GEOGRAPHY NOTES FOR FORM THREE AND FOUR

SETTLEMENT

A Settlement is a place or location where people live and establish their livelihood.

CONCEPT OF SETTLEMENT

Settlement; is a place where people live. Settlement can come in different sizes.

A settlement may be as small as a single house in remote area or as a large as a mega city.

A settlement may be permanently or temporary. An example of a temporary settlement would be a refugee camp. However a temporary settlement may become permanent over time. This happens to many refugees camps that have been built in conflict zones. Actual piece of land upon which a settlement is built is known as the settlement site.

Settlements usually develop in a particular pattern (but not always).

• A nucleated settlement is where the buildings are closed around a central point such as market square.
• Linear settlement is where the buildings are arranged in a line usually along the river or road.
• A dispersed settlement is where the buildings are spread out or scattered. Dispersed settlement are often found in remote, sparsely populated areas.

TYPES OF SETTLEMENT.

There are two (2) types of settlements which are urban settlement and rural settlement. The characteristics which define a settlement of urban or rural include the size, density of the population and activities being under taken in these two types of settlement.

1. URBAN SETTLEMENT.

Are geographical areas with dynamic boundaries. The growth of an urban centre refers to the expansion of a town as a result of birth rate, change of the town boundaries.

Population in urban settlements are used in many analysIs as an important variable in social, environment and demographic studies.

Characteristics of urban settlement.

• The number of urban settlement and their boundaries will change overtime, depending on construction activities and change of present population.
• The delimitation of the urban settlements are independent of the administrative boundaries
• Urban centre are characterized by denser engaged industrial activities
• Trading is a major activities under taken in urban areas

2. RURAL SETTLEMENT.

Are geographical morphologies, comprising of all places with less than 10,000 population;- They comprise of small rural town villages and homesteads.

In Tanzania about 80% of the population live in rural areas. To supplement their farming activities some rural communities engage in other traditional activities such as weaving, carving, fishing and extracting of timber from the forest.

Characteristics of rural settlements.

• It is sparsely populated pattern of settlement
• Agriculture is the major activity undertaken in rural areas.

SETTLEMENT PATTERNS

Is the layout of dwelling in a particular place. Settlement patterns assume a distinct form as it grows, settlement patterns may be influenced by different factors such as topography of an area and availability of suitable land for farming. Transport routes and communication lines also may influence the pattern that emerges. Human factors such as an increase in population may lead to the spread of settlements because may be searching for new land to settle on.

Types of settlement patterns

1. Nucleated Settlement Pattern.

This settlement pattern consists of cluster of dwellings, shops and other buildings in one place. The settlement is close to one another forming a cluster. Nucleated settlement may develop as a result of the availability of social services, the presence of industrial plants and limitation of building land leading to the clustering of building in one place.

Settlement such as Mwadui in Tanzania and Kimberley in South Africa are nucleated mining settlements.

2. Linear Settlement Pattern.

Linear settlement pattern may develop along communication lines or along specific physical feature such as river, the house and other structures appear to be arranged in a line along a road, a river, or canal or a coastal line such settlement may form a curve depending on the shape of the features.

Linear settlements are common along the coast of East Africa, along the shores of lake Tanganyika and a long some parts of lake Victoria. They are also common along many roads and foot paths.

3. Dispersed Settlement Pattern.

Is also referred to as scattered settlement pattern because it consists of houses and other structures which are scattered. The houses may be separate from one another by physical features such as valleys, rivers, and ridges. Dispersed settlement is common in areas where people own individual traits of land.

FUNCTIONS OF SETTLEMENT

The functions of settlement describe all the activities that occur in it, there are three common functional classifications of settlement rural settlement and institutional settlement. Settlements established for a specific purpose. In this aspect there are categories which includes.

Ø  Market towns;- Originate as centres for sale and distribution

Ø  Mining towns;- are located in areas that contain a supply of natural resources such as coal, diamond and tin.

Ø  Manufacturing and industrial towns;- grown  around the source of raw materials often in conjuction with mining towns.

Ø  Route centres;- located at nodal points that develop from the transportation of raw materials for processing of manufactured products to the marketing centres.

Ø  Administrative centres;- Involve settlement that are strategically well placed to combine several functions and provide a administrative services on a regional or national basis.

Ø  Port centres;- The original function of ports is the settlement of raw materials, goods and passengers with development of national and international trade, such centres have naturally acquired additional functions like business.

GROWTH OF SETTLEMENT

This refers to the increase or expansion of the place or areas where people live and engage in different economic activities.

There was the rapid growth of settlement in Europe after the industrial revolution.

The growth of settlement of a given place is always dynamic as it changes time after time due to the different factors.

THE FACTORS WHICH INFLUENCE THE GROWTH OF SETTLEMENT.

• Provision of social services,

 People migrate from their original places and live near areas where social services are easily available to them. Example of social services are health centres, schools, electricity and water supply.

• Climate condition.

People settle in good climatic areas. Rainfall and temperature have a great influence from human settlement. Areas that receive abundant rainfall and favourable temperature attract more people. This is because people are able to engage in both subsistence and commercial farming such areas are Kilimanjaro, Mbeya, Ruvuma and Iringa region where there is abundant rainfall.

• Relief;

It is a strong factor influencing settlement. Gentle slopes are ideal areas for building houses as they are well drained. Steep stops are usually uninhabited because they have thin soils which inhibit growth of crops and pasture.

• Vegetation cover;

Vegetation is the total plants cover over an area. Thick vegetation discourages establishment of settlement. Dense forest such as Congo of central Africa and Amazon, in South America are not accessible. They may also be habitants for dangerous wild animals and disease carrying vectors.

