EFFECTS OF SOIL EROSION ON SETTLEMENT

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 effect 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 becomes 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.

As a prelude to other parts of this study, this chapter will discuss the background upon which this study was initiated, the statement of problems that led to this study, the Aim and Objectives of the study. Others are Significance of the study, Scope of work, Research hypothesis and questions, Limitation of the study and Definition of terms.

1.2 Background of Study

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 Problems

Investigation revealed that 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.

1.4 Aim and Objectives of Study

The aim of the study is to examine the effects of soil erosion on settlement in Agbor, and its environs. In achieving this aim, the following specific objectives were laid out as follows:

1. To identify the problem, conservation, strategies control techniques and suggest proper management practices;
2. To examine the factors responsible for the high erosion degradation in the study area;
3. To identify the causes of soil erosion in the study area;
4. To examine the extent to which the Agbor environment has been degraded by soil erosion; and
5. To examine the effects of soil erosion on settlement in Agbor and its environs;
6. To recommend measures to prevent or ameliorate to help eradicate soil erosion in Agbor and its environ.

Furthermore, for the purpose of this study, the researcher will determine soil erosion problems in Agbor which will go a long way to address the socio-economic welfare of the people.

1.5 Research Questions

The study came up with research questions so as to be able to ascertain the above stated objectives. The specific research questions for the study are stated below as follows:

• What are the immediate and remote causes of soil erosion in the study area?
• What are the major factors responsible for environmental degradation in the area under review?
• To what extent has Agbor environment been degraded by soil erosion?
• What are the effects of soil erosion on settlement in Agbor and its environs?
• What are the possible solution to address the problems of soil erosion and its adverse effect on settlement in Agbor and its environment?

1.6 Research Hypothesis

In order to pursue the objective of this study, the following generalized statements have been designed to guide and aids in obtaining the result for the experiment to be conducted. For this work, the null hypothesis will be represented with H0 while the alternative hypothesis will be represented with hypothesis H1.

• H₀1: There is no significant relationship between the effects of soil erosion and the level of settlement development in Agbor.
• H₀2: There is no significant relationship between the causes of soil erosion and the factors responsible for the degradation of Agbor and its environs.
• H₀3: Soil erosion has no significant effect on the settlement of Agbor.

1.7 Significance of Study

There is a great need to examine the effects of soil erosion on settlement in Agbor, Delta State-Nigeria. This study will help to know if there is any significant relationship between the effects of soil erosion and the level of settlement development in the study area. The researcher is interested whether soil erosion has significant effect on the settlement of Agbor. The study will also look at the factors responsible for the degradation of the natural environment especially in Agbor, Delta State.

This research work will cover the entire of Agbor and it's to look intensely at the effects of erosion on buildings. It would offer suggestion(s) on the causes of soil erosion and its advance effect on settlement development.

Therefore, the research work will unfold the deteriorating effects of soil erosion on settlement development and other related land use in Agbor. It will educate the general public on the various causes of soil erosion in the area and proffer solution to combat the soil erosion problem(s) on settlement development in the study area.

This study gives us information about the effects of soil erosion on settlement in Agbor, Delta State-Nigeria as well as to proffer solution(s) to problems of soil erosion and its adverse effect on the settlement of Agbor, Delta State. This opens new horizons for new researchers. The findings of the research are helpful for the policy makers to introduce some new strategies for the betterment of the society. However, the findings will also provide useful background information to future research in the contribution of geography towards nation's buildings.

This work is expected to guide geographers, geologists, pedologists, geomorphologists, environmentalists, agriculturists, builders, engineers, surveyors, educationists, academicians, experienced soil analysts, etc., and all those whose field of study is associated with solving soil erosion issues to gain understanding of how soil erosion affects settlement development and control measures and mitigation strategies and management techniques can help to advert the enormous problems of environmental degradation especially those caused by soil erosion.

Finally, the study is also carried out to enlighten the entire people of Agbor and Delta State on the need to establish a good and favorable condition to enhance better living among the urban and rural dwellers.

1.8 Scope of Study

The scope of the research is focused on the Effects of Soil Erosion on Settlement using Agbor located at the Niger Delta Region as a case study.

1.9 Limitations of the Study

During the course of this study, many things militated against its completion, some of which are:

1. Time Constraint: The time frame given to accomplish this project was very short due to school academic calendar and it was carried out under pressure which made the researcher not to implement some necessary features.
2. Financial Constraint: Insufficient fund tends to impede the efficiency of the researcher in sourcing for the relevant materials, literature or information and in the process of data collection (internet, questionnaire and interview).
3. Lack of Initial Cooperation from Respondents: A particular limitation of this work came as a result of the respondent refusal to offer their cooperation at the initial time they were contacted. This contributed in making the success of this research study difficult.

1.10 Study Area

Agbor is located in the Niger Delta Region of Nigeria and lies in the South-South geo-political zone of Nigeria. The dialect belongs to the Igbo group (Williamson, 1986). Agbor came from the word “Gbon” meaning “develop” or “rise”.

1.10.1 Location and Size

Agbor lies between the geographical co-ordinate of latitudes 060 051N to 060 161N of the equator and longitudes 060 051E to 060 091 E of the Greenwich Meridian. Agbor is one of the major towns in Delta State and located in Ika south Local Government Area of Delta State. The neighborhoods of Agbor includes; Boji-Boji Agbor, Emuhu, Ekuku Agbor, Agbor Nta, Alihami, Alisemen, Alifekede, Alizomor, etc.