Form_1_Geography_notes_New_curr_online_print-1.pdf

GEOGRAPHY FORM 1 NOTES 2021 ZJC SYLLABUS 4022 TOPICS # Introduction……….………..…………………………………1-3 1: Weather and Climate…………………………………...........4-18 2: Landforms and Landscape processes……………………....19-32 3: Ecosystems………………………………………………......33-7 4: Natural Resources…...

GEOGRAPHY FORM 1 NOTES 2021 ZJC SYLLABUS 4022 TOPICS # Introduction……….………..…………………………………1-3 1: Weather and Climate…………………………………...........4-18 2: Landforms and Landscape processes……………………....19-32 3: Ecosystems………………………………………………......33-7 4: Natural Resources…………………………………………...38-9 5: Energy and Power…………………………………………...40-3 6: Map work and GIS………………………………………....44-60 7: Minerals and Mining………………………………………...61-5 8: Environmental Management………………………………...66-9 9: Agriculture and Land Reform……………………………….70-5 10: Industry…………………………………………………….76-8 11: Settlement and Population………………………………...79-83 12: Transport and Trade………………………………………84-93 [email protected] 0775777982 1 | P a g e  Introduction to Geography Definition of Geography  It is a study of the Earth and the interaction between the human race and nature. Environment  The surroundings  All external conditions surrounding an organism which has influence over its behaviour. Environment can be divided into two: 1. The Physical Environment  Natural physical conditions of weather, climate, vegetation, animals, soil, landforms and drainage. 2. The Human Environment  Human activities such as farming, forestry, mining, tourism, settlement, transportation, trade and industry. Why Geography matters? 1. Facilitates good relationship among nations by studying geography of other regions of the world. 2. It’s a career subject in that it enables one to go for advanced studies in specialised fields e.g. geography teachers, meteorology, surveying etc. 3. Enables us to appreciate other people’s way of life by learning economic activities of different communities within our country and other parts of the world. 4. Enables us to conserve our environment when we learn negative and positive effects of human activities on the environment. 5. Enables us to conserve our resources when we learn wise use of resources in conservation and management of resources e.g. wildlife, forests, energy, etc. 6. Inculcates in us virtues of cooperation and patience as we work in groups. 7. Makes us to appreciate manual work as we are involved in practical geography which may lead to self-employment. 8. Promotion of industry such as tourism by guiding tourists to places of interest by using maps, calculations of distances etc. Branches of Geography 1. Physical Geography  Deals with the study of natural physical environment of human kind. The areas covered include: a) Geology-study of the origin, structure and composition of the earth. It includes study of rocks. b) Geomorphology- the study of internal and external land forming processes and landforms. c) Climatology- the study of climate and weather d) Pedology- the study of soils e) Biogeography - the study of soils, vegetation and animals. f) Hydrology- the study of water bodies g) Spatial geography-study of space 2. Human and Economic Geography  Study of people and their activities on the earth’s surface. [email protected] 0775777982 2 | P a g e The areas covered include: a) Mining b) Forestry c) Agriculture d) Fishing e) Wildlife and tourism f) Industry g) Energy etc. 3. Practical Geography  A smaller branch which equips the learner with practical skills that enhance their understanding and interpretation of human and physical geographical information. The areas are: a) Statistical methods b) Map work c) Field work d) Photograph work [email protected] 0775777982 3 | P a g e  TOPIC 1 WEATHER AND CLIMATE STUDIES Weather  Weather is the current condition of the atmosphere of a place at a given time.  It is described as hot, cold, warm, wet, dry, humid, overcast etc. Climate  Refers to the average weather conditions recorded over a long time period of 30-35years  For example the climate of Zimbabwe is describe as cool dry winter with hot wet summer The difference between the terms weather and climate Differences in climate weather Definition Is the average weather conditions Daily/ present state of the taken over a long time period ( 30 to atmosphere at a given place 35years) and time Time measure 35 to 40 years, measured over long At that very time, measures for period short term Study of it is called Climatology Metrology Forecast Is done by taking aggregates of Simply by collecting present weather statistics over long periods of atmospheric conditions of 30 to 35 years temperature, pressure, humidity, solar radiation etc. Basic elements of weather, instruments and their units of measurement Weather element Instrument used Units of measurement Temperature Six’s Thermometer/ Max and Min Degrees Celsius (℃ ) thermometer Humidity Hygrometer/Wet and dry bulb Percentages (%) thermometer Rainfall Rain Gauge Millimeters(mm) Pressure Mercury barometer Millibars(mb) Aneroid barometer Fortin barometer Wind direction Wind vane Cardinal points /Compass points Wind speed Cup anemometer Killometres per hour (km/hr.) Nautical miles / Knots Sunshine Sunshine recorder Hours and mins Cloud cover Eye observation / estimation Oktas [email protected] 0775777982 4 | P a g e Measuring and recording temperature Temperature: - Is the degree of hotness or coldness of the atmosphere. The maximum thermometer  This thermometer records the highest temperature during the day. The thermometer is filled with mercury and the metal index (indicator) is above the mercury.  Mercury is used because it has a very high boiling point of about 250 ℃ and is also clear.  Temperature rises causing mercury to expand.  Mercury pushes the index up.  When temperature falls mercury contracts.  The maximum temperature is read from the scale at the lower end of the index.  Thermometer is reset by shaking it to force mercury back into the bulb.  The metal index may be reset by using a magnet or by tilting the thermometer. The minimum thermometer  This thermometer records the minimum temperatures.  This thermometer contains alcohol and the metal index lies inside the liquid.  Alcohol is used because it has a very low freezing point of -70℃ or -115 ℃ and it does not stick to the sides of the glass tube.  Temperature falls causing alcohol to contract.  Alcohol pulls the index down.  When temperature rises alcohol expands and rises in the tube.  The index remains where it was pulled.  Minimum temperature reading is obtained from the scale at the lower end of the index.  Just like the maximum thermometer, the index is reset by a magnet or by tilting the thermometer so that the indicator slides back to rest against meniscus. The Six’s thermometer  This is a piece of equipment which combines the maximum and minimum thermometers used to measure maximum and minimum temperatures.  It was developed by a man called Six, hence the name.  The instrument contains two liquids, mercury and alcohol. [email protected] 0775777982 5 | P a g e The six’s thermometer  Mercury is used because it has a very high boiling point of about 250℃ and is also clear.  Alcohol is used because it has a very low freezing point of -70 or ℃-115 ℃ and it does not stick to the sides of the glass tube. How it works  Records max. & min. temps over a 24hr period.  Maximum thermometer contains mercury the minimum contains alcohol.  As temperature rises mercury expands & pushes up a metal index when it cools & mercury contracts the index is left in place at highest temp.  As temperature falls alcohol contracts & pulls metal index with it, but as the alcohol expands it flows passed the index leaving it in place at the lowest temp.  Both indexes are read once every 24hrs from the bottom of the index. Problems in using the instrument  Failing to identify mercury or alcohol.  Failure to identify max and min thermometer.  Reading erroneously, that is, taking the measurement of the max thermometer above the metal index and that of the min thermometer below the index. Factors influencing the temperature of locations are:-  Latitude or distance from the equator  Altitude - The atmosphere is mainly heated by long wave radiation (heat energy) from the earth's surface (land or sea surfaces). Thus, the higher the altitude, the cooler the air temperature.  Distance from the sea (continentally) - Land heats up and cools faster than water or the sea.  