Civil Engineering Reference
In-Depth Information
Figure 1.21
Basic components for earthquake loss estimations
retrofi tting for example. Vulnerability can also be reduced by other means, such as long- term land - use
management and education. Obtaining accurate inventories of exposed assets and their values remains
a signifi cant challenge that requires not only technical tools, but also political will and national com-
mitment, especially in regions where private industry holds large inventory data sets that are not in the
public domain.
Earthquakes can cause devastating effects in terms of loss of life and livelihood. The destructive
potential of earthquakes depends on many factors. The size of an event (expressed by either intensity
or magnitude as described in Sections 1.2.1 and 1.2.2), focal depth and epicentral distance, topographi-
cal conditions and local geology are important earthquake characteristics. However, the causes of
fatalities and extent of damage depend to a great extent on the type of constructions and the density of
population present in the area. Earthquakes exact a heavy toll on all aspects of exposed societal systems.
They can have several direct and indirect effects as shown in Figure 1.22 .
Ground shaking is by far the most important hazard resulting from earthquakes, with some exceptions
(e.g. the Asian tsunami of 26 December 2004 with about 280,000 people killed). Structural damage,
which is a feature of the primary vertical and lateral load-resisting systems, may vary between light
damage and collapse. Non-structural damage consists of the failure or malfunctioning of architectural,
