Abstract
For thousands of years, sand and gravel have been used in the construction of roads and buildings. Today, demand for sand and gravel continues to increase. Mining operators, in conjunction with cognizant resource agencies, must work to ensure that sand mining is conducted in a responsible manner.
Excessive in-stream sand-and-gravel mining causes the degradation of rivers. In-stream mining lowers the stream bottom, which may lead to bank erosion. Depletion of sand in the streambed and along coastal areas causes the deepening of rivers and estuaries, and the enlargement of river mouths and coastal inlets. It may also lead to saline-water intrusion from the nearby sea. The effect of mining is compounded by the effect of sea level rise. Any volume of sand exported from streambeds and coastal areas is a loss to the system.
CHAPTER ONE
1.1Background of the study
For thousands of years, sand and gravel have been used in the construction of roads and buildings. Today, demand for sand and gravel continues to increase. Mining operators, in conjunction with cognizant resource agencies, must work to ensure that sand mining is conducted in a responsible manner.
Excessive instream sand-and-gravel mining causes the degradation of rivers. Instream mining lowers the stream bottom, which may lead to bank erosion. Depletion of sand in the streambed and along coastal areas causes the deepening of rivers and estuaries, and the enlargement of river mouths and coastal inlets. It may also lead to saline-water intrusion from the nearby sea. The effect of mining is compounded by the effect of sea level rise. Any volume of sand exported from streambeds and coastal areas is a loss to the system.
Excessive instream sand mining is a threat to bridges, river banks and nearby structures. Sand mining also affects the adjoining groundwater system and the uses that local people make of the river.
Instream sand mining results in the destruction of aquatic and riparian habitat through large changes in the channel morphology. Impacts include bed degradation, bed coarsening, lowered water tables near the streambed, and channel instability. These physical impacts cause degradation of riparian and aquatic biota and may lead to the undermining of bridges and other structures. Continued extraction may also cause the entire streambed to degrade to the depth of excavation.
Sand mining generates extra vehicle traffic, which negatively impairs the environment. Where access roads cross riparian areas, the local environment may be impacted.
Sand and gravel are used extensively in construction. In the preparation of concrete, for each tonne of cement, the building industry needs about six to seven times more tonnes of sand and gravel (USGS, 2013b). Thus, the world’s use of aggregates for concrete can be estimated at 25.9 billion to 29.6 billion tonnes a year for 2012 alone. This production represents enough concrete to build a wall 27 metres high by 27 metres wide around the equator. Aggregates also contribute to 90% of asphalt pavements and 80% of concrete roads and the demand for aggregates stems from a wide range of other sectors, including production of glass, electronics and aeronautics. Added to this are all the aggregates used in land reclamation, shoreline developments and road embankments (for which the global statistics are unavailable), plus the 180 million tonnes of sand used in industry. This sand and gravel are mined world-wide and account for the largest volume of solid material extracted globally and the highest volume of raw material used on earth after water (about 70-80% of the 50 billion tons material mined/year). Formed by erosive processes over thousands of years, they are now being extracted at a rate far greater than their renewal.
Despite our increasing dependence on the colossal quantities of sand and gravel being used and the significant negative impact that their extraction has on the environment, this issue has been mostly ignored by policy makers and remains largely unknown by the general public. Indeed, the absence of global data on aggregates mining makes environmental assessment very difficult and has contributed to the lack of awareness about this issue. As a consequence, a large discrepancy exists between the magnitude of the problem and public awareness of it.
1.2 STATEMENT OF PROBLEM
The impact of sand and gravel dredging or mining on the environment is enormous; this is so because when they see is dredge Excessive in stream sand-and-gravel mining causes the degradation of rivers. … Any volume of sand exported from streambeds and coastal areas is a loss to the system. Excessive in stream sand mining is a threat to bridges, river banks and nearby structures.
With advancement in technology and infrastructural development, the need for sand and gravel is on the high side, and dredging happens to be the only solution to meet this needs. However if dredging and is not control it impact on the infrastructure can be very fatal.