Cloud cover - Blanket effect of cloud produces small diurnal and annual ranges of temperature. Measuring and recording humidity Humidity is the amount of water vapour in the atmosphere. Label the parts A-B for the hygrometer below: [email protected] 0775777982 6 | P a g e   It is measured using a hygrometer/ psychrometer  Weather satellite can also be used to measure humidity  A hygrometer measures the humidity using two sets of thermometers: the dry and wet bulb thermometers  The wet bulb is wrapped in a thin muslin cloth dipped in container with pure/distilled water to keep it wet  If the air is dry, water evaporates from the muslin cloth and cools the wet bulb such that mercury contracts to give lower temperature.  The dry bulb is not affected and so mercury in it expand to give atmospheric temperature readings  Thus the wet bulb gives a lower reading while the dry bulb gives higher reading  Depression of wet bulb/ Difference between the dry and wet bulb is calculated by subtracting wet bulb reading from dry bulb reading  The humidity is then found by reading humidity tables  If there is no difference between the dry bulb and the wet bulb it means the air is saturated  Relative humidity is given in percentage. Types of humidity Absolute humidity- the total mass of water vapour in a given volume of air Relative humidity- the amount of water vapour in a given volume of air at a given temperature Specific humidity- the ratio of the mass of water vapour compared to the mass vapour of the parcel of air Pressure  Is the force/weight exerted by the weight of air in the atmosphere on the earth.  It is measured in millibars using an instrument called barometer.  There are two different types of barometers namely the mercury barometer and the aneroid barometer  When air is warm it normally rises and creates an area of low pressure, when it is cool it sinks and creates an area high pressure.  The standard units of pressure are millibars.  Areas of the same pressure are joined together on a map using isobar. [email protected] 0775777982 7 | P a g e Simple Mercury barometer  The mercury barometer is made of a glass tube of about 1m high  Its open end is dipped in a bowel filled with mercury  When atmospheric pressure rises, it exerts force on mercury in the bowel compressing it,  This forces mercury to push up the glass tube, at sea level the mercury would rise to about 760mm  When pressure decreases, the mercury contracts and moves down the bowel. Advantages of a mercury barometer  It gives accurate readings  Glass tube must be at least a meter long  It is simple to construct and maintain  It breaks easily hence it is too delicate  Cannot produce continuous readings so have Disadvantages to be taken regularly  It is too large and cumbersome  Mercury is poisonous hence dangerous to work with. Aneroid barometer Barometers are normally kept inside Stevenson screens to keep them safe. A barometer has a movable needle (pointer). The pointer can be moved to the current reading so that you can then make a comparison with the reading from the following day. Aneroid barometer of levers and a pointer that gives readings on a scale  If pressure increases the box is squashed inwards  If pressure decrease, the box expands outwards  During these inward and outward movements, the levers attached to the box are also moved.  The lever movement cause the pointer to move and indicate amount of pressure exerted on the scale  The lever amplifies the expansion and  Aneroid barometer is a small portable air- contraction of the box in accordance to tight partial vacuum box fitted with a system atmospheric pressure. Advantages of aneroid barometer  It is small and portable  It can be safely used in the home or at school since it does not rely on poisonous mercury  It is easier to read since it comes with a calibrated scale  Can make continuous readings  Can be attached to a computer to make automated continuous readings. [email protected] 0775777982 8 | P a g e Disadvantages  It is less accurate  It requires great skill and expertise to make some readings. Wind speed and wind direction  Wind is the movement of air across the earth’s surface due to difference in pressure between two areas.  Air moves from high pressure region to low pressure region.  The difference in pressure can be caused by differential heating of the earth’s surface by the sun.  Two aspects of wind are measured at a weather station, namely wind speed and wind direction. Wind vane and wind sock to measure wind direction  Wind vanes are used to check wind direction  It is made up of fixed compas showing cardinal points which gives direction on top of which there is a rotating pointer  The pointer has has a narrow end with an arrow that pionts wind direction and broad flat tail that is moved by the wind  The pointer points the direction from which wind is coming from  Wind vanes are often placed on top of buildings or on open spaces so that they are freely moved by wind.  Wind direction refers to the direction that the wind is blowing from  Wind direction shown by the wind vane above is south  A windsock is a kite made from a tube of nylon cloth  One end of the tube is held open by a ring  Windsocks point in the direction opposite of wind  For example, if a windsock is pointing west, the wind is coming from the east i.e. it goes were the wind is going  The faster the wind blows the straighter and more horizontally the windsock extends. [email protected] 0775777982 9 | P a g e  The compass  The four points N,S,E and W are referred to as the cardinal points  The additional four points SW,SE,NE, and NW are called the inter-cardinal or intermediate points  The SSW,SSE, NNE and NNW are called secondary inter-cardinal points  Wind direction is given using the cardinal points or the ordinal points. Cup Anemometer  Anemometers measure wind speed and its units are knots/km/hr/ nautical miles.  Anemometers are normally placed on top of buildings so that they can freely measure wind speed.  Anemometer is an apparatus for measuring the speed of wind.  The commonest kind of anemometer is a kind of horizontal three-armed windmill, with a hollow hemispherical cup on the end of each arm  The pressure on the inside of a cup when it blocks wind forces it to revolve . The mill moves a pointer round a graduated dial that indicate the speed of the wind.. [email protected] 0775777982 10 | P a g e Sunshine recorder  Sunshine recorder consists of a glass sphere surrounded by a metal frame that support/hold a sensitive card.  The glass sphere focuses the sun’s rays onto the card  As the sun moves across the sky, it burns a trace on the card  At the end of each day the card is taken out and the length of the burnt section is measured in hours and minutes. Rain Gauge to measure the rainfall 1. Rain gauges are used to measure ………... 2. Precautions that must be taken when using Rain gauges are:- should be placed on  Short grass areas, because if they are placed on concrete………………………  It should be placed in an open area away from trees and buildings to avoid ……………………………………………………..  Rain gauges should also be checked regularly to avoid ………………..  Rain gauges should be placed on slabs that are ………………………m high to avoid …………………………………………………………………………..  Rain gauges should made of ………………. or ……………………………. to prevent ………………………………………………………………………  The rainwater that is collected must be emptied after every ……… hours into a …………… to find out the amount received. 3. Draw the diagram of the rain gauge below into your book and label A-D [email protected] 0775777982 11 | P a g e 4. The height H or D is ………………………. 5. The standard with of A shown as x is ………………………. Weather station A weather station is a facility, either on land or sea with instruments and equipment for measuring atmospheric conditions to provide for weather forecast and to study weather and climate. Important points about weather station  Most instruments used in measuring weather elements are found in a weather station  A weather station is a place where weather events are recorded. Important factors to consider when selecting a site for the school weather station  Should be in an open area, away from buildings that may block wind movement.  Should be away from tall trees that may cover the instruments with their shade and may also intercept rainfall.  Should be on short grass that allow water to soak or flow without splashing into instruments.  Should not be on hard ground/ concrete surfaces because the hard surfaces will cause water to splash into rain gauge and may also radiate heat to instruments.  