• Political factor;

Political factor has great influence on settlement establishment. A settlement may be located in a certain area because of political reasons for example in 1967 the government of Tanzania introduced ujamaa village where by people were settled in villages.

• Economic factor;

People establish settlement in places which offer economic opportunities. Migration from rural to urban centres is mainly due to prospects for employment and trading opportunities. Mining activities also leads to the establishments of settlements for example development of Mwadui towns was the results of Mwadui Diamond mines.

• Cultural factors;

Some areas may be productive but due to some cultural beliefs people may be prohibited to establish settlements on such areas. Example mumbanitu forest in Njombe.

• Historical factors;

Prior to the division of Africa some communities moved in various directions and settled in their present homelands. Those movements were caused by various factors mainly wars for example Mfecane war in South Africa.

SOCIAL AND ECONOMIC PROBLEMS ASSOCIATED WITH URBAN GROWTH

Numerous attempts have been made to classify settlements based on functions, but this tended to refer to places in industrialized countries, and is not longer applicable to post-industrial societies.

Urbanization is associated with a number of problems, some of these problems include environmental degradation, rise in criminal activities, inadequate housing, traffic congestion, unemployment, immorality, shortage of public utilities such as water, and emergence of street children.

Overcrowding, Great number of immigrants and people are coming from farms. There is an increase in birth rate and drop in mortality rate. People migrate from original places due to corruption, poor water supply and poor health services.

 Political instability, the increase of the people at certain areas cause the increase of bad behaviors like crime which lead to political instability at a given area.

Eruption of diseases like cholera, malaria, HIV/AIDS and other outbreaks due to population pressure caused by the increase of people.

Unemployment, Due to the increase of people in urban areas from the rural most of them search for jobs in the urban centres which result in lack of job vacancies.

Traffic Congestion, These refer to the presence of high number of vehicles especially private cars, these lead to noise pollutions as well as air pollutions for example Dar -es salaam.

Shortage of social services, like water, schools. Some urban centres do not have reliable sources of water. As population increase water sources are strained and most residential areas experience water shortage for instance Dar es salaam suffer from water shortage throughout the year.

Emergence of street children, As people increase resulting to the lack of social services and conflicts in the family and at the end family break-ups which result to street children. These people decided to run away due to the lack of social services in their family.

WAYS OF SOLVING EXISTING PROBLEMS RELATED TO URBAN GROWTH

The following are the ways of solving existing problems related to urban growth as;

Improvement of social services like water, electricity, churches, schools for example construction of more dams to preserve water for the population in the cities also there be improvement of infrastructure so as to facilitate economic activities.

Creation of employment opportunities. The city council has to create more jobs so as to cure the problem of unemployment for example increase in investments in industries as well as agriculture, which will lead to the provision of jobs to youths.

Good urban planning, There must be good planning in the constructions of buildings so as to avoid the poor arrangement of housing in the cities. Housing design must try to meet the demand of the citizen.

 Improvement of infrastructure to accommodate the motor vehicles. Private cars have been increasing extensively and becoming a problem. It is necessary to set up a reasonable system and width of roads, reserve necessary parking place.

 Family planning, As street children are caused by the lack of social services, this can be reduced by using the family planning to reduce the number of children in the family. This will make the provision of social services as well as the employment opportunities.

ENVIRONMENTAL ISSUES AND MANAGEMENT

This topic deals with problems that occur within our environment; causes, effect on living things and how to mitigate these problems.

 This topic deals with problems that occurs within our environment, causes, effect on living things and how to mitigate these problems.

 In this topic we are going to deal with the sub topic called environment conservation.

ENVIRONMENTAL CONSERVATION

Concept of environmental conservation

Refers to the protecting of environment from being destructed through practicing various ways of environment protection such as destocking, afforestation and planting of cover plants.

WAYS OF CONSERVING THE ENVIRONMENT

Destocking, refers to the process of reducing number of animals on the environment because when the number of animals increase on the environment, they can feed on all the plants which help to prevent soil erosion or land slides.

Afforestation and Reforestation refer to the process of planting trees in bare land and re planting trees in the presence of other trees.

Control industrial gases and industrial sewage system, industrial location should be far apart from the water sources

Practicing proper irrigation skills. When irrigation is practiced improperly especially on the land with slope the water can wear out the nutrients and cause poor production.

Control of industrial fertilizers instead of depending on industrial fertilizer we can use manure since manure has no effect on the soil while industrial fertilizers add acid on the soil

To control fishing activities, bad fishing method should be discouraged for example charging and punishing for those who practicing bad methods.

Control construction of road and buildings to avoid construction of building on steep slopes because this can accelerate soil erosion.

PRACTICING ENVIRONMENTAL CONSERVATION AND MANAGEMENT AT SCHOOL LEVEL.

This part is practically based on students in groups to practice various ways of conserving the environment such as planting trees, flowers, cleaning environment around the school campus.

CAUSES AND EFFECTS OF FAST RATE OF POPULATION AND URBAN GROWTH ON ENVIRONMENT.

Population can be higher in particular areas due to the availability of social services, (food, shelter, hospital), good economic activities, agriculture, trade, good infrastructure, climatic condition. When the population is high, it can cause the following effect on the environment.

EFFECT OF FAST RATE POPULATION AND URBAN GROWTH ON THE ENVIRONMENT

• Soil erosion. This is because when the population grows high, it leads to expansion of settlement and residence because they will need to build houses which involves digging the land for setting the foundation of the houses.
• Deforestation when the population is higher it leads to the expansion of settlement and residence. That people will cut trees in order to create space and for building.
• Loss of biodiversity, This is due to risky human activities that endanger the life of living organisms for instance using chemicals in agriculture and fishing and deforestation also cause biodiversity.
• Desertification is a condition where the land is bare that it allows the sun to heat directly on the land since there is no land cover
• Air pollution since the number of people increasing on the environment improve industrialization. That will produce large amount on gases.

