◄UNIT 2:BEARINGS, DIRECTIONS, DISTANCES AND AREAS ON A MAPUNIT 4:THE UNIVERSE AND THE SOLAR SYSTEM►

UNIT 3:MAP WORK INTERPRETATION

  • UNIT 3:MAP WORK INTERPRETATION

    Key unit competence : The student-teacher should be able to explain
                                                   the relationship between the physical and human

                                                    activities on maps.

    Introductory activity

    M

    A map is a representation of all or part of existing things on the earth surface
    on a flat surface. A photograph is a picture of an object or environment taken
    by a camera at a particular time in a given place. Maps and photographs
    represent both physical and human features. The aspects represented on map/
    photographs are shown using several types of signs and symbols. This helps
    map /photograph users to extract the needed information from a given map /

    photograph.

    Referring to the map above and the definition above;
    a) Identify the main physical features represented on the map.
    b) Identify the human features represented on the map.
    c) Use the following map to represent approximately the same features as

    those represented on the map above.

    X

    d) Take a photograph of the environment around your school and then

    identify all physical and human aspects taken on that photograph.

    3.1. Interpretation of physical aspects from maps/photographs
    Activity 3.1
    Make a research on:
    a) The major physical aspects which may be represented on a map/
    photograph.
    b) The signs and symbols which may be used to represent physical
    features on a map/photograph.

    Physical features are also called natural features. They include the following:
    • Relief which comprises rocks, slopes, soils, valleys, plains, plateau,
    hills, and mountains.
    • Drainage features like rivers, dams, lakes, seas and oceans.
    • Vegetation cover like forests made of several types of trees, crops and
    ground vegetation, wetland vegetation.
    • Climate which is defined through various parameters like rainfall,
    temperatures, relative humidity, cloud cover, wind speed and direction,
    atmospheric pressure, sun shine.

    3.1.1. Interpretation of geological features
    The main geological features commonly represented on a map/photography
    include rocks, cliffs and boulders.
    ── A rock is a solid matter which is found on the surface or in the interior
    of the earth.
    ── A cliff is a vertical or nearly vertical rock face in mountainous and
    hilly areas. Cliffs are found along the shores of lakes and seas. Cliffs
    and rocks are shown on topographical maps using contours that are
    close to each other. Boulders are large pieces of rocks that resisted
    weathering.
    ── A crater is a bowl-shaped depression, or hollowed-out area, produced
    by the impact of a meteorite, volcanic activity, or an explosion.
    ── A quarry is a place from which stones, rocks, construction aggregate,
    riprap, sand, gravel, or slate are excavated from the ground. A quarry

    appears like a place where open cast mining is practiced.

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    3.1.2. Interpretation of slopes from a map/photograph
    The slopes are classified according to their inclination, constancy or shape. The
    slopes are represented on the map by help of contours. Contours are lines on
    a map linking places of the same height above the sea level. They are drawn at
    fixed intervals, known as vertical interval or VI.
    Contours are labeled from the lowest to the highest. Where they are too close
    to each other, the relief is steep. Where they are far apart, the land may be a
    plain or a plateau. The main types of slopes are: gentle, steep, regular, irregular,
    convex and concave slopes.
    • Gentle slopes: Spaced contours are used to indicate gentle slopes. In
    that case the land may be a plain or plateau which is a flat elevated
    landform that rises sharply above the surrounding area.
    • Steep slopes: Very close contours are used for steep slopes. The closer
    the contours, the steeper the slope. In that case the landform may be

    a mountain.

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    • Regular slopes: Regular slopes are also called constant or even
    slopes    . The contours have constant spaces. The slopes can be either
    gentle or steep slopes.
    • Irregular slopes: These are uneven or inconstant slopes. They are
    represented by unequally spaced contours. They can be either gentle
    or steep slopes. These slopes are found mostly in rugged, mountainous

    or hilly areas.

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    • Convex slopes: Convex slopes are gentle at the top and steep at the
    bottom of the hill or mountain. The contours are closely spaced at the
    bottom section (steep slopes) and widely spaced at the top section

    (gentle slopes).

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    3.1.3. Interpretation of drainage and landforms from a map/photograph
    i. Interpretation of drainage features from a map/photograph
    The lake, sea and ocean occupy a very large area. They are seen in blue color on
    a color photograph and in dark color on black and white photograph. However
    other conventional symbols may be applied on a map to represent a lake, sea

    and ocean; the most important thing is to put in legend/key the used symbols.

    S

    The rivers originate from mountains or hills and flows on steep slope to end in
    the depression that are usually found in valleys or low-lying areas. The streams
    and rivers are seen on a coloured photograph/map as blue lines and they have
    different patterns or arrangements which can be detected easily on a map or

    photograph.

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    ii. Interpretation of landforms:
    1. Valley: A valley is an elongated depression sloping towards a drainage
    basin like a sea, lake or swamp and which may contain water or not.
    The valley is normally represented on a topographic map by using the

    contours having “V shape”.

