Topography and Map Reading for Beginners Pdf

TOPIC 5

MAP READING AND Interpretation

Nosotros have Three Types of Notes for you

Notes 1, Notes 2 and Notes 3

NOTES 1

Definitions of Map

- Map is a diagrammatic representation of an area of land or ocean showing physical features, cities, roads, etc.

- Map is a cartoon of the world'south surface, or part of that surface, showing the shape and position of different countries, political borders, natural features such as rivers and mountains, and artificial features such as roads and buildings.

- Map is a representation commonly on a apartment surface of the whole or a function of an area

- Map is a drawing of a particular area, for instance a city or state, which shows its main features, such as its roads, rivers, mountains etc

- Map is a symbolic depiction emphasizing relationships between elements of some space, such as objects, regions, or themes.

Map of Tanzania

Map reading is the process of identifying features on a map past using symbols and signs or names. This technical work requires certain skills that any map reader must possess.

Map interpretation is the interpretation of the symbols and signs used on map into ordinary language by indicating the features they represent and draw logical conclusions from the information every bit represented by the symbols.

Cartography is the study of making or drawing maps

Cartographer is a person who draws or produces maps

Cartographer

TYPES OF MAPS

According to Functions:

1. Topographical Maps .Are maps which show concrete features which are natural features east.g. mountains, valleys, hills etc and man-made features e.yard. bridges, ponds, roads, settlements etc

two. Statistical Maps . Are maps which show the distribution of things in quantitative manner e.k. distribution of rainfall, temperature, crops etc.. Examples of statistical maps are dot maps, choroploth maps, Isoline maps etc

1. Large scale maps . Are those maps fatigued to large scale size e.grand. 1:10000 These maps gives a larger representation of minor area, they are also more detailed (shows a lot of data). They represent areas like cities, towns and villages.

2. Medium Calibration Maps . Are those maps fatigued to medium calibration size e.one thousand. ane:100000 They show a moderate amount of details. They represent areas similar districts, regions and countries.

3. Small-scale scale maps Are those maps drawn to small scale size e.grand. 1:meg They give a small presentation of a big area; they show little content (little information) They represent areas like continents and the earth.

Topographical Map

Importance of Map Reading

1. They provide footing for description of geographical miracle

2. They are useful for traveling purpose i.e. they guide people to attain their destination

3. Maps are useful for storage of geographical information

iv.They are important for field studies

v. They are important for land use planning

6. They are useful for armed forces purposes e.k. during wars.

ESSENTIAL ELEMENTS OF A MAP

The basic skills required in agreement how to read a map include Title, Scale, Primal, Indication of the north direction, Margin/Boundary and Appointment of compilation.

ane. Tittle  gives the name of the country and the area where mapped. It helps the map reader to know what the map is all well-nigh. The heading is usually printed in bold majuscule used on the map

2. Scale  is a ratio between the distance on the map and actual altitude on the ground. It is used to find bodily altitude and areas on the ground. On topographical maps scales are given in form of ratio or lines

3. Key  / legend is a feature which explains the signs and symbols which are used on the map. Not all symbols which are used in the key are applicable to the particular map just all signs and symbols applied on the map are shown on the key. Definition of terms which should be added on others terms nether the tittle "Basic skills of map reading/Essential elements of a map" are " margins/Bounder

4. Indication of north direction . Information technology gives an idea near the orientation of the map specially in identifying where the north direction is.

5. Margin /Boundary. A frame which borders the map. This guide and limit the map user in reading and interpreting the map. The aim of the margin is to enclose the area covered by the map

6. Appointment of compilation . Gives the publisher name and when the map was published. This date is important because physical and human settlements features changes with time only the map drawn representing the land does not. For instance between 1960 and 2007 Dar es salaam has inverse in many ways.

Areas of Regular and Irregular Figures

The figures whose areas are to exist calculated on maps can either be regular or irregular

In map reading, position is a place where an object is situated on the globe'southward surface. The geographic position of a place may be shown by using:

1. Place names
2. Compass begetting
3. Latitude and longitude
4. Grid reference
5. Political and administrative boundaries

Direction and Bearing of Object on Maps

The begetting of a lace on a map can be found when the north is given. The North is normally an pointer sign pointing to the due north.

Example v

Notice the bearing of point B from betoken A.