DESERTIFICATION

Is the development of desert-like condition in regions that have experienced human disturbance such as deforestation, overgrazing, poorly managed agriculture. Although the extent of the world deserts expand and contract in response to naturally changes in climatic condition

CAUSES OF DESERTIFICATION

• Overgrazing, overgrazing was not a problem long ago because animals would move in response to rainfall. Now, animals can graze in a single area for a long time.
• Farming of arable land. Farming of arable land is causing desertification worldwide farmers are clearing arable land and using it takes away the richness of the soil
• Destruction of plants in dry regions this is causing desertification to occur. People are cutting down trees to use them as a source of fuel once these trees are cut down there is nothing to protect the  soil.
• Incorrect irrigation in arid regions cause a build up of salt in the soil. This is commonly used in poorer areas farmers use poor techniques because of lack of water.
• Deforestation since it involve cutting down of trees without planting more trees causing the land to be bare that the soil can be easily carried by the wind

EFFECT OF DESERTIFICATION.

• Soil becomes less usable, The soil can be blown away by wind or washed away rain nutrients in the soil can be removed by wind or water. Salt can build up in the soil which make it hard for plant growth.
• Damaged loose soil may bury plants or leave their roots exposed also when overgrazing occur plants species may be lost
• Places that have war and poverty are most likely to have famine occur. Drought and poor land management contribute to famine.
• Food loss. The soil is not suited for growing food, Therefore the amount of food being grown will decline. If the population is still growing this will cause economic problems and starvation.
• Desertification can cause flooding, poor water quality, dust storms and pollution. All of these effects can hurt people living near an affected region.

IMPACT OF POVERTY ON ENVIRONMENT 

• Poverty influences environment degradation. Environment degradation is the process induced by human behavior and activities that damage the natural environment.
• Poverty considered as a great influence of environment degradation in many regions of the world, regional overgrazing has resulted in destruction of grazing lands, forest and soil
• The carrying capacity of the natural environmental has been reduced, As the people become poorer they destroy the resources faster
• They tend to overuse the natural resources because they don’t have anything to eat or any means of getting money except through the natural resources so starting to depend more on natural resources
• Due to the lack of sufficient income people start to use and overuse every resource available to them when their survival is at stake.

GLOBAL CLIMATIC CHANGE

Is a significant and lasting change in the statistical distribution of weather patterns over periods ranging from decades to millions of years.

CAUSES OF GLOBAL CLIMATIC CHANGE

• Both natural and human factors change earth’s climates
• Before human changes in climate, changes resulted entirely from natural causes such as changes in Earth’s orbit, changes in solar activity or volcanic eruptions
• Since the industrial era began humans have had an increasing effect on climate particularly by adding billions of tons of heat trapping green house gases in the atmosphere.
• Most of the observed warming since the mid 20^th century is due to human caused greenhouse gas emission.

CONSEQUENCES OF GLOBAL CLIMATIC CHANGES

Loss of biodiversity, since when the climate change there is occurring of drought that can cause plants and micro-organism die

Causes disease such as skin cancer, when the ozone layer is destructed it can cause the sun rays to penetrate directly to the earth surface since the ozone layer previously acting as a blanket to prevent the sun rays is now destructed

Famine or hunger. It is difficult to practice agriculture when climate is changing. it may cause drought making it difficult for plant growing

Increase in sea levels since the climate change can cause the melting of ice due to increase in temperature on the earth surface that cause increase of the sea level.

Loss of habitat for living organism since there are some living organisms living in cold areas or in ice so when the climate changes due to increase in temperature those organism fail to survive and die.

7.1 THE CONCEPT OF ENVIRONMENT

The term “environment” refer to the surrounding and the influence surroundings have on living things. Surroundings include the living and the dead things. Thus environment include land, water, atmosphere and living things. In the environment, human beings are taken to be the centre because they influence the environment and in turn it influences them.

Simply environment includes everything surrounding us including ourselves.

THE COMPONENTS OF ENVIRONMENT

Our environment is often divided into three components. These are the physical, the living and the cultural environment.

1. The Physical Environment
    It consist of air, water, soil and rocks form the non – living or physical environment.
2. The living Part of the Environment
   The second component is the habitat which is the home of living things (all living things). The habitat provide conditions necessary for life to prosper. The various creatures depend on each other for survival E.g. animals depends on plants for foods, plants depends on insect for pollination and dispersal.
3. The Cultural Environment.
   The cultural or human environment is unique for two ways

• People are part of the living environment
• People are capable of influencing each and every other part of the environment

Thus the cultural environment reflects the impact of human being such as;

• Homes, industries, ports, transport and communication
• Their capability for agriculture
• Their capability to conserve or destroy the environment.

THE ENVIRONMENT AS A SYSTEM

Environment is made up of independent components and processes, hence what is part of the environment can relate to something else. The destruction of one of these mean damaging a lot others E.g. If we destroy a forest;

• We destroy habitants for so many other creatures.
• We are destroying natural cycles which involve the production or consumption of gases for sustaining life.

Therefore we should note that environment is a big system of parts, in which none can work alone.

Environment is important for the following aspects.

1. General life support
2. The environment contains ingredients essential for live, health and human welfare
3. Supply of raw materials and energy necessary for production and consumption.
4. Absorption of the waste products of the social and economic activities. This absorption is done through air, soil or water.

ENVIRONMENTAL PROBLEMS AND MANAGEMENT.  

Environment problems refer to the issue of harmful processes which are introduced or natural occurrences to the environment and make it unsafe for the users.

Environment management: Refer to the solution of controlling or conserving or caring of environment for the future use.

