Himachal Pradesh has witnessed a six-time increase in major landslides in the past two years with 117 occurring in 2022 as compared to 16 in 2020, according to data compiled by the disaster management department.
There are 17,120 landslide prone sites in the state out of which 675 are near critical infrastructure and habitations. The maximum of such sites are in Chamba (133) followed by Mandi (110), Kangra (102), Lahaul and Spiti (91), Una (63), Kullu (55), Shimla (50), Solan (44), Bilaspur (37), Sirmaur (21) and Kinnaur (15).
High intensity rainfall coupled with cutting of hill slopes or rocks at the foothills are the main reason behind the significant number of landslides, experts say. Extensive cutting of hill slopes for construction and widening of roads, blasting for tunnels, hydro projects and mining are cited as reasons behind the increase in landslides, geological expert Prof Virender Singh Dhar said.
Though the time span of rains has been reduced, their intensity has increased. High temperatures coupled with heavy rains lead to landslides due to loosening of the strata in places which have undergone cutting downstream on the foothills, said Scientist (Climate Change) Suresh Attre.
Out of the 117 major landslides witnessed in 2022, a maximum number of 21 were reported in Kullu followed by 20 in Mandi, 18 in Lahaul and Spiti, 15 in Shimla and 14 in Lahaul and Spiti, nine in Sirmaur, eight in Bilapsur, five in Kangra, three each in Kinnaur and Solan, one in Una while no landslide occurred in Hamirpur.
Majority of slides were witnessed during the monsoon season, Special Secretary, Disaster Management, Sudesh Mokta told PTI. Increased human activity and exploitation of natural resources for development has posed a serious threat to ecology, said a former bureaucrat.
The major active landslides/sinking sites in the state included villages Jhandota and Kakroti and Sapdoth Panchayat in Chamba, Mcleodganj hill and Bariara village in Kangra, Baridhar to Kalyan Ghati road, Mansar near Salogra and Jabalpatwar village in Solan, Kotrupi, Doada Hanogi, 5, 6 and 7 mile near Pandoh and village Nagani in Mandi district.
The other sites include Urni Dhank, Batsari, Nesang, Purbani Julha in Kinnaur besides Nigulsari where 28 people were killed and 13 were injured in a major landslide on August 11, 2021. A maximum of ten such sites have been identified in Shimla district. Chief Minister Sukhvinder Singh Sukhu said recently that the National Highway Authority of India (NHAI) will present a concept paper suggesting remedies to minimise and prevent landslides which occur due to expansion of roads in the state and Rs 300 crore will be spent on remedial measures.
According to the Landslide Atlas of India prepared by the National Remote Sensing Centre, ISRO, all 12 districts of Himachal are susceptible to landslides.
The landslide exposure analysis carried out in the mountainous areas covering 147 districts in 17 states ranked Mandi district of Himachal at the 16th place, followed by Hamirpur 25, Bilaspur 30, Chamba 32 , Solan 37, Kinnaur 46, Kullu 57 Shimla 61, Kangra 62, Una 70, Sirmaur 88 and Lahaul and Spiti 126 in socio-economic parameter risk exposure map.
In view of the frequent landslides, early warning and land monitoring systems, which would give information about landslide activity in advance are being installed at some places in the state, officials said.