Chapter 5: Map of India

In 1866 oil was struck at Digboi, in the far north-east of the country. It is the oldest oil field in India and it has been running from that year onward. Much later, a second field was opened in a place with no ground at all — Mumbai High, an offshore field lying 176 km north-west of Mumbai, out in the Arabian Sea. There the oil sits below the sea floor and the field has no coastline of its own to stand on. Now put both of them on a map of India drawn to a scale of 1:20,000,000, the scale used on the maps in this chapter. At that scale one centimetre on the page stands for 200 km on the ground. Digboi becomes a single dot near the eastern edge of the sheet. Mumbai High becomes a dot floating in open sea, held in position only by its distance from a city. Place either dot a centimetre out and you have shifted an oil field 200 km. That is what map work asks of you. Not remembering a name, but putting it in the right place on a blank outline.

Map

Map 5.A1 Caption: Two oil fields, one on land and one at sea, placed on a map of India. Brief: Outline map of India showing the full extent of India as officially defined; mark Digboi in the north-east and Mumbai High offshore in the Arabian Sea, each as a labelled dot; show the Tropic of Cancer as a broken line and print the scale bar for 1:20,000,000; no other minerals, cities, rivers or shading to be shown.

Curiosity Corner

Q1. Why does one line of longitude drawn near Prayagraj set the time on every clock in India? Q2. Rain reaches Kerala at the start of June but the north-west only by the middle of July. What is moving across the map in those six weeks? Q3. The Coromandel Coast gets its rain when much of India is drying out. Where does that rain come from? Q4. Why is the Kosi called the ‘Sorrow of Bihar’? Each of these is answered somewhere in this chapter, and each answer is a mark you will be able to make on a blank outline of India.

5.1 Mountains, Peaks, Passes, Plateaus

This chapter works through a set of maps of India, one theme at a time. Each of them is a model of a map-filling exercise: what you are shown here is what you will later be asked to draw, shade and name on a blank outline. The first of them carries the country’s relief — its high ground and the gaps through it.

Four kinds of feature share this one map, and it helps to be clear about each before you start marking. A range is a long line of mountains running as a chain, drawn here as a single dark line. A peak is one named summit within such a chain, marked by a triangle with its height in metres beside it. A pass is a low gap through a range, the point where crossing it is possible, and it carries its own symbol. A plateau is a raised block of land with a broadly level top, and on this map the plateaus are picked out in yellow.

Map

Map 5.1 Caption: The ranges, peaks, passes and plateaus of India, drawn at a scale of 1:20,000,000. Brief: Map of India showing the full extent of India as officially defined; mark the mountain ranges as dark lines, the named peaks as triangles with heights in metres, the Karakoram Pass with a pass symbol and the plateaus in yellow shading; label Himalayas, Karakoram Range, Hindu Kush, Aravali Range, Vindhya Range, Satpura Range, Maikala Range, Mahadeo Hills, Kaimur Hills, Balaghat Range, Gir Range, Western Ghats, Eastern Ghats, Nilgiris, Anaimalai Hills, Patkai Bum, Garo, Khasi and Jaintia Hills, Naga Hills, Mizo Hills, Deccan Plateau, Chota Nagpur Plateau, Plain of the Ganga, Rann of Kutch, Kathiawar, Cape Comorin, the coastal strips and the Tropic of Cancer; index box for range, peak, pass and plateau, and a scale bar for 1:20,000,000.

Read It

Map 5.1 Lines mark ranges, triangles mark peaks with heights in metres, a small gate symbol marks a pass, and yellow marks plateaus. The pattern reads at a glance: ranges rim the north and the two coasts, plateaus fill the middle of the peninsula. What the map cannot give you is relief. One line for a range says nothing about how wide it is or how steeply its sides fall.

The Mountain Wall In The North

The Himalayas form an arc which covers a distance of about 2,400 km. They run in a west-east direction, from the Indus to the Brahmaputra, and the two rivers are the honest way to fix the ends of the chain in your memory. North-west of them lies the Karakoram Range, carrying the highest ground in the country, and the Karakoram Pass is the gap through it.

These are the mountain features you must be able to locate, mark and name on an outline map. (a) The Himalayas, the arc of ranges lying right across the north of the country. (b) The Karakoram Range, north-west of the Himalayas, with the Karakoram Pass cutting through it. (c) The Aravalli, a range running across the west of the country, well away from the northern arc. (d) The Vindhyas, running roughly east to west across central India, just north of the Narmada. (e) The Satpura, lying immediately south of the Narmada and running parallel to the Vindhyas. (f) The Western Ghats, running down the western edge of the peninsula close to the coast. (g) The Eastern Ghats, running down the eastern edge in a broken line rather than a continuous wall. (h) The Nilgiris, in the south, where the Western and the Eastern Ghats come together. (i) The Khasi hills, in the north-east, south of the Brahmaputra and beside the Garo and Jaintia hills.

Two peaks are named for marking, and both are labelled on Map 5.1 with their heights. Mount Godwin Austin, better known as K2, stands at 8611 m in the Karakoram, and Mount Kanchenjunga stands at 8586 m in the eastern Himalayas. The map also labels Nanga Parbat at 8126 m and Nanda Devi at 7816 m, so read the triangles carefully and do not mark the wrong summit.