The main environmental problems facing the environment are,

1. Pollution, these includes Air, Water, Soil, and Noise pollution
2. Environment hazards which include, Floods, Drought, Desertification, Famine and loss of Biodiversity both plants and animal (flora and fauna)
3. Global warming
4. Global climatic change.

CAUSES OF VARIOUS ENVIRONMENT PROBLEMS

ENVIRONMENT POLLUTION.

Environment pollution these are problems which lead to pollution of environment due to addition of unwanted product or substance, these includes Air pollution, Soil pollution, Water pollution and Noise pollution.

WATER POLLUTION;

Water pollution is the addition of unwanted substance to the sources of water example River, Lake, Ocean, Dams, Swamp

CAUSES OF WATER POLLUTION.

1. Mining activities, due to the exploitation of minerals when rain falls it sweeps the soil to the source of water resulting in pollution.
2. Disposal of untreated sewage (effluent) into the water bodies from various sources e.g. Industrial wastes or domestic wastes.
3. Dumping of waste from the industries into the water bodies from various sources e.g. industrial waste.
4. Oil spills from the leaking oil containers of pipes during the transportation of such raw materials
5. Some chemicals and other waste from the farms can get into the water bodies through the surface run-off
6. Volcanic eruption, Eruption of magma on the surface could lead to water pollution because it can flow to the source of water
7. Testing of bombs.
8. Wind
9. Use of chemicals by fishermen

AIR POLLUTION;

Air pollution refers to the addition of unwanted substances to the atmosphere.

CAUSES OF AIR POLLUTION.

1. Industrial activities. These industries produce some gases which affect the atmosphere e.g. carbon dioxide, carbon monoxide and sulphur dioxide
2. Automobiles, The presence of cars lead to air pollution due to the burning of oil which produce gases like CO₂ .
3. Casual burning lead to air pollution due to gases produced
4. Mining activities lead to air pollution due to the dust moved by wind
5. Construction activities also pollute the air by dust.
6. Agricultural activities
7. Volcanic Eruption.

SOIL POLLUTION;

Soil pollution refers to the introduction or addition of any substance in the soil which is unwanted or harmful to plants and animals and having adverse effects to the soil quality.

CAUSES OF SOIL POLLUTION;

1. Poor dumping of waste products from various sources e.g. industries, homesteads
2. Mining activities, this lead to soil pollution due the fact that when these activities take place they leave a hole to the land as the result of soil erosion
3. Agricultural activities through shifting cultivation. E.g. the use of chemical fertilizers.
4. Acidic rain, this can lead to the killing of vegetation over which protect soil from destructive means.
5. Overgrazing lead to pollution of soil as the result of erosion caused by large number of animals kept.
6. Deforestation due to the cutting down of trees
7. Monoculture which affects the fertility of soil due to the monotonous production of one crop.

NOISE POLLUTION;

Noise pollution is any disorganized loud sound. Sound is a form of energy but when it become so loud it cause negative effects

CAUSES OF NOISE POLLUTION;

1. Automobile e.g. Dar es salaam there so many cars so it facilitate noise
2. Presence of factories or workshops
3. Low flying air crafts
4. Homesteads like slamming of the doors
5. Thunderstorms and explosion of bombs.

DESERTIFICATION.

Desertification is the process by which the deserts are encroaching on potential agricultural land

OR

Is the process in which the fertile land is demanded and degraded to initiate a desert – producing cycle that feeds itself and cause long term changes

CAUSES OF DESERTIFICATION

1. Mismanagement of land leads to desertification
2. Deforestation, meaning that cutting down of trees make the land bare and as a result rainfall decreases because trees act in rain formation.
3. Scarcity of water, this lead to death of some flora.
4. Population explosion, this accelerate desertification due to cutting down of trees in order to establish settlement.
5. Global warming this is the gradual increase of temperature on the earth’s surface that kills vegetation and leads to desertification.
6. Burning of vegetation also lead to desertification.   

DROUGHT

Drought is a state of an area facing prolonged condition of dry weather without precipitation. OR

Is the long period of dry weather when there is no enough water

CAUSES OF DROUGHT

1. Desertification due to long term changes
2. Global warming due to high temperatures which lead to evaporation of water
3. Population growth which lead to deforestation of trees which contribute to rain formation.
4. Casual burning of natural fire due to eruption of volcanoes.
5. Location of the place e.g. Lee ward side of the mountain therefore experience dryness due to rain shadow effect.
6. Overgrazing, this leads to drought because the cattle will use all water available for consumption and lead to destruction of water sources.

FLOODS

Floods refer to the period of either high river discharge (when a river overflows its banks because of excess water) or overflow of water along the coast due to extremely high tides and storm waves

OR

Is the surface run-off of water from one place to another due to the influence of high rainfall.

CAUSES OF FLOOD.

1. Earthquake; that place below the sea tends to lead to the formation of a large wave called Tsunami.
2. Blocked up drainage system in town or cities can also trigger the problem
3. Damming of the river by human beings or by lava spewed out during volcanic eruption
4. Presence of many distributaries of the river can cause flood
5. Clearing of vegetation accelerates flooding because of the bare surface, water run faster.
6. Shallowness of the soil due to the presence of impermeable rock layer just near the surface

GLOBAL WARMING

Global Warming is an unusual increase in the temperature of the earth’s atmosphere caused by green house effects. Green house effect refer to the situation in which the atmosphere traps and retain heat energy from the sun in the lower levels leading to the rise of temperature.

The atmosphere traps the heat with green house gases that hang in it such as carbon dioxide, methane(CHg) released from ruminant animals, decomposing wet rice paddies, chlorofluorocarbons (CFC’S), Nitro oxide (N₂ O) and sulphur hexafluoride

CAUSES OF GLOBAL WARMING

1. Green house effect these are gases like CO₂ ChlorofluoroCarbons (CFC’S)
2. Industrial activities these produce gases like CO₂ CO, (Carbon Noxide)
3. Casual burning.

