Geography Reference
In-Depth Information
perties estimated to worth 1.1 billion dollars, Yangtze river flood of 1998
displaced 14 million people, claimed hundreds of lives and damaged proper-
ties worth billions of pounds.
Recent examples are the 2012 Thailand devastating flooding episode
which flooded 65 of 77 Provinces of the territory and resulted in a total of 815
deaths, left about 13.6 million people homeless and submerged 20,000 square
kilometers of farmland. The 2012 Niger-Benue river floods in Nigeria affected
14 of the 36 states in the country, displaced an estimated 1.3 million people,
claimed about 431 lives and submerged over 1,525 square kilometers of farm-
land.
The devastating effect of flooding is felt more in urban centers especially
those located in coastal regions. This is because, on the one hand, the terrain is
generally low and the presence of numerous water bodies (such as lake,
lagoon, river, creek, etc.) which are prerequisite and essential source of
flooding. On the other hand, littoral cities are prominent centers of high popu-
lation concentration and prosperous economic region.
The economic boom that characterized such cities further initiate high
population density. Consequently, there is need for more space with respect to
residential and other developmental purposes. To cope with this rapid growth
and satisfy the need, developmental activities spring up sporadically around
the available urban space. In most cases, along sea shoreline, low lying terrain,
close to swamp, lagoon and on a river valley. The fact that urban planning
regulations in most African cities are not keenly enforced further aggravate the
issue of flooding and vulnerability.
In Nigeria littoral cities for instance, it is common to find developmental
activities and structures erected along natural flow paths, near shoreline,
floodplain and lowland areas. Such anthropogenic actions obstruct excess
runoff and discharge in the case of river flooding which has been reported
(Sanyal and Lu, 2004) to be a recurrent natural phenomenon in the humid,
tropical and subtropical climatic regions, especially in the wet seasons.
Basically, three major types of flooding occur in African coastal cities-
river flooding, coastal flooding and urban flooding. River flooding is induced
by heavy rainfall, excess runoff, and discharge within the river valley and its
destructive impact is a function of distance from natural channel. Coastal
flooding is typically a function of storm surge, waves (driven by wind) and
heavy rainfall. Urban flooding results when development is concentrated
within or along stream channels (Nkeki et al., 2013).
The consequences and severity of flooding is graver in littoral cities
compared to cities in the hinterland. Apart from submergence of urban pro-
