Effects of Gully Erosion on the Environment in Insunjaba LGA Imo State
Chapter One
AIMS AND OBJECTIVES OF STUDY
The main aim of the study is examine the effects of gully erosion on the environment. Other specific objectives of the study include:
- to determine the extent to which gully erosion affects the environment.
- to determine the causative factors of gully erosion.
- to determine the effect of gully erosion on the environment.
- to proffer possible solutions to the problems.
CHAPTER TWO
REVIEW OF RELATED LITERATURE
Soil Erosion
Soil erosion is a common term used to either mean soil degradation or the physical removal of soil. Soil erosion is the detachment and transportation of soil particles by agents such as wind or water (Toy et al. 2002). This term can apply easily to gullies because soil is removed and is usually caused by some sort of soil degradation. However, most classify the type of erosion by the erosive agent, wind or water, which causes the erosion. Water erosion can be caused by rainfall, surface runoff from rainfall, and surface runoff from irrigation. Runoff occurs once the precipitation rate exceeds the infiltration rate of the soil. As precipitation continues to exceed infiltration, water begins to move down slope as overland flow or in defined channels (Ward and Stanley W. Trimble 2004). The detached soil particles that result from runoff and erosion are deposited in receiving water bodies, which has led to a higher impairment of water quality. Erosion is more likely to take place on lighter textured soils and on slopes rather than in valley floors (Boardman and Favis-Mortlock 1998). Soils containing more fine sand are more likely to give way and erode, which results in sedimentation (Dvořák and Novák 1994). Sedimentation is a major problem causing pollution in streams and rivers. Sediment does not only carry soil particles but also carries nutrients that are found in the soil such as large amounts of phosphorous. These excess nutrients can cause overgrowth of algae, leading to the depletion of oxygen and ecosystem disruption (USEPA 2007a). Sedimentation caused by erosion can alter aquatic habitat, suffocate fish eggs and bottom-dwelling organisms, and impair drinking water treatment processes and recreational use (USEPA 2007a). Erosion and nonpoint source pollution are interrelated. As erosion increases, so does nonpoint source pollution while water quality decreases. Therefore, if erosion can be controlled, nonpoint source pollution can be minimized and water quality can be improved. This can be done by gaining a better understanding of the causes of and processes involved in the formation of erosion.
Gully Erosion
Gullies most often occur on areas that have a low density vegetative cover and highly erodible soils. They are thought to form when a break in the vegetative cover allows erosional hollows to form; water accumulates here and results in even more erosion (Dressing 2003.). Gully erosion is the resultant of two main processes: downcutting and headcutting. Downcutting is the vertical lowering of the gully bottom that leads to gully deepening and widening (Ffolliott et al. 2003). Headcutting is the upslope movement that extends the gully length (Ffolliott et al. 2003). Erosion is focused at the gully head, where overland flow erodes the lip of the head as the water flows over it before plunging into the plunge pool at its base (Charlton 2008). This is where the deepening and undercutting of the gully take place. It undermines the headwall and allows the gully head to retreat further upslope. Subsurface flow moving towards the gully head can weaken the walls and result in the development of pipes or channels of aid within the soil that run along the side of the gully (Ffolliott et al. 2003). The collapse of pipes further contributes to gully head retreat (Charlton 2008). The presence of deep tension and desiccation cracks allow concentrated overland flow to penetrate the soil surface (Charlton 2008). Gullies are classified as either ephemeral or classic. Ephemeral gullies occur on land where vegetation is removed. They are commonly found on cropland and are temporarily filled in by field operations, only to recur after concentrated flow runoff. This filling and recurrence of the ephemeral gully can occur numerous times throughout the year if left untreated. Classic gullies may occur in many places but are so large that they cannot be crossed by agricultural equipment or vehicles (Dressing 2003.). Classic gullies are characterized by headward migration and enlargement through a combination of headcut erosion and gravitational slumping, as well as stress of concentrated flows (Dressing 2003.). Erosion caused by water or runoff is a major contributor to nonpoint source pollution. Development of new gullies of the rapid expansion and deepening of older gullies can often be traced to removal of vegetative cover through some human activity (Ffolliott et al. 2003).