The station should be in a fenced and gated place so as to protect the instruments from theft, vandalism and destruction by people and animal. [email protected] 0775777982 12 | P a g e State two advantages of the modern digital weather station compared to the traditional weather station  Modern digital weather station is small and compact such that it does not require large area as done by the traditional weather station.  Modern digital weather station records data automatically which eliminates human errors experienced when using traditional weather station  Modern digital weather station can be installed in remote places and recordings are sent automatically to faraway places by means of GIS and satellites. The Stevenson screen Is used to house instruments such as Maximum thermometer, Minimum thermometer, Six’s thermometer and hygrometer-wet bulb and dry bulb thermometer. Importance (i) Provide shade conditions for accurate temperature recording. (ii) Ensure safety of thermometers because they are delicate. Describe the characteristics of the Stevenson screen (iii) [email protected] 0775777982 13 | P a g e Features of a Stevenson screen  It is made up of wood: i.e. to prevent absorption and conduction of heat.  Panted white or silver grey; - in order to reflect sunshine.  Stands are 1,2 metre high: - to avoid the influence of ground conditions.  The sides and floor are made of louvers or slats to allow free circulation of air and to keep off direct sun rays.  It has an insulated roof to create a bad conductor of heat. This is done by creating an air space between the layers of the roof.  The roof is slanting to avoid the accumulation and stagnation of rain water.  It stands on grass covered ground.  It is fixed or placed far from buildings or obstacles to avoid any interference.  The ideal location is one where it is away from trees and buildings. This means that the trees or buildings will not act as a shield, making the measurements unrepresentative  The stand of the Stevenson screen should be set in the ground so that the bulbs of the thermometers are at approximately 1, 2.m above the ground. The ground on which the Stevenson screen is placed should not be concrete or bare rock because these surfaces may absorb heat and reflect it onto instruments.  In the southern hemisphere, the door of the screen should face north so that when it opens, the sun does not shine directly on instruments Home work 1. Distinguish between weather and climate (3) 2. List any four elements of weather (4) 3. Describe in using diagrams any 2 instruments used to measure weather elements (4) 4. Describe the characteristics of the Stevenson screen (4) Weather symbols and synoptic charts - A synoptic chart is any map that summaries atmospheric conditions or a chart that makes use of shorthand showing weather conditions of a place at a given time [email protected] 0775777982 14 | P a g e Rainfall types and patterns  Precipitation occurs when warm moist air rises.  Water vapour cools and condenses to form clouds.  Condensation produces small droplets which join together and grow to fall of their own weight.  Types include relief, cyclonic and convectional rainfall. Forms include sleet, hail, frost, fog, snow and others. a. Sleet – a mixture of snow and rain formed by snow melting as it falls. b. Hail – a solid form of precipitation comprising chunks of ice falling from the sky. c. Dew – is snow droplets of water that appear on grass in the morning and evening due to condensation. This result when temperature of a surface cools down to a point below the dew point of air next to it. d. Frost – is the deposit of ice that may form in humid air during the night or in winter especially in mountainous areas. e. Fog – is a visible mass of cloud water droplets or ice crystals suspended in the air near the earth`s surface. f. Rime – is a white ice due to water droplets in fog freezes to the outer surfaces of objects such as trees. g. Snow – flakes of ice particles that fall from the clouds and does not occur in Zimbabwe but UK in winter. h. Drizzle – very fine rain falling from stratus clouds. Types of rainfall Relief or orographic  Results when warm moist air rises over a barrier e.g. mountain.  SE trade winds are forced over a barrier and rises, cools and condense and rain occurs on the windward side e.g. Chimanimani or Inyanga.  Leeward side or rain shadow area is dry with little or no rainfall e.g the Save valley and Marange area. [email protected] 0775777982 15 | P a g e  Convectional  Ground surface is overheated and air gets hot to generate convectional currents.  Air is heated by conduction, absorbing more moisture, expands and rises.  The ascending air remains warmer and hence become unstable.  It cools and produces cumulonimbus clouds.  Due to heat released by latent heat at condensation and freezing, thunderstorms are generated.  Rainfall in West and Central Africa is convectional. Hazards due convectional rainfall  Lightning, fires, death, flooding, strong winds, landslides, destruction of homes, crops, and property. Measures  Lighting conductors, early warning systems, education, cloud dissipation, afforestation/reforestation, resettlement, evacuation, settling on high ground and storm drains. Frontal or cyclonic  Two or more winds with different temperatures meet for example in Southern Africa.  The two air masses don’t mix but form a front.  The cold air mass is heavier than warmer air mass therefore, the light rises over the denser one.  Warm air cools,  Condensation and clouds form.  Rain occurs along the front. [email protected] 0775777982 16 | P a g e Weather Focasting  First appearance of sparrows; flock of swallows preceding dark clouds  Is a prediction of weather phenomena, trend indicates rain is at hand and farmers and events. should prepare for above normal rains.  Migration of butterflies also indicates it  Is made through data collection on will rain. temperature, rainfall and humidity and use  Croaking of frogs during dry season of complicated modelling and simulations to indicate it’s going to rain. predict future weather.  The singing, nesting and chirping of Importance of weather forecasting certain birds appears to be a useful indicator for the onset of the rains.  Helps us to be aware of natural calamities  Appearance of cicadas (nyenze), day related to weather before they occur so as to flying chafers (mandere), dragon flies take precautionary measures. (mikonikoni) signifies imminent  Guiding tourists on when to visit national rainfall. parks.  Frequent appearance of tortoises  Helps farmers to plan their activities such as indicates good rain season. planting, harvesting, etc.  Appearance of certain insects e.g.  Ensures air and water transport is carried out millipedes, spiders Indicates coming of safely. heavy rains.  Helps sporting people to plan their training  If the goat intestines are empty at and competition schedules. slaughter it indicates drought or famine  Helps people to plan many other activities ahead, and vice versa. such as mining, electricity generation,  Changes in the intensity of sunshine holiday events, etc. indicate it’s going to rain.  Helps fishing communities to plan their  Moon crescent facing upwards indicates activities. upholding water and when facing downwards is releasing water in the next Methods of weather forecasting few days.  Mist-covered mountains is a signal of Indigenous Knowledge Systems (IKS) good rains.  Are those forms of knowledge that the  Appearance of fog/haze in the morning people survived on before the advent of is an indicator for no rain. modern technology.  Frequent appearance of wind swirls is a  Prediction of weather based on traditional sign of good rains. beliefs and facts.  Plants shedding leaves or dropping off Modern methods of young avocado fruits indicates period of drought.  Prediction of weather using modern  Flowering of certain plants e.g the peach instruments and new technology of tree and budding of acacia species collecting, transmitting, processing and indicates the onset of rainfall. analysing weather data.  Abundance of wild fruits such as hacha, gan’acha and mashuku during the Instruments used months of December to February signify an imminent challenging farming 1. Satellites-electronic devices which orbit the season, earth which collect and transmit weather data  Heavy flowering of the mango trees which is interpreted by computers. indicate a potential drought season. 