Procedures

1. Bring together points B and A with a direct line.
2. At point A, depict a line parallel to the north-south line.
3. Using a protractor, mensurate the angle B from the north towards line BA as shown below.

READING AND INTERPRETING TOPOGRAPHICAL MAPS

Topographical maps are types of maps which describe the physical (natural) and man-made (artificial or cultural) features of a given area. The physical features include relief, vegetation, and drainage, among others. Some of the cultural or bogus features are roads, railways, cities, towns, dams, schools, and many other structures built by human being.

1. DRAINAGE

Drainage

 is the plan or layout of the river with its tributaries until it reaches its destination i.e. lake, main river, swamps or an ocean, therefore the concept drainage includes rivers , swamps, lakes, waterfalls ,flood areas

Note

: The common drainage shown on the map is rivers, swamps, lakes and ocean. Merely await to see even waterfalls especially on coloured topographical map.

DRAINAGE PATTERNS

This is the programme or layout of the river with its tributaries, or the network displayed by a river and its tributaries. Drainage of the river usually posses different network/organisation depending on the style how tributaries convey to the master river and the general appearance, hence drainage design

Types of Drainage Patterns

The following Patterns are Commonly Displayed in Topographical Maps:

1. Dendritic Pattern

Is a design in which its tributaries convey (bring together) to the principal river at an acute angle resembling to the shape of tree trunk and its branches. Dendritic design are common in areas of gentle gradient and of uniform (homogeneous) rock hardness. Therefore it can be made from granitic or metamorphic rock

Dendritic Design

ii. Trellised Pattern

Is the design in which its tributaries convey or bring together to the main river at almost right angle. This blazon is unremarkably found in areas with astringent cracks or fractures more often than not to the rocks with an alternating hard and soft rock. Therefore this is associated with sedimentary rocks.

Trellised Pattern

3. Radial Pattern

Is the pattern or layout in which its tributaries flow outward from the center (tiptop) or at the peaks of mountains. Its pattern resemble a spoken band of bicycles where stream menstruum out in every direction from the center. Therefore radial drainage design is unremarkably associated with volcanic mountains /region composed of granitic stone or igneous rock

Radial Blueprint

four. Centripetal Pattern

Is the blueprint in which almost all streams are following from all direction converging to the heart can be to the swamp, lake or depression. The determinant factor of stream menstruation is a slope .Therefore the drainage blueprint tin can be associated with sedimentary rock.

Centripetal Pattern

five. Rectangular Pattern

Is a pattern which resemble trellised, but it has tributaries joining the main river at a right angle. The design is common in areas which are faulted.Therefore can be institute along sedimentary rocks/granitic rock or whatever faulted rock.

Rectangular Design

6. Annular Pattern

Is the blueprint with series of streams flowing on flanks or around the dissected dome, depression or crater. Where there are an alternate band of soft and difficult rocks. Notation: This type is not and so common, but is plant around Lake Bosumtwi in Ghana .Is usually found in areas affected past back tilting.

Annular Pattern

7. Parallel Drainage Pattern

This consists of a serial of streams running parallel to 1 some other. In some cases, streams may flow into one large river. It is common in areas of uniformly dipping rocks such as fault scarps or recently emerged coasts. Rivers Athi, Nairobi, Ruiru, Chania, Thika and Sagana in Republic of kenya.

Parallel Drainage Design

2. ROCK Blazon / STRUCTURE

The surface stone on the topographical maps is not direct indicated. They some clues are needed in lodge to identify rock type and structure of the mapped surface area.

The Indicators Used to Testify the Blazon of Rock presented in a sure Area :

1. LAND FORMS

State forms shown on the topographical maps aid on interpretation of rock type for example:

a) The presence of volcanic state form such; crater, caldera, proper noun of the volcanic mountains suggest the presence of igneous rock .

b) The presence of erosion and depositional features such as depression, sand dunes, coral reef suggest the presence of sedimentary stone. Inundation plain suggests sedimentary rock .

c) The presence of highland with steep slope indicated that rock are hard and resistance stone that may indicate presence of metamorphic stone .

Rocks

two. VEGETATION

a)Thick forest suggests the presence of igneous stone .

b)Poor vegetation embrace suggests the presence of sedimentary rocks or metamorphic rock.

c)Nature of the stone. Absence of streams indicates that the rocks are permeable. Thus this depict that the rock is soft which can either be sedimentary , limestone or sandstone.

d) Presence of many streams on surface, indicate that the stone are impermeable such equally igneous  or granitic rock.

