TECHNIQUES OF TEACHING MAPWORK

1. TECHNIQUES OF TEACHING MAPWORK AT THE SENIOR SCHOOL LEVEL

2. TYPES OF QUESTIONS ON MAP WORK In West Africa, examination questions on Map work take the following forms: • 1. Candidates are asked to do one of these. (i) Identify and use abbreviations to mark some features on the topographical map; or (ii) Reduce a map or enlarge a marked area on the map, or (iii) D raw an annotated cross section.

3. TYPES OF QUESTIONS[Continued] • 2. Questions are set on (i) the description of relief (ii) Description of Drainage • 3. Candidates may be asked to calculate: (i) Distances on maps (ii) Areas (iii) Gradient (iv) Bearing. • 4. Candidates may also be asked to comment on the Distribution of communication routes • routes in relation to relief, drainage, settlements, etc. • 5. There may be questions set on • (i) Situation and functions of settlements • (ii) Distribution of settlements • (iii) Land use types and human activities.

4. HOW TO IDENTIFY AND MARK FEATURES ON THE TOPOGRAPHICAL MAP • Examination questions may ask candidates to identify and mark some features on the topo sheet. These include spurs, valleys, scarp, peaks, knoll, outliers, conical hill, saddle, ridge, plateau, confluence, source of a river, estuary, delta, meander, lake, braided pattern. They may also be asked to shade some features such as heights. • To mark the feature accurately, draw a circle or a ring around the feature and write the abbreviation or letters in the circle or ring. • You could use this second method: Write the name or abbreviation across the feature. • Or write the name near the feature and point an arrow directly at it.

5. CALCULATIONS IN MAP WORK • 1. MEASURING OF DISTANCES ON MAPS • An examination question may ask candidates to measure the length of a road, river, footpath, a straight line distance (“ as the crow flies”) , etc. • Measure the length on the map in centimetres. Eg. The length of a river is 4cm on the map. • Then use this procedure. Length on Map = 4cm √[mark] • Scale of map = 1:50,000 • Distance on the ground= length on map x scale factor = 4cmx 50,000 √[mark] • Conversion to Km = 4 x 50,000 √ [mark] 100,000 • = 2 km √ [marks]

6. 2. MEASURING OF AREAS • i. Measure the length and width of the map in centimetres [ e.g. Xcm and Ycm.] • ii. Convert them into kilometres [Xkm and Ykm.] • iii. Multiply the length- in-kilometres by the width-in-kilometres and your answer should be XYkm² • Here is an example: A map with a scale of 1:50,000 has a length of 36cm and a width of 34cm. • Use this procedure: Length of map =36cm Width of Map =34cm • Actual length = 36cm x 50,000 = 18km 100,000 • Actual width = 34cm x 50,000 = 17km 100,000 • Area = Length x Width =18 x 17km • = 306 km²

7. 3. GRADIENT • Gradient refers to the steepness of a slope. It is the ratio of the vertical interval (V.I) to the horizontal distance or equivalent (H.E) and is expressed as a fraction with a numerator of one (1). • How To Calculate Gradient • (a) Find the difference in height between the two places to get the vertical interval. This is done by subtracting the lowest contour line from the highest one. • (b) Measure the distance between the two places (i.e. horizontal equivalent) along a straight line, road, footpath or river as the question may state and convert the answer to miles or kilometers i.e. actual distance on ground. • (c) Work out the gradient either in Metric Scale or Imperial Scale

8. Example 1: Using the Metric Scale • For example, the scale of a map is 1: 50,000. Settlements Santo and Ta are located on 2100ft and 1950ft respectively. A road from Santo to Ta measures 9.5cm. Calculate the gradient of the road. • ANSWER: (Note that the contours are in ft [imperial] but you measured the road in cm [metric]. You can calculate the gradient using the metric scale). • Gradient = Vertical Interval(VI) • Horizontal Equivalent(HE) • Height at Santo = 2100ft. Height at Ta = 1950ft. • Vertical Interval = 2100-1950ft = 150ft • Horizontal Distance = 9.5cm • Scale = 1:50,000 = 2cm to 1km • Horizontal Equivalent = 9.5cm x 1km = 4.75 km • 2cm • Gradient = 150ft = 150 x 12ins x 2.54cm [NB: 1ft = 12ins and 1in = 2.54cm] • 4.75km 4.75x 100,000cm • = 4572 = 1 = 1 • 475,000 103.8 104 • Gradient = 1 in 104

