Question world. Resources and environmental carrying capacity seems

Question 1

Write a comprehensive note on the
Carrying Capacity of a selected resource of interest to you in Nigeria or your
Local Government Area (LGA).

We Will Write a Custom Essay Specifically
For You For Only $13.90/page!


order now

1.1  INTRODUCTION

Countries all over the world especially developing
countries are generally characterized by a large population; unprecedented
growth and massive reliance on the available natural resources to service their
desired want, and or need as the case may be. As human society advances in
knowledge and technology, especially in the last decade, human conditions has
increased drastically, at the same time, resulting in challenges and depletion
to the natural resources to which their advancement is dependent on. However,
to achieve sustainable development and avoid the limits of resources and environment
became one of the important challenges facing the twenty-first century world.
Resources and environmental carrying capacity seems to be the promising method
to solve these problems. It aims at coordinating the relationship between the
social economic activities and environment, so that it is the best tool to
realize regional sustainable development and becomes regional planning
foundation. In recent years, this concept has been used in many places, and
numerous access methods appear in the meanwhile (Tian and Wang, 2013). The
process of the concept and the access methods have been summarized in this
paper so that it may facilitate the research of resources and environmental
carrying capacity in the future.

There
are different types of natural resources in the environment for use by man to
satisfy his needs and wants. They do not require the action of mankind for
their generation or production. These resources include land, rocks, forests
(vegetation), water (ocean, lakes, streams, seas, and rivers), fossil fuel,
animals (fish, wild life, and domesticated animals), minerals, sunlight and
air. As the human population keeps on enlarging, there is a lot of pressure on
the utilization of almost all natural resources. This often causes
over-exploitation of the natural resources. To worsen matters, exhaustible
natural resources such as arable land, coral reefs, fresh water, fossil fuels,
and wilderness forests drop sharply due to over-exploitation to sustain the
ever increasing population. This creates competitive demands on the vital
life-sustaining resources and contributes to an incredible decline in the
quality of life. The usage and availability of these resources are linked with
population growth. The carrying capacity of the environment is exceeded when
the available resources cannot sustain the population. This could lead to
conflict (population matters, 2011).  

The
concept of carrying capacity can be traced back to the 1970s and it refers to a
group of people which can be sustained within the limits of a natural resource
which is devoid of natural, social, cultural and economic environmental
degradation for both the present and future generations. However, the carrying
capacity of a resource can be altered by factors such as population increase,
technological advancement, etc. When the environment is degraded, carrying
capacity of a resource automatically decreases and people will have to compete
for the available ones for survival. Due to the limits placed on sustainable
development by resource scarcity, different concepts for carrying capacity were
introduced, e.g., land, environment, agriculture, and water. Specifically, water has been
playing an increasingly important role in current socio-economic development,
so water resources carrying capacity (WRCC) has attracted considerable
attention (Qin et al, 2016).

The
term carrying capacity stems from the mechanical, and borrowed by theoretical
genecology firstly. Initially carrying capacity refers to the maximum number of
specific species in a biota that could be maintained by the biota’s various
resources (Tian and Wang, 2013). The carrying capacity of resources was
gradually noticed first due to the land resources shortage. The accelerated
process of industrialization made the research of single factor resource
carrying capacity gradually extended to the water resources, mineral resources
and forest resources because it started to have problem in these areas. In
1980s, UNESCO gave the concept of resources carrying capacity which made all
kinds of resources to be considered as a union, and used population size as the
expression of resources carrying capacity. It preliminary formed the basic
framework of the concept of carrying capacity.

Carrying
capacity has been researched in different ways such as ecological carrying
capacity, environmental carrying capacity, regional carrying capacity,
resources carrying capacity, etc. Although, these are comprehensive carrying
capacities but they are differentiated by certain factors (Tian and Wang,
2013).

Nigeria
is one of the few countries in the world that is blessed with natural resources
which include; water, land, forest, mineral, resources, etc. however, over time
population increase, industrialization and technological advancement has
exerted pressure on the carrying capacity of these resources in the country and
it is the people that bear the brunt. Unfortunately, in Nigeria, there is poor
sensitization about the sustainable utilization of environmental (natural)
resources.

