ABSTRACT
This study examined the effects of soil
erosion on settlement in Agbor, and its environs. It identifies the problems,
conservation, strategies, control techniques and suggest proper management
practices. The study adopts the survey research design in data collection
through administration of 150 questionnaires to the respondents in Agbor coupled
with direct field measurement of gully erosion effect on building structure in
Agbor region. The data collected were analzed using PPMC and t-test statistical
techniques. The PPMCC correlation value obtained for hypothesis 1 (0.935) is
greater than the critical value (0.754) at 0.05 level of significance and the
t-test calculated value (12.542) for hypothesis 2 is greater than t-critical
value (3.182) at 0.05 level of significance. The PPMCC coefficient correlation
value obtained for hypothesis 3 (6.235) is greater than the critical value
(3.182) at 0.05 level of significance. This indicated that the hypotheses
tested shows that there is a significant relationship between the effects of
soil erosion and the level of settlement development in Agbor. Furthermore,
hypothesis 2 shows that that there is a significant relationship between the
causes of soil erosion and the factors responsible for the degradation of Agbor
and its environs. The result of hypothesis 3 shows that soil erosion has
significant effect on the settlement of Agbor. The implication is that soil
erosion has resulted to the collapse of buildings and poor settlement structure
in Agbor. This shows that, soil erosion has significant effect on the
settlement of Agbor. The study recommended that government/private individuals
should construct drainage, embankments and sand fill burrow pits.
CHAPTER ONE
1.1 INTRODUCTION
Soil erosion is a
naturally occurring process whether it is by water, wind or ice, involves the
actions of soil detachment, movement and deposition. It could be a slow process
that continues relatively unnoticed or can occur at an alarming rate, causing
serious loss of top soil (Jim, 2012). Loose soil, low organic matter, loss of
soil structure, poor internal drainage, salination and soil acidity problems
are other serious soil degradation conditions can accelerate the soil erosion
process.
Erosion is a natural
process that is prompted by man-made human (anthropogenic) activities such as
deforestation that involves the removal of vegetation, overgrazing, unmanaged
construction of building and roads. Excessive erosion can produce ecosystem
damage, loss of soil and receiving water sedimentation. The effect of soil
erosion is sometimes linked to over population (Cohen, 2007). He further stated
that erosion tends to remove topsoil at a faster rate than soil is accumulated
in an area. This results in collapse of buildings, especially those of poor
foundation. This affects settlement development by residents within the study
area. However, increased soil erosion at a much faster rate than soil is
accumulated materially or artificially is a recent problem due to mankind’s conservation
which in action makes the land unprotected and vulnerable to degradation. Other
natural causes are occurring adduced the rainfall with wind storms to make
wreck havoc on the environment. This ugly effects occurs both in residential
and agricultural/farming areas as well as the natural environment. The effects
of soil erosion are found insitu (on-site) where the soil become detached), as
well as off-site where the eroded soil is transported. Also, in form of the high
rainfall, storms obviously cause deep gullies, but erosion due to smaller
events can seem in form of sheets with no consequence, but in fact there is a
cumulative effect on a long-term basis.
1.2 STUDY BACKGROUND
Cohen (2007) stated
that, the most serious consequence of soil erosion globally is the treat to
long-term sustainability of agricultural productivity and hindrance to settlement
development. This eventually leads to development of rugged terrain and
collapse of buildings. The destructive impact of erosion is felt on developing
countries such as Africa and Asia, and developed countries for which there is a
huge environmental concern.
