Cause and effect of Soil Erosion in Boqol

Transcription

Cause and effect of Soil Erosion in Boqol-jire Hargeisa ,Somaliland
2015
University of Hargeisa
Collage of Applied Science
Faculty of Environmental Science
“Cause and effect of Soil Erosion in Boqol-jire
Hargeisa, Somaliland”
A Thesis By
Mohamed Hassan hersi
IN PARTIAL FULFILLMENT OF THE REQUIREMENTS
FOR THE BACHELOR DEGREE OF ENVIRONMENTAL SCIENCES
Supervised by
Prof. Hamse Ibrahim Mohumed
July 2015
Author: Mohamed Hassan Hersi
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DECLARATION A
I hereby declare that this thesis my original research work and effort, and that all the sources of
material used for this thesis have been duly acknowledge. This topic has not submitted been
anymore for any award,
Candidate: Mohamed Hassan Hersi
Signature:_____________________
Date___________________
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DECLARATION B
I hereby to declare that this thesis project has been carried out under my supervision by the
candidate whose name is Mohamed Hassan Hersi in University of Hargeisa , Collage of
Applied Science , Faculty of Environmental Science.
Supervisor: Hamze Ibrahim Muhumed
Signature: ______________________
Date: _________________________
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APPROVAL SHEET
This thesis entitled Cause and effect of Soil Erosion in Boqol-jire Hargeisa, Somaliland,
submitted and prepared by Moahmed Hassan Hersi to the University of Hargeisa for the award
of Bachelor degree in Environmental Science. It has been examined and approved by the
supervisor with the grade of ______________________
Supervisor: Hamze Ibrahim Muhumed
Signature: ______________________
Date:__________________________
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DEDICATION
I dedicate this thesis to my beloved mother Mother Shukri Askar Ismail and all my beloved
brothers and sisters, their support and encouragement, for everything I have done possible. This
work is dedicated to my beloved family.
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ACKNOWLEDGEMENT
I would like to thank Allah to Allah; allow us to complete this thesis book. I praised allah for
giving me strength, courage and health to finalize my study.
I am very thankful to my thesis supervisor Dr. hamze Ibrahim , for his extensive encouragement
and guidance throughout my thesis work and to gratitude the head of the faculty Abdifatah Omar
Mohamoud, for having provided us with adequate facilities to complete my thesis and whenever we
ever needed help and moral support.
Thanks go to my brother, Mustafa Ahmed Mohamed, for sharing the burden of entering the
data into the computer. And thank Daaha Mohamed Abdi, for assisting and providing me with
the software SPSS.12.0 which was used for the analysis of the data my heartfelt appreciation and
thanks are extended to Prof, Adam H.Ali, my co-supervisor, for her invaluable assistance in
reviewing and commenting on the content and layout of the dissertation.
I would also like to thank my classmates for always being with me during field observations and
collection of questions, I also thank my family members who were the backbone behind my
manners and other individuals who have either directly or indirectly contributed to our needs.
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Abbreviations
SWV
soils water and vegetation
CSL
Compared to soil loss
CAPSLO
Common Agricultural Policy subsidies leading to overstocking
S/L
Somaliland
NOAO
number of animals owned
RS
raindrop splash
CCFS
carrying capacity for sediment
SS
spring and summer
TSHR
trees, shrubs, residue
DS
drying of soil.
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Table of Contents
Dedication ............................................................................................................................................... 4
Acknowledgements .................................................................................... Error! Bookmark not defined.
DECLARATION ............................................................................................ Error! Bookmark not defined.
Abbreviations .......................................................................................................................................... 7
1.0:Chapter One: Introduction ............................................................................................................... 14
1.1
Background ............................................................................................................................ 14
1.2 Problem statement ...................................................................................................................... 18
1.3 Purpose of the Study ................................................................................................................. 19
1.4 Research Objectives ..................................................................................................................... 19
1.4.1General: ................................................................................................................................. 19
1.4.2Specific: ................................................................................................................................. 19
1.5
Research Questions .................................................................................................................. 20
1.6
Scope ....................................................................................................................................... 20
1.6.1Geographical Scope ............................................................................................................... 20
1.6.2 Time scope .......................................................................................................................... 20
1.7 Significance of the Study .............................................................................................................. 20
1.8 Key Terms .................................................................................................................................... 21
2.0: ChapReview of related literature .................................................................................................... 22
Concept, opinions, Ideas from Authors/expert ...................................................................................... 22
2.1 Soil erosion ...................................................................................................................................... 22
2.1 Causes and effect of soil erosion ...................................................................................................... 22
2.2.1 Causes................................................................................................................................... 22
2.2.2:Growing crops on inappropriate land - .................................................................................. 23
2.2.3:Animal production on inappropriate land .............................................................................. 23
2.2.4:Overstocking - ....................................................................................................................... 23
2.2.5:Bad timing of agricultural practices ....................................................................................... 24
2.2.6:Degradation of river banks by stock ...................................................................................... 24
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2.2.7: Bad management of livestock feeding and drinking areas .................................................... 24
2.2.8:Lack of ground cover over winter months ............................................................................. 24
2.3. Effect ...................................................................................................................................... 24
2.3.1:Loss of Biodiversity ............................................................................................................... 25
2.3.2:Damage to roads and footpaths ............................................................................................ 25
2.3.3Impacts on strategic reservoirs .............................................................................................. 25
2.3.4: Nutrient enrichment of freshwater water bodies ................................................................. 26
2.3.5:Contamination of drinking water........................................................................................... 26
2.4 Erosion by Water ......................................................................................................................... 26
2.4.1:Soil Erodibility ....................................................................................................................... 27
2.4.2:Slope Gradient and Length .................................................................................................... 27
2.4.3:Vegetation ............................................................................................................................ 27
2.5:Erosion by Wind........................................................................................................................... 28
2.5.1:Erodibility of Soil ................................................................................................................... 28
2.5.2:Soil Surface Roughness ......................................................................................................... 28
2.5.3:Climate ................................................................................................................................. 28
2.5.4:Unsheltered Distance ............................................................................................................ 29
2.5..5:Vegetative Cover.................................................................................................................. 29
2.6: Types of soil erosion ................................................................................................................... 31
2.6.1: Sheet Erosion ....................................................................................................................... 31
2.6.2: Rill Erosion ........................................................................................................................... 31
2.6.3: Gully Erosion ........................................................................................................................ 31
2.6.4: Bank Erosion: ....................................................................................................................... 31
2.6.5: Splash erosion ...................................................................................................................... 32
2.7: Impact of soil erosion Agriculture ............................................................................................... 32
2.7.1:Waterways............................................................................................................................ 33
Downstream effects of soil erosion include: ....................................................................................... 33
2.7.2:Reef water quality ................................................................................................................. 33
2.7.3:Infrastructure........................................................................................................................ 33
2.8 Control Options ........................................................................................................................... 34
2.8.1EROSION CONTROL ................................................................................................................ 34
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2.8.2 Biotechnical methods ............................................................................................................ 34
2.8.3 Erosion Control Plan .............................................................................................................. 35
2.8.4 Physical methods .................................................................................................................. 35
2.8.5 Vegetative methods .............................................................................................................. 35
3.0: CHAPTER THREE: METHODOLOGY .................................................................................................. 36
3.1Research Design ........................................................................................................................... 36
3.2 Research Population .................................................................................................................... 36