 

1.2       Natural resources

Resource
generally is simply a source or supply from which benefit is produced. It is
the available source of livelihood or wealth creation available to an
individual, organisation or country. Resource may occur in small or large
quantities, located everywhere or in very few places, and may be used by few or
many people, not in use at a time, in use at a time. In other words, resource
is not static; it changes from time to time and place to place depending on
human wants and capacity to satisfy their wants. This is perhaps why there is
no universally accepted definition of what is considered a resource.

Resource
from an ecological point of view is anything in the environment which can be
used. Unlike other discipline of study, natural sciences view resources from
the natural or environmental perspective (natural resources).

Natural
resources can thus, refer to the untamed natural essence of the environment.
The religious bias refers to it has “God given”. The physical/natural sciences
are more interested in natural resources because it is the zone where the major
components of nature are found. They contain a significant amount of material
as well as aesthetic values that exist relatively undisturbed by mankind, in a
natural form. Examples such as land or raw materials occur naturally within
environments. Many of them are essential for our survival while others are used
for satisfying our wants.

For
the purpose of this research, water resources will be examined. The purpose of
focusing on this resource is because; although it is a renewable resource, it
is a scarce commodity in most places of the world. It is no news that some
countries of the world are already water stressed and that they import water
from other countries. Some parts of Nigeria especially the North is no
exception while other places lack the technological know-how to ensure
continued availability of clean water to households. This explains the long
queues in front of boreholes where people struggle to fetch water even the
so-called urban centers.   

1. 3 History of water resources in Lagos

Lagos is
littoral to the Atlantic Ocean and its topography consists of lying coastal
beaches, extensive inland lagoons, marshes, creeks and mangrove wetlands at
elevations of 0 to 2 meters, and upland areas with moderately drained soils and
an elevation range of 2 to 50 meters above sea level The major rivers that
drain into the lagoons and water bodies within the study area (Lagos and Lekki
Lagoon)are the Yewa River, Osun River, Owo River, Aye River, Oworu River and
most significantly, Ogun river which yields 461MGD (Fasona et al, 2005).
Brackish water sources include Ologe Lagoon, Lekki Lagoon, Badagry Creek, and
Lagos Lagoon, which the Ogun River discharges into (Lagos State Water
Corporation, 2010). Lagos is also blessed with abundant groundwater from the
Coastal Plain Sands Aquifer that gets amply recharged as Lagos experiences an
average annual rainfall of about 2 meters. With the rapid population growth
rate of Lagos, the Lagos State Water Commission (LWC) has not been able to meet
the growing demand of water. This has resulted in residents looking to the most
readily accessible source, groundwater. This has led to unplanned and
uncontrolled groundwater exploitation with siting of boreholes by both skilled and
unskilled technicians with varying degrees of success (Fasona et al, 2005).
Because Lagos is adjacent to the Atlantic Ocean, over extraction of groundwater
leads to high risks of saltwater intrusion. The groundwater is contained in
four aquifers in the sedimentary basin: the first and shallow aquifer, is the
Recent Sediments along the Atlantic Sea coast and along river valleys. It is
used for very small private domestic supplies through dug wells and shallow
boreholes.  The second and third aquifers
are in the Coastal Plains Sands Formation. They are exploited through dug wells
in places, shallow – and deep – boreholes (maximum depth of 300 m at the
coast). These aquifers provide substantial quantities of water for private-,
public- and industrial–water supplies. This is the main aquifer exploited in
Lagos megacity. The fourth aquifer is the deep and highly productive Abeokuta
formation. Only a few boreholes located mainly in Ikeja industrial area,
extract water from the fourth aquifer. The water from this aquifer is hot with
temperatures as high as 80 °C recorded in a few of the boreholes (Coode Blizard
Ltd et al, 1966). This aquifer is undergoing massive development in adjoining
Ogun State in recent times where it is encountered at shallower depths of between
300 to 550 m. 

