CHAPTER ONE
INTRODUCTION
1.1 Background of the Study
This
study focuses on the environmental impacts of flooding on agricultural
activities in Kwale and its environs. Flooding has been a long-term issue which
affects the inhabitants of Kwale. In many natural systems, floods play an important role in
maintaining key ecosystem functions and biodiversity. They link the river with
the land surrounding it, recharge groundwater systems, fill wetlands, increase
the connectivity between aquatic habitats, and move both sediment and nutrients
around the landscape, and into the marine environment (Apan, et al., 2010). For many species, floods
trigger breeding events, migration, and dispersal. These natural systems are
resilient to the effects of all but the largest floods. The environmental
benefits of flooding can also help the economy through things such as increased
fish production, recharge of groundwater resources, and maintenance of
recreational environments (Bunn and Arthington, 2002).
The environmental resources in Kwale most especially the land and soil resources
are greatly threaten by flooding. The Kwale and its environ is covered by beautiful vegetation
naturally checking the menace. This flooding menace has destroyed arable land
for agricultural purposes which are the major socio-economic activities of the Kwale people. The government in his attempt to curb
the situation has constructed a drainage system some meters away from the major
road to redirect and channel all the water flowing to the erosion sites into
the drainage system which is emptied into the river. Despite all this effort,
the situation still remains the same.
Areas that have been highly modified by human activity tend
to suffer more deleterious effects from flooding. Floods tend to further
degrade already degraded systems. Removal of vegetation in and around rivers,
increased channel size, dams, levee bank and catchment clearing all work to
degrade the hill-slopes, rivers and floodplains, and increase the erosion and
transfer of both sediment and nutrients (Douglas, et al., 2005). While cycling of sediments and nutrients is
essential to a healthy system, too much sediment and nutrient entering a
waterway has negative impacts on downstream water quality. Other negative
effects include loss of habitat, dispersal of weed species, the release of
pollutants, lower fish production, loss of wetlands function, and loss of
recreational areas (Kingsford, 2000).
Flooding
is one of the environmental problems that have confronted man since immemorial.
Flooding is a widespread and age long phenomenon. In Kwale, flooding has created and causes untold
hardship such as destruction of building and properties, interruption of
socio-economic development of the area. Jon (2011), defined flooding as a
condition, which exist when any overland flow over an urban or rural area, that
is sufficient to cause property damage, health hazard, nuisance and the
obstruction of the socio-economic activities in the area. He went further the
types of flooding to include rivers flood, flash flood, splash flood and flood
bondages.
Agriculture has changed significantly in terms of
the production patterns and structure and a significant trend has been the
development towards fewer and larger holdings with more intensified and
specialized production. This development has included an increased
mechanization and use of fertilizers and pesticides. Biodiversity has been
affected negatively both by the physical changes in the landscape and by the
changes in the production methods. As the agricultural production has
intensified, all levels of biological diversity (genetic, species, and
habitats)
have declined in farming environments. The more intensive land use corresponds
for example to the decrease in the populations of farmland birds.
Many of our coastal resources, including fish and other
forms of marine production, are dependent on the nutrients supplied from the
land during floods. The negative effects of floodwaters on coastal marine
environments are mainly due to the introduction of excess sediment and
nutrients, and pollutants such as chemicals, heavy metals and debris. These can
degrade aquatic habitats, lower water quality, reduce coastal production, and
contaminate coastal food resources (Poff, et
al., 2003). It is against this background that this
study is carried out to examine the environmental impacts of flooding on
agricultural activities in Kwale and its environs.
1.2 Statement
of Problem
Flooding in key agricultural production areas can lead to
widespread damage to crops and fencing and loss of livestock. Crop losses
through rain damage, waterlogged soils, and delays in harvesting are further
intensified by transport problems due to flooded roads and damaged
infrastructure. The flow-on effects of reduced agricultural production can
often impact well outside the production area as food prices increase due to
shortages in supply (Prosser, et al.,
2001). On the other hand, flood events can result in long-term benefits to
agricultural production by recharging water resource storages, especially in
drier, inland areas, and by rejuvenating soil fertility by silt deposition
(Apan, et al., 2010).
Damage to public infrastructure affects a far greater
proportion of the population than those whose homes or businesses are directly
inundated by the flood. In particular, flood damage to roads, rail networks and
key transport hubs, such as shipping ports, can have significant impacts on
regional and national economies. Short-term downturns in regional tourism are
often experienced after a flooding event. While the impact on tourism
infrastructure and the time needed to return to full operating capacity may be
minimal, images of flood affected areas often lead to cancellations in bookings
and a significant reduction in tourist numbers (Apan, et al., 2010).
Flooding of urban areas can result in significant damage to
private property, including homes and businesses. Losses occur due to damage to
both the structure and contents of buildings. Insurance of the structure and
its contents against flooding can reduce the impacts of floods on individuals
or companies. As most people are well aware, the immediate impacts of flooding
include loss of human life, damage to property, destruction of crops, loss of
livestock, and deterioration of health conditions owing to waterborne diseases.
As communication links and infrastructure such as power plants, roads and
bridges are damaged and disrupted, some economic activities may come to a
standstill, people are forced to leave their homes and normal life is disrupted
(Kingsford, 2000).