3.3 Sample size .................................................................................................................................. 37
3.4 Sampling procedure ..................................................................................................................... 37
1.5 Research Instruments .................................................................................................................. 37
1.6 Validity and Reliability of the Instruments .................................................................................... 37
3.7 Data Gathering Procedures .......................................................................................................... 37
3.7.1 During the administration of the questionnaires ................................................................... 38
3.7.2After the administration of the questionnaires ....................................................................... 38
3.8 Data analysis ............................................................................................................................... 38
3.9 Limitations of the study .............................................................................................................. 38
3.10 Ethical Considerations................................................................................................................ 38
4.0Chapter four presentation, Analysis and Interpretation of data ........................................................ 39
4.1: Gender ....................................................................................................................................... 39
4.2:Age .............................................................................................................................................. 40
4.3: Educational Level ........................................................................................................................ 40
4.4Knowledge of Soil Erosion ............................................................................................................. 41
4.5: Livestock Husbandry ................................................................................................................... 42
4.6: Any Questionnaire Taken this Area ............................................................................................. 42
4.7: Type of Soil Erosion occur Boqoljire ............................................................................................ 43
4.8:Is there Control Option exist Boqoljire ......................................................................................... 44
4.9: What are the control options ...................................................................................................... 45
4.10: Factors Cause Soil Erosion ......................................................................................................... 45
4.11: Any Organization discussion with soil erosion of Boqoljire ........................................................ 46
4.12: If yes what is the organization ................................................................................................... 47
4.13: Level of Soil Erosion .................................................................................................................. 47
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4.14: Last year's how soil Erosion was increasing ............................................................................... 48
4.15: Did you see Last 20 Years, Farmers use chemical Fertilizers....................................................... 49
4.16: Is the Soil Conservation Practices in Boqoljire ........................................................................... 49
4.17:What is Sources of Energy for Cooking ....................................................................................... 50
4.18: How is Soil Fertility of Boqoljire ................................................................................................ 51
4.19: Does Families Have Livestock Boqoljire ..................................................................................... 51
4.20: If yes what Kind of Livestock ..................................................................................................... 52
4.21:Do you thing that Livestock Participate Soil Erosion ................................................................... 53
4.22: Does soil erosion Effect Livestock Production ............................................................................ 54
5.0 Chapter 5: Conclusions and Recommendations ................................................................................ 55
5.1. Conclusions................................................................................................................................. 55
5.2. RECOMMENDATION ................................................................................................................... 56
Appendix ............................................................................................................................................... 59
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ABSTRACT
Soil erosion is recognized as one of the world's most serious environmental problems (Pimentel
et al 1995, Shiferaw and Holden, 1999). Globally, about 80% of the current degradation of
agricultural land is caused by soil erosion.
In most developing countries, including Somaliland, human activity triggers these losses this is
associated with rapid population growth, inadequate attention to the basic natural resources
S.W.V (soils, water and vegetation), and the need to maximize production to meet the needs of
the growing population This situation is more serious in poor developing countries like
Somaliland where subsistence production predominates.
Soil is one of the natural resources on Planet Earth. Though soil is a renewable natural resource,
yet it can become finite, with the passage of time, through its degradation. In Somaliland soil
erosion is a problem and there are several causes for this. These causes are in fact various factors
as a result of which soil erosion takes place. Some of the contributing factors are certain
agricultural practices of conventional agriculture and environmental problems. There is a
universal acceptance that such agricultural practices degrade the soil.
This study deliberate to explore the prevention of soil erosion problems and damage of the
environmental component such as the effects of agricultural production and land degradation that
soil erosion caused in boqol jire, Hargeisa.
The main objective of this study is to know the possible cause and effect of soil erosion in boqol
jire district, hargeisa. And to be sought further in this study was be as follows:
The aim of this thesis is to have clear understanding the cause and effect of soil erosion from the
environment and the necessity to implement conservation measures in the study area.
The study is only one district Ibraahin koodbuur specially boqol jire which is located in hargeisa
west.
The study was used a descriptive co-relational design; the study also was used a cross sectional,
comparative and ex-post facto designs. Descriptive in that data collected was used to describe a
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phenomenon; co-relational in that it was interested in relating cause and effect of soil erosion in
boqoljire, hargeisa.
Both soil causes and effect of soil are major drivers of land degradation and pose key problems
to livelihoods of the community members in the study area. Sheet, rill and gully erosion are the
main types of erosion within the study area and the latter form of erosion, namely gully erosion,
is the most alarming problem removing huge quantities of soil, dissecting land and damaging
infrastructure.
Deterioration in soil fertility as a result of severe soil erosion is a critical deterrent to crop
production and a lack of fodder has been a major factor in the decline in livestock production. As
charcoal is the major source of energy for cooking in the study area, deforestation has seriously
depleted forest resources. This has compelled community members to travel long distances and
spending significant amount of time for collection of wood.
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Chapter One:
1.0 Introduction
Introduction In total there are five chapters: The First Chapter provides an overview of the
background, the problem area identified, the problem formulation question, the research question
and the objectives. The Second Chapter discusses review of related literature and third chapter
methodology chapter four presentations Analysis and Interpretation of Data chapter five findings
conclusion, Recommendation
1.1
Background of the study
Soil erosion is recognized as one of the world's most serious environmental problems (Pimentel
et al 1995, Shiferaw and Holden, 1999). Globally, about 80% of the current degradation of
agricultural land is caused by soil erosion. Erosion by water, at a global scale, is the main soil
degradation process in agricultural areas It generates strong environmental impacts and major
economic losses from decreased agricultural production and from off-site effects on
infrastructure and water quality by sedimentation processes Soil erosion creates severe
limitations to sustainable agricultural land use, as it reduces on-farm soil productivity and causes
food insecurity.
In most developing countries, including Somaliland, human activity triggers these losses this is
associated with rapid population growth, inadequate attention to the basic natural resources
S.W.V (soils, water and vegetation), and the need to maximize production to meet the needs of
the growing population This situation is more serious in poor developing countries like
Somaliland
where subsistence production predominates. The Boqol-jire environment, is
nowadays dependent on natural conditions and cannot tolerate further deterioration of soil
productivity Increasing urbanization, intense land cultivation, uncontrolled grazing, and
deforestation often lead to, or exacerbate, soil erosion These factors undermine agricultural
productivity and frustrate economic development efforts, especially in developing countries
where there is heavy land dependence in low external-input farming systems Somaliland has a
total surface area of 137,600 sq . However, whilst soil erosion is a feature of any natural
Ecosystem, the rate at which it is taking place has been significantly accelerated by
anthropogenic influences.
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Soil erosion in the Areas has increased markedly in recent decades the impacts of soil erosion
have major implications for society from an economic, social and, environmental perspective.
In terms of ecological service provision, soil performs many, ecological functions including
nutrient cycling, regulating water and nutrient flows, filtering toxic compounds, providing a
medium for plant roots and supporting the growth of a variety of animals and soil microorganisms by providing a diverse physical, chemical and biological habitat. As such, it is a vital
natural resource and forms a key building block upon which life on earth depends. In economic
terms, soil erosion inflicts significant costs on society as the ecological services we derive from
soil have an economic value; as soil is eroded, the economic value we are able to derive from it
is diminished. The financial implications of soil erosion do not stop here. For example, soil
erosion can transmit pollutants into water which have to be removed through costly processes.
Eroded soil often needs to be removed from roads, reservoirs and estuaries which again can
involve considerable costs to society.
Soil is a precious natural resource and in Somaliland especially this study Area boqoljire there is
an ever increasing awareness of the declining soil quality. To inhibit this decline, soil
conservation has been given due consideration in organic farming in the boqoljire village.
To conserve means ‘to protect from loss and harm’. Hence soil conservation means to protect the
soil from both loss and harm. 'Soil Loss' and 'Soil Harm' are two different unique
terms/categories, with reference to soil degradation, that have been introduced separately (in this
thesis). Soil Loss implies soil degradation that occurs naturally e.g. erosion and other factors are
responsible for the loss of soil. Soil Loss can occur in the three basic dimensions of loss, i.e.
physical, chemical and biological. Conversely, Soil Harm implies soil degradation that is
anthropogenic in nature, i.e. induced by mankind e.g. chemicals and mechanics are responsible
for the harm of the soil. Physical, chemical and biological dimensions of harm can take place in
Soil Harm. With this background, organic farming practices propagate soil conservation by
reducing both Soil Loss and Soil Harm.
As manifested from experience that soil harm has been pre-dominantly higher as C S L