The Plateaus Of The South

Two plateaus are shaded on the map, and the flowchart below sets out how the whole map divides. The Deccan Plateau is a triangular landmass that lies to the south of the river Narmada, which means the river is the line you use to find its northern edge. The Chota Nagpur Plateau lies further east and is rich in mineral resources, a fact that will matter again when minerals are mapped later in this chapter.

Flowchart

Fig. 5.A1 Caption: The relief features on this map divide into four kinds, each with its own symbol. Nodes: Relief features on Map 5.1 → mountain ranges / peaks / passes / plateaus; mountain ranges → Himalayas, Karakoram, Aravalli, Vindhyas, Satpura, Western Ghats, Eastern Ghats, Nilgiris; peaks → K2 (Mount Godwin Austin), Kanchenjunga; passes → Karakoram Pass; plateaus → Deccan Plateau, Chota Nagpur Plateau

Working With The Scale

The scale printed on this map is what turns a distance on the page into a distance on the ground, and it works in both directions.

Worked Case

WC 5.A1 — The Himalayan Arc At 1:20,000,000 The situation: This chapter states that the Himalayan arc covers about 2,400 km from the Indus to the Brahmaputra, and Map 5.1 is drawn to a scale of 1:20,000,000. The working: A scale of 1:20,000,000 means one unit of length on the map stands for 20,000,000 of the same units on the ground, so both distances must first be put in the same unit. \[\text{Map distance} = \frac{\text{Ground distance}}{\text{Scale denominator}}\] Here the ground distance is 2,400 km, the scale denominator is 20,000,000, and the map distance comes out in centimetres. Converting the ground distance: \[2{,}400 \text{ km} = 2{,}400 \times 100{,}000 = 240{,}000{,}000 \text{ cm}\] Dividing by the scale denominator: \[\frac{240{,}000{,}000}{20{,}000{,}000} = 12 \text{ cm}\]

Twelve centimetres is about the span of an open hand. The entire northern mountain wall of India, from one great river to the other, occupies roughly that much of the page — and every peak and pass named on it has to be fitted inside that span. At this scale K2 and the Karakoram Pass sit only a few millimetres apart, which is why marking them is a test of care rather than of memory.

5.2 Plains, Desert

The second map turns from high ground to low. A plain is a stretch of land that is broadly flat and lies at a low level, so on a map it is shown by shading rather than by a line — a plain covers an area, while a range runs along one. Two kinds of shading appear here, one for the Gangetic Plains and one for the coastal plains, and the Thar is marked separately in the west.

Map

Map 5.2 Caption: The Gangetic Plains, the coastal plains and the Thar desert, drawn at a scale of 1:20,000,000. Brief: Map of India showing the full extent of India as officially defined; shade the Gangetic Plains in one tint and the western and eastern coastal plains in a second, contrasting tint; label the Thar (Great Indian Desert) in the west, and name Konkan, Kanara, Malabar Coast, Coromandel Coast and Northern Circars along the two coasts; show the drainage lines and the Tropic of Cancer faintly for reference, with an index box naming the two shadings and a scale bar for 1:20,000,000.

The Plain Across The North

The Gangetic Plains are spread over the states of North India — Haryana, Delhi, Uttar Pradesh, Bihar, partly Jharkhand and West Bengal. Named that way, the shaded band on the map stops being a shape and becomes a list of places you can already point to. It is the widest continuous stretch of low, level land in the country, and it is the belt through which the Ganga and its tributaries run.

Read It

Map 5.2 Two shadings only: one band across the north for the Gangetic Plains, one narrow strip down each coast for the coastal plains. The pattern to hold on to is that low land rims the peninsula and fills the north. The shading shows where a plain is, not what its surface is made of, how it slopes, or how thick the material beneath it is.

The Two Coastal Strips

A coastal plain is squeezed between the sea on one side and higher ground on the other, and India has one on each coast. The Western Coastal Plains stretch from the Arabian Sea to the Western Ghats, while the Eastern Coastal Plains lie between the Bay of Bengal and the Eastern Ghats. Each is therefore bounded by water on the outside and by a wall of hills on the inside, which is why both appear on the map as long, thin ribbons rather than broad areas.

Each strip is divided into named stretches, and the divisions run in order from north to south. (a) The Konkan is the northern part of the Western Coastal Plains. (b) The Kanara is the central stretch of the same western plain, lying below the Konkan. (c) The Malabar is the southern part of the Western Coastal Plains. (d) The Northern Circars is the northern part of the Eastern Coastal Plains. (e) The Coromandel Coast is the southern part of the eastern plain, running down to the tip of the peninsula.

Flowchart

Fig. 5.A2 Caption: The plains of India divide first by position and then by named stretch. Nodes: Plains of India → Gangetic Plains / Coastal Plains; Gangetic Plains → Haryana, Delhi, Uttar Pradesh, Bihar, partly Jharkhand and West Bengal; Coastal Plains → Western Coastal Plains / Eastern Coastal Plains; Western Coastal Plains → Konkan (north) → Kanara (centre) → Malabar (south); Eastern Coastal Plains → Northern Circars (north) → Coromandel Coast (south)

The Desert In The West

One desert is named for marking on this map: the Thar, also called the Great Indian Desert, lying in the west of the country. It is the one large area on the sheet where the shading of plains gives way to a labelled name rather than a tint, so on an outline map you mark it by writing the name in the correct position rather than by shading a boundary you cannot see.

5.3 Rivers And Water Bodies

The third map carries the country’s drainage together with the seas, gulfs, straits and lakes around and within it. Rivers on this map are to be identified rather than drawn from memory: the lines are already printed on the outline, and your task is to recognise which line is which and name it correctly.