POPULATION EXPLOSION /POPULATION PRESSURE

Population explosion/population pressure refer to the increase of the total number of people in a given area compared to the resources available

OR

Is the increase of the number of people in a geographical area compared to the resources available

CAUSES OF POPULATION EXPLOSION

1. Soil fertility; People tend to concentrate in areas with fertile soil because of high production than in infertile soil
2. High birth rate this is due to increase of births in a given area without using family planning
3. Immigration, due to incoming people from various parts due various problems eg civil war, hunger and famine
4. High life expectancy
5. Availability of social services like Water, Hospital, Schools
6. Mining activities eg Geita, North Mara, and Buswagi
7. Presence of Transport and Communications

DEFORESTATION

Deforestation is the process of cutting down trees or is the destruction of the forest through depletion or disappearance of different trees species

CAUSES OF DEFORESTATION

1. Population growth this lead to deforestation due to the establishment of settlements
2. Construction of road and railways causes cutting down of trees
3. Source of energy eg charcoal, wood
4. Industrial activities like mining activities
5. Lumbering activities also facilitate deforestation
6. Poor organized agriculture activities example shifting cultivation.

ACIDIC RAIN

Acidic Rain is the rainfall that result from solution of gases like carbon dioxide that react with water to form acids. Therefore acidic rain is the rain containing more acids than normal amount.

FORMATION OF ACID/CAUSES OF ACIDIC RAIN

It is formed in the air from sulphur dioxide and nitrogen oxide which are emitted by thermal power stations, Industries, Motor vehicles, burning of coals and also industrialization.

LOSS OF BIODIVERSITY.

Biodiversity; refer to a variety of species of living organisms both plants and animals (flora and fauna)

Loss of biodiversity; Refer to the disappearance of different plants and animal species in a particular geographical unit or community

Ecosystem. Is a natural system in which plants and animals (fauna) interact with each other and the non-living environment.

CAUSES OF LOSS OF BIODIVERSITY

Bush fires, this lead to the disappearance of plants and fauna because some of the fauna will die due to the fire and some plant also die and disappear completely.

Poaching, this is facilitated by hunting illegally the animals in various places example killing of Elephants, Rhino and Zebra for various purposes.

Introduction of new species in a geographical unit for example Lions introduced to the place where there are herbivorous animals.

CLIMATE AND NATURAL REGIONS

The World’s climate is neither uniform nor static. Climatic conditions vary from one region to another throughout the world. Temperature and rainfall are the most important element-determining climate and they vary from one region to another.

World climatic types and their characteristics;

The world climate is neither uniform nor static. Climate conditions vary from one region to another throughout the world. Temperature and rainfall are the most important element determining climate which themselves vary from one region to another. Since rainfall and temperature are the most important elements determining climate, they form a good basis for classifying climate.

World climate can be classified as follows;

Equatorial climate, Tropical(Savannah) climate, Tropical desert climate, Warm temperature desert climate, Warm temperature western margin climate, Warm temperature continental climate, Warm temperature eastern margin climate, Cool temperature western margin climate, Cool temperature continental climate, Cool temperature eastern margin climate, Cold temperature western margin climate, Cold temperature continental climate, Cold temperature eastern margin climate, Tundra climate, Polar climate, and Mountain climate.

But the major climates of the world are;

Equatorial climate, Tropical (Savannah) climate, and Desert climate.

EQUATORIAL CLIMATE

This climate commonly occurs in the lowland between 5^o North and South of the equator. However in some part of the world, it may extend up to 10^o North and South of the equator, Example Congo Basin in Africa and Amazon Basin in South America. Equatorial climate is characterized by the following characteristics;

1. High temperatures throughout the year with an average of 27^oC and an annual range at about 3^oC.
2. Heavy rainfall throughout the year with double maxima.
3. Mean annual range of 1,500 mm.
4. Rainfall is commonly convectional type.
5. Lightning and thunderstorms are common.
6. Relative humidity is very high
7. There are no seasons.

TROPICAL (SAVANNAH) CLIMATE

This climate prevails in the region within the tropics between 5^o and 15^o on either side of the equator. Characteristics of this climate include;

1. Temperature are high during the hot and dry seasons up to 32^oC.
2. During the coolest months, temperatures drops to 21^oC.
3. Annual range of temperature is relatively high at 11^oC, which is relatively high.
4. Temperatures are highest just before the onset of the rainy season.
5. Rainfall is moderate and is higher near the areas that experience equatorial climate.
6. Rainfall is usually of convectional type.
7. Presence of two distinct seasons, the hot and dry seasons.

TROPICAL DESERT CLIMATE. 

This occurs between 15^o and 30^o North and South of the equator. For example Namib Desert and Sahara Desert. It has the followings characteristics;

1. High mean monthly temperature of 29^oC during the hot season.
2. During the cool season, temperature can be as low as 10^oC.
3. Daytime temperatures can rise to 47^oC or more.
4. Night temperatures can drop to as low as 5^oC.
5. Annual temperature range is very high. It can reach 26^oC while diurnal range of temperature is high as approximately 40^oC.
6. Rainfall is very low, rare and erratic.