Vegetation

3. RELIEF

Read the contour and the conventional symbols or signs on the map to identify types of relief. Can either be highland relief with lower arts or lowland relief. Describe the relief with associated state forms. When you make up one's mind types of relief offset await on the units on vertical interval (5.I) whether the unit of measurement is in meters or feet. If units are in feet take the highest value the convent into meter finally determine type of relief (1m=3.3ft)

Relief

4. CLIMATE

Climate is the average weather condition experience in a given area over a long flow of fourth dimension non less than 30 years. Topographical maps may be used to identify the climate of given mapped area. Some hints used in interpreting climate from topographic map Breadth of the area.

a)Altitude from equatorused to decide kind of climate of a certain area. For example the area with latitude v degrees northward or south of equator the expanse is considered to exist in equatorial climatic status while the area between five to 15 N/S is in tropical climatic status, 15-30 Due north/S of the equator imply Semidesert thirty-40 North/S implies desert climate or Mediterranean climate.

b)H2o bodies. a general loftier density of streams indicates that the surface area receives high rainfall, presence of low density or seasonal streams, salt lakes and boreholes indicate aridity .

c)Vegetation, presence of forest in the map indicates heavy rainfall while woodland vegetation indicates moderate rainfall. shrubs, thickets and grassland bespeak dry condition  or light rainfall Crops, crops abound in those areas where water and temperature conditions are favorable for their growth. For example area with tea, coffee and carbohydrate pikestaff bespeak that area receives heavy rainfall .

Crops

 such as cotton, sisal and sorghum indicate medium rainfall Relief/altitude, altitude of features such as high mount or mountain ranges and plateaus tend to take orographic rainfall and woods making them makes their own mountainous climate . Mountains do likewise create their own climate due to effect of aspect which creates rain shadow.

Climate

5. Human being ACTIVITIES

Topographical map may contain data on economical activities undertaking usually the post-obit are shown on topo maps.

ane. Agriculture : look on the presence of Rural settlement in absence of other activities scattered tillage storage houses/center plantation or estate (point large calibration agriculture) industry such as Ginneres, Hulleries and Decotecator. seldom symbols or signs are used eastward.g. S-sisal, CC-coffee, Su-sugarcane

Agriculture

2. Pastoralism : wait on the presence of cattle market-cattle dips veterinary installation (Vet. Office)/center Creamers (lace where milk, foam butter and cheese are processed Scattered vegetation or dominated by scrub/shrubs) Bore holes (Bore holes (BH) or water hole (wh)

Pastoralism

3. Mining : look on the presence of; symbols of Movie () and shovel (common salt piece of work quarrying Roasting Sign Tin-TN, Atomic number 26-Fe.

Mining

4. Fishing : look on the presence of; water bodies such as lakes, seasonal swamps, rivers, dams, ocean. These should be surrounded by settlement.

Fishing

v. Trade and  Transportation ; look on the presence of Road, railway, towns and market

Trade and  Transportation

6. Lumbering ; look on the presence of; forest with track-roads catastrophe on their edges. Saw-mill Sao hill forest -Note: thicket, scrubs/shrubs and bamboo copse cannot be exploited as a timber.

Lumbering

vii. Tourism : wait on the presence of; National parks, Game reserve Recreational centre's east.g. museum, archives beaches etc Mural e.g. crater depression etc.

Tourism

8. Administration : Various administrative activities can be identified from abbreviations on the map. These are given in a list in the margin of the map. They include:

a) Provision of security as evidenced by the presence of a Police Station or Police Post

b) Judicial services as evidenced by the presence of courthouse

c) Other authoritative offices such as District Commissioner (DC)

d) Regional Commissioner (RC).

Administration

6: SETTLEMENT

A settlement is a place where people live. It may be every bit small equally single house in a remote area or as large as a mega city.