Compared to soil loss. The harm or damage to the soil caused by human induced activities is
ever increasing due to factors like conventional agricultural practices, urbanization,
Industrialization, increasing population, etc. Some of the problems of both soil loss and Soil
harm are irreversible, e.g. soil erosion (whether it occurs naturally or as human Induced)
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Whereas, other problems of both soil loss and soil harm can be dealt with and Improved with
specialized tactics and measures, e.g. soil leaching can be improved with crop rotations of
legumes and catch crops; soil contamination can be alleviated with remediation procedures; etc.
Here the soil management practices play a vital role in the Soil conservation.
The pressure on arable land is growing and this forces people to convert more marginal,
available forest and grazing lands to arable lands. Hence, forest resources are very few and
continuously decreasing both in quantity and quality. These results in firewood shortage and
people are forced to use animal dung as a fuel wood substitute. The major source of organic
matter is thus not brought back to the soil but used further purposes. Soil erosion is the most
significant ecological restriction to sustainable agricultural production, mainly under subsistence
agricultural production system like west of Hargeisa including this Area boqoljire.
Soil Erosion and Conservation Practices in ibraahin koodbuur District, particularly boqo ljire ,
Somaliland call for immediate action to reverse soil erosion. Hence, to protect soil resources
from erosion different remedial action should be taken with the help of soil conservation
mechanisms to sustain the productivity of the land. This study was conducted in ibraahin
koodbuur district (west of flat land of Hargeisa). The district, as one part of productive region, In
Hargeisa
it is affected by land degradation particularly soil erosion. Farmers’ perception and
attitudes towards soil erosion and conservation practices is decisive in protecting soil losses from
erosion. Hence, farmers’ perception of soil erosion is a key social factor that is also important in
deciding options for controlling soil losses However, for many years, soil conservation programs
in Somaliland were premised on the notion that farmers did not perceive erosion and had little or
no interest in combating it Most soil conservation planning approaches rely on empirical
assessment methods by experts and hardly consider farmers knowledge of soil erosion. As a
result, conservation programs and approaches performed poorly in ibraahin koodbuur district
specially boqoljire both traditional and modern methods of soil conservation are used by local
farmers with different proportions. For selecting and implementing appropriate conservation
methods, it is important to identify constraints that affect farmers to adopt or apply both
traditional and modern soil conservation methods and their farming practices. Therefore, this
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present study was designed to assess farmers’ perception about soil erosion and conservation
practices in Ibraahin koodbuur district, North-western Hargeisa. A review of the relevant
literature points to the fact that number of empirical studies have been undertaken on perception
of farmers on soil erosion and conservation practices, the existing soil conservation practices
adopted by farmers on their farms and pasture lands and the socio-economic, bio-physical, policy
and institutional related constraints influencing farmers’ perceptions to implement different soil
conservation practices in the Somaliland context. However, nearly all of them have been
addressing issues of adoption in relation to improved production technologies. Available
evidence shows that studies on the determinants of adoption of soil conservation measures are
few and far between. Therefore, this study was conducted in view of bridging this gap. The
objectives of this study were to assess how farmers’ perceive soil erosion problems and the
causes that trigger soil erosion problems, identify the existing soil conservation practices adopted
by farmers on their farms and pasture lands and examine the socio-economic, bio-physical,
policy and institutional related constraints influencing farmers’ perceptions to implement
different soil conservation practices (TT Belay 2014). Pertaining from agricultural production
to the environment.
Organic agriculture aims at creating an environmentally sustainable form of farming which
emphasizes on a self-sustaining biological system rather than providing external inputs. That is
why such a system is termed as a low-input farming system. The crux of organic farming and its
management practices is its approach to finding solutions to agricultural problems keeping in
view environmental protection. This approach is antagonistic to the approach of conventional
farming. Organic farming addresses problems in a preventive manner, which relies on long-term
solutions, giving due regard to nature and our environment. For example, crop rotations are
designed for nutrient cycling, integrated pest management is applied for the prevention of pests,
reduced tillage is carried out for soil conservation. has a reactive approach to the problems and
relies on short-term solutions, e.g., application of chemical pesticides and inorganic artificial
fertilizers(ASIF KHAN KHATTAK 2008).
The basic ideology of organic agriculture differs from conventional agriculture. At the practical
level, the difference is that organic agriculture must live up to the Expectations and aims of
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taking special regard to the environment and nature as a whole. This further leads to the concept
of environmental sustainability.
The periphery of organic farming is not only restricted to agricultural production but it has a
holistic approach. Due to this approach, organic farming is considered as a highly relevant tool
that has the potential to contribute in finding solutions simultaneously to a range of problems
However, the fact remains the same that soil erosion carried the main responsibility for the acute
environmental degradation that Somaliland experienced throughout the 1960s and 1970s.
1.2 Problem statement
Soil is one of the natural resources on Planet Earth. Though soil is a renewable natural resource,
yet it can become finite, with the passage of time, through its degradation. In Somaliland soil
erosion is a problem and there are several causes for this. These causes are in fact various factors
as a result of which soil erosion takes place. Some of the contributing factors are certain
agricultural practices of conventional agriculture and environmental problems. There is a
universal acceptance that such agricultural practices degrade the soil.
In Somaliland, the issue of soil degradation ranges from erosion and contamination of the
topsoil to contamination of ground water. Soil degradation is an issue of growing concern in the
public.
In Somaliland, the excessive use of synthetic chemicals and mechanical methods (not too much)
in conventional agriculture has degraded the soil and their increased use is against soil
sustainability in the country. This ultimately goes against the development of overall Sustainable
Agriculture. E.g. the increase of nitrates and other synthetic chemicals can find their way into
the food chain that ultimately affects the human health as well as other Living organisms. The
presence of these chemicals in the soil may hamper the soil quality itself through soil pollution,
which affects the soil sustainability. These synthetic chemicals are also hazardous to other
environmental components (e.g. water).Hence there is a need to conserve the soil and avoid its
degradation in order for soil to contribute in the long term development of sustainable agriculture
of the country. The threats associated with consequences of soil Erosion similar to the threats of
other long-term environmental problems like global warming and loss of biodiversity. Since
these issues are given excessive publicity and coverage, the public are well aware of the global
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warming problem. Unlike the global warming problem, the Public is, generally, not aware of the
seriousness of the soil Erosion problem.
This short thesis focuses on soil erosion in Somaliland specially maroodijeex region in Ibrahim
koodbuur district, where, in common with many Regions across Africa, the negative impacts of
degraded soils and inappropriate land Management have become increasingly apparent,
particularly since the early 1990’s.
1.3 Purpose of the Study
This study deliberate to explore the prevention of soil erosion problems and damage of the
environmental component such as the effects of agricultural production and land degradation that
soil erosion caused in boqol jire, Hargeisa Further, this study was identified the strengths and
weaknesses/gaps in the soil erosion in the environment.
1.4 Research Objectives
1.4.1General:
The main objective of this study is to know the possible cause and effect of soil erosion in boqol
jire district, hargeisa.
1.4.2 Specific:
The aim of this thesis is to have clear understanding the cause and effect of soil erosion from the
environment and the necessity to implement conservation measures in the study area.
The specific objectives are:
1 To identify soil erosion process in the study area.
2 Analyze the spatial distribution of soil erosion in Boqoljire.
3
To study and understand how soil Erosion is reduced/prevented through organic
agriculture in Somaliland specially this research Area boqol jire
4 To determine the levels of cause and effect of soil erosion in boqol jire hargeisa
5 To determine the level of environmental damage that soil erosion caused in boqol jire
hargeisa, Somaliland.
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Research Questions
This study was sought to answer the following research questions:
1. To identify soil erosion process in the study area?
2. Analyze the spatial distribution of soil erosion in Boqoljire.?
3. To study and understand how soil Erosion is reduced/prevented through?
4. What were the demographic characteristics of the respondents as to:
a. 1.1 Gender?
b. Age?
5. To determine the levels of cause and effect of soil erosion in boqol jire hargeisa
1.6
Scope
1.6.1Geographical Scope
The study is only one district Ibraahin koodbuur specially boqol jire which is located in hargeisa
west.
1.6.2 Time scope
This study estimated to take four months that is running from April 2015 up to July 2015. It is
mainly to give the researcher ample time to conduct the study.
1.7 Significance of the Study
The following disciplines will benefit from the findings of the study.
The farm owners will recognize the soil erosion can have long term effect of their production
and will use the way they can prevent soil erosion to make their proclivity good
The Ministry of agriculture and also ministry of environment will use the findings as
empirical information to encourage the conservation of the environment and to become the
Agriculture production sustain
The future researchers will utilize the findings of this study to embark on a related study
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1.8 Key Terms:
Soil erosion: is the action of exogamic processes (such as water flow or wind) which remove
soil and rock from one location on the Earth's crust, then transport it to another location where it
is deposited.
Industrialization: The process in which a society or country (or world) transforms itself from a
primarily agricultural society into one based on the manufacturing of goods and services.
Conservation: is the protection of soil from erosion and other types of deterioration, so as to
maintain soil fertility and productivity. It generally includes watershed management and water
use.
Environmental sustainability: A state in which the demands placed on the environment can be
met without reducing its capacity to allow all people to live well, now and in the future.
Renewable resource: is an organic natural resource which can replenish to overcome usage and
consumption, either through biological reproduction or other naturally recurring processes.
Non-renewable resource: A resource of economic value that cannot be readily replaced by
natural means on a level equal to its consumption. Most fossil fuels, such as oil, natural gas and
coal are considered non-renewable resources in that their use is not sustainable because their
formation takes billions of years.
Urbanization: When populations of people grow, the population of a place may spill over from
city to nearby areas.
Soil loss: Removal of topsoil faster than the soil forming processes can replace it, due to natural,
animal, and human activity.
Vegetation: plants considered collectively, especially those found in a particular area or habitat.