2. Radar-an instrument used to see cloud  Safari ants (termites) indicate it will formation. rain. [email protected] 0775777982 17 | P a g e 3. Sensors/radiosodes-instrument fixed on a 4. Computers-electronic device used to store, balloon used to measure atmospheric pressure, analyse and display weather information. temperature and humidity. Weather focasting zones in Zimbabwe  Midlands  Mazoe  Eastern Highlands  Gwaai  Gwanda Factors hindering weather forecasting a) Lack of skilled man power due to limited training facilities. b) Lack of modern equipment leading to wrong forecasts. c) Natural calamities such as storms and earthquakes. d) Extreme weather conditions which may damage or displace instruments. e) Use of faulty instruments. f) Human error. g) Poor sitting of instruments. Weather report  Is a systematic statement of the existing and predicted meteorological conditions over a particular area e.g. Kutsaga. [email protected] 0775777982 18 | P a g e  TOPIC 2 LANDFORMS AND LANDSCAPE PROCESSES Landforms  These are natural features found on the earth`s surface.  Landforms form a specific terrain and their physical arrangement result in the landscape form known as topography.  These landforms include mountains, hills, plateaus, canyons, valleys, buttes and basins. Difference between landforms and landscape Landforms Landscapes Is a natural geographic feature that appears Are made up of several landforms such as on the earth`s surface hills and valleys. Created by natural forces such as tectonic Are made by a variety of landforms. movement and erosion Major landforms of world and Africa  Worldwide, there are wonderful landforms such as rift valleys, lakes, river basins, mountains, valleys, tors/ cattle kopjes, plateaus, glaciers, hills, deserts, waterfalls and rivers. 1) Basins  Africa`s rivers contain many waterfalls, rapids and gorges. These features affect navigation. The Congo River has the largest waterways in the continent but some waterfall make the river impassable.  Meandering channels also affect navigation for example River Niger.  To be covered in form 4 syllabus. 2. Landforms from folding Folding  Is the transformation of the earth`s structure into folded landforms as a result of compressional forces.  When forces move horizontally towards each other they are compressional forces.  Rocks are subjected to this force in a process called folding.  Rocks either fold or fault due to their brittleness or flexibility.  In folding, some rock layers buckle and form folds. Landforms  Anticlines, Nappe folds, Overthrust, Overfold, Recumbent, Fold mountains. Anticline and Syncline 1. Anticline  Is a fold that is arched upwards to form a ridge of mountain.  It can be defined as a highland area or ridge formed due to compressional forces.  It is convex shaped and is formed out of rock units that are folded in the same pattern. [email protected] 0775777982 19 | P a g e   It results from a simple fold and each side of a fold is called a limb.  The topmost point is called a crest / axial line.  The crest acts as a line of symmetry between two limbs. 2. Syncline  Is a fold that arches downwards to form a fold.  Are made up of rocks units that are folded in the same pattern. Usually concave shaped.  Usually occur in conjunction with anticlines which is like the letter n. 3. Over thrust  If compression forces continue to act on the rock layers, a simple fold is formed; progresses into an asymmetrical fold, then an over fold and lastly into an over thrust which is actually a fault. 4. Over – fold  Occurs when one fold is pushed over the adjoining limb due to increasing compressional forces.  Also known as overturned fold. 5. Recumbent  Occurs when the limbs are nearly parallel to each other and the axis of the fold is horizontal. 6. Fold mountains  Fold Mountains are usually formed from sedimentary rocks and are usually found along the edges continents.  This is because the thickest deposits of sedimentary rock generally accumulate along the edges of continents.  When plates and the continents riding on them collide, the accumulated layers of rock crumple and fold like a table cloth that is  Result due to folding in the upper layers of pushed across a table. the earth`s surface.  The process of mountain formation is  Is a result of compressional forces when orogenesis. tectonic plates move against each other acting  Many fold mountains are formed in narrow on flexible rock but not brittle. elongated seas called geocynclines.  The movement of the two plates forces  Fold Mountains have a short width but are sedimentary rocks upwards into a series of long extending to thousand killometres e.g. folds. Rockies and Himalayas, Urals Mountains (in USA), the Cape Range and Mt Everest in Nepal Human activity in fold mountains - The Alps - Roads and other communications links have - This region is based on the exploitation of the to snake their way up wherever they can, and coniferous forest. often these roads are not big enough to - Pasturing dairy cattle. adequately service a large community. - Tourism. - The climate is very cold and wet, meaning - The combination of tectonic and glacial that most industrial and agricultural activity processes makes the area ideally suited for HEP is difficult. For farmers they have a very short schemes. HEP schemes often involve many growing season, and it is difficult to use different watersheds. machinery on the steep slopes. - Avalanches are a constant threat, as was seen Problems to devastating effect in Ranrahirca, Peru, in - Difficult to build in due to the steep sided 1962. Huge amounts of money are spent each valleys. year to try and combat the avalanche threat, [email protected] 0775777982 20 | P a g e  especially with the large amount of tourists using the mountains. Hot springs and Geysers - Usually found near or on dormant volcanoes. Hot spring and geysers  The water then flows out as a spring naturally as a fountain e.g. Nyanyadzi and Rupisi near Mutare in the Eastern Highlands of Zimbabwe. Geyser  Is a hot spring that throws jets of hot water and steam into the air due to heating in the pipe of the geyser.  The temperature of water rises resulting in pockets of steam trapped in the twisted portions of pipe.  Eventually steam builds enough pressure and forces the water in the upper part of the pipe to  A spring is a point on the earth`s surface where be spouted and sprayed violently into the air. water flows naturally from the ground.  E.g. is found in Yellowstone National Park in the  A hot spring is a stream of hot water flowing out USA. of the ground.  The water is heated when it comes into contact with molten hot rocks below the earth`s surface. 3. Landforms from faulting Faulting  Refers to the fracturing of breaking of the earth`s crust due to both compression and tension forces as a result of tectonic movements.  Lateral earth movements often produce very great stresses due to compressional forces and tensional forces.  These forces can cause fractures or breaks in the earth`s crust forming joints.  If the rocks are displaced on both side of the crack it is called a fault.  Faulting normally displaces the crustal blocks along lines and eventually rocks are pushed above or dropped below the general level of land. Rift valleys, Lakes and Block mountains Rift valleys  Most are found in East Africa.  Formed as a result of continental plates pulled apart forming huge cracks in the earth and the land sank to form rift valleys such as Great East African Rift Valley.  Lake Tanganyika is the longest freshwater lake in the world.  Lake Victoria is the largest lake in Africa and the second being Lake Mutirikwi in Zimbabwe. [email protected] 0775777982 21 | P a g e Rift valley and Block Mountains  Alluvial deposits from which can be found precious minerals such as gold.  Fishing provides livelihood to people for example Lake Malawi and Lake Tanganyika.  Recreation activities and tourism. Disadvantages of rift valleys Advantages of rift valleys  Hot weather can be stiffing and enervating on valley floors.  Source of water for domestic and industrial  Diseases such as malaria, bilharzia and use. typhoid abound in within.  Pastures for animals can be found in most  Dangerous animals can be found in forests. valleys e.g. East Africa Rift Valley.  Flood occurrence.  Fertile soils. Advantages of block mountains  Associated with relief rainfall. Disadvantages of block mountains  They have cooler environments which discourage diseases.  High erosion rates.  Have pastures for animals.  Associated with dangerous wild animals.  Firewood and fruits.  