Table1.1:
Water Resources of Lagos Megacity

S/N

Type

Quality
of Water

Source

Safe
Yield (mm3/

Surface
Area Km2

1

Surface Water

Fresh

Ogun River

2.092

 

2

Oshun River

0.207

 

3

Yewa 
River

0.1889

 

4

Aye River

0.11271

 

5

Oworu/Solodo

0.0944

 

6

Brackish

Lagos Lagoon

 

500

7

Badagry Creek

 

200

8

Lekki Lagoon

 

300

9

Ologe Lagoon

 

64

10

Ground Water

Fresh  

 Groundwater

Modelled aquifer through put 650,000m3

Source:
LWC.,2011

1.4       Challenges
of Water Supply in Lagos state

The
influx of people into Lagos state in search of greener pastures has made it
difficult for government to provide the basic services. Traditionally, the
provision of water supply in the state of Lagos has been regarded as a
responsibility of the government, through the Lagos State Water Corporation

From
independence in 1960 until the 1980s, the Lagos state government provided
potable water to communities that had water boards; the taps were flowing and
all Lagosians had access to treated drinking water.

However,
since then the situation has deteriorated and a reliable water supply of good
quality water has been hard to find. Reasons for the change include (Samson,
2013):

a.      
 A rapidly increasing population,

b.     
Poor
planning,

c.      
Insufficient
funding,

d.     
Failing
infrastructure,

e.      
Climate
change and;

f.      
Corruption.

Those factors, coupled with the
failure of the government to properly manage and implement goals and effective
polices, have further exacerbated the water supply crisis (Afooma, 2014).  

The carrying capacity of water in
Lagos has really reduced and a good percent of its population depend on private
boreholes, private tankers, water carts, boreholes and wells; providing up to
70% of the water consumed. This in turn has created its own issues with regards
to water purity standards, potential contamination from septic tanks or drains,
higher delivery costs, and the ultimate impact on the state’s groundwater
levels from the improper tapping of groundwater reserves.

 

 

1.5       Methodology
for Water Resource Carrying Capacity (WRCC)

There
are two methods that will be discussed in calculating Water Resource Carrying
Capacity. These include:

i.                   
Design
water resources.

ii.                 
WRCC
Quantification model.

Design water resources

The
design water resources Wp refer to the water resources derived from the
hydrological calculation with P probability of exceedance. Wp has two
characteristics: firstly, Wp is a determined value; secondly, the probability
of future water resources exceeding Wp is P. When the water resources are
greater than or equal to Wp, WRDCC can be guaranteed with a probability of P.
Otherwise, the probability of water resources less than Wp is (1 _ P) and the
risk of not reaching the design status is 1 _ P. The choice of P should be made
based on the balance of the two aspects, i.e., water resources being fully
utilized (requiring P not too large) and WRDCC with the appropriate guarantee
rate (Requiring P not too small). P should be selected by considering the social,
economic, technology and others at the national level, which is not an easy job
currently. P is suggested to be selected according to:

 (1) The importance of the city; and

(2)
The amount of water resources (water-rich area, water-limited area) (Qin et al,
2016).

WRCC Quantification model.

The
objective of the WRCC quantification model is to find the maximum socioeconomic
scale of any urban centre. The socioeconomic scale is usually represented by a
series of indices, i.e., urban population, rural population, GDP, industrial
added value, agricultural added value, and grain yield. If these indices are
included in the objective function, solution of the model will become one
solution of the multi-objective optimization problems. For the sake of a
convenient solution, all of these indices change proportionally with one
another during the search for optimal values. Therefore, the objective function
is simplified as a single-objective function based on a change ratio ?
and can be expressed as follows (Dou et al, 2014):

QWRCC= max

However, water resources design carrying capacity will be used to
calculate the carrying capacity of water in Lagos because it is simpler to use.

Using the table below, carrying capacity will be calculated.

Table 1.2: Demand Gap Estimates (Short, Medium,
Long Term)

Year

Population

Water
Demand (MGD)

Water
Production (MGD)

Demand
Gap (MGD)

2010

18,000,000

540

210

330

2016

24.121.722

724

317

407

2018

26,594,198

665

577

88

2020

29,320,103

733

745

12

             (Source: LWC, 2010b)

 

 

x

Hi!
I'm Mack!

Would you like to get a custom essay? How about receiving a customized one?

Check it out