Map

Map 5.3 Caption: The rivers of India and the water bodies around it, drawn at a scale of 1:20,000,000. Brief: Map of India showing the full extent of India as officially defined; draw the drainage lines and label Indus, Shyok, Jhelum, Chenab, Ravi, Beas, Sutlej, Ganga, Yamuna, Gomti, Ghagra, Gandak, Kosi, Son, Chambal, Betwa, Damodar, Brahmaputra, Narmada, Tapti, Mahanadi, Godavari, Tungabhadra, Krishna and Cauveri; label Wular Lake and Chilka Lake, and name the Gulf of Kutch, Gulf of Khambhat, Gulf of Mannar, Palk Strait, Arabian Sea, Bay of Bengal, Lakshadweep Sea and Andaman Sea; show the Tropic of Cancer and a scale bar for 1:20,000,000.

Read It

Map 5.3 Trace a river as one continuous line from the high ground where it starts to the sea where it ends, and name it at the mouth where the line is thickest and least crowded. The pattern is that the northern rivers run in wide bends while the peninsular ones run straighter. The line does not tell you how much water is in it, or that most of it arrives in four months.

Two Families Of Rivers

The Indian rivers are divided into two groups, and the division is worth learning because it sorts a long list into two short ones. The Himalayan rivers include the Indus, the Ganga and the Brahmaputra along with their tributaries — a tributary is a smaller river that joins a larger one instead of reaching the sea itself. The Peninsular rivers include the Narmada, the Tapti, the Godavari, the Krishna, the Mahanadi, the Cauveri and other small rivers with their tributaries.

Flowchart

Fig. 5.A3 Caption: The rivers named for identification sort into two groups, each with its own main streams. Nodes: Indian rivers → Himalayan rivers / Peninsular rivers; Himalayan rivers → Indus → Jhelum, Chenab, Ravi, Beas, Sutlej; Himalayan rivers → Ganga → Yamuna → Chambal, Betwa; Ganga → Ghagra, Gomti, Gandak, Kosi; Himalayan rivers → Brahmaputra; Peninsular rivers → Narmada, Tapti, Mahanadi, Godavari, Krishna, Cauveri

When A River Floods

A river collects its water from the whole area of land that slopes towards it, and that area is its catchment area. The large catchment area of these rivers and the seasonal monsoon rains together lead to flooding, because a great deal of water is gathered from a wide area and delivered in a short part of the year. Two rivers carry names earned that way: the Kosi is known as ‘Sorrow of Bihar’, while the river Damodar is ‘Sorrow of Bengal’.

Curiosity Corner

Q4. Why is the Kosi called the ‘Sorrow of Bihar’?

A. Because it floods the land it crosses. Its catchment is large and the monsoon delivers the rain in a few months, so the river takes in more water than its channel can hold and spills across the plain. The Damodar earns the matching name in Bengal.

Gulfs, Straits And Lakes

Two terms need pinning down before the water bodies can be marked. A gulf is a large area of sea or ocean partially enclosed by land, so it is water reaching into the coast. A strait is a narrow channel of water that lies between two land masses, so it is water separating two coasts; the Palk Strait is a strait between Tamil Nadu and Sri Lanka. The one is an inlet, the other a gap, and both are named on this map.

Two lakes are labelled, and they differ in the water they hold. Chilka Lake is the largest salt water lake in India and falls in the category of brackish water lakes, which means water saltier than a river’s but less salty than the open sea. Wular Lake is a fresh water lake, in the Bandipora district in Jammu and Kashmir.

These are the water bodies you must be able to locate, mark and name on an outline map. (a) The Gulf of Kutch, on the western coast in the north-west. (b) The Gulf of Khambhat, on the same western coast, south-east of the Gulf of Kutch. (c) The Gulf of Mannar, at the southern end of the country, on the side facing Sri Lanka. (d) The Palk Strait, immediately north of the Gulf of Mannar, between Tamil Nadu and Sri Lanka. (e) The Andaman Sea, in the east, on the far side of the Andaman and Nicobar Islands. (f) Wular Lake, in the far north, in the Bandipora district in Jammu and Kashmir.

5.4 Latitude And Longitude

This map carries no relief, no drainage and no shading. It carries lines — and only two of them have to be identified, drawn and numbered on an outline map. A latitude is a line running east to west, measuring how far a place lies north or south of the equator. A longitude, or meridian, runs north to south from pole to pole, measuring how far a place lies east or west of the 0° line. On this map the meridians are the straight lines running down the sheet, and one latitude is drawn as a broken line across it.

Map

Map 5.4 Caption: The Tropic of Cancer and the Standard Meridian, drawn at a scale of 1:20,000,000. Brief: Map of India showing the full extent of India as officially defined; draw the meridians as straight lines running down the sheet and the Tropic of Cancer as a broken line across it; label the Standard Meridian (82°30’ E) along its line and mark Prayagraj (Allahabad) with a dot beside it; name the Arabian Sea, Bay of Bengal and Andaman Sea, and print a scale bar for 1:20,000,000; no relief, drainage or shading to be shown.

Read It

Map 5.4 The straight lines running top to bottom are meridians and the broken line running across is the Tropic of Cancer; the labelled meridian is India’s Standard Meridian. Read the two together and they cross near the middle of the country. What a line of latitude cannot tell you is anything about the land it crosses — its height, its rainfall or its soil. It fixes position, nothing else.