Ecology: the political movement concerned with protection of the environment.
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Chapter two
Review of related literature
Concept, opinions, Ideas from Authors/expert
2.1 Soil erosion
Soil erosion is one form of soil degradation along with soil compaction, low organic matter, loss
of soil structure, poor internal drainage, Stalinization, and soil acidity problems. These other
forms of soil degradation, serious in themselves, usually contribute to accelerated soil erosion.
Soil erosion is a naturally occurring process on all land. The agents of soil erosion are water and
wind, each contributing a significant amount of soil loss each year in Ontario. Soil erosion may
be a slow process that continues relatively unnoticed, or it may occur at an alarming rate causing
serious loss of topsoil. The loss of soil from farmland may be reflected in reduced crop
production potential, lower surface water quality and damaged drainage networks. Soil also can
be defined in several ways depending on the context and perspective of the study. Which: “Soil
is an integral part of the Earth’s ecosystems and is situated at the interface between the Earth’s
surface and the bedrock. It is subdivided into successive horizontal layers with specific physical,
chemical and biological characteristics and has different functions. From the standpoint of
history of soil use, and from an ecological and environmental point of view, the concept of soil
also embraces porous sedimentary rocks and other Permeable materials together with the water
which these contain and the reserves of Underground water.”
2.1 Causes and effect of soil erosion
2.2.1 Causes
When considering appropriate policy instruments to address soil erosion from agriculture, it is
vital to have a thorough understanding of the underlying causes of erosion; why it takes place,
where it is most likely to develop in the short term and where it is most likely to occur in the
future. Many of the underlying causes of soil erosion relate to a complex mix of policy failure
CAPSLO(e.g.Common Agricultural Policy subsidies leading to overstocking), declining levels
of land husbandry skills within the agricultural sector and a whole host of other, often
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interrelating socio-economic factors. These fundamental problems need to be addressed if a
genuinely long term solution to the soil erosion problem is to be found. The purpose of this
section of the document is to outline some of the main on-farm activities that contribute to the
erosion problem. These can loosely be grouped into two main categories: inappropriate cropping
or livestock regimes, and bad management practices:
2.2.2: Growing crops on inappropriate land - In many areas of the country, it is possible to
identify cropping regimes that are inappropriate for the types of soil and topography present. For
example, maize can often be found growing on steeply sided slopes adjacent to water courses.
Given the fact that maize tends to be harvested in the autumn, it is often the case that harvesting
takes place in wet conditions which leads to problems with soil compaction and an associated
increase in run-off and soil mobilisation. Once maize is harvested, fields of bare soil are often
left exposed to autumn and winter rainfall events which can result in extremely high rates of
erosion taking place.
2.2.3:Animal production on inappropriate land - As with cropping patterns, inappropriate
positioning of livestock production activities can also cause soil erosion to occur. Outdoor pig
farming, whilst favourable from an animal welfare perspective, has been found to produce high
racteristic ‘rooting’ of the land. If land used for pig production is on sloping land, the impacts
levels of soil erosion, given the fact that pigs often expose soil to rainfall events due to their
chaof soil loss on surrounding water courses can be dramatic.
2.2.4:Overstocking - Excessive numbers of livestock on a given area of land can cause
significant soil erosion problems due to overgrazing and poaching of the soil which can lead to
high rates of soil exposure, capping and increased overland flow. Upland areas have proved
particularly susceptible to soil erosion caused by sheep. Recent moves by the European Union to
reduce stocking densities have involved switching livestock production subsidies from a ‘per
head’ basis NOAO(i.e. number of animals owned) to an area basis in an attempt to reduce the
incentive for farmers to concentrate too many animals into too small.
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2.2.5:Bad timing of agricultural practices - A significant cause of soil erosion is often down to
inappropriate timing of agricultural practices, particularly ploughing or harvesting land in wet
conditions. Such activities cause soil compaction and also lead to ‘panning’ of the soil, both of
which lead to increased rates of run-off and associated soil erosion. Modern tractors have the
power to plough land in wet conditions which simply wasn’t possible with earlier models (e.g. in
the 1960s) when the land had to be sufficiently dry for tractors to be able to pull a plough.
2.2.6:Degradation of river banks by stock - As well as soil erosion taking place ‘in field’, an
increasing proportion of soil entering water courses in recent years has been caused by livestock
denuding river banks of vegetation, thus making the banks susceptible to erosion during high
water or flood conditions. Grazing animals also enter watercourses to drink during which they
often destroy the bank structure. Fencing off river banks to preclude livestock from grazing and
breaking down bank structures is a technique that has been used to good effect in many parts of
the country.
2.2.7; Bad management of livestock feeding and drinking areas - In livestock production
areas, soil erosion can often occur around feeding and drinking areas where these are not rotated
or moved often enough by farmers. Concentrations of animals over lengthy periods of time can
cause a breakdown in soil structure which will increase the likelihood of soil erosion occurring.
2.2.8: Lack of ground cover over winter months - Modern farming systems have increasingly
favoured the use of winter sown cereal varieties, due to the high yields these produce. The
problem with winter cereals is that unless they are sown early enough in the autumn, there is not
time to establish sufficient crop cover to protect the soil from erosion by winter rainfall events. A
crop rotation involving spring cereals will usually result in fields being protected by crop
stubbles over the autumn and winter months. The problem with spring cereals, from the farmers
perspective, is that they tend to produce lower profit margins and are, therefore, less attractive
than the winter varieties.
2.3. Effect
The effects of soil erosion can be sub-divided into on-farm and off-farm impacts. On-farm
impacts are predominantly borne by the farmer and are essentially related to loss of production
capacity. As soil erosion takes place, the ability for cereal crops and grass to flourish is reduced
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which, in turn, has a direct impact on the productivity of the land. The upper soil horizon or ‘top
soil’ is the most productive component of any soil series and it can take upwards of 150 years for
1cm of topsoil to develop. Off-farm impacts of soil erosion are largely inflicted on wider society
and take a number of forms such as flooding, declining water quality and pollution of air;
involving emissions of greenhouse gases such as carbon dioxide, methane and nitrous oxide. The
scope of this paper precludes an examination of air related pollution but readers should note this
is an issue that should not be underestimated and requires further research and exploration by
policy makers. Soil eroded from agricultural land will often find its way into a main river
channel from where it can be transported downstream as far as the sea. In order to illustrate the
off farm impacts of water induced soil erosion in a logical manner, it is helpful to visualise a
hypothetical ton of soil as it moves from land situated in the headwaters of a catchment
progressively downstream into the marine environment. By tracking the pathway of soil erosion
in this way, it is possible to identify some of the main impacts of eroded soil at each stage of the
journey. These impacts are briefly outlined below:
2.3.1:Loss of Biodiversity e.g. siltation of fish spawning gravels - Many fish species, particularly
salmonids, require clean gravels within which to lay their eggs successfully. Pristine gravels
ensure that eggs receive sufficient oxygen to develop correctly. Soil erosion can have a
devastating impact on fish stocks because in-stream soil particle deposition can smother
spawning gravels, thereby preventing the eggs from receiving sufficient oxygen to survive.
2.3.2: Damage to roads and footpaths - When significant quantities of soil are eroded from
agricultural land, roads and footpaths can become blocked which has a negative impact on
motorists and walkers. Soil deposition on roads can induce traffic accidents due to the creation of
slippery surfaces and can also increase localised flooding when drains become blocked by
excessive sediment loads.
2.3.3Impacts on strategic reservoirs - Sediment entering reservoirs can reduce storage capacity
and can also create infrastructural difficulties e.g. blocking outlet valves. Management solutions
take many forms from the creation of up-stream silt traps (‘ponds’) through to dredging, all of
which have cost implications. The process of transporting and disposing of silt can be
particularly costly.
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2.3.4: Nutrient enrichment of freshwater water bodies - Soil particles often have phosphate
attached to them due to a chemical bond between phosphates and clay fractions within the soil. If
phosphate levels in water bodies become too high, excessive nutrient loadings can occur
resulting in eutrophication taking place and a corresponding depletion in oxygen levels. This can
have fatal effects on macro phytes, fish and other freshwater flora and fauna. Certain forms of
algae are toxic to humans which mean their proliferation due to nutrient enriched waters is less
than desirable on human health grounds.
2.3.5: Contamination of drinking water - Soil erosion has a significant effect on the quality of
potable drinking water supplies. Not only do suspended sediments affect the taste of water but
the associated phosphate loads also have to be removed by water companies to provide drinking
water fit for human consumption.
2.4 Erosion by Water
The rate and magnitude of soil erosion by water is controlled by the following factors:
Rainfall Intensity and Runoff
Both rainfall and runoff factors must be considered in assessing a water erosion problem. The
impact of raindrops on the soil surface can break down soil aggregates and disperse the
aggregate material. Lighter aggregate materials such as very fine sand, silt, clay and organic
matter can be easily removed by the raindrop splash and runoff water; greater raindrop energy or
runoff amounts might be required to move the larger sand and gravel particles. Soil movement
by rainfall RS(raindrop splash) is usually greatest and most noticeable during shortduration,
high-intensity thunderstorms. Although the erosion caused by long-lasting and lessintense storms
is not as spectacular or noticeable as that produced during thunderstorms, the amount of soil loss
can be significant, especially when compounded over time. Runoff can occur whenever there is
excess water on a slope that cannot be absorbed into the soil or trapped on the surface. The
amount of runoff can be increased if infiltration is reduced due to soil compaction, crusting or
freezing. Runoff from the agricultural land may be greatest during spring months when the soils
are usually saturated, snow is melting and vegetative cover is minimal.
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2.4.1: Soil Erodibility
Soil erodibility is an estimate of the ability of soils to resist erosion, based on the physical
characteristics of each soil. Generally, soils with faster infiltration rates, higher levels of organic
matter and improved soil structure have a greater resistance to erosion. Sand, sandy loam and
Loam textured soils tend to be less erodible than silt, very fine sand, and certain clay textured
soils. Tillage and cropping practices which lower soil organic matter levels, cause poor soil
structure, and result of compacted contribute to increases in soil erodibility. Decreased
infiltration and increased runoff can be a result of compacted subsurface soil layers. A decrease
in infiltration can also be caused by a formation of a soil crust, which tends to "seal" the surface.
On some sites, a soil crust might decrease the amount of soil loss from sheet or rain splash