1.3 OBJECTIVE OF THE STUDY
The main objective of this study was to ascertain the impact of sand and gravel dredging on environment. However at the completion of the study, the researcher seeks to achieve the following objectives:
1. The impact of gravel dredging on the Lagos bar beach coastal area
2. The impact of sand dredging on Nigerian waters
· To ascertain the consequences of gravel dredging in coastal area
1. The challenges of dredging on Nigeria coastal area
1.4 RESEARCH QUESTION
For the successful completion of these studies, the following research question was formulated:
1. What is the impact of dredging on Lagos coastal area?
2. What is the impact of sand dredging on Nigerian waters emphasis on Lagos coastal area?
· What are the consequences of gravel dredging on infrastructural development in Lagos coastal area?
1. To what extent has dredging affect the infrastructural development of the region?
1.5 SIGNIFICANCE OF THE STUDIES
It is conceived that at the completion of the studies, the findings will be beneficial to the environmental agency and coastal guard who is saddle with the responsibility of protecting the region, the study will also be of benefit to the NIMASA who are responsible for protection of Nigerian water ways.
Finally, the study will also be useful to academia, teachers, lecturers, researchers and the general public
1.6 SCOPE AND LIMITATION OF THE STUDIES
The scope of this studies covers the impact of sand and gravel dredging on Lagos coastal area, however, the studies have some constrain which are:
1. a) AVAILABILITY OF RESEARCH MATERIAL: The research material available to the researcher is insufficient, thereby limiting the study
2. b) TIME: The time frame allocated to the study does not enhance wider coverage as the researcher have to combine other academic activities and examinations with the study.
3. c) FINANCE: The finance available for the research work does not allow for wider coverage as resources are very limited as the researcher has other academic bills to cover.
1.7 DEFINITION OF TERMS
DREDGING
Dredging is an excavation activity usually carried out underwater, in shallow seas or freshwater areas with the purpose of gathering up bottom sediments and disposing of them at a different location. This technique is often used to keep waterways navigable. It is also used as a way to replenish sand on some public beaches, where sand has been lost because of coastal erosion. Fishing dredges are used as a technique for catching certain species of edible clams and crabs.
SAND
Sand is a naturally occurring granular material composed of finely divided rock and mineral particles. It is defined by size, being finer than gravel and coarser than silt. Sand can also refer to a textural class of soil or soil type; i.e. a soil containing more than 85% sand-sized particles by mass.
The composition of sand varies, depending on the local rock sources and conditions, but the most common constituent of sand in inland continental settings and non-tropical coastal settings is silica (silicon dioxide, or SiO2), usually in the form of quartz. The second most common type of sand is calcium carbonate, for example aragonite, which has mostly been created, over the past half billion years, by various forms of life, like coral and shellfish. For example, it is the primary form of sand apparent in areas where reefs have dominated the ecosystem for millions of years like the Caribbean.
GRAVEL
Gravel is composed of unconsolidated rock fragments that have a general particle size range and include size classes from granule– to boulder-sized fragments. Gravel is categorized by the Udden-Wentworth scale into granular gravel (2 to 4 mm or 0.079 to 0.157 in) and pebble gravel (4 to 64 mm or 0.2 to 2.5 in). One cubic metre of gravel typically weighs about 1,800 kg (or a cubic yard weighs about 3,000 pounds).
Gravel is an important commercial product, with a number of applications. Many roadways are surfaced with gravel, especially in rural areas where there is little traffic. Globally, far more roads are surfaced with gravel than with concrete or tarmac; Russia alone has over 400,000 km (250,000 mi) of gravel roads.[1] Both sand and small gravel are also important for the manufacture of concrete
1.8 ORGANIZATION OF THE STUDIES
This research work is organized in five chapters, for easy understanding, as follows
Chapter one is concern with the introduction, which consist of the (overview, of the study), statement of problem, objectives of the study, research question, significance or the study, research methodology, definition of terms and historical background of the study. Chapter two highlight the theoretical framework on which the study its based, thus the review of related literature. Chapter three deals on the research design and methodology adopted in the study. Chapter four concentrate on the data collection and analysis and presentation of finding. Chapter five gives summary, conclusion, and recommendations made of the study.