    Z

    2. Plain: Most of the plains are in low-lying areas but some of them may be
    raised but the slopes remain gentle. On the topographical maps, a plain
    is represented by widely spaced contours. The river passing in plain

    areas may also be shown on the map.

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    D

    3. Plateau: A plateau is an extended landform which is bordered by steep
    slopes. On the map, a plateau is shown as a wide area surrounded by one

    or two contours having the same height on both sides.

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    4. Mountain: A mountain is an extended landform with steep slopes. On
    the map, a mountain is shown as a wide area with very close contours
    surrounded by one or two wider contours showing the depression areas

    surrounding the mountain.

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    3.1.4. Interpretation of soils on the map
    Assorted colors or symbols are used to show several types of soils on a
    topographic map. Tiny brown dots called stipples are used to represent a
    surface covered by sand or mud. The types of soil can be also shown by help of
    dots having varied sizes according to the texture of the soil. The types of soils
    can be differentiated on a photograph based on their texture (sizes) and color.

    Surfaces covered by lava flows are shown by symbols that look like inverted V’S.

    S

    Application Activity 3.1
    a) Identify the physical features in area where you live and describe
    how they are represented on a topographic map.
    b) Draw a sketch of your home area, on it, name and mark the physical
    features identified in (a) above.
    c) Suggest ways through which the above features can be protected

    and conserved.

    3.2. Interpretation of human aspects on maps
    Activity 3.2
    Make a research on:
    a) The major human aspects which may be represented on a map/photograph.
    b) The signs and symbols which may be used to represent human
    features on a map/photograph
    Human aspects on a map reflect human activities of a given area represented on
    a map. These include agricultural development, mining, industry, settlement,
    etc.

    3.2.1. Agricultural activities
    Crop plantations are drawn on a topographical map by using light-green
    shading. A letter may be used over the shade to indicate the name of the crop

    growing in each area. For example, C for coffee, T for tea.

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    Several types of crops may be taken on a photograph and be identified based on

    their shapes, sizes and colors.

    D

    3.2.2. Mining and quarrying activities from a map
    Mining refers to all the processes by which minerals are obtained from the
    earth’s crust. Minerals may be in gaseous, liquid or solid form. Quarrying is the
    digging of stones, sand or soil from the ground. Mining and quarrying activities
    on a map are shown by symbols as represented on the figure below. The mining
    activities may be taken on a photograph and different types of minerals/

    quarries may be differentiated based on their colors.

    A

    3.2.3. Industrial areas
    An industrial area is a geographically localized set of specific industries. Such

    areas are subject to important production, marketing and other interrelationships.

    T

    3.2.4. Settlements
    Settlement refers to a place where people live. It also means the process
    of settling in such a place. Settlement on the map can be shown by dots or
    rectangles which may be black or grey in colour. Dots indicate rural semipermanent
    settlements while rectangles show permanent buildings like those
    built of stone or bricks, with iron or tile roofing.

    The dots or rectangles are spaced in relation to the concentration of settlement.
    Nucleated settlements are represented by the dots and rectangles close to one
    another while they are much spaced for scattered settlement.

    The settlement is also represented according to its shape, for example ring or
    linear. The shapes of settlement may be influenced by communication networks
    like roads, railways, landforms like valley, plain, plateau, mountain among

    others.

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    Application Activity 3.2
    1. Use a photograph/map to identify and describe mining/quarrying areas.
    2. Visit the nearest mining/quarrying areas and represent them on

    sketch map using appropriate signs and symbols.

    3.3. Relationship between physical and human aspects on
    maps/photographs

    Learning activity 3.3
    The following map represents both physical and human aspects which are

    interrelated.

    D

    In reference to the map above from Kigali Suburbs and the knowledge
    acquired from the influence of relief on the human activities; answer the
    following questions:
    a) Identify the existing relationships between main physical and
    human features represented on the map.
    b) Discuss the existing relationships between main physical and human
    features available in the environment around your school and your village.
    Physical aspect of an area plays a key role in the activities people do. It also has
    an influence on the number of people who settle in an area. For instance, the
    relief affects human activities in the following ways:
    ── Mountainous places are less populated because of steep slopes being
    unfavorable for settlement and for mechanized agriculture. Such
    landscape makes the establishment of social facilities (hospitals,
    schools, shopping centers) in such places to be difficult.
    ── Places that are poorly drained like swamps and marshes are also
    not suitable for settlement because they do not favour activities like
    agriculture, transport etc. that most people rely on for survival.
    ── Some plains and plateaus have good soils. These allow growing of
    crops and keeping of livestock. It is also possible to use machines
    in farming. Therefore, more food is produced, and more people live
    there.
    ── The depressions or valleys areas are also suitable for agriculture since
    they contain fertility brought by depositions from the surrounding
    high altitude areas.
    ── Fishing is developed in areas that have seas, oceans and lakes.