erosion, however, a corresponding increase in the amount of runoff water can contribute to
greater rill erosion problems. Past erosion has an effect on a soils' erodibility for a number of
reasons. Many exposed subsurface soils on eroded sites tend to be more erodible than the
original soils were, because of their poorer structure and lower organic matter. The lower
nutrient levels often associated with sub soils contribute to lower crop yields and generally
poorer crop cover, which in turn provides less crop protection for the soil.
2.4.2: Slope Gradient and Length
Naturally the steeper the slope of a field, the greater the amount of soil loss from erosion by
water. Soil erosion by water also increases as the slope length increases due to the greater
accumulation of runoff. Consolidation of small fields into larger ones often results in longer
slope lengths with increased erosion potential, due to increased velocity of water which permits a
greater degree of scouring CCFS (carrying capacity for sediment).
2.4.3: Vegetation Soil erosion potential is increased if the soil has no or very little vegetative
cover of plants and/or crop residues. Plant and residue cover protects the soil from raindrop
impact and splash, tends to slow down the movement of surface runoff and allows excess surface
water to infiltrate.
The erosion-reducing effectiveness of plant and/or residue covers depends on the type, extent
and quantity of cover. Vegetation and residue combinations that completely cover the soil, and
which intercept all falling raindrops at and close to the surface and the most efficient in
controlling soil (e.g. forests, permanent grasses). Partially incorporated residues and residual
roots are also important as these provide channels that allow surface water to move into the soil.
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The effectiveness of any crop, management system or protective cover also depends on how
much protection is available at various periods during the year, relative to the amount of erosive
rainfall that falls during these periods. In this respect, crops which provide a food, protective
cover for a major portion of the year (for example, alfalfa or winter cover crops) can reduce
erosion much more than can crops which leave the soil bare for a longer period of time (e.g. row
crops) and particularly during periods of high erosive rainfall SS (spring and summer). However,
most of the erosion on annual row crop land can be reduced by leaving a residue cover greater
than 30% after harvest and over the winter months, or by inter-seeding a forage crop (e.g. red
clover). Soil erosion potential is affected by tillage operations, depending on the depth, direction
and timing of blowing, the type of tillage equipment and the number of passes. Generally, the
less the disturbance of vegetation or residue cover at or near the surface, the more effective the
tillage practice is in reducing erosion.
2.5Erosion by Wind
The rate and magnitude of soil erosion by wind is controlled by the following factors:
2.5.1: Erodibility of Soil
Very fine particles can be suspended by the wind and then transported great distances. Fine and
medium size particles can be lifted and deposited, while coarse particles can be blown along the
surface (commonly known as the saltation effect). The abrasion that results can reduce soil
particle size and further increase the soil erodibility.
2.5.2: Soil Surface Roughness
Soil surfaces that are not rough or ridged offer little resistance to the wind. However, over time,
ridges can be filled in and the roughness broken down by abrasion to produce a smoother surface
Susceptible to the wind. Excess tillage can contribute to soil structure breakdown and increased
erosion.
2.5.3: Climate
The speed and duration of the wind have a direct relationship to the extent of soil erosion. Soil
Moisture levels can be very low at the surface of excessively drained soils or during periods of
Drought, thus releasing the particles for transport by wind. This effect also occurs in freeze
drying of the surface during winter months.
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2.5.4: Unsheltered Distance
The lack of windbreaks TSHR (trees, shrubs, residue, etc.) allows the wind to put soil particles
into motion for greater distances thus increasing the abrasion and soil erosion. Knolls are usually
exposed and suffer the most.
2.5.5: Vegetative Cover
The lack of permanent vegetation cover in certain locations has resulted in extensive erosion by
Wind. Loose, dry, bare soil is the most susceptible, however, crops that produce low levels of
Residue also may not provide enough resistance. As well, crops that produce a lot of residue also
May not protect the soil in severe cases. The most effective vegetative cover for protection
should include an adequate network of living windbreaks combined with good tillage, residue
management, and crop selection.
Human activity Soil is a non-renewable resource that once it is eroded it is not renewed. Soil
erosion is the permanent change of the main characteristics of soil that could see it lose its
fertility, pH, color, humus content or structure. Soil erosion occurs naturally by wind or harsh
climatic conditions but human activities include overgrazing, over cropping and deforestation.
2.5.6: Overgrazing occurs when farmers stock too many animals such as sheep, cattle or goats
on their land. The animals damage the soil surface by eating the vegetation and either digging
into wet soil or compacting dry soil with their hooves. This can prevent grass growing and slow
down the percolation of water through the soil. This leads to the damaging of the soil structure
as the level of nutrients is removed and the air between peds is compressed out. This then can
reduce the amount of water between the soil crumbs as the weight and movement of the animals
flattens and compresses the soil. Soils with less vegetation become exposed, drier and prone to
further erosion by the wind and rain. Soils that become drier tend to be vulnerable to the winds
blowing the top soil away. The Sahel region of Africa is an example of soil erosion caused both
by overgrazing and population growth. In the West of Ireland additional funding from the EU in
the 1990’s saw an increase in the sheep population. However, areas of West Mayo suffered soil
erosiovfd88 n by the additional hooves and further funding was needed to sort this problem.
2.5.7: Over cropping is when the land is being continuously under cultivation and is not
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allowed to lie fallow between crops. This constant farming of the land reduces the soils ability to
produce valuable humus for soil fertility as it is constantly being ploughed or stripped for crop
growth. The soil becomes drier and less fertile. While humus is primarily needed for the
addition of nutrients and minerals it is also a valuable source of air and water needed by soil to
keep it moist and aerated. With less humus the soil dries out and is open for wind and rain
erosion. Usually over cropping occurs in areas where there is a demand for crops either for
market or a large local population. Many farmers attempt to restore soil fertility by adding
fertilizers or artificial nutrients but some countries do not have this opportunity due to poverty or
lack of education. In South America soya is a quick-growing and valuable crop. The leading
producers of soya in this region are Brazil and Argentina. Despite some artificial fertilisers
being added the soil is not allowed enough time to recover its fertility or structure and is
ultimately being eroded by this human activity.
2.5.7; Deforestation is the cutting down of large areas of forests leaving an open, exposed
landscape. Deforestation occurs for many reasons such as the sale of wood, charcoal or as a
source of fuel, while cleared land is used as pasture for livestock, plantations of commodities,
and settlements. The removal of trees without sufficient reforestation has resulted in damage to
habitat, biodiversity loss and aridity DS (drying of soil). This human activity quickly accelerates
natural erosion in two ways. Firstly the removal of trees is a removal of nutrients and minerals
from the soil as the source of humus is greatly reduced. The natural dead organic material that
supplies the soil with its humus is generally leaves that have fallen from the trees, animal
droppings, tree fruit or decaying trees in the soil. Secondly, deforestation accelerates soil erosion
by leaving large areas exposed to heavy rainfall (which can cause leaching or flash floods) or
wind erosion. Without the roots of the trees to keep the soil structure in place the soil is loose
and easier to erode. The tropical rainforests of Brazil are seeing huge areas of forest being cut
down each day. Each year about 13 million hectares of the world’s forests are lost due to
deforestation.
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2.6: Types of soil erosion
2.6.1: Sheet Erosion
Sheet erosion is the movement of soil from raindrop splash and runoff water. It typically occurs
evenly over a uniform slope and goes unnoticed until most of the productive topsoil has been
lost. Deposition of the eroded soil occurs at the bottom of the slope (Figure 3) or in low areas.
Lighter-coloured soils on knolls, changes in soil horizon thickness and low crop yields on
shoulder slopes and knolls are other indicators.
2.6.2: Rill Erosion these distinct channels where the soil has been washed away are called rills
when they are small enough to not interfere with field machinery operations. In many cases, rills
are filled in each year as part of tillage operations.
2.6.3: Gully Erosion Gully erosion is an advanced stage of rill erosion where surface channels
are eroded to the point where they become a nuisance factor in normal tillage operations (Figure
5). There are farms in Ontario that are losing large quantities of topsoil and subsoil each year due
to gully erosion. Surface water runoff, causing gully formation or the enlarging of existing
gullies, is usually the result of improper outlet design for local surface and subsurface drainage
systems. The soil instability of gully banks, usually associated with seepage of groundwater,
leads to sloughing and slumping (caving-in) of bank slopes. Such failures usually occur during
spring months when the soil water conditions are most conducive to the problem. Gully
formations are difficult to control if corrective measures are not designed and properly
constructed. Control measures must consider the cause of the increased flow of water across the
landscape and be capable of directing the runoff to a proper outlet. Gully erosion results in
significant amounts of land being taken out of production and creates hazardous conditions for
the operators of farm machinery.
2.6.4: Bank Erosion: Natural streams and constructed drainage channels act as outlets for surface water
runoff and subsurface drainage systems. Bank erosion is the progressive undercutting, scouring and
slumping of these drainage ways Poor construction practices, inadequate maintenance, uncontrolled
livestock access and cropping too close can all lead to bank erosion problems. Poorly constructed tile
outlets also contribute to bank erosion. Some do not function properly because they have no rigid outlet
pipe, have an inadequate splash pad or no splash pad at all, or have outlet pipes that have been damaged
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by erosion, machinery or bank cave-ins. The direct damages from bank erosion include loss of productive
farmland, undermining of structures such as bridges, increased need to clean out and maintain drainage
channels and washing out of lanes, roads and fence rows.
2.6.5: Splash erosion: Splash erosion or rain drop impact represents the first stage in the erosion
process. Splash erosion results from the bombardment of the soil surface by rain drops. Rain
drops behave as little bombs when falling on exposed or bare soil, displacing soil particles and
destroying soil structure. Studies in America have shown that splashed particles may rise as high
as 0.6 metres above the ground and move up to 1.5 metres horizontally. Splash erosion results in
the formation of surface crusts which reduce infiltration resulting in the start of runoff. Is the first
stage in the erosion process Results from the bombardment of the soil surface by raindrops Is the
primary cause of soil detachment and soil disintegration Means that resettled sediment blocks
soil pores resulting in surface crusting and lower infiltration.
2.7: Impact of soil erosion Agriculture Soil erosion removes valuable top soil which is
the most productive part of the soil profile for agricultural purposes. The loss of this top soil
results in lower yields and higher production costs. When top soil is gone, erosion can cause rills
and gullies that make the cultivation of paddocks impossible.
The impacts of erosion on cropping lands include:

