Urban disasters

URBAN DISASTER

An urban area can be defined as an area with large population and high density. An urban disaster occurs mainly due to urbanization. Urban cities have lifelines like electricity line, water line, sewage
line, telephone line etc.
Urbanization of the world's population is accelerating. More than 50% of the global population is already urban with more than one billion people living in slums. This trend continues and it is estimated that by 2050 more than 67% of the world's population will be living in cities.

Based on the damage caused, urban disasters are classified into:

1. Urbanizing natural disaster is seen mostly in the developing world where substantial natural environment is not affected by human activities. It mainly occurs when residential areas and urban infrastructure are developed in rural areas.
2. Pseudo-urban natural disasters are disasters where there is little or no damage to human life whereas urban infrastructure and lifeline systems are completely destroyed. In such type of disasters, population density is not large and only property damages are prevalent.
3. Urban natural disasters are disasters that are largely amplified due to overpopulation and socioeconomic activities.

Urbanization is a major cause of concern in the current time due to the following reasons:

1. The marginalized rural populace invariably lives a nomadic life, constantly on the move, in search of a better life. They live as workers in rural areas toiling in agricultural fields or performing menial jobs
2. Upon arrival in urban cities, they are attracted to the luxurious and comfortable lifestyle preferring to stay back and work as unskilled laborers in the organized as well as unorganized job sector. This leads to formation of slums that lack sanitation services, supply of clean water, reliable electricity, law enforcement and other basic services.
3. Hence, slums in urban cities are a major centres of crime. Lack of healthy environment contributes to vector borne diseases that become the epicenter of epidemics
4. Statistics indicate that crimes originate in slums and spread across entire metropolitan cities making it an unsafe place to stay

EFFECT OF POPULATION ON URBAN NATURAL DISASTER

1. Ratio of amplification
2. Effect of population density on disasters

Urban natural disasters are characterized by catastrophe due to overpopulation and dense concentration of social capital which has not invested enough for disaster prevention. Highly populated cities amplifies the injury to its inhabitants and damage to property.

Other type of urban disasters include:

1.  Chernobyl nuclear disaster that devastated Pripyat city that was a major bustling center of activity
2. 1926 Miami hurricane, Hurricane of 1900 in Galveston, TX, 1994 Earthquake in Northridge, CA, Kanto Earthquake in 1923, Earthquake in San Francisco in 1906, Hwang He floods in 1931 in China, Tropical cyclone in Bangladesh in 1998.
3. The great Chicago fire in1871, Starvation in Bengal in 1943,

Higher losses of life and property in a given hazard intensity in urban areas are due to:

1. Increasing urbanization
2. Expansion of habitat into unsuitable vulnerable areas
3. Higher population densities
4. Vulnerable construction due to loss of traditional skills 
5. Ignorance, apathy and the false belief that disaster will not occur in the area
6. Complacency due to long gap between two events
7. Non-engineered unsafe construction
8. Structurally unsound and unauthorized vertical constructions and additions to houses