitch failed to

”
farming on landslide resistance during the storm (World Neighbors 2000). Use of
agro-forestry, contour cropping, physical and vegetative erosion barriers, or inte-
grated weed management were found to reduce soil degradation and surface erosion
on farms affected by Mitch, but these techniques did not correlate with a reduction
in landslides. While it is possible that soil conservation farming truly has no effect
on slope stability, the experience of geotechnical engineers and landslide modelers
indicates that land management targeted to soil or site-speci

nd any bene cial effect of “ agro-ecological

c conditions can
reduce the probability of slope failure (Montgomery et al. 2000; Collison et al.
1995; Royster 1979).
The number of variables involved makes it dif

cult to characterize the influence
of land management on landslide susceptibility and even more dif cult to predict

how changes in management will impact the current state. In recent years, the eld

of physical landslide modeling has made excellent progress in dealing with the
complexities of slope failure. Applications of simpli

ed slope-stability models have
proved effective as descriptive and predictive tools in temperate zones, allowing for
rapid stability assessment over a wide area (Jibson et al. 2000 ). Knowledge of a
stability index alone may be useful for planning timber harvests (e.g. Montgomery
et al. 2000) or for citing infrastructure (e.g. Carrara et al. 1995 ), but it is not helpful