The Tropic Of Cancer

The Tropic of Cancer lies at 23°30’ N, where the 30’ is half a degree, since a degree is divided into sixty minutes of arc. It divides the country into almost two equal parts, which makes it the single most useful reference line on a blank outline: anything you mark can first be judged as lying above it or below it.

It also marks the northernmost limit of the sun’s apparent motion. Through the year the sun appears to shift north and then south again, and this line is as far north as it gets. North of the Tropic of Cancer, therefore, the sun is never directly overhead at any time of year.

The Standard Meridian

The Standard Meridian of India is 82°30’ East longitude. It passes through Mirzapur near Prayagraj (Allahabad) in Uttar Pradesh, and it marks IST — Indian Standard Time — which is 5½ hours ahead of GMT, the time kept on the 0° meridian. A standard meridian is the one line of longitude whose local time a country agrees to use everywhere within it.

Worked Case

WC 5.A2 — From 82°30’ East To Five And A Half Hours The situation: This chapter states that India’s Standard Meridian is 82°30’ E and that Indian Standard Time is 5½ hours ahead of GMT. The two figures are connected, and the arithmetic joins them. The working: The earth turns once through 360° in 24 hours, and 24 hours is 1,440 minutes, so the time difference for one degree of longitude is \[\frac{1{,}440 \text{ minutes}}{360°} = 4 \text{ minutes per degree}\] The standard meridian is 82°30’ E, and since 30’ is half a degree this is 82.5°. Multiplying, \[82.5° \times 4 \text{ minutes} = 330 \text{ minutes}\] Converting minutes to hours, \[\frac{330}{60} = 5 \text{ hours } 30 \text{ minutes}\] The meridian lies east of 0°, so the time there runs ahead of GMT rather than behind it.

The figure 5½ hours is therefore not a rule someone chose; it is the distance of one line from another, measured in time instead of in degrees. And because every clock in the country is set to that one line, a place near the eastern edge of India sees the sun rise well before its clock says the day has begun, while a place in the far west sees it rise well after. One standard time is convenient, but the map is what shows you the difference it papers over.

Curiosity Corner

Q1. Why does one line of longitude drawn near Prayagraj set the time on every clock in India?

A. Because the country keeps one standard time rather than a different local time in every town. The meridian at 82°30’ E is the agreed clock line, and its time, 5½ hours ahead of GMT, is used from the far west of India to the far east.

5.5 Direction Of Monsoon Winds (South West Monsoon)

Every map so far has shown something that stays where it is. This one shows something that moves. A monsoon is a wind system that reverses its direction with the season, and the map records both the direction the summer wind blows and the dates on which it reaches different parts of the country.

The summer monsoon winds blow from the south-west, which is why they are known as the South West Summer Monsoon. The same winds are also called the Advancing Monsoon, because they arrive over the country in stages rather than everywhere at once. The rains they bring last from June to September.

Map

Map 5.5 Caption: The advance of the south west monsoon, with its normal dates of onset and withdrawal. Brief: Map of India showing the full extent of India as officially defined, with international and state boundaries and all states named; draw the south west monsoon winds as bold arrows entering from the Arabian Sea towards the west coast and from the Bay of Bengal towards the north-east and then turning westward along the northern plain; draw the normal dates of onset as one set of lines labelled June 1, June 5, June 10, June 15, July 1, July 11 and July 15, and the normal dates of withdrawal as a separate broken set labelled Sep 1, Sep 15, Oct 1 and Oct 15; index box distinguishing boundaries, onset lines, withdrawal lines and wind arrows, with a scale bar for 1:20,000,000.

Two Branches Of One Wind

The arrows on the map do not all come from the same sea. One set crosses the Arabian Sea and strikes the west coast; the other crosses the Bay of Bengal, reaches the north-east, and then swings westward along the northern plain. These are the Arabian Sea branch and the Bay of Bengal branch of the same south west monsoon, and on an outline map you mark each with an arrow drawn in the direction the wind travels, not merely with a name. Both are moist winds arriving from the sea, and both are moving inland; what separates them is the water they cross and the coast they strike first.

Read It

Map 5.5 One set of lines gives the normal date of onset, the other the normal date of withdrawal, and the arrows give wind direction. Read the onset dates in order and the advance runs from the south towards the north-west. ‘Normal’ means usual, not certain: the map cannot tell you the date in any one year, nor how much rain fell once the wind arrived.

Reading The Dates

Each dated line joins places where the monsoon normally arrives on about the same day, so the lines are a calendar laid over a map. Read them in order and the wind’s progress becomes visible: June 1 on the far south-west coast, then the middle of June across much of the peninsula and the north-east, then July across the north, and July 15 in the north-west.

The withdrawal lines run the other way about. They begin at Sep 1 in the north-west, the last area the monsoon reached, and end in the middle of October in the south of the peninsula. The season is therefore not the same length everywhere, and the two sets of dates together are what show it.

Worked Case

WC 5.A3 — How Long The Advance Takes The situation: Map 5.5 gives June 1 as the normal date of onset in the far south-west and July 15 as the normal date of onset in the north-west, with Sep 1 as the normal date of withdrawal there. The working: Counting the advance from the first date to the last, June has 30 days, so from June 1 to July 1 is \[30 \text{ days}\] and from July 1 to July 15 is a further \[14 \text{ days}\] giving a total advance time of \[30 + 14 = 44 \text{ days}\] which is a little over six weeks. Counting the season in the north-west, from July 15 to Sep 1 is \[16 \text{ days (July)} + 31 \text{ days (August)} + 1 \text{ day} = 48 \text{ days}\] against rains that last from June to September for the country as a whole.

