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Flood Drainage

Coastal Land Use

Urban Planning

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Tsunami-Proof Buildings  

Urban Planning

  • Layout and Urban Plan of a city, such that the damage by an incoming tsunami could be minimized.
    • Urban Plan includes –
      • Public policy
      • Environment
      • Law and order
      • Education of the Population

 

 

    • Layout includes –
      • Consideration of the topography of the city
      • Utilization of natural barriers e.g. coastal mountainous range, coral reefs, etc
      • Planning to minimize mechanical damage

 

            An urban plan of a city in terms of natural disasters must incorporate a workable public policy for the benefit and satisfaction of the people, care for the environment where the city is being built, a law and order system which keeps the activities of the city in check and assists the people in case of an emergency, and the education of the people so that when face natural disasters, they know what to do.

            Law and order in times of natural disasters is especially important; distributing aid, saving lives, and preventing looting and hoarding. In this regard, local policemen, sheriffs, tribal leaders can play a very important role. Aaron D Kennard in When natural disaster strikes: Sheriffs important leaders in emergency response proposes how important sheriffs and their agencies are when natural disasters strike, taking an example from a killer tornado which struck Salt Lake City in Aug 1999.

            Planning an urban city is a huge task in its own right, and planning one where objective is to reduce damage by tsunamis as much as possible is even harder. No one department or municipality can work alone on such a system; instead, much more can be achieved if these various departments and municipalities cooperate and concentrate together on this single effort. In April 2005, a news item appeared in the Financial Times, Amendments for disaster management discussed which detailed how collaboration between various departments and municipalities in a developing country (India) led to new ways of reducing damage caused by natural disasters. Hence, a workable system must make note of the fact that, in such a plan, the water, transportation, police, fire departments etc. must work together.

            Basic survival skills taught to people in the areas of risk is especially important. Knowledge of how to ration food, staying warm and dry, inhibiting water-borne and common infectious diseases recognizing signs of impending disasters, are all important parts of the skills. Various news items appeared after the Dec. 2004 tsunami, which noted that some of the most remote tribes in the Nicobar islands survived because the explanation for the water receding into the ocean (a sign of tsunami) had been passed down the generations. Such a system should be incorporated in a more massive and unified way, that is, in schools. Children should be taught at the elementary level how to spot the signs of an incoming tsunami in a high risk zone. And as they grow older, they should be taught, from basic to complex, survival skills which are in line with their age.

            The plan must also include monitoring of the extent of the damage and where it is the greatest via the use of the NOAA/AVHRR satellite system, which is already being done in the case of other natural disasters such as forest fires and floods.

 

Urban Planning Quantitative Proposals

Urban Planning for tsunamis should focus on building codes and city layout.

The World Health Organization in a report states that wave heights reach 30-40 feet at their maximum and waves penetrate roughly 1km-2km inland maximum [1] .

In conjunction with this, another study stated that waves in a tsunami in 1932 were able to destroy buildings 500m inland [2] .

 

Our recommendation is therefore that buildings should not be built less than 500m inland and be below 30 feet above sea level whenever possible. When this is not possible, then it should be made with reinforced concrete according to the specifications of the tsunami proof buildings section. From 500m to 1km, the buildings still should be held to having solid, water proof foundation with the bottom 3 feet saltwater resistant as well as having frontal reinforcements. From 1km to 2km inland, the buildings should have water proof foundations and roughly 1 foot of saltwater resistant wall. Beyond 2km, there is no significant danger of direct wave damage and building codes do not have to be as strict. This tiered approach will enable safety in case of tsunamis and also be practical economically. Contour charts such as the one to the left need to be studied carefully.

One thing that is important to note is that these distance inland estimates are based upon lack of mangrove/sea wall protection. Given particular configurations of these near shore dampeners, the safe distance inland may be decreased, further reducing cost. Cost benefit analysis is necessary for determination of amount of near shore protection to have.

 

Another thing that is of vital importance is having sufficient road ways. Ample arteries of transportation allows for rapid evacuation of the populace as well as rapid response for emergency relief. A study provides a clear estimation on how much road coverage there should be for a given population density [3] . For example, for a densely populated city like Manila in South East Asia, the population density can exceed 16,000 per square mile with high density areas of up 21,000 [4] . In order to serve that population, one needs roughly 25-33 miles of local roads per square mile. Many cities on the coast do not meet such requirements.

 

One may want to revise such figures as the Reilly and Gottlieb article was a case study in America. Considering the high degree of automobile penetration in America compared to elsewhere, we may want to pursue alternative methods of rapid evacuations such as development of high volume light rail systems. These systems would also have the benefit of being more environmentally friendly and aid in the development of the target cities.

 

 



[1] World Health Organization. Assessing Needs and Measuring Impact of the Grorokhovich Tsunami. http://www.who.int/hac/events/tsunamiconf/presentations/2_1_assessing_needs_measuring_impact_gorokhovich_ppt.pdf

 

[2] Salvador F. Farreras; Antonio J. Sanchez.  “The tsunami threat on the Mexican west coast: A historical analysis and recommendations for hazard mitigation”

[3] James Reilly; Paul Gottlieb. "PROJECTING COSTS FOR ROADS UNDER VARIOUS GROWTH SCENARIOS"

[4] Wikipedia, Manila. http://en.wikipedia.org/wiki/Manila

           

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