A Abstract
This research examines the implications of land fill emission and their impact on Nigeria. This has some socio economic and political implications on sustainable development, while the management of waste is a matter of national and international concern. Recent events in major cities of world have shown that the problems of waste management have become a “monster” that has aborted most efforts made by international, federal governments, and state city authorities. It has been established that the process of waste management contributes to increasing generation of green house gases that causes climate change and ozone layer depletion.
CHAPTER ONE
INTRODUCTION
· Background of the study
The increase in population as a result of industrial revolution in major towns and cities of the world have necessitated rapid growth or high rate of urbanization and development for instance; Nigeria cities in recent time have witnessed rapid population growth resulting from influx of migrants from rural area to the cities. This brings about the concentration of industrial, commercial, infrastructural, administration and government activities in urban centers. Thus, as the population of cities grows, the rate of waste generation also increases leading to increase burning of refuse (in the developing countries) and high rate of air pollution ,which increased concentration of green house gases that causes global warming and eventually Climate change. In the last decades the greenhouse gases produced by human activities have been predominating over those of natural origin (Intergovernmental Panel on Climate Change-IPCC, 2000), thereby upsetting the natural atmospheric balance. This increased concentration of greenhouse gases (GHGs) raises global temperatures which have adverse impacts on our environment and public health. The waste sector is a significant contributor to GHGs emissions and is accountable for approximately 5% of the global greenhouse budget (IPCC, 2006). The majority of these emissions are a result of landfills, which remains the primary waste disposal strategy globally (Attenborough, Gregory,& McGeochan, 2002). Municipal solid waste (MSW) contributes to greenhouse gas emissions through decomposition and life-cycle activities/ processes (Farguhar and Rovers, 1973). The greenhouse gases emissions related to waste deposits are mainly due to methane (CH4) and carbon dioxide (CO2) present in the biogas produced by anaerobic bacteria using as carbon source the biodegradable carbon contained in the waste (Hoeks, 1983; Barlaz, Ham & Schaefer, 1990). In particular the disposal of waste in landfills generates methane that has high global warming potential (Yesiller, Hanson and Liu, 2005). Energy consumption contributes directly to climate change by adding carbon-based molecules to the atmosphere in excess of naturally occurring amounts. Carbon molecules, primarily carbon dioxide from burning petroleum products, trap radiant heat and keep it from escaping from the Earth’s atmosphere (IEA, 2005). The resulting warming of the air is changing our global climate. Thus, landfills are among the nations’ largest emitters of CO2 and CH4, the key greenhouse gases (GHGs) which modify the Earth’s climate, and as such effective mitigation of these greenhouse gas emissions is important and could provide environmental benefits and sustainable development, as well as reduce adverse impacts on public health (Sheehan, 2000; Briney, 2013). Methane is regarded as one of the most important GHGs because its global warming potential has been estimated to be more than 20 times that of carbon dioxide. Although there is no immediate danger from the methane emitted in atmosphere from landfills, over time it could accumulate inside the landfill mass, thus increasing its concentration with attendant potential to modify the Earth’s climate. 36 percent of human caused methane releases come from our municipal solid waste landfills (USEPA, 1999). A ton of municipal solid waste land-filled produces 123 pounds of methane- a potent greenhouse gas, 20 times more effective at trapping heat in the atmosphere than carbon dioxide (EA, 2008). Hulme et al. (1995) list the adverse impacts of the increased concentrations of greenhouse gases in the atmosphere to include: a threat to disrupt the diversity of habitats and the life dependent on them. In particular, our health, agriculture, water resources, forests, wildlife, and coastal areas are vulnerable to the changes that global warming may bring. It further state that a rise of only a few degrees in the Earth’s average temperature could result in more frequent and intense storms, flooding of beaches, bay marshes, and other low-lying coastal areas; more precipitation in some areas and not enough in others and wider distribution of certain infectious diseases. Such significant changes, note NEST (1991), Hulme et al. (1995) and Nicholson (2001) could damage communities and national economies as well as alter the natural world.