Rock falls can be fatal to humans and damage  Offered fortification during tribal wars. infrastructure  Minerals such as gold and diamonds found  Prone to volcanic activities and can lead to within their vicinity. loss of life.  Water can be obtained from springs.  Transport networks are difficult and expensive to construct. 4. Volcanic landforms Vulcunicity Qn: What is intrusive and extrusive Vulcunicity? (4)  Refers to various ways by which molten rock A Volcano and gases are forced into the earth and onto its surface.  Is an opening in the earth`s surface through  Includes volcanic eruption forming volcanoes, which magma is injected into the earth or ejected lava plateaus and geysers. as lava onto the earth`s surface.  Also involves intrusive and extrusive features  Rocks below the earth`s crust have a very high e.g. batholith and sills. temperature but the great pressure exerted on  When magma (molten rock) reaches the surface them by the earth`s crust keeps them in a semi – is known as lava. solid state.  Vulcunicity occurs most at plate boundaries.  Friction at plate boundaries raises their  Vulcunicity is divided into intrusive and temperature and fuelling great pressure due to extrusive Vulcunicity. faulting and folding hence rocks become molten and semi- fluid. [email protected] 0775777982 22 | P a g e  It is this magma that flows up into cracks in the  Volcanoes erupt violently or quietly. earth`s surface forming landforms like dykes, batholiths, sills and lapolith. Calderas  Are large craters that form at the top of a volcano usually two or more killometres in diameter.  They are deep and can extend downwards for some hundred meter with lakes as in active volcanoes e.g. Lake Bosumtwi in Ghana. Formation Violent eruption  A composite volcano may explode violently that its top is blown off and disintegrates into rock masses and ashes. Thereby forming a crater at the top of the volcano. Subsidence  It may form due to block subsidence or downward displacement of the central block.  After an eruption, the supply of magma is depleted causing a huge chasm to form beneath the volcano.  The weight of the cone sometimes develops faults which may cause the cone to collapse into the chasm beneath e.g. Longonot in Kenya. Meteor theory  This suggests that solid objects from space fall by gravity and on impact with the volcanic cone. Mountain collapse  A mountain may collapse if it has a large mass floating on a wetter surface resulting in a caldera. [email protected] 0775777982 23 | P a g e Extrusive volcanic landforms  Magma sometimes reaches the earth`s surface through a vent, fissures and cracks (called lava).  Are those landforms resulting as a result of  If the lava emerges from through the vent form magma solidifying on reaching the earth`s a cone shaped mound called volcano. surface e.g. cinder cone, acid cones, composite  If it emerges out of a fissure it builds and forms cones and plug cones. a lava plain or plateau. Volcanic cones  The mount of a volcano is its cone.  It is made up of lava or lava and rocks torn by molten magma.  It may contain layers of ashes and small bits of lava known as cinders.  The shape and size of the cone depends on the nature of materials and type of eruption.  It has a pipe where the lava flows out and the exit of the pipe is the crater. Cinder cone  Is made up of successive layers of ash deposited on each eruption.  Lava is blown a great height when it is ejected i.e. pyroclastic eruption.  It breaks into smaller fragments which fall back to the earth and form a cone.  Has steeper sides and is small as to other volcanic cones.  They are short lived due to processes of denudation. e.g. Jose Plateau in Nigeria and Likaiu and Teleki in Kenya. Lava cone [email protected] 0775777982 24 | P a g e  The shape and slope depends on whether the lava  It spreads over some distance and forms gentle is fluid or viscous. slopes e.g. Nyamuragira in DRC and Mauna Loa  Basic / shield/ fluid lava is very fluid or mobile. in Hawaii with a diameter of 400km and a height of 9km from sea bed. Basic lava cone  Acid / viscous lava produces steeply sloping cones.  Viscous lava contains a lot of silicates and is stick.  It travels over a short distance before it cools.  Sometime the viscous lava may form a plug dome that may block the vent e.g. Pico Cao Grande in Gulf Guinea.  Examples of acid lava are the Hoggar Mountains in Algeria. Composite cone  As eruption continues lava pours out forming a layer on top of ash.  Lava escapes from the sides of the main cone where it forms small conelets.  Sometimes its features include dykes, conduits, ash and lava, a crater and a pipe.  It’s very high and it has alternate layers of cinder and lava and ash hence named stratovolcano i.e. layered volcano e.g. mount Kilimanjaro in Tanzania and Mt Cameroon in Cameroon. Intrusive and extrusive landforms - Dykes, Sills, Batholith, Lopoliths, and Laccoliths. [email protected] 0775777982 25 | P a g e 1. Dyke  Due to erosion they may form ridge like  Is a sheet of magma that solidifies across escarpments and others remain as caps on top of bedding plane. hills.  It can be vertical or inclined.  They can be dissected by rivers forming isolated  Dykes are easily eroded forming shallow hills. trenches.  The Three Sisters in Cape Province South Africa  Those that resist erosion form ridges. are buttes which have sills.  Dykes normally give rise to waterfalls for example Howick Falls in South Africa. 3. Batholith  A deep-seated dome like igneous intrusion made up of granite.  Other examples are the Jos Plateau in Nigeria  Is formed when a large mass of magma that and Kaap in South Africa. accumulates in the earth`s crust which cools and 2. Sills solidifies within or near the earth`s crust.  A sheet of magma that lies along bedding planes.  Sometimes they form the root or core of  A sill is a body of tabular rock that solidifies mountains. along bedding planes sometime are igneous  They form features like dwalas and low lying intrusions. hills after denudation processes.  They are essentially massive underground hills.  Example is Domboshava near Harare. 4. Lopoliths  They form depression which holds water or form lakes.  Example is the Great Dyke in Zimbabwe is not a dyke according to geological fact. 5. Laccolith  Is convex shaped massive sheet of magma that solidifies within the earth`s crust and usually near the earth`s surface.  They are arch – like igneous intrusions as a  A saucer concave shaped sheet of magma that result of magma solidifies within sediments. solidifies in the earth`s crust. [email protected] 0775777982 26 | P a g e  They have a pipe-like feeder coming from the  For example Mt Mlanje in Malawi. magma pool very deep down.  Laccolith forces sedimentary rock to curve up and when exposed to erosion and denudation, they form low lying hills. Bedding planes  Are layers of sedimentary rocks.  They result from fossil deposits or layers of sedimentary materials. Lava Plateau  Lava eruption through cracks tends to be very quiet and subdued.  The lava spreads out over the surrounding countryside causing layers of lava to build up.  Eventually covers up the features of the surrounding area resulting in lava plateaus.  Some lava plateaus are very extensive in size and cover thousands of killometres e.g. Haruj al Aswad Plateau in Libya, part of Drankensberg Mountains in South Africa and Mt Nyiragongo. 5. Desert landforms Landforms produced by wind erosion Rock pedestals  Wind abrasion attacks rock masses and sculptures them into strange shapes. [email protected] 0775777982 27 | P a g e Zeugen  The heaviest material is deposited first while the finer material and dust is carried further  Wind abrasion turns a rock surface with layers before being dropped. of horizontal resistant rock underlain a non-  As a result loess (which consists of fine resistant rock into a ridge and furrow. particles) is sometimes deposited thousands of kilometers from deserts.  Large mounds of sand result from sand depositions within the desert.  These result in the formation of erg landscapes such as those found in the Sahara.  Three major types of features result from wind deposition and form part of the erg landscape: sand ripples, barchan dunes and seif dunes. Sand ripples  These are small wave-like features which develop on sand which move easily.  They range from a few centimeters to about a meter in height Yardang  They are often temporary and suffer  Develops when bands of hand and soft rock lie destruction when the wind changes direction. parallel to prevailing winds, wind abrasion produces a ridge and a furrow e.g. Salah in Sand Dunes Algeria.  