Earthquake Hazard Study

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Recently GIS and remote sensing has been adopted for solving worldwide problems in terms of natural and manmade hazard assessment and management including surrounding natural and manmade resources. The main terminology here in GIS and Remote sensing to earthquake hazard assessment is to do investigation and analysis of sub and site surface geomorphology and geological features including historical seismicity data. Theilen (2010) discussed that the important factor that must be accounted for in local earthquake hazard studies is a site’s surface and subsurface conditions and expected response in the form of ground motions(earthquake shaking). According to Gupta (2003), earthquake damage within a region may perhaps differ locally, since it depends …show more content…

The soil attributes and rock structures are the main factors needed to do further investigated and assessed into delineation of liquefaction potential zones. According to Greene et al. (1994), during any shaking hazard at the time of earthquake events the sediments that are saturated and soft i.e., clay-free deposits of sand and silts are more vulnerable to lose strength and behave as a viscous liquid, thus this is simply a process of liquefaction. Greene et al. (1994) further discussed that the seismic waves that passes through saturated granular layers during earthquake events are the main actions taking place in the soil that leads to liquefaction and at this time of action, the granular structures are distorted, and cause loosely packed groups of particles to collapse where any infrastructures that are built on top are also more likely to collapse. Liquefaction is common in any earthquake event of greater magnitude (Justin, Baldwin and Hoeft, 2005). The shaking intensity is the main cause of any Liquefaction to occur. Thus Liquefaction is the process in which water is combined extremely with soft and saturated sediments or soils, normally from the actions of shaking intensity and the pressure it implies, which causes the soils to behave like quicksand (CRC, 2006). This physical acts leads to ground failure or subsidence resulting in demolition of existing infrastructure. According to NBMG (1980) …show more content…

Likewise liquefaction, it is the way forward in analysing and integrating several factors in a GIS environment to delineate specific areas of hazard zones related to earthquake. The environmental factors can be identified and extracted from remotely sense data or through integration from existing databases within a GIS environment (Yagoub, 2015). Microzonation is the process of sub division of region in to number of zones based on the earthquake effects in the local scale (Sitharam and Anbazhagan, 2016). According to Mohanty et al. (2006), earthquake hazard micro-zonation is a way forward to discover or demarcate vulnerable zones and or areas of earthquake hazard or risk where this can assist in adopting safety measures during an earthquake event.. It is also the process of estimating response of soil layers under earthquake excitation and thus the variation of earthquake ground motion, magnitude and depth characteristic on the ground surface (Sitharam and Anbazhagan, 2016). According to Pal et al. (2006) the earthquake hazard zonation in Sikim Himalaya was prepare from analysing 8 thematic layers within the GIS platform. Pal et al. (2007) have integrated several environmental and seismic data layers namely: Geology (GE), Soil Site Class (SO), Slope (SL), Landslide (LS), Rock Outcrop (RO), Frequency Wavenumber (F–K) simulated Peak Ground

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