Monday, July 9, 2018

52 MONDAY, JULY 9, 2018
homes &
property
Collective efforts critical to tackling erosion – NMGS
‘Femi Asu
The Nigerian Mining
and Geosciences
Society has said there is a
need for concerted efforts
to stem the growing tide
of erosion in the coastal
region of the country.
The NMGS stated this
at its annual lecture in
Lagos, which focused on
scaling erosion processes
and their possible control
measures in the coastal
zone of the country.
The Chairman,
Distinguished
Lectureship Programme,
NMGS, Prof Olusola Ojo,
said on the sidelines of
the lecture, “Government
needs to have data and
information, and all the
relevant agencies that are
already in place need to
be up and doing. Where
are the areas that are
liable to flooding and
erosion? They need to
know; they need to have
data, process the data and
make it available in such
a way that Nigerians will
understand.
“There should be
massive education on
this issue of erosion,
and everybody should
be involved in tackling it
because the destruction
can be very massive.
Today, our population
is said to be about
200 million; that can
contribute to erosion if we
don’t have the right way
of living. Everywhere,
you see people felling
trees. That’s a major
source of erosion.”
The President, Global
Institute for Sustainable
Development, Advanced
Analysis and Design,
United States, Prof Hilary
Inyang, who delivered the
lecture, said, “Erosion
constitutes a major
ecological problem in
the coastal region of
Nigeria and leads to loss
of farmland; deposition
of sediments in pristine
habitats, streams and
ponds; destruction of
houses, bridges and other
structures; and spreading
of contaminants.”
According to him, the
coastal region of Nigeria
comprises terrain of
relatively low elevation
with high rainfall
intensity that provides
high raindrop impact
energy for erosion of
exposed geo-materials.
The professor of
Geoenvironmental
Engineering and Science
and honorary professor,
China University of
Mining and Technology,
said in addition to
the sheet and gully
erosion prevalent in the
hinterland areas of the
coast, shoreline erosion
had ravaged many
locations in the region.
He stated, “Erosion
rates in Nigeria range
from 0.8 to 5.3 tonnes per
hectare per year. Each
year, Nigeria loses billions
of naira in agricultural
damages, environmental
degradation, structural
damages and human
health problems (e.g.
asthma and water qualityrelated
diseases) that are
directly and indirectly
caused by erosion.
“Furthermore,
turbidity of streams and
lakes in the region impose
high costs on treatment of
surface water resources
for industrial and
domestic applications.
In many areas of the
region, exposed soils
do not exhibit adequate
cohesive strength due
to their mineralogical
composition and textural
characteristics to
withstand stresses that
are imposed on them.”
According to Inyang,
the exploitation of fissures
and poor cementation in
some soils make them
particularly vulnerable to
the development of deep
gullies.
He said, “In many
areas, there are slope
failures that progressively
damage the terrain and
exposed infrastructure.
“Although a wide
variety of stabilisation
measures have been
used in other countries
to control erosion costeffectively,
such measures
are rarely implemented
appropriately in Nigeria
where most control
measures basically rely on
temporary stabilisation
of the ground without
adequate geotechnical
analyses.”
According to him,
control measures
include revegetation and
forestation; surface water
run-off reduction and
control; and geotechnical
stabilisation; covering
slope stabilisation;
gully repair; shoreline
stabilisation; and
physico-chemical
stabilisation using
cementitious and
polymeric materials.
Inyang stressed
the need for technical
guidance manuals to
support field projects in
the country.