reduced ability of the soil to store water and nutrients

exposure of subsoil, which often has poor physical and chemical properties

higher rates of runoff, shedding water and nutrients otherwise used for crop growth

loss of newly planted crops

deposits of silt in low-lying areas
Erosion was seriously threatening the productivity of fertile cropping areas such as the Darling
Downs and the Inland Burnett. Around 3 million hectares or 2% of Queensland is now used for
growing crops. Our principal cropping areas are the Western Downs, Darling Downs, Inland
Burnett, Dawson–Callide, Central Highlands, Atherton Tablelands and the horticulture and
sugarcane areas along the east coast. Around 80% of the state’s cultivated area is vulnerable to
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soil erosion. If nothing is done to protect the soil, losses can be very high. Soil erosion has been
so severe that some areas of Queensland are now unsuitable for cropping. Soil losses from
unprotected cultivation in upland cropping areas of the Darling Downs can average between 20
and 60 tonnes per hectare per year. Steep, unprotected cropping lands in tropical areas can lose
up to 400 tonnes of soil per hectare per year.
2.7.1: Waterways
Downstream effects of soil erosion include:

siltation of watercourses and water storages

Reduction in water quality of creeks, rivers and coastal areas.
Eroded soil, which can contain nutrients, fertilisers and herbicides or pesticides, can be deposited
where there is a reduction in the slope of the land. This can be in sediment traps, along contour
banks, or in grassed waterways, dams or wetlands. Heavier soil particles are the first to be
deposited, while finer colloidal clay particles may remain in suspension. Soil removed by gully
erosion (especially finer colloidal clay) may be transported directly to creeks or rivers.
2.7.2: Reef water quality
The Great Barrier Reef is the largest coral reef in the world. The quality of water flowing from
the land into the reef lagoon has deteriorated over the past 150 years. Major floods deliver large
levels of pollutants (including eroded soil) from river catchments onto the reef.
2.7.3: Infrastructure:
Some properties these soils are especially vulnerable to most forms of soil erosion and can affect
infrastructure projects such as:

Dams and embankments if dispersible soils are not compacted properly during
construction, air voids occur. Water can easily get into these void spaces and cause
dispersion of the surrounding soil. Small ‘pipes’ can form which quickly develop into
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tunnels. This has been known to cause piping and bank failure within a few hours when a
new dam is filled for the first time.

Road and tracks bitumen and concrete readily produce runoff. To build roads, the land
has to be disturbed, so erosion and siltation can occur if special stabilising techniques are
not used.

Urban development’s can cause severe soil erosion if the land is unsuitable to be built on
and developments run through existing drainage lines.