FACTORS INFLUENCING CLIMATE

Climate is made up of elements that are the same as those of weather. The characteristics of various types of climate are the result of influence of the following factors:

a. atitude

Latitude influence temperatures on the surface of the earth such that areas that are nearer to the equator experience high temperature than those further away.

b. Altitude

This factor influences mainly temperature and atmospheric pressure of a region. Low attitude regions are warmer and experience high atmospheric pressure while high-altitude area are cooler and have low atmospheric pressure.

c. Distance from the sea

This factor is also referred to as the effect of being nearer to the sea. The influence of the sea is both on temperature and rainfall of a region. The area which is near to the sea have high temperature and rainfall which modified by the effect of wind while the area which is far apart from the sea has low temperature and rainfall due to the blowing of wind and scarcity of vegetation

d. Aspect

Refer to direction in which the slope faces in the northern hemisphere, the southward facing slopes are warmer than the northward –facing slopes. Thus because the northward  - facing slopes never receive direct sunshine as the sun in this region never get overhead.

e. Ocean currents

Ocean currents following along the coast tend to modify the climate of the coastal regions. Warms ocean currents along the coast lead to the formation of rainfall like Mozambique ocean current which is warm, while cold ocean currents lead to the dry of the area like western part of South Africa. Example of that current is Benguela ocean currents.

d. Prevailing winds.

Wind is the medium of transfer of heat and moisture over the land, that blow from high to low pressure area.

The areas which characterized by the wind from ocean, lake or forest experienced by moisture which lead to the formation of rainfall, while the areas which that have no moisture from ocean, lakes or forest lack rainfall.

f. Human activities

Human activities such as development of settlements, agriculture and construction of dams and creating of man- made lakes have a considerable influence on climate especially on local areas. Also due to activities such as clearing of forest it changes climate

IMPORTANCE OF STUDYING CLIMATE AND THEIR CHARACTERISTICS;

1. It helps to identify the nature of the area
2. It helps to determine the nature of the location of the specific area. Example by considering latitude and longitude.
3. It helps to improve economic activities such as agriculture by looking at the nature of climate example sugarcane along the tropical area.
4. It helps in controlling natural hazard.

NATURAL REGIONS OF THE WORLD

MAJOR NATURAL REGIONS OF THE WORLD.

1. The equatorial region
2. Tropical grasslands/savannah
3. Mediterranean regions
4. Warm temperature/steppe
5. Monsoon region
6. Tundra/Polar regions

1. THE EQUATORIAL REGION

The equatorial regions lies between latitude zero degree and 5^o degree North and South of the equator.

The areas include Indonesia, Colombia, Congo basin, Amazon basin and West African Coast.

CHARACTERISTICS OF EQUATORIAL REGIONS.

1. Equatorial regions has dense forests with broad leaves throughout the year.
2. The temperature of this region is high about 27^oC
3. There is high humidity

ECONOMIC ACTIVITIES OF EQUATORIAL REGIONS

1. Agriculture, due to availability of rainfall throughout the year and the soil is fertile.
2. Tourism activities due to the presence of wild animals such as elephant, Monkeys, Crocodile, Hippopotamus etc.
3. Navigation due to the presence of numerous water bodies such as rivers example Congo River.
4. Lumbering due to the presence of many tree species suitable for timber production.

2. TROPICAL GRASSLANDS/SAVANNAH

Savannah grasslands lie between the tropical rainforest and semi-desert vegetation in a broad Latitudinal zone 5^o – 20^o North and South of the equator.

Examples of the areas with savannah climates are Sudan, West Africa, and Western Madagascar and East and Central Africa.

CHARACTERISTICS OF TROPICAL GRASSLANDS.

1. There is domination of scrub forests and thickets
2. There are two periods yearly one period is of rain season which takes shorter period and the other period of the dry season which take larger periods.
3. The day condition is hot while the night condition is cold during the dry season.
4. The equatorial climate is mostly dry in nature

ECONOMIC ACTIVITIES OF THE SAVANNAH CLIMATE

1. Agriculture due to the presence of fertile soils
2. Pastoralism due to the presence of scrubs
3. Fishing activities
4. Industrial activities eg wire making, food processing, flour milling and fruit canning

3. WARM TEMPERATURE/STEPPE

Warm temperature region lies between latitude 20^o – 30^o North and South of the equator.

e.g Canada, Argentina, Eurasia etc

CHARACTERICTICS OF WARM TEMPERATURE

(i) There is extensive grassland areas having many names given according to the area found;

Example;

• Steppe of Eurasia
• Prairie of Canada
• Pampas of Argentina

(ii) The climate is very hot in summer and very cold in winter

(iii) There is light rainfall between 380 mm – 700 mm

(iv) There is short vegetation

ECONOMIC  ACTIVITIES.

1. Pastoralism of animals such as cattle and sheep.
2. Agriculture of crops such as maize, wheat and fruits.
3. There is a presence of industries due to the presence of agricultural products.
4. Tourism due to presence of wild animals such as lion, cheetah, elephant, hyena, and so many.
5. Lumbering due to presence of some tree species suitable for timber production.

4. MEDITERRANEAN REGION

Mediterranean region lies between latitude 30^o – 45^o in the Northern hemisphere and between 30^o – 40^o in the Southern hemisphere,

Example of Mediterranean regions are Israel, Spain, Greece, Italy and Egypt.

CHARACTERISTICS OF MEDITERRANEAN REGIONS

1. Mediterranean regions are marked by warm summer temperatures
2. Annual temperature ranges are generally smaller since locations on the western sides of the continents are not well positioned to receive the coldest polar air.
3. The rainfall is normally light and it varies from 500 mm – 760 mm.
4. The vegetation is normally hard –leafy forests and scrubs.

ECONOMIC ACTIVITIES OF THE MEDITERRANEAN REGIONS

1. Agriculture activities mainly irrigation schemes and the crops grown are citrus fruits
2. The animals kept are cattle, sheep and goats

5. MONSOON REGIONS

Countries which are included in the monsoon region are Vietnam, Cambodia, South China, North Australia and Horn of Africa (Somali

CHARACTERISTICS OF MONSOON REGIONS

1. There is a high rate of heating during the summer period and cool in the cool season.
2. The vegetation type ranges from monsoon forest to scrubs
3. There is little amount of rainfall annually

ECONOMIC ACTIVITIES OF MONSOON REGIONS

1. Agriculture e.g. Rice in Burma.
2. Livestock keeping example pigs, water buffaloes and goats.
3. Light industries due to presence of agriculture activities
4. Fishing activities.