Similarly, disruption to industry can lead to loss of
livelihoods. Damage to infrastructure also causes long-term impacts, such as
disruptions to supplies of clean water, wastewater treatment, electricity,
transport, communication, education and health care. Loss of livelihoods,
reduction in purchasing power and loss of land value in the floodplains can
leave communities economically vulnerable. Floods can also traumatise victims
and their families for long periods of time. The loss of loved ones has deep
impacts, especially on children (Bunn and Arthington, 2002). Displacement from
one's home, loss of property and disruption to business and social affairs can
cause continuing stress. For some people the psychological impacts can be long
lasting. Floods impact on both individuals and communities, and have social,
economic, and environmental consequences. The consequences of floods, both
negative and positive, vary greatly depending on the location and extent of
flooding, and the vulnerability and value of the natural and constructed
environments they affect (Douglas, et al.,
2005). This study “environmental impacts of flooding on
agricultural activities in Kwale and its environs” is therefore carried out to address the aforementioned
problems.
1.3 Aim
and Objectives of the Study
The main of this study is to examine
the environmental impacts of flooding on agricultural activities in Kwale and its
environs. The specific objectives of this study includes:
1.
To
examine the environmental impacts of flooding on agricultural activities in the
study area;
2.
To
identify the causes of flooding in the area;
3.
To
examine the consequent effect of flooding on agricultural activities in the
study area;
4.
To
identify the various types of farm practices and agricultural productivity in
the study area;
5.
To
identify the problems of flooding and areas seriously affected by flooding in
the study area; and
6.
To
suggest mitigation measures to control the problems of flooding in Kwale and
its environs.
1.4 Research
Questions
The following question(s) raised by
the researcher will be answered in this study;
1.
What
are the environmental impacts of flooding on agricultural activities in the
study area?
2.
What
are the causes of flooding in the area?
3.
What
are the consequent effects of flooding on agricultural activities in the study
area?
4.
What
are the various types of farm practices and agricultural productivity in the
study area?
5.
What
are the problems of flooding and areas seriously affected by flooding in the
study area?
6.
What
do you think are the mitigation measures to control the problems of flooding in
Kwale and its environs?
1.5 Research
Hypothesis
The following hypothesis stated in the
null and alternative form will be tested in this study;
1.
There
is no significant relationship between the environmental impacts of flooding
and the various types of farm practices/agricultural productivity in Kwale and
its environs.
2.
Crop
yield is not significantly dependent on flooding and heavy rainfall in Kwale.
3.
Occurrence of flooding in Kwale is not
significantly depended on heavy rainfall, lack of drainage system.
1.6 Significance
of the Study
This
study will cover the whole of Kwale and its environs and its to look at the environmental impacts of
flooding on agricultural activities in Kwale and its environs.
It would also offer suggestion (s) on the causes of flooding and its effect on agricultural
activities in the study area.
Therefore, the study will help to
unfold the deteriorating effects of flooding on agricultural activities in
Kwale and its environs and other related land use in Kwale, and also to look at
the various cause (s) of flooding and the areas mostly affected by flooding in
the study area and also to look at or proffer solution (s) to combat flooding
problem (s) on agricultural activities and socio-economic life of the people in
the study area.
1.7 STUDY AREA
The study area (Kwale) is located in
Ndokwa West Local Government Area of Delta State and it’s the administrative
headquarters of Ndokwa West L.G.A of Delta State.
1.7.1 Location
and Size
Kwale is
located between latitude 60 09N and 60 29N of the equator
and longitude 50301E and 60031E of
the Green Witch meridian. Kwale is a town in Ndokwa West Local Government Area
of Delta in southern Nigeria. As a matter of fact, it is the headquarter of
Ndokwa West Local Government Area which occupies an area of 816km2.
Like any other community, Kwale is divided into six (6) quarters as follows:
Umusederi, Isumpe, Umusam, Umusadege, Umuseti and Ogbe-ani. Majority of the
population of Kwale are affected by water pollution due to presence of oil
companies in the area such as Agip Petroleum Company, Sterling Global Company
etc. and the people are prompt to different kinds of diseases. The area also
experience destruction of fishes, plants animal life.
Source: Ministry lands, survey and
Urban Development Asaba (2004).
m
Fig 1.2: Map of Kwale in Ndokwa West L.G.A
Fig 1.2: Map of Kwale showing the quarters
1.7.2 Relief
and Drainage
The
topography is a low plain with elevation of 21 meters above sea level (Ndakara,
2011). The area consists mainly of sedimentary rocks formations deposited in
three cycles of marine transgression.
According to Odemerho (2007) the
surficial geology comprises the sombreiro-warri deltanic plan formation. The
sombreiro-warri, am area also referred to as the “Urhobo Plains” (Aweto, 1987).
The soil in this study area, like
those of the forest ecosystems difference somewhat in different areas of the
region, mainly in response to pollutions experience in the area and the
underlying parent materials. The soil classified according to the U.S soil
taxonomy system (soil survey staff, 1994) under the Affisls, Oxisols/utisols
orders.
Warn temperatures and abundant
available of moisture increases the rate of leading in utisols, and this cause
the soil to have low qualities of base cation. Also, the nature of the land
makes for severe water erosion during and after rainfall.
The velocity of the water is high as
it flown along the sloppy surface because of the factors of pollution e.g oil
spillage, surface run-off containing pesticides and insecticides, discharge of
untreated sewage, industrial discharge of chemicals waste and by product,
underground storage tank leakage lending to soil contamination etc. The rivers
and creeks in this area are bordered by natural leaves, which are of great
topographical importance because this is where most farming activities takes
place.