These are hills of sand which are found in a variety of shape, size and direction.  Dunes develop when sand grains moved by saltation and surface creep are deposited (remember suspension material forms loess which is deposited outside deserts).  Some dunes, but not all, form around obstacles such as trees, bushes, rocks, a small hill or even a dead animal. Landforms by wind deposition  Most dunes form on areas that are flat and Sand dunes sandy rather than those areas that are rocky and  As soon as wind velocity drops wind uneven. deposition occurs.  Dunes vary in size from a few meters to over a 100 meters in height. [email protected] 0775777982 28 | P a g e  Although they take many shapes, there are two Seif dunes common types of dunes: Barchan and Seif dunes. Barchan  Are also known as transverse dunes, linear dunes.  They are ridge-shaped with steep sides and lie parallel to the prevailing wind.  They are also formed and appear parallel to  A barchan dune is a small crescent shaped each other. dune.  A seif dune has a sharp crest which may be a  It has a height can range from a few meters to 100 meters in height and they can stretch for up about 30 meters in height and it can be 400 to 150 kilometers in length. meters wide.  They are separated by flat corridors which are  They lie at right angles to the prevailing wind. between 25 and 400 meters wide.  It has its “horns” pointing downwind.  These corridors are swept clear of sand by the  They usually form around an obstacle such as prevailing wind. a rock, piece of vegetation or even a dead  Eddies blow up against the sides of dunes and animal. drop deposit sand that is added to the dunes.  As the mound, which is wind ward grows due  They usually develop from small sand ridges. to continued sand depositions,  They slowly move forward in the direction of  Its leading edges are slowly carried forward in the prevailing wind as they move forward. a downwind direction.  They feature in parts of the Namib Desert and  The windward slope of the dune is gentle. the Sahara Deserts as well as other deserts.  The downwind side is steep and slightly curved. Deflation hollows  This is caused by eddies that are set up by the prevailing wind.  A barchan dune moves as grains of sand are moved up the windward slope to fall onto the leeward side.  They can occur both singly or in groups.  Are also known as closed hollows or blowouts  These are enclosed depressions caused by wind erosion.  In deserts the wind erodes loose material from flat areas which have, uncemented sediments such as those occurring in tropical deserts.  Deflation hollows develop in areas where the transported materials is deposited. [email protected] 0775777982 29 | P a g e  As already mentioned deposition occurs when  The removal of the fine particles the lowering the wind meets with an impediment. of the landform leads to the formation of a  Deflation hollows are usually formed on depression. surfaces patches where the protective  An example is the Qattara Depression vegetative cover has been lost for example due  Sometimes water that falls in these depression to human activities or periods of extended hollows during freak storms collects to form droughts. pools in the midst of deserts providing an  Since that portion becomes unprotected, the essential source of water for local ecosystems, wind deflates and scours continuously at animals and humans and their activities. relatively unconsolidated material,  If an area is eroded down to the water table,  The material is deposited on the edges of the further deflation is prevented unless the water hollow that are still protected by vegetation table is also lowered by evaporation. such as marram grass. The Qattara Deflation hollow A diagram showing the formation of deflation  Dunes are made from sand that is deposited at hollows. the leeward side of the wind.  Some deflation hollows may be formed in part due to the presence of faults within the rocks which are exploited and widened by weathering and the regolith removed by wind erosion.  Note: all oasis are formed by deflation some are naturally occurring springs and some result as a result of freak storms and the underlying geological rocks limiting the amount of infiltration.  Some oases in the Sahara were formed in this manner and may be below sea level. Water action  Various landforms result from water erosion and deposition in deserts viz: wadis, mesas and buttes, bahadas, playas [email protected] 0775777982 30 | P a g e Wadis / canyon Alluvial fans/Bahadas/Bajadas  During the sudden rain storms, flash floods rush  As already pointed out freak storms occur in down the wadis, deserts characterised by excessive precipitation  They carry large amounts of materials including over short periods of time. a lot of silt (all this material is referred alluvium)  Due to infiltration excess flow and even forming a mud flow saturation excess flow there is significant run off  As the water dissipates after the end of the storm in the form of sheet floods, and when it loses its energy upon reaching less  This flow occurs in the form of rills which later steep slopes the alluvium is deposited to form join to form gullies which in turn form into fan shaped features at the base of the piedmont wadis, zone.  These are deep canyons resulting from sustained erosion, the have steep banks and flat floors. Desert piedmont zone  At times the floor may have material deposited by stream floods.  Is made up of water landforms formed by  Wadis may also be formed by stream floods erosion, transportation and deposition. which erode valley sides although some wadis  The landforms found on the piedmont zone can be dry and only have water during and in the include: mountain front, bajada, peri pediment, immediate aftermath of these storms. playa and rock pediment.  An example is the Grand Canyon in the United States. Features of a piedmont zone. [email protected] 0775777982 31 | P a g e Mountain front  It is formed as a result of erosion along a steep slope and sometimes as a result of headward erosion.  It may also be a made up of large rock boulders resulting from weathering. Bahada  A depositional feature see above. Knickpoint  A sharp change in profile that marks the transition from the mountain front into a pediment. Rock pediment  It is the gentle slope that starts at the knickpoint at the foot of the mountain.  This may be made out of bare rock or it can be covered in alluvium deposited during floods Peripediment  It is made up of deposited material washed across the pediment.  The peri pediment is a depositional feature that is formed in the same way as bajadas but it is larger. Playas  These are sometimes known as inland drainage basins.  Due to the fact that there are no permanent drainage patterns in deserts any rain that falls either evaporates or infiltrates into the soil or runs off and drains into basins.  Basins are depressions.  When rain falls temporary rivers that flow in canyons/ bahadas are formed and these may eventually drain in a basin/depression.  These rivers form lakes in these depressions.  When these lakes dry up due to evaporation they are turned into salt flats.  These temporary lakes and salt flats are known as playas or sebkhas.  Examples of these can be found in the Sahara desert.  When alluvium is deposited at the edge and overlies the edge of the pediment around the playa it is known as a peri-pediment.  Most deserts are characterised by inland drainage basins as few rivers e.g. the Nile have enough water supply to flow and persist through the deserts.  Most form inland drainage basins/lakes/playa. Benefits of landforms (Summary)  Tourism – tourist attraction e.g Victoria  Mountains leads to formation of relief Falls, Vumba, Alps, Inyangani mountains rainfall e.g in the Eastern Highlands of and Chinhoyi caves. Zimbabwe.  Hydroelectric power generation foe example  Landform such as rivers and ridges form Kariba Hydroelectric power generation at international boundaries for example deep gorges. Zambezi and Limpopo.  Provision of fertile soils for example on  Provide precious minerals. flood plains.  Provision of building materials e.g granite and limestone rocks. [email protected] 0775777982 32 | P a g e  TOPIC 3 ECOSYSTEMS Ecosystems A system is a set of components connected together in an organised way. It is simply a series of materials, components (parts) or variables linked together by flows or processes. Ecosystem  Is a community of organisms involved in a dynamic network of biological, chemical and physical interactions between themselves and with the non-living components.  