Mining and exploration activities interfere with the natural drainage of the landscape
which can cause erosion and siltation of waterways. Mining exploration requires the
development of hundreds of kilometres of tracks and roads from which vegetation is
cleared, leaving the soil more vulnerable to erosion.
2.8 Control Options
2.8.1EROSION CONTROL on roads is fundamental for the protection of water quality Soil
stabilization and erosion control practices are needed and should be used in areas where soil is
exposed and natural vegetation is inadequate. Bare ground should be covered, typically with
grass seed and some form of matting or mulch. This will help prevent erosion and subsequent
movement of sediment into streams, lakes and wetlands. This movement of sediment can occur
during and after road construction, after road maintenance, during logging or mining activities,
as the road is being used, if a road is closed but not stabilized, or from poor land management
practices near the road roughly half of the erosion from a logging operation, for instance, comes
from the associated roads. Also, most erosion occurs during the first rainy season after
construction. Erosion control measures need to be implemented immediately following
construction and every time an area is disturbed. Soil erosion prediction models such as the
Water Erosion Prediction Project (WEPP) or Unified Soil Loss Equation (USLE) can be used to
quantify erosion and compare the effectiveness of various erosion control measures.
Concentrated water flow can begin as minor sheet flow, produce rills, and eventually result in
major gully formation
2.8.2 Biotechnical methods Such as brush layering, live stakes, and contour hedgerows offer a
combination of structures with vegetation for physical protection as well as additional long-term
root support and aesthetics Erosion control practices include surface armoring and ground cover
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with netting vegetative material or slash rock, and so on; installing water and sediment control
structures; and mulching, seeding, and various forms of re vegetation, as seen in Figures 13.1
through Effective erosion control requires attention to detail, and installation work requires
inspection and quality control.
2.8.3 Erosion Control Plan
use of erosion control measures should be an integral part of any
road construction or resource extraction project. Most disturbed areas, including landings,
construction storage areas, skid roads, road fills, some road cuts, drainage ditches, borrow pits,
the road surface and shoulders, and other working areas should receive erosion control
treatment. It is more cost effective and efficient to prevent erosion than to repair the damage or
remove sediment from streams, lakes, or groundwater. Elements of an Erosion Control and Re
vegetation Plan include project location and climate, soil types, type of erosion control measures,
timing of implementation of the vegetative erosion control measures, source of seeds and plants,
and planting methods. Presents the many aspects of planning, implementation, and care involved
in an Erosion Control Plan for roads projects.
2.8.4 Physical methods include such measures as armoured ditches beams, wood chips, ground
cover mats, and silt or sediment fences These control or direct the flow of water, protect the
ground surface against erosion, or modify the soil surface to make it more resistant to erosion
2.8.5 Vegetative methods, using grasses, brush, and trees, offer ground cover, root strength, and
soil protection with inexpensive and aesthetic “natural” vegetation, as well as help control water
and promote infiltration ideally; vegetation should be selected for good growth properties,
hardiness, dense ground cover, and deep roots for slope
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CHAPTER THREE: METHODOLOGY
3.1Research Design
The study was used a descriptive co-relational design; the study also was used a cross sectional,
comparative and ex-post facto designs. Descriptive in that data collected was used to describe a
phenomenon; co-relational in that it was interested in relating cause and effect of soil erosion in
boqoljire, hargeisa. Comparative, in that the study determined whether there is a significant
difference in the level of cause and effect of soil erosion on environment of boqoljire, hargeisa.
Ex-post facto since the researcher has no control over the variables and only seeks to report what
was happening in the field. The study was being a survey since it involved a large sample
(Creswell, 2003; Kahn, 1993; Kothari, 2004).
3.2 Research Population
The target population where the number of villages produced which dived the valley in hargeisa
the researcher took a sample size from each side there for the given target population will be 30.
The researcher took a sample size from target population from two side in boqoljire in order to
collect accurate information about two variables. The table 1 below shows the respondents of the
study with the following categories: village, target population and sample size. The Sloven’s
formula is used to determine the exactly sample size.
Table 2: Respondents of the study
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The two sides
Target population
Sample size
Side one
15
13
Side two
15
13
Total
30
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3.3 Sample size
The sample size of the study from two side of boqoljire, hargeisa so the sample size was ( 26 )
3.4 Sampling procedure
Simple random sampling is being used to collect this data or select the respondents because the
respondents live different districts around the boqoljire village has equal chance to be selected.
1.5 Research Instruments
There is a set of data collection instrument in which the researcher used to obtain information:
questionnaires, which researcher deliberate to gather information directly from respondents in
two sides. The questionnaire was being used to discover the co-relation between the cause and
effect of soil erosion on the environment
1.6 Validity and Reliability of the Instruments
In the case validity and reliability a researcher was used content validity and was device a
questionnaire of both standardized and self administered. To insure the content questionnaire
was being pre-test to small number of participants before being taken to the field to measure
whether it is suited to the needed information from the respondents. The test-retest technique was
being used to determine the reliability (accuracy) of the researcher devised instruments to ten
qualified respondents, from the different sides areas of boqoljire. These respondents were not
being included in the actual study. In this test- retest technique, the questionnaires were being
administered twice to the same subjects. The test was reliable and the trait being measured is
stable, the results were being consistent and essentially the same in both times
3.7 Data Gathering Procedures
The procedures of data gathering will undertake in three faces which are: Before the
administration of the questionnaire: when the research will obtain a preliminary letter approved
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by the university to conduct the study. The researcher will prepare more than as much as
necessary questionnaires for distribution and list the qualified respondents from the two sides a
3.7.1 During the administration of the questionnaires
1. The respondents were being requested to answer completely and not to leave any part of
the questionnaires unanswered.
2. The researcher was emphasized retrieval of the questionnaires within five days from the
date of distribution.
3. On retrieval, all returned questionnaires were being checked if all are answered.
3.7.2After the administration of the questionnaires
The data gathered were being collated, encoded into the computer and statistically treated
using the Statistical Package for Social Sciences ( CHDR).
And selected through systematic random sampling from this list and inwards at minimum
3.8 Data analysis
The study will be used in both quantities and qualitative data analysis for the end of each section.
The researcher will be using data-analyzer software called SPSS in order to help for the
researcher for accurate and précised analyzed-data.
3.9 Limitations of the study
During this study, the researcher may meet many challenges that limited to get more information
about the cause and effect of soil erosion on the environment in boqolijire hargeisa.
There are also time limitation for preparing, gathering information and interpretation financial
limits that may face researcher to go field and get eye witness the exactly situation in the field
3.10 Ethical Considerations
To make sure confidentiality of the information provided by the respondents and to
ascertain the practice of ethics in this study, the following activities were being implemented by
the researcher:
1. Sought permission to adopt the standardized questionnaire.
2. The respondents were being coded instead of reflecting the names.
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3. Solicit permission through a written request to the concerned officials of the farm owners
included in the study.
4. Request the respondents to sign in the Informed Consent Form (Appendix 3)
5. Acknowledged the authors quoted in this study and the author of the standardized instrument
through citations and referencing.
6. Presented the findings in a generalized manner.
Chapter four
Presentation, Analysis and Interpretation of data
4.1: Gender
S/No
Sex
Number
Respondents
Percentage
1
Male
14
73.7
2
Female
5
26.3
19
100%
Total
Gender
73.7
26.3
male
S/No
Age
1
2
15-25
26-35
female
Number
Respondents
9
3
Percentage
47.4
15.8
Page 39
3
4
5
Total
36-45
46-60
61-80
4
2
1
19
2015
This table can
be clearly
noted that the
respondent of
21.1
10.5
5.3
100.
this research were 76.7%where male where 26.3%where female
4. Age
Age
47.4
15.8
15-25
26-35
21.1
36-45
10.5
5.3
46-60
61-80
The age of respondents were 15-25 years 47.4% were 26-35 years 15.8% were 36-45 21.1%
were 46-60 10.5% were 61-80 years 5.3%
4.3: Educational Level
S/No
1
2
3
4
Total
Educational
Level
Primary
Secondary
University
Other
Number
Respondents
2
1
13
3
19
Percentage
10.5
5.3
68.4
15.8
100.0
Page 40
2015
68.40%
15.80%
10.50%
Primary
5.30%
Secondary
University
Other
The education level of respondents 10% were primary while 5% were secondary, and 68% were
university level while 15% were others.
4.4Knowledge of Soil Erosion
S/No
Knowledge
1
2
Total
Yes
No
Number
Respondents
9
10
19
Percentage
47.4
52.6
100.0
Know;edge of Soil erosion
54.00%
52.00%
50.00%
48.00%
46.00%
44.00%
Series1
Yes
47.40%
No
52.60%
Figure # Shows: the 19 respondents were asked them knowledge of soil Erosion 47% say yes
were 52% No
Page 41
2015
4.5: Livestock Husbandry
S/No
Livestock
Number
Respondents
Percentage
13
6
19
57.9
42.1
100.0
Husbandry
1
2
Total
Yes
No
60
50
40
30
20
10
0
Yes
No
Figure # Shows: the 19 respondents were asked if there is livestock husbandry 57% were
answered yes were 42%were No
4.6: Any Questionnaire Taken this Area
S/No
Number
Percentage
Any
Questionnaire Respondents
1
2
Total
Yes
No
7
12
19
36.8
63.2
100.0
Page 42
2015
Any Questionnaire Taken this Area
63.2
36.8
Yes
No
This question were asked the respondents Any Questionnaire Taken this Area 36%were answer
Yes were 63% No
4.7: Type of Soil Erosion occur Boqoljire
S/No
Type of Soil
Erosion
Number
Respondents
Percentage
1
2
3
4
Total
Splash erosion
Sheet erosion
Rill erosion
Gully erosion
2
3
4
10
19
10.5
15.8
21.1
52.6
100.0
Type of Soil Erosion occur Boqoljire
52.6
10.5
Splash erosion
21.1
15.8
Sheet erosion
Rill erosion
Gully erosion
Page 43
2015
The respondent were asked the type of soil erosion occurred in boqoljire 10%were splash
erosion