9. EXAMPLE 2: Using Imperial Scale For example, the scale of a map is 1: 50,000. Settlements Santo and Ta are located on 2100ft and 1950ft respectively. A road from Santo to Ta measures 3.7inches. Calculate the gradient of the road. • Gradient = Vertical Interval(VI) • Horizontal Equivalent(HE) • Height at Santo = 2100ft. Height at Ta = 1950ft. • Vertical Interval = 2100-1950ft • VI = 150ft • Horizontal Distance = 3.7inches • Scale = 1:50,000 = 1.25ins to 1 mile • 3.7ins = 3.7 = 2.96miles 1.25 • NB; 1 mile = 5280ft • Gradient =150ft • 2.96miles [change the miles into feet by multiplying it by 5280ft] • =150ft = 150 = 1 • 2.96 x 5280ft 15628.8 104 • =1 in 104

10. DESCRIPTION OF RELIEF • 1. Description of Highlands • Highlands should be described under the following points: • Type of Highland: Mention or state the type of highlands e.g. ranges, ridge, lines of hills, mountains, plateau, dissected plateau or dissected ridge. • Alignment: Describe the trend or alignment of the highland. e.g. The Akwapim-Togo Ranges have a northeast-southwest trend. • Valleys: Generally, valleys of highlands are deep, steep and narrow. • Spurs: Most spurs of highlands are steep, short and narrow. • Summits: Describe the tops of the highland. E.g. open, flat-top, round top, pointed peaks. • Saddles: State whether there are saddles (cols). • Height: State the lowest and highest contour lines. • Slopes: Describe the slopes of the highlands at the various directions. e.g. The northern slopes are gentle. The western slopes are steep, etc. State, also, whether there are escarpment or dip, concave or convex slopes, etc.

11. Description of the Lowland • Lowlands should be described under the following points: • Type of Lowland: State the type of lowland. It should be noted that most lowlands shown on Ghana’s and other West African’s topographical maps are undulating (rolling) and dissected. For example, it is undulating and dissected lowland. • Valleys: Describe the valleys. Note that lowlands usually have valleys that are wide, shallow and gently sloping. • Spurs: Describe the spurs. The spurs are generally broad, long and gently sloping. • Slopes: Lowlands are generally flat or gently sloping. • Height of the land: State the lowest and highest contours of the lowland: usually, lowlands are between Sea level 0ft and 600ft. • Other features: Identify and describe other features in the lowlands e.g. State whether there are hills, knolls (isolated low hills), conical hills, low ridges on the lowland.

12. HOW TO DESCRIBE THE DRAINAGE CHARACTERISTICS OF RIVERS • 1. Name: Mention the name(s) major river(s). • 2. Direction of flow: Show the direction of flow of the main rivers e.g. generally • southwards, northwards, north-westerly, south-easterly, north to south, east-westerly, west to east etc. • 3.Tributaries: State whether the river has tributaries and give examples of the tributaries. • 4.Gradient: The major river has a gentle or low gradient. • 5.Patterns: State that the major river forms braided pattern. It also forms dendritic pattern with its tributaries. • 6.Meanders: The major river meanders in its lower course. • 7. Fluvial islands, etc.: State whether there are fluvial islands, sand deposits and rock outcrops in the river. • 8.Other water bodies: State whether there are lakes, ponds, or marshes in the river’s course. • 9.Estuary: State whether the main river enters the sea, lagoon, or lake. • 10.Stage of river: State whether the river is in its youthful stage, mature stage or old stage (lower course).