    3.3.1. Drainage patterns
    A drainage pattern is a network formed by rivers and their tributaries on the
    landscape. The development of the drainage patterns is influenced by the
    gradient of the slope, nature of the bedrock in terms of hardness, structure of
    the basement rock. The drainage pattern can also result from human activities
    which may change the original patterns.
    The some examples of drainage patterns which can be seen on a topographic
    map/photograph are as follows:
    ─ Trellised drainage pattern: Such patterns are developed in simple
    folds characterized by parallel anticlinal ridges alternated by parallel

    synclinal valleys.

    ─ Dendritic drainage pattern: The dendritic pattern is associated
    with the areas of similar lithology, horizontal or very gently dipping
    strata, and rolling extensive topographic surface having extremely

    low reliefs.

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    3.3.2. Settlement patterns
    Settlement refers to a place where people live. It also means the process of
    settling in such a place. The settlement patterns of a given area are influenced
    by both physical and human factors like topography, road network, community
    services, cultural and economic factors, etc. This results into several types of
    settlement patterns as follows:

    • Nucleated settlement:     This refers to the grouping of many houses
    around a center called nucleus; often around a central feature like
    a church or a pub. Houses are built close to each other. This type of
    settlement is mainly influenced by cultural and social factors. For

    example, the houses in “imidugudu” settlements may have such pattern.

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    • Linear settlement: This is where houses are well planned. They are

    built along the road, railway and river or along the coast.

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    Linear settlement
    • Sparse or scattered or dispersed settlements: The settlement
    associated with houses which spread out over a wide area (houses are
    built far from each other). They are often the homes of farmers and can

    be found in rural and mountainous areas.

    E

    Scattered settlements
    • Isolated settlement: This is where a few people live away from other
    people. These people could be hunters in a forest.
    • Ring settlement: In this type of settlement, houses make a circle.

    There is an open ground at the center.

    S

    • Planned settlement: This type of settlement is well organized and

    planned in specific ways as directed for instance by the government.

    A

    3.3.3. Vegetation
    Human activities are related to vegetation. The distribution of vegetation on a
    photograph/map in each area is linked with human activities taking place in that
    part/dwelling. Below are some of the examples that show the interrelationship
    between man and vegetation:
    • In areas with dense forests: The main activities are timber harvesting.

    The timber is used to make furniture and paper.

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    • In savannah grasslands: The main activities are livestock keeping

    and agriculture. This is because in these areas soils are fertile.

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    • Desert vegetation: Agriculture is only possible in oases. Very few
    animals can survive in the dry areas like the camels, goats and sheep

    and reared under nomadic pastoralism.

    C

    • In tundra and taiga forests: The low rainfall and temperature affect
    human activities. Only hunting, fishing and mining are the main

    activities done in these regions.

    F

    3.3.4. Communication networks
    Communication networks facilitate the movement of people and commodities
    from one place to another over a given distance. Communication networks may
    also refer to the physical facilities which help the transmission of information
    in the form of news and messages. The communication networks represented
    on map/photograph are most of time influenced by both physical and human
    factors. Some of them are discussed below:

    •     Relief: Steep slopes make the construction of roads and railway lines
    expensive. On the other hand, valleys have swamps; they contain water
    logged soils that are too soft to allow the movement of heavy objects

    like trailers, lorries and trains.

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    • Climate: Too much rainfall results into floods and landslides and these
    disturb land transport. On the other hand, accumulation of fog and

    clouds reduce visibility hence affecting air transport.

    A

    • Vegetation: Thick vegetation cover makes construction of road and
    rail networks difficult because it requires uprooting big trunks of
    trees. Areas with thick vegetation are invested with wild animals that

    pose danger to the people.

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    • Drainage: Navigable rivers, lakes, seas and oceans provide natural

    route-ways used for transportation.

    C

    • Topography: Mask towers for communication are usually placed on

    the top of mountain

    C

    • Economic activities: The economic activities (mining, agriculture,
    industries, etc) taking place in given areas influence the construct of

    communication networks.

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    Application Activity 3.3
    1. Identify several types of communication networks on any map/
    photograph.
    2. Explain how the identified communication networks are related to
    physical and human features.
    3. Move around your village and identify the existing communication
    networks and explain their relationships with physical and human

    features.

    Skills lab
    Map interpretation is an important skill needed in different areas of life like
    military, land mapping, tourism etc. Use the knowledge you have acquired in
    this unit to draw a sketch map of your school, calculate its area and present

    your findings to the class.

    End unit Assessment
    1. “As it is difficult and costly to reach all parts of the world; the
    photographs and maps help people most especially geographers to
    explore different physical and human features of the earth.”
    a) Identify physical features on topographic map of Rwanda.
    b) Identify the human features on thematic maps of Rwanda.
    2. Show different signs and symbols to be used in representing
    physical and human features on maps/photography.
    3. Examine the relationships existing between settlement patterns
    and physical features in your district and present them on a sketch
    map using signs and symbols.
    4. Take photographs from different places in Rwanda, and prepare
    a sketch map of captured physical and human features by using

    conventional signs and symbols.

    ◄UNIT 2:BEARINGS, DIRECTIONS, DISTANCES AND AREAS ON A MAPUNIT 4:THE UNIVERSE AND THE SOLAR SYSTEM►