An ecosystem can be classified according to nature (artificial or natural), its size (large or small) and duration (temporary or permanent).  Small / micro ecosystem can be temporary or permanent e.g. pond, flowerpot etc.  Large / macro ecosystem is always permanent and mostly natural e.g Ocean, river, forest and desert. Two components are biotic and abiotic. Biotic Components  The living organisms present in an ecosystem form the biotic component.  They are connected through food, some organisms are producing food whereas others are consuming. i) Producers  The role of producers is to manufacture food to provide nutrition to the other organisms.  Two types of producers are photoautotrophs and chemotrophs. Phototrophs - These are green plants which can trap sun light to form carbohydrate, simple sugar from carbon di-oxide and water (photosynthesis). Chemoautotrophs -few bacteria such as sulfur bacteria, nitrifying bacteria, to utilize free energy released from the chemical reactions to prepare organic food (chemosynthesis). ii) Consumers  These are mainly the animals, unable to synthesise their own food but depends on producers.  Some consumers doesn’t get the food from the producers but they are depended on other consumers (hetrotrophs) Primary consumers - grasshopper, rabbit, goat, sheep etc. Secondary consumers – Carnivores-are flesh eaters. e.g. - Hawks, Tiger and Lion. Omnivores - eat both vegetables and flesh (cockroaches, fox, and humans). Tertiary – predators of predators e.g vultures, iii) Decomposers 33 | P a g e   These are mainly bacteria and fungi to decompose complex organic material into simple inorganic material so that it can be used by producers to prepare food e.g bacteria, fungi, worms, nematodes, mites, etc. Abiotic components  These factors include the non-living physiochemical factors of the environment.  Abiotic factors are as follows: i) Inorganic substances  Inorganic substances like carbon, nitrogen, oxygen, water, carbon di-oxide, calcium, phosphorus and their inorganic compounds.  These are available as free form or dissolved in water and may be adsorbed on the soil particles. ii) Organic compounds  These are carbohydrates, proteins, lipids, nucleic acids etc.  This material is present in dead organic matter. These are broken into the simple compounds by decomposers in ecosystem for recycling of matter. iii) Climatic factors  These are factors present in the environment such as temperature, humidity, light, wind, rainfall and atmospheric gases etc. Components of micro ecosystems Inputs (things going into it)  Precipitation, heat or solar energy.  Carbon dioxide from the atmosphere. 34 | P a g e   Mineral salts e.g. calcium, nitrates, potassium. All these are used to make food for the plants.  The inputs contribute to healthy trees, grass and other plants. Processes  Key processes in ecosystems include the capture of light energy and carbon through photosynthesis, the transfer of carbon and energy through food webs and the release of nutrients and carbon through decomposition. Outputs (things coming out of the system)  The healthy plants resulting from the use of the inputs  More water vapour added to the atmosphere through evapo-transpiration from plants.  More surface water resources-leading to fish resources.  Decomposed plants, litter or vegetation, adds to soil fertility and enables farmers to reap more crops.  Pastures or food for animals, birds and insects come from trees and grass.  Birds and insects help to propagate seeds and fruit resulting in more plant germination. Interdependence in organisms A food chain  Is the sequence of steps through which  Through the process of photosynthesis, the process of energy transfer occurs in plants use light energy from the sun to an ecosystem. make food energy.  Energy flows through an ecosystem in one direction – through food chains.  Primary consumers eat plants,  Food chains illustrate how energy secondary consumers eat primary flows through a sequence of consumers, and tertiary consumers eat organisms, and how nutrients are secondary and primary consumers. transferred from one organism to another.  Food chains usually consist of producers, consumers, and decomposers.  The sun is the ultimate source of energy for all food chains. A food web is a diagram of a complex, interacting set of food chains within an ecosystem. Human beings feed on plants, birds and other animals. A lion eats a number of animals including a human being. A zebra is a prey to a number of carnivores and omnivores. 35 | P a g e Pyramids of numbers  It shows the relationship between the producers, herbivores and carnivores in terms of their numbers.  This indicates the number of organisms at every trophic level.  In a grassland the producers, which are mainly grasses, are always maximum in number.  This number shows a decrease towards apex,  The secondary consumers, snakes and lizards are less in number than the rabbits and mice.  In the top (tertiary) consumers hawks or other birds, are least in number. 36 | P a g e Pyramid of energy Pyramid of Biomass  In an ecosystem the pyramid of energy shows the amount of total energy trapped  The amount of living material in an by the organism at each trophic level in a organism is called biomass. unit area and time and expressed as kcal/  Pyramid of biomass shows quantitative 𝑚2 /year. relationship existing at various trophic levels.  The energy pyramid gives the best picture of overall nature of the ecosystem. 37 | P a g e  TOPIC 4 NATURAL RESOURCES Natural resource  Anything that exist naturally or without humankind (all of the Earth’s organisms, air, water, and soil, as well as materials such as oil, coal, and ore that are removed from the ground).  Categorised into Renewable resources and Non-renewable resources Renewable Resources  are any resource that cycles or can be replaced within a human life span e.g. water, crops, biogas, wind, soil, sunlight, animals, etc… Non-renewable Resources  Any resource that cannot be replaced during the time of a human life span.  Took thousands of years to form and exist in fixed amounts in the Earth.  They need to be conserved before they become depleted e.g metallic ores include (gold, silver, copper, aluminium, zinc, etc… and non-metallic ores and fossils include: coal, limestone, salt, sand, gravel etc…) Resource Exploitation Involves the deliberate use and exploitation of a resource either to satisfy domestic or commercial needs. Sustainable utilisation of resources Resource conservation This is about using our resources, both renewable, and non-renewable carefully so that future generations could also benefit. The following are some of the resource conservation methods which can be implemented. Forests/wood  Afforestation.  Reforestation.  Education campaigns, for example, the National Tree Planting Day.  Penalties against those people who indiscriminately cut down trees.  Limiting timber extraction/harvesting.  Using less resources (twigs/tsotso). Water  Treat waste before disposing it into water courses.  Avoid stream bank cultivation.  Limit the use of chemicals on land, for example, fertilizers which cause eutrophication 38 | P a g e   Recycling used water.  Penalties for those people who carelessly use and or pollute water.  Turning off tapes after use.  Education.  Water harvesting  Mulching to conserve moisture. Land and gold panning  Proper methods of farming.  Land redistribution, so as to relieve pressure on overcrowded areas.  Stiff penalties on indiscriminate dumping of wastes.  Education campaigns so as to enlighten people about the need to use our only one and fertile land resource.  Fencing off degraded/bad land topography so as to protect it from further damage and thus lesson or limit the impact/damage.  Ban gold panning.  3 RS (reduce, reuse and recycle).  Substitution of minerals.  Improved technology 39 | P a g e  TOPIC 5 ENERGY AND POWER Energy Forms Non-renewable energy: Energy that cannot be reproduced in the time that it takes to consume it e.g. coal. Renewable energy: Energy that is naturally occurring and potentially infinite. Fossil fuels: Any combustible organic matter that is made from the remains of former flora and fauna. Siting and production of HEP Factors  A gorge and water falls – much water in the narrow valley, a large head of water at the falls, low cost of construction, firm dam wall on hard rocks e.g Kariba gorge, Cabora Basa gorge in Mozambique.  