地理と自然災害のジャーナル
オープンアクセス

概要

Earthquake Risk Assessment around Nainital in Uttarakhand Himalaya, India

Piyoosh Rautela, Girish Chandra Joshi, Bhupendra Bhaisora, Sushil Khanduri, Suman Gildiyal, Chanderkela Dhyani and Ashish Rawat

Earthquake is a major hazard for all tectonically active areas and high probability of landslides being induced by seismic ground shaking in the hilly areas makes the situation worse as these often hinder post–disaster relief, search and rescue efforts. Seismic risk is evaluated for the Himalayan township of Nainital that falls in Zone IV of Earthquake Zoning Map of India where damage during an earthquake is expected to reach MSK (Medvedev– Sponheuer–Karnik) intensity VIII. Condition of the built environment and its ability to withstand seismic tremors is assessed using RVS (Rapid Visual Screening) technique of FEMA (The Federal Emergency Management Agency) and the likely earthquake induced damage is depicted as a function of the damage grades of EMS–98.14 percent of the surveyed buildings of the township are observed to fall in Category 5 damage class while another 22 percent fall in Category 4 damage class in case of damage reaching intensity VIII on MSK scale. 604 buildings falling in high landslide hazard zone are also likely to be most adversely affected by seismogenic landslides. Total economic losses are thus estimated to be US$ 208.13 million which is around 4 percent of the current average annual revenue receipts of the state government and devastation in a seismic event is not going to be restricted to Nainital alone. Nearby located and densely populated areas of Haldwani-Kathgodam, Kaladhungi, Ramnagar, Kashipur and others are likely to sustain major losses. Actual economic loss could therefore be manifold and cause serious setback to the economy of the state. The study is intended to be utilized for effective risk communication and recommends changes in building bye laws and their strict compliance, demolition and retrofitting of vulnerable structures together with mass awareness and promotion of risk transfer tools for making the built environment safer and state’s economy resilient to disasters.