Types of Settlement

There are 2 types of settlements which include, urban settlement and rural settlement.

a) Urban Settlement; Is commonly constitute in areas of District authoritative centers, Regional administrative centers, and Capital urban center of a country.

b) Rural Settlement; Is an expanse where the majority of people approximately to cover lxxx% engage in agriculture

SETTLEMENT PATTERNS

It is a layout of dwellings in a particular identify. The signs showing settlements on topographical maps are observed to take varied organisation. The most mutual pattern include the following:

ane. Dispersed Settlement Design : It is alternatively called scattered settlement pattern. The houses are widely spaced one to another

Dispersed Settlement Design

2. Nucleated Settlement Pattern : Houses and other related course are compacted to some other.

Nucleated Settlement Blueprint

three. Linear Settlement Blueprint : Houses are concentrated along an elongated objected of economic significance similar a route, river, railway lines and others

Linear Settlement Pattern

Factors Encouraging Settlements

1. A reliable source of water supply due east.g. presence of permanent rivers, lakes.

ii. Gentle gradient i.e. people adopt to establish settlement in less hazardous areas

iii. Skilful soil for agriculture

iv. Pleasant climate condition

5. Ship and communication.

Means OF SHOWING POSITION ON A MAP

A place can be located past its proper name where it is constitute. A more than accurate style of locating a place is the use of latitudes and longitudes, this method is used by scalars at sea and shipping in their flights. Generally position of any place tin be located by using;

- Place names

- Bearing

- Latitudes and longitudes

- Filigree reference

Methods of Showing Relief on Topographical Map

i. Contour Lines

These are lines drawn on topographical maps to join all places or areas with the equal height or mental attitude from the mean body of water level. Contour are very important in determining relief features whether the relief is steep sided or gentle sloping. This measurement of heights shown by contour lines starts from the mean ocean level which is regarded as nada height.

Profile Lines

ii. Trigonometric Station

This is a point on a map with its exact height stock-still commonly on a hill height, mount peak or other visible positions. They are the highest points on any locality. The trigonometrical points are commonly marked by a triangle followed by the numbers indicating the height for example Δ725

Trigonometric Station

3. Spot Height

Spot height is a betoken on a map with its exact top to a higher place a known level e.g. from the

bounding main level. The position and summit of the points have been determined past surveyors. The spot pinnacle is marked with a dot followed by the numbers indicating height of the land for instance .750

Spot Elevation

4. Layer coloring /  Tinting

Is besides done to testify the relief features on the map, unlike coloring shades on the map to indicate unlike heights

Layer coloring /  Tinting

5. Hachures

Huchures are short, broken lines drawn on a relief map showing direction and steepness of a slope

Huchures

6 .  Grade Lines

Form lines are unremarkably unnumbered lines fatigued on a map joining of about the same height areas, Are broken lines fatigued between ii contour lines

Form Lines

Relief Features on Topographical Maps

1. Ridge . Ridge is a narrow and long relief feature with steep slopes on all sides.

Ridge

2. Escarpmen t

An escarpment is an area of highland with very steep slopes on one side and a gentle slope on another side. The steep slope of an escarpment is chosen the scarp gradient and the gentle gradient is known every bit dip slope.

Escarpment

three. Plateau

A plateau is an extensive highland region and whose top surface is almost flat. A plateau is easily identified on the map past the absence of profile lines on the higher land surface and with a serial of contours shut together on either sides.

Plateau

4. Slopes

A slope the inclination or slant of the state. This inclination varies considerably, resulting in the following types of slopes A concave slope are widely spaced at the lower ground and closely spaced at the higher ground. A convex slope on the other hand has a steep slope at the lower ground and a gentle slope at the college footing. Contours of this slope are closely spaced at the lower footing and widely spaced at the higher ground. However some slopes behave both characteristics, a concave slope is gentle at the lower ground and gets steeper at the college ground.

Slopes

5. Col .A Col is the country betwixt ii peaks of a mountain or in the mountain ranges.

Col

six. Saddle  (laissez passer). A saddle is generally wider than a col. Saddles provide user-friendly passages beyond mount ranges. Contours showing peaks are usually closed.

Saddle

6. Valley . Valley is the depression lying part of the land which is bound over higher ground and steep slope. Valleys are indicated by contours forming '5' shape pointing the higher ground and some valleys take rivers flowing in them.

Valley

7. Spur . Spur (Salient) is a project of the raised land from the side of a hill or mountain into lowland, contours showing a spur form a 'V' shape pointing to the lower ground.