13. DISTRIBUTION OF DRAINAGE ON MAPS • State whether the whole area has high, medium or low drainage density. • Describe the regional distribution of streams. State the density in the East, West, South and North. For example, drainage density is high in the south-west. • Show the direction of the major rivers and chief tributaries. • Show the source of the rivers or watersheds. • Point out areas that are marshy, liable to flood. • State whether there are lakes, ponds, lagoons and sea in the area.

14. DISTRIBUTION OF ROAD NETWORK • Mention the various classes of road in the area. • State whether the density is low/ moderate/ high in the north/ south/etc. • State the class of roads that dominates and show the direction they run. For example, the road network is dominated by class 1 roads running roughly east-west/ north-south/ northwest-southeast/ or northeast-southwest. • State whether the class 1 roads are straight or winding. E.g. The roads in the south are winding in nature. Those in the north are fairly straight. Give reasons.

15. Distribution of roads on maps • Example 1: The road is straight because of gentle slopes, flat lands, and valleys. • Example 2: The road is winding because of steep slopes, steep spurs, large water bodies. • Describe the other classes of road. For example, there are two long class 2 roads and a short class 3 road in the south/north/east/west. • Show areas where there are no roads and give reasons. For example extensive areas in the north/south/east/west are not covered by the road network. The reasons may be due to any of the following: Absence of settlements / Presence of marshes, floodable areas / Presence of steep slopes, numerous rivers, forest reserve / absence of human activities.

16. DISTRIBUTION OF SETTLEMENTS ON MAPS • METHOD 1 • 1. Show areas where there is high concentration of settlements (areas of high settlement densities). • State whether there are minor or major settlements in the area. • Mention the names of some of the settlements in the area. • Give reasons for the concentration of settlements in the mentioned areas by relating settlement sites and situations to relief, communication, drainage, economic activity. • 2. Mention areas with sparse settlements and give reasons e.g. “The area is sparely settled because of …… (marshy areas, floodable area, very steep gradient, reserved forest etc)”. • 3. Show uninhabited areas (areas without settlements) and give reasons for the absence of settlements. • The reasons include absence of communication routes / presence of steep slopes, marshes, forest reserve, floodable area, numerous streams.

17. SITUATION AND FUNCTIONS OF SETTLEMENTS SITUATION OF A SETTLEMENT • The following steps should be taken: • 1. Relief: (i) Describe the nature of the landon which the settlement is built e.g. on a dry land, lowland, spur, ridge, in a valley, in a gap, on watershed watershed. • (ii) Give the height of the land. State the value of the nearest contour. between 250 and 300ft above sea level. • (iii) State whether it is near (a)hills, ridges, plateauor mountains • 2. Direction: Mention the direction in which the settlement is located on the map or to other major features E.g. it is in the northeast of the area. It is on the west of a hill, etc. • 3. Drainage Features: State whether the settlement is near rivers, lake, lagoon, floodable area, marshy area or the sea. • (4) State whether it is (a)near a road, railway, etc (b)at a nodal point • 5. State whether it is near an economic activity e.g. mines, farms • 6. Statethe longitude and latitude or the grid reference of the settlement.

18. FUNCTIONS OF SETTLEMENTS • Symbols and letters are used to indicate the functions of settlements on maps. When you are asked to describe the functions of a settlement first, mention the type of function and second support it with an example or evidence from the map. E.g. “The town performs administrative√ function because of the presence of the police station and court house”√

19. Other Functions • . The other functions include: • Administrative: This is indicated by government buildings or offices, e.g. Ps for Police Station; Ct. H or Court House and Chief’s palace. • Educational Function: Sch for Schools; university; etc • Commercial Function: the presence of market (Mkt) • Religious Function: indicated by church [Ch] or mosque • Health care services: shown by hospital [Hosp]; clinic • Telecommunication Services: e.g. Post Office [P]; Telegraph Office [T] • Transport Service: e.g. roads, railways, ferry, station [Sta.] • Recreational Function: Rest House (R), Stadium etc.

20. CONCLUSION • For the students to understand and acquire the skills of map interpretation, • The teaching of map Work should start from the year and continue to the final year • Each student should own topographical maps on lowlands, high plains and highlands so that they can practice on their own, at prep and at home.

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