Those two numbers are the point of the map. The same wind system gives the south-west coast a season running from the start of June, and gives the north-west a run of about seven weeks squeezed between a late arrival and an early withdrawal. Marking an arrow on an outline map says only where the wind goes; the dates say how long it stays, and that is what makes the difference from one part of the country to another.

Curiosity Corner

Q2. Rain reaches Kerala at the start of June but the north-west only by the middle of July. What is moving across the map in those six weeks?

A. The monsoon itself. The rain-bearing winds advance inland from the seas in stages, and the dated lines mark where they have reached. Six weeks is the time the advance takes to cross the country.

5.6 Direction Of Monsoon Winds (North East Monsoon)

The previous map showed the wind arriving. This one shows it leaving, and shows what takes its place. Three things are drawn on it: the normal dates on which the monsoon withdraws, the winter winds that blow after it has gone, and a second, quite separate system that reaches India from outside the country.

Map

Map 5.6 Caption: The retreat of the monsoon, the north east winter winds and the western disturbances. Brief: Map of India showing the full extent of India as officially defined; draw the normal dates of withdrawal of the monsoon as a set of lines labelled 1 Sept, 15 Sept, 1 Oct, 15 Oct, 1 Nov, 15 Nov, 1 Dec and 15 Dec; draw the north east monsoon winds as arrows blowing outward from the land towards the seas, including the arrows crossing the Bay of Bengal towards the south-eastern coast; draw the western disturbances as a separate labelled set of arrows entering from the north-west; index box distinguishing the withdrawal lines from the two sets of wind arrows, with the Tropic of Cancer and a scale bar for 1:20,000,000.

Read It

Map 5.6 The lines carry withdrawal dates running from 1 Sept in the north-west to 15 Dec in the far south; the arrows carry wind direction. Read them together and the country empties of the monsoon from the north-west downwards. The dates say when the rains left, not when winter rain arrives, and not how much of it falls when it does.

The Wind That Blows Back

The winter monsoon winds blow from the north-east, so they are known as the North East Winter Monsoon. They are the same seasonal system reversed: where the summer winds came in off the seas, these blow outward from the land towards them, and on an outline map they are marked with arrows pointing away from the interior.

The retreat is a much slower business than the advance. The withdrawal lines run from 1 Sept in the north-west to 15 Dec in the far south, which is a little over three months, against the six weeks the monsoon took to cross the country in the opposite direction. Reading the two maps side by side is the honest way to see that the seasons of India do not turn on and off; they travel.

Rain On The Coromandel Coast

One part of the country is watered by these winter winds. The Southern Coromandel Coast, in Tamil Nadu, gets rain from the winter monsoons, and the map shows why the arrows reaching it are different from the rest: they cross the Bay of Bengal before they strike that coast. A wind blowing off the land is dry, but the same wind after a sea crossing is not.

Curiosity Corner

Q3. The Coromandel Coast gets its rain when much of India is drying out. Where does that rain come from?

A. From the north east winter monsoon. Those winds blow outward from the land, but the arrows reaching Tamil Nadu cross the Bay of Bengal first and pick up moisture on the way, so they arrive at that coast wet.

Western Disturbances

The third feature on this map does not begin in India at all. Western disturbances are low pressure systems — areas where the air pressure is lower than in the air around them, which draws air in and often brings cloud and rain. They originate in West Asia and the regions near the Mediterranean Sea, reach India during the winter season, and bring the much-needed winter rainfall over the plains and snowfall in the mountains.

On an outline map they are marked as arrows entering from the north-west, and they must not be confused with the north east monsoon arrows leaving from the opposite side. One is a system travelling in from outside the country; the other is the country’s own seasonal wind on its way out.

5.7 Distribution Of Minerals

Relief was drawn with lines, plains with shading and winds with arrows. Minerals are drawn with points. Each symbol on this map stands for one named place where a particular mineral is worked, and the index at the top right tells you which symbol means which mineral — oilfields, coal and iron ore.

Map

Map 5.7 Caption: The mineral locations named for identification on the map of India. Brief: Map of India showing the full extent of India as officially defined; mark Digboi in the north-east and Mumbai High offshore in the Arabian Sea with the oilfield symbol, Jharia with the coal symbol and Singhbhum with the iron ore symbol, each labelled; index box naming the three symbols; show the Tropic of Cancer and a scale bar for 1:20,000,000; no other mineral sites to be shown.

Read It

Map 5.7 The index gives one symbol each for oilfields, coal and iron ore, and every symbol is a point rather than an area. The pattern is that three of the four sites lie in the east of the country and one lies offshore in the west. A dot marks where the mineral is worked. It says nothing about how large the deposit is, or how much is taken from it.

The Four Locations

These are the mineral locations you must be able to recognise and name on this map. (a) Mumbai High is an offshore oil field, lying in the Arabian Sea 176 km north-west of Mumbai. Offshore means it is worked out at sea, away from the coast, with no land beneath the workings. (b) Digboi, in the north-east of the country, is the oldest oil field, running from 1866. (c) Jharia, in Jharkhand, is a coal field, and the Jharia coal mines are located in that state. (d) Singhbhum, lying south of Jharia in the same eastern belt, is an iron ore area — this is the Chota Nagpur Plateau country, which this chapter has already noted is rich in mineral resources.