6. TUNDRA/POLAR REGIONS

The tundra region lies between 60^o – 75^o of latitude mostly along the Arctic coast and lowlands of North America and on the coastal margins of Greenland.

Examples of polar countries areas are North America (Canada), Sweden, Finland, Norway and Soviet Union.

CHARACTERISTICS OF POLAR REGIONS

1. Days are long as a result of the high latitude
2. The snow corner of winter melts in warmer season
3. Winter precipitation consists of dry snow
4. Annual total rainfall is less than 35 mm
5. The area has scarcity vegetation due to the presence of very cold climate

ECONOMIC ACTIVITIES OF POLAR REGIONS

1. Hunting practices done by Eskimos
2. Fishing of whales and seals
3. Tourism especially during the winter period for winter sports such as skiing

ELEMENTARY SURVEYING

Surveying is the science of measuring and record distances, angles and heights on the Earth’s surface to obtain data from which accurate plans and maps are made

Competence to be developed at the end of the topic:

• Students should have knowledge on surveying techniques and the ability to use survey equipment for proper land use planning. 

General Objectives:

• Students should develop an understanding of the meaning, types, equipment and application of simple surveying.

Specific Objectives:

At the end of this sub-topic each student should be able to:

1. Correctly explain the meaning of simple land surveying.

2. Explain the types of simple land surveying.

3. Explain the Importance of surveying

MEANING AND TYPES OF SURVEYING

Meaning of surveying:

Surveying is the science of measuring and record distances, angles and heights on the Earth’s surface to obtain data from which accurate plans and maps are made.

Or

Surveying is also the art and science of making or taking measurements both linear and angular on the Earth’s surface at different positions for the purpose of producing a plan or map.

 Angular measurement means measuring the distance from a given reference point to an observed object. The distance is measured in a clockwise direction from North.

Linear measurement is the distance measured along the surface of the ground such as a horizontal distance. 

 Purpose of surveying

1. To prepare maps and plans
2. To calculate areas and distance

 Types of Surveying/Branches of Surveying

Surveying can be categorized into various types or branches depending on its purpose, function and nature. The types or branches include:

 A. Topographical survey

This kind of survey is carried out for the purpose of preparing topographical maps.

 B. Geodetic survey

This kind of survey is carried out with the aim of knowing the Earth’s shape and size (the Earth's configuration)

C. Cadastral survey

This kind of survey is conducted with the aim of preparing a legal document such as house plans, town or city boundaries, etc. It is mainly used for ownership purposes.

 D. Engineering surveys

This kind of survey is conducted for the building and construction layout of railways, bridges and roads.

 E. Geological survey

This kind of survey is conducted with the aim of knowing the distribution of rocks and minerals under the Earth’s surface.

 Topographical surveying

This kind of survey is carried out for the purpose of preparing topographical maps.

 Topographical maps are those maps whose contents include both man-made features such as linear features (roads, railways, telephone lines, water systems, and electricity poles) and natural features such as rivers, oceans, mountains, etc.

The topographical survey has the following ways or methods of conducting the survey:

1.  Chain or tape survey
2.  The prismatic compass survey
3.  The plane table survey
4. The technique of leveling

 CHAIN SURVEYING

Specific Objectives:

Students should be able to:

1. Describe chain and tape survey
2. Explain the different types of equipment used in chain and tape surveying
3. Practice chain and tape surveying activities at a school level
4. Explain the importance of chain  surveying

Meaning:

It is a method of Surveying in which no angles are measured but only linear measurement is taken in the field by using a chain or tape measure.

It measures a series of straight lines on the ground with a chain or tape measure and all fixed points relative to the line of traverse either by right angles (offsets) or tie lines.

 Equipment used in chain surveying

i. Chain 

• The chain is made up of steel wire which is divided into links and togs (rings) to facilitate folding.
•  It is sometimes used as a unit of measurement
• It has brass handles at both ends for easy handling. The link is 0.2m or 200mm in diameter.
• The length is 20m or 30m.

ii.Tape

• Steel tape
• Linear tape

A tape is made from fiberglass or a steel strip and is 10m, 20m or 30m in length graduated in 10mm divisions and numbered at each 100mm (10) divisions

It is used for measuring short distances

 iii. Ranging poles

Ranging poles are made up of wood or light metal and measure about 2m long at the top. The equipment has steel shades on its legs so it can be stuck into the ground. Ranging poles are painted red and white so that they can be easily seen even from a distance. They are used for making stations.

 iv. Arrows

Arrows are made of steel wire of diameter 4mm and their ends are bent into a circle where red cloth is tied to facilitate visibility. They are used for showing points on the ground.

They are also used for counting the number of chains while measuring a chain line.

 v. Pegs

Pegs are made of wood 40mm square by 50cm long and are used for permanently marking positions during survey

 vi. Surveyors' band

The surveyor’s band is made of a steel strip which is rolled into a metal frame with a winding handle. It is 30m, 50m or 100m long. Is used in projects where more accuracy measurement is required.

 vii. Cross staff

The cross staff is made of metal or wood with eye slips at right angles and is used to measure right angles from the line of traverse

 viii. Notebook

Notebooks are used during field work to record data obtained. The notebook should be of good quality and 150mm x100mm in size

 ix.A hard pencil and a rubber

Hard pencils are used for drawing in the field and a rubber is used to erase mistakes or errors which are made. A pencil should be HB or HHB.