Soil erosion results in
the loss of soil fertility that makes the land barren that accumulate more than
25 million hectares of barren lands in the world and to desertification (Tutor Vista,
2013). High rainfall of short duration and torrential downpour results in flash
floods that make rivers overflow their banks, destroy foundation and collapse
buildings, washed away live stock and act as hindrance to settlement
development (Adelye and Rustum, 2011). Also, it could damage bridges and causes
a dam to overflow to submerging buildings, displace people from homes, with
attendant loss of personal valuables and ongoing psychological fear and
insecurity caused by such event (Bariweni, Tawari and Abowei, 2012). Like wind
and water, coaster erosion is a natural process but can be exacerbated by human
activities. Activities that can influence Agbor erosion of river droughts,
include, mining of sand for construction purposes, building on the beach, to
interfere natural movement of sand and impedes beach recovery, removal of
vegetation from sand dunes, to destabilize protective barriers, from waves and
currents. Erosion not only cause damages to the immediate area where it occurs
but also have negative effects on the surrounding environment. Water erosion
often destroys buildings, roads and fences and other type of structures,
including bridges, cars, buildings, sewage systems, roadways and canals, etc.
The economy can also be
severely affected by flooding. Businesses may lose stock, patronage, data and
productivity and cause disruption to utilities and transport infrastructure with
knock-on effects to a wider area. Tourism, farming and livestock’s can equally
be affected. The built environment may be damaged or destroyed as a result of erosion
and flooding with high repair costs and long periods required for
reinstatement. The public realm is often badly affected through damage and
deposit of potentially large quantities river accumulated of debris. Land
contamination may occur and spread during erosion. Individual properties and vital
infrastructure may also be damaged or disrupted, communication, electricity and
gas supplies can be interrupted, to wider communities if sub stations and
transport are eroded. Road links, railways,
canals, etc, may be blocked causing disruption to the wider transport network
and accessibility and also result in severely disrupted local inhabitants
settings, especially amongst those considered most vulnerable (Bariweni, Tawari
and Abowei, 2012). This phenomenon is a common site in Agbor and its environs,
posing direct threat to settlement development in the area and the destructions
of building infrastructures in its surrounding rural areas. Cohen (2007) said
that improved land use techniques such as terracing, of building and tree
planting can limit erosion. It is against this background that this study is
carried out to find lasting solution to curb the problems caused by soil
erosion especially as it affects settlement in the study area.
1.3 STATEMENT OF RESEARCH PROBLEM
Environmental hazards including
erosion gave rise to lopsided concentration of vehicles in some of the roads
thus making the roads, a place of great conflict between man and the
environment.
It has also been
observed that improper planning in Agbor has resulted to in erosion, streets
flooding, because in most areas, it was observed that settlements, buildings
and other structures were built across River Plains and along flood water path
as well as erosion sites and flood plains, thus obstructing the free flow of run-off
result causing erosion.
Soil erosion has posed
a serious threat to Agbor and its environs, facing the problems resulting from
erosion. During the wet or raised season, some areas are become inundated to uninhabitable
and unmotorable. Local Government and
individual in affected areas, have tried to control erosion problem without
professional input by filling up the affected areas with gravel, building
embankment, placing sand bags and planting trees.
Erosion is now
synonymous with disaster, dangers, despair, destruction, death and damage to
economic properties. Environmental problems caused by urbanization, removal of
the natural cover exposes the soil to the action of running water. This greatly
reduces the fertility of the soil to cause development of monstrous soil
gullies in the land.
Though, there is no
statistics data on the extent of soil erosion and fertility in degraded areas
of Agbor, there is enough evidence to show that, the topsoil is increasingly
depleted by soil erosion though outdated and unscientific practices. The impact
of unchecked settlement development as a result of rapid urbanization has
further aggravated the problem.
Some of the natural
factors which tends to increase soil erosion in Agbor include: soil type, soil
slope and topography. The inherent low statues of soil has much impact on the effects
of organic matter on soil properties. Soil is also lost when it is down slope,
road network, commercial places, building which result from urbanization and
other life and properties.
It has been observed that
the dual factors of topography and heavy rainfall affect the entire land area of
Agbor. That is, most part of the region has been plagued and subjected to
erosion which has resulted to menace to her inhabitants. A lot of studies have
been carried out by scholars on the causes of erosion and this research will
therefore focus on the effects and solution to soil erosion on settlement in
Agbor and its environs.