Placing An Offshore Field

Marking a point in open sea is harder than marking one on land, because there is no coastline, no river bend and no state boundary to fix it against. The only thing you are given is a distance, and the scale is what turns that distance into a position on the page.

Worked Case

WC 5.A4 — Where The Dot For Mumbai High Belongs The situation: This chapter states that Mumbai High lies 176 km north-west of Mumbai, and the maps in this chapter are drawn to a scale of 1:20,000,000. The working: The distance must first be put into centimetres before the scale can be applied, so \[176 \text{ km} = 176 \times 100{,}000 = 17{,}600{,}000 \text{ cm}\] Dividing the ground distance by the scale denominator gives the distance on the map, \[\frac{17{,}600{,}000}{20{,}000{,}000} = 0.88 \text{ cm}\] which is a little under one centimetre, measured from Mumbai towards the north-west.

Less than a centimetre is a useful thing to know before you pick up a pencil. A dot placed two or three centimetres out to sea, which looks reasonable on a page, would put the field several hundred kilometres from where it is. On a map of a whole country the sea is wide and the fields in it are close to shore, and the scale is the only guard against a mark that looks right and is wrong.

5.8 Soil Distribution

Soil is shown by shading, like the plains, because a soil covers an area rather than sitting at a point. Four tints appear in the index of this map: alluvial, black, red and yellow, and laterite. What makes them worth more than four colours is that each one is the record of a different process, and once you know the process you can usually work out where the tint has to be.

Map

Map 5.8 Caption: The distribution of soils across India, drawn at a scale of 1:20,000,000. Brief: Map of India showing the full extent of India as officially defined; shade alluvial soil, black soil, red and yellow soil and laterite soil in four clearly distinct tints, following the extents shown in the original; index box naming all four; show the Tropic of Cancer and a scale bar for 1:20,000,000; no relief, drainage or place names to be shown.

Read It

Map 5.8 Four tints, one for each soil, named in the index. The pattern to read is that alluvial soil follows the northern plain and the coastal strips, while black soil holds the western half of the peninsula. What the map cannot show is the soil in any one field. Each tint is the soil that dominates a wide area, and the boundaries between them are nothing like as sharp on the ground.

Four Soils, Four Processes

Each of these soils is named for what it looks like, but formed by what happened to it. The chapter gives the process behind each one. (a) Alluvial soil is formed by deposition of sediments by rivers, so it lies where rivers slow and drop the material they have been carrying — which is why its shading follows the northern plain and the coastal strips. (b) Black soil is formed by weathering of lava rocks, so it lies where those rocks are, in the western part of the peninsula. Weathering is the breaking down of rock where it stands, without the broken material being carried away. (c) Red soil is formed by prolonged weathering of crystalline rocks, and its shading, together with yellow, covers much of the eastern and southern peninsula and reaches into the north-east. (d) Laterite soil is formed due to leaching in areas of heavy rain, and it appears as narrower patches, including a strip along the western coast. Leaching is the washing down of material through the soil by rain soaking into it, which strips out some substances and leaves others behind.

Flowchart

Fig. 5.A4 Caption: Each soil on this map is traced back to the rock or the material it came from. Nodes: Parent material and process → soil type; river sediment → deposition by rivers → alluvial soil; lava rock → weathering → black soil; crystalline rock → prolonged weathering → red soil; rock under heavy rain → leaching → laterite soil

Three of these are the soils you are asked to mark and name on an outline map: alluvial, black and red. Marking them means shading a region and labelling it, so the region has to be chosen with some care. A shaded patch put down in roughly the right part of the country is not the same as a shaded patch whose edges follow the plain, the coast or the peninsula the way the tints on this map do.

5.9 Cities

Eight cities are named on this map, and each is shown as a dot with its name beside it. Unlike a range or a soil, a city has no shape you can shade at this scale, so the whole of the marking task is precision of position: the dot has to sit in the right part of the right region, and the name has to be written clearly enough to be read.

Map

Map 5.9 Caption: The eight cities named for identification on the map of India. Brief: Map of India showing the full extent of India as officially defined; mark Delhi, Mumbai, Kolkata, Chennai, Hyderabad, Bengaluru, Kochi and Prayagraj (Allahabad) as labelled dots of equal size; show the Tropic of Cancer and a scale bar for 1:20,000,000; no other settlements, relief or drainage to be shown.

The Eight Cities

Fixing each city against a feature you have already mapped is more reliable than remembering a position on a blank page. (a) Delhi lies in the north, on the plain country you shaded in an earlier map. (b) Prayagraj (Allahabad) lies further east on the same northern plain, and the Standard Meridian passes near it. (c) Kolkata lies in the east, close to where the land meets the head of the Bay of Bengal. (d) Mumbai lies on the western coast, on the northern part of that coastal strip. (e) Kochi lies much further south on the same western coast. (f) Chennai lies on the eastern coast in the south, on the Coromandel side of the peninsula. (g) Hyderabad lies inland, within the plateau country of the peninsula. (h) Bengaluru lies inland in the south, below Hyderabad and away from both coasts.

Read It

Map 5.9 Every dot on this map is the same size, and the name beside it is all the information given. That is the limit worth noticing: the map separates a coastal city from an inland one, but it cannot show you which of these is the largest. Size of population is not drawn here at all — it has to come from a count, not from the sheet.

