The picture to the left shows the front of a
residential house of an average wealthy man in my town. The floors within and
in front of the building are usually 100% impervious, due to the fact that they
are completely cemented as this is what is in vogue for the wealthy. It is as if any vegetative
cover or presence is viewed as dirt or a sign of poverty. The right-hand side
picture shows the luxurious vegetative cover that my town enjoys but all of it
is quickly cleared without consideration when a new edifice is in the balance.
It is no longer new to us that when rain falls a good
amount of it naturally sinks into the ground while some run off or are
eventually evaporated. However, in a rainforest zone such as my town with
abundance of rainfall, the impervious surfaces coupled with the built-up areas
make the amount of run off that will be generated a significant ecological
problematic.
This is the hapless state of our poor red soil and my careful investigative observations have linked this to the increasing number of impervious surfaces in my town (Adazi-Nnukwu, Anambra State, Nigeria). So, whenever the average wealthy townsman or woman decides to put up
their building, not only is the vegetation completely cleared, the impervious surfaces increase, the volume of the runoff generated goes up and the velocity of flow
of the runoff becomes so erosive.
The amount of soil lost is enormous and costly and it
takes only one rainy season for the road to be rendered "un-motorable". When those in-charge of the seasonal maintenance of the road (usually before Christmas)
come to work on it, they merely cover the potholes with laterites or more red
soil excavated from other geographical location, usually an upland. Since the road maintenance is unsustainably executed, the red soil will be washed away again at the next rainy season leaving the road
even worse than before. And as this upland soil excavation is repeated, the relatively ecological stable upland is exposed to other problems such as landslide, sand flow and eventually full blown erosion.
Imagine what vegetation can do to salvage the
situation. Even in this deplorable state, the picture below shows that the
runoff is powerless against vegetation. The runoff snake around in its attempt
to avoid the vegetation but ferociously feeds on the totally exposed red soil
catering tons away.
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