Flood is caused by excess water surpassing the live of its confines. A flood
can happen during myriad of event, including he heavy rainfall and over flowing river bank. Floods
present significant danger with enough force to sweep away massive object such
as cars and trees.
Flood is a natural process in which the river
uses to spill to its plan. The flood compact has been mainly due to lack of flood plain manhunt. The flood hazard of
communities on the banks of major river had major social and economics import
which can be seen after many years without a major flood event. Conceptually,
flood may occur as a result of urbanization, these kind of floods are related
to the king of event happening in our major cities in Nigeria, to the increase
of the impermeable areas and man-made drainage such as condicts and channels.
Usually the land use surfaces to storm sewers, it changes the hydrologic cycle,
increasing the overland flow.
Flood may also occur when there is occupation
of flood plan these are natural flood which mainly occur in modern and large
sizes river modification of natural landscape In many ways. Sometimes human
activities to modifying drainages systems to prevent flooding in there effort
have adverse effect and actually help to cause flooding in other areas. Any
modification of these landscapes has the potential to cause in the drainage
system, and such, changes can have several consequences. Human often decides that
a stream should flow along a specified path for such reason as flood control,
enhancement of drainage, controls erosion increases access to flood plan for
development or improving of the appearances of the channel, this involve measures
such as the straightening the channel with concrete leading to water overflow,
if the modification is economized as the determinant of the water volume.
Flooding is one of the environmental problems confronting many residential
areas in our cities. Presently, it is more peculiar to the most urbanized
portions of most urban centres. Certain features characterized the flooding and
erosion problems.
These incidences is not limited to
rain fails seasons only, its occurs mostly when there is heavy rain,
including the dry season, followed by its attendant issues of transport and
traffic problem, accommodation shortage, building collapse, environmental
degradation , health hazards, destructions of lives and properties,
psychological problem such as phobia of rainy season and urban environmental
aesthetic problem. For instance, the rapid increase in population size in urban areas
has lead to massive housing development, these, has an implication, has lead to
high competition for use of land leading to indiscriminate use. As I write,
many residential areas, boy squatters and shops are built at ant any available
space without due regard to environmental implications. these building were
mostly built without drainage facilities, because of lack of professional
enrollment in the building of environment, some of this building were built
without raising the floor concrete adequately above the floor-plan. The
consequence is the run off water, resulting from increase roof coverage because
of lack of proper planning, the building and the occupant becomes the victim of
own misfortunes. This scenario has created a malfunctioning urban structure
leading to a number of environmental planning problem, such as land use
planning problem, land fragmentation, poor supervision of building construction,,
non compliance to and poor implementation of development control rules an
regulations.
Others include lack of finishing
touches to building before habitation, lack of adequate provision of essential
urban infrastructures and facilities, lack of adequate protections of fragile
land and flood plain and encroachment into flood and natural areas. Section27
of the Nigeria urban and regional planning law of 1992 makes provision for
effective development control law but the challenges remains the non compliance
to the facto. Apart from these unfortunate happenings, report indicate that
some buildings were constructed without building plan, while some are without
developmental approval. Quite easily, an appropriate approaches remains a needed tonic in mitigating
flooding visa-vis ensuring land use planning standards that is one of the basic
duties of urban design which involves organizing, arraigning and
planning of land use with the utmost aim of achieving a conducive built
environment. Apart from its social values, it helps in urban land management.
it support the government, firms and individual property owners to plan for the
use of their land in economic way, in such a way that the land will be used of
their value, and at the same time prevent environmental degradation. Good to
mention is flood hazard mapping that is used to determine areas susceptible to flooding when drainage of
a stream water exceed the fool bank stage. These meaningful options can be
controlled to slow areas expected to be covered with flood for various
discharges or stages were flood impact to down stream and up stream
reaches, given priority to source control measures; in addition to flood control evaluation
that is taken in to account future city development. A
situation where the progress of slum is matured, it normally determine the amount
of rain fall degree of ground saturation, therefore, it is possible to give
short term prediction of possible floods. It should be noted that one of the
essential ingredients for sustainable urban development is sound policy that would response
to environmental changes and its accompanied problems. Over the years
professional organizations within the environmental development have been
making frantic efforts to promote sustainable urban development, through policy
dependent. Urban and regional planning law of 1992 is bye product of such
effort, national building code could have been a supplementary policy to this
development control laws if it has been enacted into law. The code makes
provision for building construction from pre –design stage to post construction
stage which would have helped in encouraging good site preparation,
proper good design, good construction and effective building maintenance. Since
the code has been drafted and adopted in 2006, report reveals that it has not
seen the light of the day to become a policy law toward building a sustainable
city that would be saved from floods
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