· STATEMENT OF THE PROBLEM
Developing country like Nigeria is particularly at risk, because of her bad waste management system and unhealthy disposal practices. Global temperature will continue to increase causing further disruption to climate patterns. Ultimately, all this can only be brought under control by engaging in sustainable waste management practices, and stabilizing greenhouse gases concentrations in the atmosphere. It is on this backdrop that the researcher intends to investigate the impact of land fill emission on the environment.
· OBJECTIVE OF THE STUDY
The main objective of the study is to ascertain the land fill emission and their impact on the environment in Nigeria. But for the successful completion of the study the researcher set the following sub-objective to be achieved:
1. To ascertain the impact land fill emission on the environment.
2. To ascertain the relationship between land fill emission and environmental pollution
· To ascertain the effect of solid waste management in reducing air pollution
1. To investigate the effect of land fill emission on environmental pollution
o RESEARCH HYPOTHESES
For the successful completion of the study, the following hypotheses were formulated:
H0: land fill emission has no significant impact on the environment
H1: land fill emission has a significant impact on the environment
H0: there is no significant relationship between land fill emission and environmental pollution
H2: there is a significant relationship between land fill emission and environmental pollution.
· SIGNIFICANCE OF THE STUDY
It is believed that at the completion of the study, the findings will be of great importance to the ministry of environment in ensuring that the environment is devoid of pollution. The findings will also be of great benefit to the waste management agency in ensuring that the waste are properly disposed to ensure that it does not constitute a major air pollution in the society. The study will also be of importance to researcher who wishes to carry out investigation in similar topic. Finally, the study will be of importance to lecturers, students, teachers and academia’s as the findings will add to the pool of knowledge.
· SCOPE AND LIMITATION OF THE STUDY
The scope of the study covers land fill emission and their impact on environment in Nigeria. But in the course of the study, the researcher encounters some constrain which limited the scope of the study. Some of these limitations are:
(a)Availability of research material: The research material available to the researcher is insufficient, thereby limiting the study.
(b)Time: The time frame allocated to the study does not enhance wider coverage as the researcher has to combine other academic activities and examinations with the study.
(c)Finance: The finance available for the research work does not allow for wider coverage as resources are very limited as the researcher has other academic bills to cover.
1.7 DEFINITION OF TERMS
Land Fill
A landfill site (also known as a tip, dump, rubbish dump, garbage dump or dumping ground and historically as a midden) is a site for the disposal of waste materials by burial and the oldest form of waste treatment (although the burial part is modern; historically, refuse was just left in piles or thrown into pits). Historically, landfills have been the most common method of organized waste disposal and remain so in many places around the world.
Land
Land, sometimes referred to as dry land, is the solid surface of the Earth that is not permanently covered by water. The vast majority of human activity throughout history has occurred in land areas that support agriculture, habitat, and various natural resources.
Waste
Waste is any substance which is discarded after primary use, or it is worthless, defective and of no use. Examples include municipal solid waste(household trash/refuse), hazardous waste, wastewater (such as sewage, which contains bodily wastes (feces and urine) and surface runoff), radioactive waste, and others.
· ORGANIZATION OF THE STUDY
This research work is organized in five chapters, for easy understanding, as follows Chapter one is concern with the introduction, which consist of the (overview, of the study), statement of problem, objectives of the study, research question, significance or the study, research methodology, definition of terms and historical background of the study. Chapter two highlight the theoretical framework on which the study its based, thus the review of related literature. Chapter three deals on the research design and methodology adopted in the study. Chapter four concentrate on the data collection and analysis and presentation of finding. Chapter five gives summary, conclusion, and recommendations made of the study.