Hundreds of buildings in the two major tourist destinations - Nainital and Mussoorie - show high probability of Category V damage in the event of a seismic activity reaching intensity VIII on the MSK Scale. Such buildings will require reconstruction with entire contents of these buildings deemed as being lost in case of an earthquake. This is one of the findings of a study on the seismic vulnerability of Nainital and Mussoorie published in the International Journal of Disaster Risk Reduction. This study was conducted by the Disaster Mitigation and Management Centre (DMMC) executive director Dr Piyoosh Rautela, Girish Chandra Joshi, Bhupendra Bhaisora, Chanderkala Dhyani, Suman Ghildiyal and Ashish Rawat.
Both Nainital and Mussoorie are located in the zone IV of Earthquake Zoning Map of India. Of the surveyed 6206 buildings 14 percent in Nainital and 18 percent in Mussoorie show high probability of Category V damage in the event of a seismic activity reaching intensity VIII on MSK Scale. According to the study by Rautela and others, the building vulnerability is generally highest with the use of local materials without engineering inputs and lowest with the use of engineered material with engineering inputs. “The building stock of Mussoorie and Nainital towns are classified into nine categories though most constructions (94 per cent) in both the hill stations were observed to be unconfined rubble masonry (URM)- mostly stone and brick masonry with slate/CGI roofing. Of the 6206 buildings surveyed under the study the oldest was reportedly constructed in 1836 in Mussoorie where another 282 were reportedly constructed in pre-1900 period.
The building stock in Nainital is also old with 487 of the surveyed buildings reportedly constructed in pre-1900 period. Thirteen buildings in Nainital and 30 in Mussoorie are more than five storeyed,”states the study. Eight hospital buildings in Nainital and 13 in Mussoorie, 103 school buildings in Nainital and 302 in Mussoorie along with 46 hotel buildings in Nainital and 320 in Mussoorie were also covered under the study. It states that the age of both hospitals and school buildings is certain to reflect adversely on their seismic performance and is a cause of serious concern. According to the study, 13 out of 21 surveyed hospitals of these towns would probably not be in a position to deliver the intended emergency healthcare facilities because of varying degree of structural and non-structural damages.
As the remaining ill-equipped hospitals struggle under increased pressure on their resources, a total collapse of healthcare facilities in the townships in the aftermath of an earthquake is likely. The study recommends detailed seismic vulnerability assessment of all lifeline structures including healthcare facilities on priority basis. Based upon this a detailed mitigation plan needs to be evolved by blending demolition, reconstruction and retrofitting along with ensuring the required factor of safety as enumerated by the Indian Standards (IS) Code for all important buildings.
Though this study also recommends aggressive and massive awareness drive for risk communication and for bringing forth acceptability of appropriate seismic safety measures amongst the masses, observers point out that the State authorities have done little to effectively address the issue of Uttarakhand’s seismic vulnerability.