How Cities Are Sorted

Beyond their positions, cities are grouped by how many people live in them. India’s 27.8 per cent urban population lives in more than 5,100 towns and over 380 urban agglomerations, an urban agglomeration being a city taken together with the built-up settlements that have grown into it around its edge.

The Census of 2011 classifies cities in three sizes. (a) A megacity has a population above 5,000,000. (b) A metropolis has a population between 1,000,000 and 4,999,999. (c) A sub-metropolis has a population between 500,000 and 999,999.

How Do We Know

Counting An Urban Population Evidence: the Census, a national count of people taken where they live, most recently used here for 2011. Reasoning: adding the counts for every town and agglomeration gives the urban share, and the same counts sort each city into a size class. Limit: a count fixes numbers at one date. It cannot say why a city grew, or what has changed since.

The figure of 27.8 per cent is a national one, and a national figure is an average across very unlike places. It tells you nothing about any single state, and nothing at all about which of the eight cities on this map are megacities and which are not.

5.10 Distribution Of Population

The last map in the chapter is shaded like the soil map, but the shading works differently. Here a tint does not stand for a kind of thing; it stands for a range of numbers. Each state is coloured according to how many people lived in it, in millions, at the Census of 2011, and the index sets out five classes: above 100, 50 to 100, 25 to 50, 10 to 25, and below 10. The all-India figure printed with the index is 1210.19.

Map

Map 5.10 Caption: The total population of the states of India in millions, for the year 2011. Brief: Map of India showing the full extent of India as officially defined, with state boundaries; shade each state according to its total population class and print its figure in millions as given in the original; index box listing the five classes — above 100, 50 to 100, 25 to 50, 10 to 25, below 10 — headed ‘Total population 2011 (in million)’ with the all-India figure of 1210.19; show the Tropic of Cancer and a scale bar for 1:20,000,000.

Read It

Map 5.10 The index turns colours into number ranges, in millions, for 2011, so a darker shade means a larger total. Read the map and the heaviest classes sit across the north and in the west of the peninsula. The limit is scale: one shade covers a whole state, and hides every district inside it. A state’s tint says nothing about which parts of it are crowded and which are empty.

Total Population And Density

Two different questions are being asked here, and they have different answers. Total population asks how many people live in a state. Population density asks how many live on each unit of area, and it is calculated as the number of persons per unit area. A large state can hold a very large total and still be thinly settled, while a small one can hold a modest total and be packed. The map is shaded by the first; the figures below belong to the second.

The top five populous States in India are Uttar Pradesh, Maharashtra, Bihar, West Bengal and Madhya Pradesh. According to Census 2011 the density of population in India is 382. The National Capital Territory of Delhi has the highest density of population, at 11,297, and Arunachal Pradesh has the lowest, at 17. Among the other States, Bihar has the highest density of population at 1102, followed by West Bengal at 1029 and Kerala at 859.

What The Density Figures Show

Worked Case

WC 5.A5 — The Distance Between The Highest And The Lowest Density The situation: This chapter gives the density of population in the National Capital Territory of Delhi as 11,297 and in Arunachal Pradesh as 17, both from Census 2011, against an all-India density of 382. The working: To compare two densities, divide the larger by the smaller, which gives the number of times one contains the other. \[\frac{11{,}297}{17} \approx 664.5\] So the highest density in the country is about 665 times the lowest. Comparing each against the national figure in turn, \[\frac{11{,}297}{382} \approx 29.6 \qquad \frac{382}{17} \approx 22.5\] so the highest density is roughly thirty times the all-India figure, and the all-India figure is itself roughly twenty-two times the lowest.

That middle number is what makes the national average of 382 so easy to misuse. It sits between two figures that are hundreds of times apart, and it describes neither of them. A low density is a fact about land and settlement — how much area there is and how it is used — and never a statement about the people who live there. The same caution applies to the map: shading a state as densely or sparsely populated is a reading of one figure at one scale, not a description of every place inside it.

