Impediments to disaster prevention and earthquake mitigation in megacities

Mitigation of Earthquakes

Disasters are bound to strike at a given time and they more often find us unaware, this is the sole reason why the majority of the disasters that happen are usually fatal and destructive. This then calls for the need to try as much as possible to prevent these disasters and in particular in our cities. This is due to the fact that in the cities there are large populations that live close to each other or work in offices crammed together hence the likelihood of a disaster turning absolutely fatal if and when it strikes.

There are various aspects that act to exaggerate the magnitude of a disaster in many cities that turns these disasters into deadly tragedies. One of the most predominant reasons is the poor planning that is found in many cities today. There is a common trend of massive building built on the path of natural disasters or settlements located on these dangerous paths hence exposing the population living in such regions even more to such disasters. A typical example is the living too close to rivers and the larger water bodies like seas such that during the rainy seasons when the rivers break their banks or a tsunami occurs, there is a likelihood of a disaster happening (Ginger Voight, 2011). The danger in this has been experienced in Nebraska mid-2011 when snow melt combined with rainfall led to massive bursting of the banks by the Missouri River, an incident that affected 18 counties within Nebraska. To avoid such calamities, there is need to draw out a legal distance that each home must keep from the river for safety purposes.

The other trap in the urban population lives with on a daily basis is the crowded nature of the cities in particular the buildings. In the event that there is a natural catastrophe like earthquakes or tsunami, there is a difficulty in evacuating such a population amidst the congested streets, fallen buildings as well as cut off roads. In the event of floods, the raging waters will be channeled through the narrow streets hence increasing the pressure with which it flows through the city and turning a natural catastrophe to a destructive huge humanitarian disaster (The Guardian, 2010). This is a phenomenon that is very typical of the Asian cities that are populated in terms of both the people and the buildings. One instance is the incident that befell New Zealand city of Christchurch where many were trapped in rubbles and several and died due to the congested nature of the city (Paul Chapman, 2011). This was the same fate that befell Port Au Prince in Haiti where the congested buildings coming down killed more people than in the rural areas where the population was sparsely populated.

Another very significant aspect that many cities overlook yet is a precursor to disaster in the event of even very slight earth tremors is the consistency of the subsurface material. There is the habit if drilling boreholes, pipe works, underground electricity connections, sewerage systems and such like activities without giving much thought to the consistency of the subsurface material. In the case of some cities that are situated in areas that have relatively loose soil, there is the ability of such activities to interfere with the mechanical properties of the subsurface material. This exposes the city to imminent collapse even in the event of a slight earth tremor (Caroline Onyancha et.al. 2011). This is one of the factors that make Nairobi City a dangerous city to live in bearing the consistency of the subsurface material against the earth tremors. There are so many boreholes drilled into the surface, yet the whole city is situated on soil and material that were remnants of a volcanic action that formed the Great Rift Valley.

There is also the other factor that is quite hard to solve since majority of the cities in the world suffer the same due to ignorance of a possibility of catastrophes. Most of the buildings in the cities do not have the special mechanisms to withstand low magnitude quakes. This is a relatively new technology that can also be afforded by few developers. There are some special structural adjustments that can be done to the foundation of a huge building when starting up then building that will enable it to withstand medium quakes unlike the standard quakes that are likely to crumble even in the sight of a minor tremor.