Spur

8. Hills / peaks .  A colina is a rounded upland surface area not as loftier as a mountain. Hills rises above the general relative depression ground just less than a mountain. Colina top is usually about 350m-650m. Some hills are regular while others are irregular.

Hills

9. Cliff

A cliff is described as a steep rock face up that is vertical or nearly vertical. Cliffs are mutual in mountainous or hilly areas and forth the shores of lakes and seas. On topographical maps, cliffs are shown by contours that are so closely packed that they appear to merge into one some other. To emphasize the presence of the cliff, a special symbol is drawn on acme of the contours as shown in the effigy beneath.

Cliff

10. Plain

A patently is a continuous tract of relatively flat land covering a wide area of lowland. Some plains may be raised but the slopes are very gentle. Plains occur as lowlands and at the bottoms of valleys but also on plateaus or uplands at high elevations. On topographical maps, a plain is shown by contours that are very widely spaced. Some rivers, if present, may exist seen to take meanders.

Plainly

11. Depression .

A depression on a contour map is shown by contour lines with small marks pointing towards the lowest point of the depression. The first contour line with the low marks and the contour line outside it have the same elevation.

Depression

12. Mount . This refers to the upland or highland over 1000m from the mean sea level

Mountain

CROSS Department

This used to show variation of relief across a region. The post-obit stages are followed in drawing cross section:

1. Two stop points of the area in question are marked AB

2. Join the two points with directly line by a pencil

3. Take a slice of paper measure from betoken A to B

4. A vertical scale is now required after marking the values of contours on the paper.The horizontal calibration of the cross section is in the same calibration as that of the map from which the line AB is taken. The highest contour line on the map is 100m

5. The horizontal base line represents sea-level; the marked paper is placed along the base line so that A on the newspaper falls on A on the scale. Then each profile forth the horizontal line is marked with a pencil and ruler, vertical lines are lightly drawn up to the line which represents the contour tiptop.

VERTICAL EXAGGERATION

Vertical Exaggeration (Five.East) is a number of times by which the vertical calibration is larger than the horizontal scale. In Mathematics 5.East expressed, V.E=(Horizontal calibration (HS) /(Vertical scale (VS)) Horizontal scale is the map scale/basis scale Both HS and VS should be the same units of measurements when computing VE For example

if a map scale were 1cm to 100000cm and the vertical 1cm to 100m, the

VE is showtime converted from 100m to cm VE = 100000cm/10000cm VE=10cm

INTER VISIBILITY

In reading the map it is important to know from a map whether 1 place is visible from another or not. In cross section two places A and B were to represent 2 observation points conditions the two places are inter visible or not. To explain inter visibility we await in the cantankerous section if between the points (A to B) a mountain or hill develops nosotros say the 2 points are not inter visible considering the hill is an obstruction When the basin of depression develops we say the inter visibility, as a line of sight when drawn straight i.e. not obstructed But inter visibility can be affected by other factors such as buildings, vegetation etc.

GRADIENT

Gradient is the term refers to the measure of slope. Gradient/ gradient are measured by comparing vertical distance to the horizontal distance. In map reading the adding of slope is done by comparing the vertical interval betwixt 2 places and the horizontal distance betwixt them.

Vertical Interval

 (5.I) is the difference in height between the two places; it tin be obtained past subtracting the altitude of the lower point from the altitude of the higher point. V.I = highest contour

Lowest Contour

 The horizontal distance is measured on the map then it is converted into ground distance by the apply of the map scale In calculating gradient both vertical and horizontal lengths must be brought to the same unit of length The formula for slope Gradient =(Vertical interval ) / ( Horizontal altitude)

Calculating Gradient

Example: Given; highest profile 700, everyman contour 300

V.I = 400m Length from point A to B is 8.4 cm Scale of map 1cm to 2km Calculate the gradient

Solution

Step one: Change eight.4cm into ground /map scale 1cm to 2km 8.4cm to x =xvi.8km

Step 2: Change the ground scale into meters 1km =1000m sixteen.8km =? =16800m

Step 3: Slope=(Vertical interval (5.I))/(Horizontal altitude (H.D)) = 400m/16800mSlope= i/42

NOTES 2

Click Here to get a full view of the notes seen below

mooreandescols.blogspot.com

Source: https://www.msomibora.com/2018/04/geography-form-three-topic-5-map.html

Share this post