Large perennial rivers for large volumes of water e.g. Zambezi River.  Space for dam construction and the scheme, thus why people have to be relocated to other areas.  Income since it`s expensive to erect the project.  Demand. Hydro – electric power generation at Kariba  Water leaves the lake (head of water) at high pressure and goes through the penstocks (concrete and steel pipes).  The larger the depth of water, the more the pressure hence high electricity generation.  High speed water hits cups of turbines.  Turbines start spinning and rotating.  They in turn generators to which they are attached with pistons.  Generators produce electricity.  The water passes through surge chambers and return back to the river through tailrace.  Electricity is transmitted to huge transformer which regulates the power.  Electricity is transmitted through cables to homes for use. 40 | P a g e Thermal power Locational factors  Near fuel source e.g. S.E Lowveld uses baggase from sugarcane.  Market based.  Flat land.  Near large rivers or source of sufficient water.  Transport Thermal power generation  Fuel such as coal, oil and natural gas can be used to heat water in huge boilers to produce steam.  The steam at high pressure turns turbines.  Turbines turn generators to produce electricity.  E.g. Hwange and Munyati power station. 41 | P a g e Environmental impacts from generating and use of energy 1. Fossil fuel  Deforestion  Global warming  Acid rains  Dangers posed by leaded fuels  Oil spills  Water pollution caused by poorly managed coal mines  Air pollution. 2. Alternate energy resources  The initial cost of establishment of alternate energy generation is costlier than conventional resources  Maintenance of these structures is difficult.  It requires more space.  Energy supply is unpredictable during natural calamities. Management and conservation of energy  Management of energy is effective planning and control of energy resources. Management Measures  Encouraging many people to use public transport.  Educating people through mass media to create awareness on the importance of conserving energy.  Improvement and proper planning of road network to reduce traffic jams in which a lot of fuel is wasted. 42 | P a g e  Agroforestry, afforestation and reforestation programmes to reduce overexploitation of natural forests.  Banning logging, selective felling of trees and resettling people who have settled into forests. Conservation of energy  Conservation of energy is using available energy resources in the most effective manner to ensure there isn`t wastage. Conservation measures  Putting off electricity gadgets when they are not in use.  Proper motor vehicle maintenance in order for them to use fuel efficiently.  Encouraging use of public transport which carries many people at a go e.g. buses.  Encouraging use of renewable sources of energy e.g. solar, wind and biogas to save on oil and wood.  Encouraging use of energy saving stoves which use little charcoal and produce a lot of energy. 43 | P a g e  TOPIC 6 MAP WORK AND GEOGRAPHIC INFORMATION SSYTEMS Maps A map is a visual representation of the Earth’s surface, drawn to scale and made for a specific purpose. Uses of maps - To locate places. - To determine where you are going. - To show distribution of features and type of materials. Components of a good map Title Tells us what, where, when and the subject of the map Orientation Directions: North, South, East, West (compass rose) Date When the map was made Cartographer Who made the map Legend Key of map symbols and scale Symbols Markings on the map: Mts ^^^^, Rivers ~~~~, Capital* Scale Distance a unit of measurement represents on map Index Alphabetical listing to show the address of places on map Grid Letters and/or numbers on map that locate places: latitude… Glossary Definition of physical features located on map Source Bibliographic information; where did you get information 44 | P a g e Types of maps Political maps – These show political divisions of land, such as countries, districts, and provinces. Political maps also often show towns, cities and villages Physical maps -Illustrate the physical features of an area, such as the mountains, rivers and lakes. 45 | P a g e Topographic maps –will show you hills, rivers, lakes, roads, railway lines, farms and settlement areas. A topographic map shows only those features the mapmaker wants to show. Includes contour lines to show the shape and elevation of an area. Road maps – show major, some minor highways and roads, airports, railroad tracks, cities and other points of interest in an area. People use road maps to plan trips and for driving directions. Navigational maps/Directional maps – show you where you are located and where to find a location. 46 | P a g e Economic map – show the economic activities and resource distribution in a given country or region e.g distribution of different minerals or mark the areas where certain economics are concentrated. Special purpose maps Population density is the number of people per unit of area. Climate maps – Show information about climatic conditions of an area. They show elements such as temperature and rainfall. Regions receiving same amounts of temperature and rainfall are allocated the same code. Product map – shows us what kinds of things are made in and grown on the land. 47 | P a g e Drawing a map A Sketch map Is a simplified representation of the real map or features drawn not to scale. It has a title, key and direction. How to draw a sketch map Step 1: Draw the boundaries of the area which resemble the shape of the map. Step 2: Draw major roads, strets, rivers and other linear features, Step 3: Draw settlements, hills and mountains using symbols like rectangles for buildings, circles for hill and lines for roads and rivers, Step 4: Shade the features differently and insert a key to represent them, Step 5: Insert a title and direction arrow. 48 | P a g e Location Absolute Location is the exact spot on Earth where a place can be found. Relative Location Is the location of one place in relation to other places. Latitude and Longitude How do I use latitude and longitude to find the absolute location of places? Absolute Location: the exact location on the earth’s grid. Latitude - Lines run west to east - Measures distance north and south of the equator - Also called “parallels” - Lines end at 90 degrees North and South Equator - The main line of latitude - divides the world into Northern and Southern Hemispheres - measures a “0” degrees Longitude - Lines run north to south - Measures distance east and west of the Prime Meridian - Also called “meridians” - Lines end at 180 degrees east and west - two end points of longitude meridians are the North Pole and the South Pole Prime Meridians - The main line of longitude - Divides the world into Eastern and Western Hemispheres - Measures at “0” degrees - Runs through Greenwich, England 49 | P a g e Map Referencing / Co-ordinates  This is the method of finding any point on the map. Finding 4 Figure Grid References  It is used for general purpose.  Always begin from the eastings, followed by the northings. Steps 1. Locate the grid square of the particular feature to be found. 2. Read the easting for the south-west of the grid square, 3. Read the northing for the south-west of the grid square (the two lines intersect forming an L- pattern). 4. Simply write the two numbers together, with the easting first. 5. The 4 fig of the shaded box below is: 2 9 5 1 Finding 6 Figure Grid References  It is used for precise locations 50 | P a g e   It pinpoints actual location by involving the subdivision of the eastings and northings reference into 10 imaginary lines.  Each tiny square represents 1/100 of the original big (grid) square. Steps 1. Locate the grid square of the particular feature to be found. 2. Divide the grid square into 10 equal parts along both the northings and eastings. 3. Number these divisions from 0 to 9 along both northings and eastings. 4. Mark the southwest corner of the feature that you are locating. 5. Estimate how far the feature is from the easting first using the scale in tenths. 6. Estimate how far the feature is from the northing using the scale in tenths. 7. Write the value for the easting followed by the northing. 8. The six fig grid reference of the spot height below is: 6 2 5 3 3 3 Note:  The third number is part of the easting and the sixth number is part of the northing. These numbers refer to the small