CHAPTER THREE
RESEARCH METHODOLOGY
Research design
The researcher used descriptive research survey design in building up this project work the choice of this research design was considered appropriate because of its advantages of identifying attributes of a large population from a group of individuals. The design was suitable for the study as the study sought effects of gully erosion on the environment in insunjaba LGA IMO state.
Sources of data collection
Data were collected from two main sources namely:
(i)Primary source and
(ii)Secondary source
Primary source:
These are materials of statistical investigation which were collected by the research for a particular purpose. They can be obtained through a survey, observation questionnaire or as experiment; the researcher has adopted the questionnaire method for this study.
Secondary source:
These are data from textbook Journal handset etc. they arise as byproducts of the same other purposes. Example administration, various other unpublished works and write ups were also used.
Population of the study
Population of a study is a group of persons or aggregate items, things the researcher is interested in getting information on effects of gully erosion on the environment in insunjaba LGA IMO state. 200 selected residents in Insunjaba LGA of Imo state was selected randomly by the researcher as the population of the study.
CHAPTER FOUR
PRESENTATION ANALYSIS INTERPRETATION OF DATA
Introduction
Efforts will be made at this stage to present, analyze and interpret the data collected during the field survey. This presentation will be based on the responses from the completed questionnaires. The result of this exercise will be summarized in tabular forms for easy references and analysis. It will also show answers to questions relating to the research questions for this research study. The researcher employed simple percentage in the analysis.
CHAPTER FIVE
SUMMARY, CONCLUSION AND RECOMMENDATION
Introduction
It is important to ascertain that the objective of this study was to ascertain Effects of gully erosion on the environment in insunjaba LGA IMO state. In the preceding chapter, the relevant data collected for this study were presented, critically analyzed and appropriate interpretation given. In this chapter, certain recommendations made which in the opinion of the researcher will be of benefits in addressing the challenges of Effects of gully erosion on the environment in insunjaba LGA IMO state
Summary
This study was on Effects of gully erosion on the environment in insunjaba LGA IMO state. Three objectives were raised which included: to determine the extent to which gully erosion affects the environment., to determine the causative factors of gully erosion, to determine the effect of gully erosion on the environment and to proffer possible solutions to the problems. In line with these objectives, two research hypotheses were formulated and two null hypotheses were posited. The total population for the study is 200 residents of selected states in residents in Insunjaba LGA of Imo state. The researcher used questionnaires as the instrument for the data collection. Descriptive Survey research design was adopted for this study. A total of 133 respondents made farmers, elderly men, women and youths were used for the study. The data collected were presented in tables and analyzed using simple percentages and frequencies
Conclusion
The causes and impacts of gully erosion in Isunjaba LGA of Imo state had been investigated using various techniques highlighted in this work and others from previous works on gully erosion in Isunjaba LGA of Imo state. It was observed that both anthropogenic and the human-induced factors were responsible for the phenomenal, which has resulted in devastating impacts on the residents, property and their environment. Field observations by this study had shown that local geology, run-off as encouraged by most residents of community in the affected areas, nature of the soil porosity and loose sands, as well as the condition of groundwater at the sites were prominent contributors to the rates and magnitude of gullying in parts of Isunjaba LGA of Imo state community. By way of proffering tangible measures that would help in no small measures in tackling the menace of gully erosion in Isunjaba LGA of Imo state, Governments at all levels should collaborate to find a lasting solution to the phenomenal by adopting recommendations contained in this study as well as integrating other ones not mentioned here but would complement the efforts of an holistic tackling of the menace.
Recommendation
(a) There should be deliberate efforts by the Ministry to refill and construct a proper drainage system that will be channelled to a safe discharge points down steam.
(b) The local government authorities and the vulnerable communities should imbibe the culture of planting trees such as Bamboo and Cashew, in the affected areas, as vegetation cover will slow the rate of runoff as well as soil loss. This effort should be encouraged and supported by State and Federal Ministry of Agriculture.
(c) The town planning department should not approve construction of buildings along water ways.
(d) They should also recommend and prohibit new developers not to cement their compounds and also advise them to embark on rainfall harvesting.
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