DAMAGE SCENARIO UNDER GREAT EARTHQUAKES, A CASE STUDY OF 1934 BIHAR-NEPAL EARTHQUAKE

Abstract

Disaster situations are rapidly increasing due to population growth, urbanization, destruction of natural environment, climatic changes etc. Bihar is one of the multi-hazard prone states of India. During the past 180 years, Bihar has faced devastating earthquakes in 1833, 1934, followed by a less damaging earthquake in 1988 and very latest the 251h, 261h April 2015 Earthquake. Among all 1934 Bihar Nepal Earthquake was the worst. It has been seen that whenever earthquake occurs, it occurs again and again. It is quite probable that an earthquake having the intensity similar to 1934 Bihar-Nepal earthquake may replicate again. Incidentally, Seismic Zoning Map of Bihar closely follows the intensity Isoseismicity of 1 9 T3h4u. s Intensity of 1934 earthquake will be taken as base for overall study. Census of India 2001 & 2011 has been used for the Demographic and housing data for various districts of Bihar. These data includes Population growth, population density, Type of house existing in Bihar, wall & roofing material, vulnerability of houses etc. For the identification of vulnerable area, the Land use map of Bihar has been overlapped over the isoseismal map of 1934 earthquake. This study estimate the probable damages, Economic lost, loss of lives, expected injuries that may occur in various districts of Bihar, if 1934 earthquake intensity repeats in the recent years. Damage scenario under hypothetical recurrence of 1934 earthquake intensities has been estimated in the form of expected economic loss and social loss for Ilk various districts of Bihar using an open source software tool named SeisVARA (Seismic Vulnerability and Risk Assessment of Housing) in order to assess the seismic risk of housing A stock. The projected damage scenario highlights the absolute seriousness of the situation given the present building stock and demands that all new construction in Bihar, without any exception, must be earthquake resistant and the existing critical and large occupancy buildings need to be surveyed and retrofitted, if required. The main reason observed for high loss and damages in some of the districts of Bihar - are high Population Density, Zone V, close to epicentre, construction on the slump belt, Weak I-louses to face the higher intensities, no proper planning, no guidelines and building codes were followed etc. The main aim of this study is to prepare Bihar to face upcoming earthquakes with minimum loss.