Methods and procedures involved in chain survey

• A survey team involves three people, the leading chainman or leader, the follower and the booker.
• The chain is thrown to extend it and disentangle any knots
• The leader takes ten arrows and a ranging rod, and the follower takes a ranging rod
• The follower erects his ranging rod/pole at the first base point and places a brass handle of the chain against the ranging rod.
• A leader straightens the chain and inserts an arrow at end of the brass handle. Offsets and tie lines can now be taken.
• The leader drags the chain so that the follower’s end is on the leader’s arrow; the follower moves to another point and places his ranging pole behind the arrow. This procedure is then repeated.

 The importance and usefulness of chain surveying

1. It is suitable for small areas of fairly open ground.
2. It is used to fill in details on a map whose large features have been surveyed by other methods.
3. It is used in mapping small areas of flat or near-flat ground and associated objects, for example paths, roads and railways.
4. It is used in adding detail to existing plans or large maps.

 Advantages of chain surveying:

1. It is the simplest method of surveying through the old method.
2. It is suitable for surveying clear areas.
3. It tends not to attract attention.
4. It is suitable for surveying a flat surface on the Earth’s surface, for example a school compound.
5. It can be read easily and quickly.
6. It can withstand wear and tear.
7. It can be easily repaired or rectified in the field.

 Disadvantages of chain survey:

1. It is a slow method of surveying.
2. It is the oldest method of surveying
3. It is not suitable for surveying large areas.
4. More difficult areas cannot be chain surveyed.
5. Errors may be encountered due to the use of many chains and other reasons.
6. It is time consuming.
7. They are heavy and take too much time to open or fold.
8. They become longer or shorter due to continuous use.
9. When the measurement is taken in suspension, the chain sags excessively

 THE ERRORS THAT OCCUR IN CHAIN SURVEYING

What is an error?

An error is a mistake or shortcoming that happen during the survey process leading to wrong measurements. It is sometimes called discrepancies. The following are the type of errors or discrepancies in chain surveying.

 Sources of Errors in Chain Survey and Their Correction

The errors can be divided into three groups:

• Cumulative (systematic) errors
• Compensating (accidental) errors
• Gross Errors

 Cumulative Errors:

Cumulative errors are said to be systematic errors as they are one-directional hence keep on accumulating as the survey progresses. If not checked they have serious implications to the accuracy of the survey. Errors in this class include incorrect length of the tape, page of the tape or the tape not being in line. Since the sources of these errors are known, they can be eliminated.

 They can either be positive or negative errors. While positive errors shortens the measurement (e.g. where the tape length is shorter than what it should be) while negative errors elongates the measurements (e.g. where the tape is longer than what it should be). Checking the equipment can eliminate these errors.

 Compensating Errors:

Compensating errors are said to be accidental errors hence cancel out and does not pose serious problem to the accuracy of the survey. They arise as a result of not being perfect in the use of the equipment or in the whole survey process. For example, if the pull exerted on the tape in either more than or less than what should be the case, faulty results be gotten. The effect can either be positive or negative.

 Gross Errors :

These are mistakes that can be attributed to the inexperience of the team leaders. These are very serious errors which although are random in accordance may lead to faulty plans and maps if not checked. They include discontinuing the chain length (e..g where some arrows are cost or misplaced); misreading of the tape; reading tape upside down (e.g. taking 6 to be 9), etc. By taking the necessary precautions, these errors can be corrected.

Overcoming obstacles during chaining

 TYPES OF OBSTACLES

1. Visual obstacles: Is an obstacle that prevents an object but the chain remains free. An example of a visual obstacle is a forest.
2. Chain obstacles: This is the obstacle where by the chain is obstructed but visually it is free. Examples are rivers and ponds
3. Neither visual nor chain obstacles for example buildings

 HOW TO OVERCOME THOSE OBSTACLES:

1. By rectangular method
2. By triangle method
3. By using similar triangle method

 By constructing rectangles:

Chaining had reached A and encountered an obstacle. To get to B, mark A and B with an arrow. Set of perpendiculars AC and BD high enough to clear the obstacles. Join and measure DC which now equals AB. This allows chaining to continue from B.

By constructing similar triangles:

To continue chaining from B, fix a point C away from the obstacle. Range a pole at D to align with AC hence AC = CD. In line with BC range another point E in line with BC. Hence BC = CE.

 Measure ED which equals AB hence chaining can continue from B.

 

Obstacles which obstruct both ranging and chaining

Chaining has reached B from A where an obstacle like a building has been reached. Erect equal perpendiculars AC and BD from A and B along the chain line. Along CD, range E and F beyond the obstacle. Set off perpendiculars EG and FH from E and F equal to AC. AS G and H are in line with AB, then CE equals AG.

 By constructing similar triangles

Chaining had reached A and there is the need to overcome the obstacle created by the stream to really B. Set out a perpendicular AC and mark the midpoint E. Set out another perpendicular CD so that D, E and B are in a straight line. The 2 triangles created are congruent hence CD = AB which is the required length hence chaining can now proceed from B.

 Importance of surveying

1. It help to prepare a topographical map which shows the hills, valleys, rivers, villages, towns, forests, etc. of a country.

2. It helps to prepare a cadastral map showing the boundaries of the fields, houses and other properties.

3. It help to prepare an engineering map which shows the details of engineering works such as roads, railways, reservoirs, irrigation canals, etc.

4. It help to prepare a military map showing the road and railway communications with different parts of a country.

5. It helps to prepare a contour map to determine the capacity of a reservoir and to find the best possible route for roads, railways, etc.

6. It helps to prepare a geological map showing areas including underground resources.

7. It helps to prepare an archaeological map including places ancient relics exist.

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