Natural Disasters and Diagnosis of Man-made Factors, the Cases of Manjil and Bam

A review of earthquakes occurring in Iran during the last three decades (since 1983 up to the present) indicates the outbreak of many earthquakes, eight cases of which having a magnitude of above 7. Review of major natural disasters of the 20th century shows that earthquake is one of the most dreadful disasters of the world, four cases of which have occurred during the past century in Iran. According to the above evidence and the tectonic maps, Iran is located in an earthquake prone zone; therefore, reducing the risks of earthquakes should always be considered in all fields of human activity, especially in architecture and construction. Taking pre-emptive measures to tackle natural disasters especially earthquakes through observing the principles of architecture and urban construction, and observing the system of urban and rural construction management is a priority and an important strategy for sustaining the development of the country which can decrease the damage caused by earthquakes. From this point of view, the consideration of the way buildings are prone to earthquake and choosing the methods suitable for the structural socio-economic conditions and natural environment are among the most important measures to be taken. If vulnerable spots of buildings are not taken seriously, damage to buildings may continue.2 Given that among the natural disasters of the last two decades, Manjil Earthquake, June 1990, and Bam Earthquake3, December 2003, were greater than the previous disasters in terms of property damage and loss of life, and since there is more evidence available about them, examination of and diagnosis of man-made factors in theses two major earthquakes become especially important. The present article comprises three main sections. The first section focuses on the behaviour of buildings in the epicentres of the earthquakes, namely the provinces of Gilān, Zanjān and Kerman. The second section highlights the damage inflicted upon the buildings and their vulnerable weak parts, and the final section summarizes the ignored matters and concludes by providing regular strategy of diminishing the losses.