Prognosis and mitigation strategy for major landslide-prone areas Varunavat Parvat landslide in Uttarkashi

Ladari and Kansen villages are again located over terrace deposits, further west of
Uttarkashi town the villages of Badethi, Delesaur, Chamkot and Matli are again
occupying the terrace deposits (Figure 4). Indravati river the another major stream in
the area and left bank tributary of Bhagirathi river also has terraces and active flood
plain which are often subjected to flash floods and severe bank erosion during rainy
season.
Land use
Varunavat Parvat has dense pine forest on the ridges whereas the middle slopes of this
hill are having open pine forest with few pockets of sparse scrub. During the past
decades landuse changes have been conspicuous over the lower slopes of Varunvat
Parvat due to urban sprawl of Uttarkashi township (Plates 1 and 8) and this area of
natural vegetation mainly pine trees has gradually transformed into concrete jungle.
Landsliding activity in 2003 has completely buried Bus Stand and nearby hotels and
major part of Horticulture Colony, Masjid Mohalla and stretch of Rishikesh-Gangotri
National Highway at Uttarkashi (Figure 6). The crop fields of Gyansu, Padull and
Wasunga in the west of Uttarkashi township are developed over alluvial fan deposits.
Crop fields of Dang village in the south of Bhagirathi river are developed over alluvial
fan whereas the agriculture fields of Joshiyara, Mandwa, Kansen and Tiloth villages
are developed over the terraces of Bhagirathi river (Figure 4).
Landslide scenario in the area
Pre and post landslide field investigations during August, 2003 and October, 2003 have
revealed that the head-ward shifting and gradual enlargement of small slide zones and
their merging with the nearby large active slide zone (Tambakhani slide) has
transformed the former into large complex slide zone (Figure 5; Plates 1, 2 and 8).
Three major active slide zones observed on the Varunavat Parvat are Tambakhani
slide, Ramlila Ground slide and Masjid Mohalla – Horticulture Colony slide. Further
west of the slide zones an active debris flow slide zone is also developed in Gyansu
area. Some characteristic features of these slides are given below.
Prognosis and
mitigation
strategy
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Plate 8.
View of Varunavat Parvat
in August, 2003 with only
single prominent active
slide zone of Tambakhani
slide is seen