Introduction - Semi-quantitative Approaches for Landslide Assessment and Prediction - page 22

A road crack was formed along NH-55, the road to Darjiling from Siliguri, at
Tindharia following heavy rain in the past few days on 4th August, 2007.
Another landslide incident happened in the same year on 16th July along the
Hill Cart Road and completely broken down the guard wall nearby Kurseong
town (Field Survey, 2008) (Fig. 1.15 ).

￿

A major landslides at 14 mile near Paglajhora disrupted traf c along the

National Highway-55 (Fig. 1.16 ) and toy train services between New Jalpaiguri
and Kurseong on 16th June, 2010 morning (Field Survey, August, 2010).

￿

Heavy showers and the vibration caused by Sikkim Earthquake invited
destructive landslide events at Tindharia (Fig. 1.12 ) and Lower Paglajhora on
10th May, 2011.

￿

Recently, landslide risk analysis, like many other forms of management of either
natural or civil engineering hazards, is a relatively new discipline. Earlier attempts
to reduce landslide risk were largely the history of management of landslide terrain,
construction of protective structures or monitoring and warning systems, or the
ever-increasing sophisticated methods for mapping and delineating areas prone to
landslide (Dai et al. 2002 ). Risk of landslide is normally de ned as the expected

number of lives lost, persons injured, property damaged and disrupted economic
activities due to particular landslide hazard for a given area and reference period
(Varnes 1984 ). To reduce the risk from the landslide events, the knowledge about
potentiality to landslide activity is crucially needed. But the information of land-
slide events is described in the form of landslide susceptibility map of the con-
cerned region and the preparation of this map depends on the complex sets of
knowledge of slope movement factors. The process of creating the maps involves
several qualitative or quantitative approaches (Soeters and Van Westen 1996 ;
Guzzetti et al. 1999a , b , c ).
The Shivkhola, the Right Hand Tributary of the mighty Mahanadi is located at
the southern flanks of Darjiling Himalayan Range of Kurseong division of Darjiling
District in West Bengal between Kurseong to the north and Tindhria to the south
within 88 N covering an

area of about 22.05 km 2 . It is famously known as Paglajhora, the most destructive
and torrential hill stream at its upper catchment (Fig. 1.14 ). The presence of a weak
and young set of rocks, a monsoonal climate with high intensity and long duration
rainfall and steep mountain escarpment slope are supposed to be the major prob-
lems associated with landslide in the study area become clear. Landslide in the
Himalayan region has been emerged as the dominant hill slope process. In the
Shivkhola Watershed, landslides at Jogmaya Tea Garden (Fig. 1.19 ), Tindharia Tea
Garden, and Paglajhora are destroying roads and others infrastructure, eliminating
the tea garden area and also disrupting transport and communication. This has
brought a serious attention of the local people and respective authorities to take care
the vulnerable communities living with hazards.

° 17 ′ 30 ″ Eto88 ° 23 ′ 45 ″ E and 26 ° 50 ′ 15 ″ Nto26 ° 53 ′ 35 ″