And 15%were sheet erosion and 21% were rill erosion and main type of soil erosion
occur in this area is gully erosion 52%
4.8: Control Option exist Boqoljire
S/No
Any Control Number
1
2
Total
Respondents
14
5
19
Yes
No
Percentage
73.7
26.3
100.0
Control Option exist Boqoljire
73.7
26.3
Yes
No
The respondents were asked is there any control option exists in this area 73% were yes and
26% wer No .
S/No
Control
Option
1
2
3
4
Total
Biological
Physical
Mechanical
None
Number
Respondents
1
3
14
1
19
Percentage
5.3
15.8
73.7
5.3
100.0
Page 44
2015
4.9: What are the control options
what are the control options
73.7
15.8
5.3
5.3
Biological
Physical
Mechanical
None
The respondent were asked type of control options and 73%were Answered mechanical control
and 15% Answered physical and 5% were biological control were 5% were say None
4.10: Factors Cause Soil Erosion
S/No
Factors
Number
Respondents
Percentage
Cause Soil
Erosion
1
2
3
4
Total
By Water
By Urbanization
By Wind
By Human
11
2
6
0
19
73.7
26.3
_
_
100%
Page 45
2015
73.7
28
5
By Water
By
Urbanization
By Wind
By Human
The questions asked the respondent the main factors cause soil erosion 73%were answered By
water and 28%were urbanization 5% by wind and 1% By human
4.11: Any Organization discussion with soil erosion of Boqoljire
S/No
Number
Percentage
Any
Organization Respondents
1
2
Total
Yes
No
3
16
19
15.8
84.2
100.0
Any Organization discussion with
soil erosion of Boqoljire
84.2
15.8
Yes
No
The respondent were asked is there any organization discussion with soil erosion 84%were
responded No were 15% are responded yes
Page 46
2015
4.12: If yes what is the organization
S/No
Organization
Number
Respondents
Percentage
1
5.3
1
5.3
2
15
19
10.5
78.9
100.0
Discuss
1
Ministry of
Agriculture
Local
Organization
Other
None
2
3
4
Total
if yes what is the organization
78.9
5.3
10.5
5.3
Series1
Ministry of
Agriculture
Local
Organization
Other
None
The respondent were asked a question related with above question Wich is is there any
organization discussion with soil erosion the most of the respondent of the above question
respondents NO And this question is if yes what is the organization so 5%were ministry of
agriculture and 5% were local organization were 10% were other and 78%were answered None
4.13: Level of Soil Erosion
S/No
Level of
Number
Respondents
Percentage
3
7
7
2
15.8
36.8
36.8
10.5
Soil Erosion
1
2
3
4
Rare
Moderate
Extreme
Very extreme
Page 47
Total
19
2015
100.0
Level of Soil Erosion
Very extreme
Extreme
Moderate
Rare
0
10
20
30
40
This question respondent were asked the level of soil erosion so 40% say extreme and
35%modarat and 15% Rare while 10% say very extreme .
4.14: Last year's how soil Erosion was increasing
S/No
1
2
3
Total
Last year's
Low
Medium
High
Number
Respondents
4
7
8
19
Percentage
21.1
36.8
42.1
100.0
Last year's how the Erosion was
increasing
36.8
42.1
21.1
Low
Medium
High
Page 48
2015
The respondent were asked how soil erosion was increasing in the lest years 21%was responded
low and 36% medium while 42% of the respondents were answered high .
S/No
1
2
Total
4.15: Did you see Last 20 Years, Farmers use chemical Fertilizers
Number
Percentage
Last 20
Respondents
Years
Yes
No
3
16
19
26.3
73.7
100.0
did you see Last 20 Years, Farmers use
chemical Fertilizers
73.7
26.3
Yes
No
This question respondent were asked if there are famers use chemical fertilizers in lest 20 years
so 73% of the responded were say No wile 26%were say yes
S/No
1
2
Total
4.16: Is the Soil Conservation Practices in Boqoljire
Number
Percentage
Does Soil
Conservation Respondents
Practices
Yes
No
5
14
19
26.3
73.7
100.0
Page 49
2015
Does Soil Conservation Practices
Boqoljire
73.7
26.3
Yes
No
The respondent were asked is there any soil conservation practices in boqoljire so 73%were say
No and 26%were say yes
5. What is Sources of Energy for Cooking
S/No
Sources
Number
Percentage
Respondents
Cooking
1
2
3
Total
Wood
Kerosene
Charcoal
6
1
12
19
31.6
5.3
63.2
100.0
Sources of Energy for Cooking
63.2
31.6
5.3
Wood
Kerosene
Charcoal
Page 50
2015
In the question the respondent were asked sources of energy for cooking so 63%were respond
charcoal and 31%were wood wile 5%were kerosene
4.18: How is Soil Fertility of Boqoljire
S/No
Fertility of
Number
Respondents
Percentage
1
13
5
19
5.3
68.4
26.3
100.0
Soil
1
2
3
Total
Very bad
Medium
Very fertile
how is soil Fertility of Boqoljire
68.4
26.3
5.3
Very bad
Medium
Very fertile
The respondent were asked how is the soil fertility of boqoljire so 68%were respond medium
and 26% were say very fertile while 5% were very bad
4.19: Does Families Have Livestock Boqoljire
S/No
Families
Have
Livestock
Number
Respondents
Percentage
1
2
Total
Yes
No
13
6
19
68.4
31.6
100.0
Page 51
2015
does Families Have Livestock
Boqoljire
Yes
No
32%
68%
And this question respondent were asked does your family have livestock so 68%were say yes
while 32%were say No
4.20: If yes what Kind of Livestock
S/No
Kind of
Number
Respondents
Percentage
1
4
9
3
2
19
5.3
21.1
47.4
15.8
10.5
100.0
Livestock
1
2
3
4
5
Total
Oxen
Cows
Goats
All
None
Page 52
2015
if yes what Kind of Livestock
Oxen
Cows
Goats
All
None
47%
11%
27%
16%
21%
5%
The respondent were asked a question related the above question kind of livestock so
47%have goats and 21%have cows and 15%have all 10%the don’t have any livestock while
5%oxen
6. Do you thing that Livestock Participate Soil Erosion
S/No
Number
Percentage
Livestock
Respondents
Participate
Soil Erosion
1
2
Total
Yes
No
13
6
19
68.4
31.6
100.0
do you thing that Livestock
Participate Soil Erosion
Yes
No
32%
68%
This question respondent were asked do you thing that livestock participate soil erosion so
68%yes and 32%were respond No.
Page 53
S/No
1
2
Total
2015
4.22: Does soil erosion Effect Livestock Production
Number
Percentage
Options
Yes
No
Respondents
17
2
19
89.5
10.5
100.0
Effect of Soil erosion in Livestock
Production
Yes
No
11%
89%
This question respondent were asked does soil erosion effects the production of livestock so
89%were respond yes while 11% say No
Page 54
2015
Chapter 5:
Conclusions and Recommendations
5.1. Conclusions
Both soil causes and effect of soil are major drivers of land degradation and pose key problems
to livelihoods of the community members in the study area. Sheet, rill and gully erosion are the
main types of erosion within the study area and the latter form of erosion, namely gully erosion,
is the most alarming problem removing huge quantities of soil, dissecting land and damaging
infrastructure.
Deterioration in soil fertility as a result of severe soil erosion is a critical deterrent to crop
production and a lack of fodder has been a major factor in the decline in livestock production. As
charcoal is the major source of energy for cooking in the study area, deforestation has seriously
depleted forest resources. This has compelled community members to travel long distances and
spending significant amount of time for collection of wood.
As alternative sources of energy, the community members burn cow dung and crop residues,
both leading to degrading soil as the application of compost and nutrient recycling has been
adversely affected exacerbating the problem of crop failure and dwindling land productivity. The
negative effects of both soil erosion and deforestation on the livelihoods of community are well
understood by the households. The existing attempt implemented to combat the problems of soil
erosion has helped when a comparison is made between a situation as it was and the results
achieved so far.
When asked about observation of change in soil fertility, the majority of the respondents
indicated that they had observed medium in fertility (68%) and a significant reduction in
production over time.
When we asked the Chemical fertilizers have been used over
the last 20 years with an increase
in the quantity used over time as a result of decline in soil fertility.73% responded No
Page 55
2015
5.2. RECOMMENDATION
 Due to the heavy problem of soil erosion into the Environment, as we discuss chapter
four we suggest to control factors the can cause soil erosion such as water wind and
human activates
 Training for local people in boqoljire to get ability to prevent problems of soil erosion
which have an advice effect on their farmers and also their animal production
 The local municipality must interfere This problem specially place like dry river in
Hargeisa
Which is part of the study area that are tract (iskarogooyinka) tack to the white soil in
rain seasons for building purpose The rive is one of the main place the soil erosion
occurred
 it most forced those tract to top using the river of boqoljire because new this area become
urban and local municipality
assign those causes the problem and other place which
away from the urban
 Awareness should be created at all levels on the negative effects of soil erosion on the
environment, The rate of soil erosion should be quantified
 Alternative energy sources should be considered and information disseminated at grass
roots level to protect the remaining forests.
Page 56
2015
References:
1. Tegegne Tatek Belay 2014 Perception of farmers on soil erosion and conservation
practices in Dejen District, Ethiopia
2.
J. Ritter, P.Eng. 2012: Soil Erosion — Causes and Effects
3. Ikponmwosa D. Ighodaro1, Francois S. Lategan2 & Shehu F. G.
4. Yusuf1 2013: The Impact of Soil Erosion on Agricultural Potential and Performanceof
Sheshegu Community Farmers in the Eastern Cape of South Africa
5. 1Yusuf, M.B.and 2Ray H. H.: 2011 Farmers’ Perception and Reponses to Soil erosion in
Zing Local Government Area of
6. Taraba State, Nigeria
7. Assefa Derebe Zegeye May 2009: ASSESSMENT OF UPLAND EROSION
PROCESSES AND FARMER’S
8. PERCEPTION OF LAND CONSERVATION IN DEBRE-MEWI WATERSHED,
9. NEAR LAKE TANA, ETHIOPIA
10. W. E. H. Culling 2011 Theory of Erosion on Soil-Covered Slopes
11. KASSU KEBEDE BEYENE June, 2011: SOIL EROSION, DEFORESTATION AND
RURAL LIVELIHOODS IN THECENTRAL RIFT VALLEY AREA OF ETHIOPIA: A
CASE STUDY IN THE DENKU MICRO-WATERSHED OROMIA REGION
12. ASIF KHAN KHATTAK : May 2008: SOIL MANAGEMENT IN
ORGANIC AGRICULTURE A CASE STUDY OF DENMARK
13. Louis Philor April, 2011: Erosion Impacts on Soil and Environmental Quality: Vertisols
in the Highlands Region of Ethiopia
14. Sustainable Landscapes – http://ag.udel.edu/udbg/sl – http://ag.udel.edu/extension
Page 57
2015
15. OMAFRA Staff; G. Wall - Ontario Institute of Pedology: Soil Erosion Causes and
Effects:
16. Alex Inman, Tamar Consulting February 2006: Soil erosion in England and Wales:
causes, consequences and policy options for dealing with the problem
17. P.M. van Dijk 2001: Soil erosion and associated sediment supply to rivers
18. Hyeon Sik Kim APRIL 20, 2006 : SOIL EROSION MODELING USING RUSLE AND
GISON THE IMHA WATERSHED, SOUTH KOREA
19. Somaliland Vision 2030, 2010 Somaliland Food & Water Security Strategy
20. Swalim 2007 Soil Survey of a Selected Study Area in Somaliland
Page 58
2015
Appendix
FIG.1 gully erosion occurred near the river of boqoljire
8.Is there any control options exist there?
Yes
No
9.What are the Control options?
Page 59
2015
Biological
Physical
Mechanical
10. what is the main factor cause soil erosion in this area?
by Water
by Wind
by Human
by Urbanization
11.Is there any organization have a discussion with the soil erosion exist boqoljire?
Yes
No
12.If yes What is the organization?
Ministry of Environement
Ministry of Agriculture
Local Organization
International Organization
Other
None
13.What do you thing Level of soil erosion in boqoljire?
Very rare
rare
Moderate
extreme
Very extreme
14 Last year’s how the erosion was increasing?
Low
medium
high
15 did you. See some of the resident using chemical fertilizers over the last 20 years?
Yes
No
Page 60

Cause and effect of Soil Erosion in Boqol

Transcription

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