5.11 Summary

This chapter is a set of maps of India, each carrying one theme and each given as a model for a map-filling exercise. All of them are drawn to a scale of 1:20,000,000.
Relief is shown by four kinds of feature, each with its own symbol on the map.
1. Ranges are drawn as lines — the Himalayas, the Karakoram, the Aravalli, the Vindhyas, the Satpura, the Western and Eastern Ghats, the Nilgiris and the Khasi hills.
2. Peaks are drawn as triangles with their heights beside them — Mount Godwin Austin (K2) at 8611 m and Mount Kanchenjunga at 8586 m.
3. The Karakoram Pass is the one pass marked, a gap through the range it crosses.
4. Two plateaus are shaded — the Deccan Plateau, a triangular landmass lying south of the river Narmada, and the Chota Nagpur Plateau, which is rich in mineral resources.
The Himalayas form an arc which covers a distance of about 2,400 km, running in a west-east direction from the Indus to the Brahmaputra.
Plains are shown by shading, because a plain covers an area rather than running along a line.
1. The Gangetic Plains are spread over Haryana, Delhi, Uttar Pradesh, Bihar, partly Jharkhand and West Bengal.
2. The Western Coastal Plains stretch from the Arabian Sea to the Western Ghats, and are called the Konkan in the north, the Kanara in the centre and the Malabar in the south.
3. The Eastern Coastal Plains lie between the Bay of Bengal and the Eastern Ghats, with the Northern Circars in the north and the Coromandel Coast in the south.
4. The Thar, the Great Indian Desert, is the one desert named, lying in the west.
The Indian rivers are divided into two groups.
1. The Himalayan rivers include the Indus, the Ganga and the Brahmaputra along with their tributaries.
2. The Peninsular rivers include the Narmada, the Tapti, the Godavari, the Krishna, the Mahanadi, the Cauveri and other small rivers with their tributaries.
Large catchment areas and seasonal monsoon rains together lead to flooding, which is why the Kosi is known as ‘Sorrow of Bihar’ and the Damodar as ‘Sorrow of Bengal’.
Six water bodies are marked, and two terms have to be kept apart.
1. A gulf is a large area of sea or ocean partially enclosed by land; the Gulf of Kutch, the Gulf of Khambhat and the Gulf of Mannar are marked.
2. A strait is a narrow channel of water lying between two land masses, and the Palk Strait lies between Tamil Nadu and Sri Lanka.
3. Chilka Lake is the largest salt water lake in India and falls in the category of brackish water lakes, while Wular Lake is a fresh water lake in the Bandipora district in Jammu and Kashmir.
Two lines have to be drawn, named and numbered on an outline map.
1. The Tropic of Cancer, at 23°30’ N, divides the country into almost two equal parts and marks the northernmost limit of the sun’s apparent motion.
2. The Standard Meridian, at 82°30’ E, passes through Mirzapur near Prayagraj (Allahabad) in Uttar Pradesh and marks Indian Standard Time, 5½ hours ahead of GMT.
The summer monsoon winds blow from the south-west, so they are known as the South West Summer Monsoon, also called the Advancing Monsoon, and the rains they bring last from June to September.
1. One branch crosses the Arabian Sea and strikes the west coast, and the other crosses the Bay of Bengal, reaches the north-east and turns westward along the northern plain.
2. The dated lines on the map give the normal dates of onset and of withdrawal, so the advance can be read from the far south in early June to the north-west by the middle of July.
The winter monsoon winds blow from the north-east, so they are known as the North East Winter Monsoon, and the Southern Coromandel Coast in Tamil Nadu gets its rain from them.
Western Disturbances are low pressure systems which originate in West Asia and the regions near the Mediterranean Sea, reach India during the winter season, and bring winter rainfall over the plains and snowfall in the mountains.
Four mineral locations are identified, each marked as a point.
1. Mumbai High is an offshore oil field in the Arabian Sea, 176 km north-west of Mumbai.
2. Digboi is the oldest oil field, running from 1866.
3. The Jharia coal mines are located in Jharkhand.
4. Singhbhum is the iron ore location marked on the same eastern belt.
Four soils are shaded, and each is named for its appearance but formed by a process.
1. Alluvial soil is formed by deposition of sediments by rivers.
2. Black soil is formed by weathering of lava rocks.
3. Red soil is formed by prolonged weathering of crystalline rocks.
4. Laterite soil is formed due to leaching in areas of heavy rain.
Eight cities are identified — Delhi, Mumbai, Kolkata, Chennai, Hyderabad, Bengaluru, Kochi and Prayagraj (Allahabad).
1. India’s 27.8 per cent urban population lives in more than 5,100 towns and over 380 urban agglomerations.
2. According to Census 2011 a megacity has a population above 5,000,000, a metropolis between 1,000,000 and 4,999,999, and a sub-metropolis between 500,000 and 999,999.
Population is mapped as the total for each state in millions for 2011, against an all-India figure of 1210.19.
1. The top five populous States are Uttar Pradesh, Maharashtra, Bihar, West Bengal and Madhya Pradesh.
2. Population density is the number of persons per unit area, and according to Census 2011 the density of population in India is 382.
3. The National Capital Territory of Delhi has the highest density at 11,297 and Arunachal Pradesh the lowest at 17.
4. Among the other States, Bihar has the highest density at 1102, followed by West Bengal at 1029 and Kerala at 859.

Flowchart

Fig. 5.A5 Caption: Everything this chapter asks you to place on a blank outline of India, sorted by the way it is drawn. Nodes: Features on the outline map of India → drawn as lines / drawn as points / drawn as shading / drawn as arrows; drawn as lines → mountain ranges → Himalayas, Karakoram, Aravalli, Vindhyas, Satpura, Western Ghats, Eastern Ghats, Nilgiris, Khasi hills; drawn as lines → rivers → Himalayan rivers (Indus, Ganga, Brahmaputra and tributaries) / Peninsular rivers (Narmada, Tapti, Mahanadi, Godavari, Krishna, Cauveri); drawn as lines → latitude and longitude → Tropic of Cancer (23°30’ N), Standard Meridian (82°30’ E); drawn as points → peaks (K2, Kanchenjunga) / pass (Karakoram Pass) / minerals (Mumbai High, Digboi, Jharia, Singhbhum) / cities (Delhi, Mumbai, Kolkata, Chennai, Hyderabad, Bengaluru, Kochi, Prayagraj); drawn as shading → plains (Gangetic, Konkan, Kanara, Malabar, Northern Circars, Coromandel) / desert (Thar) / plateaus (Deccan, Chota Nagpur) / soils (alluvial, black, red) / water bodies (Gulf of Kutch, Gulf of Khambhat, Gulf of Mannar, Palk Strait, Andaman Sea, Wular Lake) / population (dense and sparse); drawn as arrows → South West Monsoon (Arabian Sea branch, Bay of Bengal branch) / North East Monsoon / Western Disturbances

What This Chapter Cannot Tell You

Every map here is drawn at 1:20,000,000, and at that scale a whole state is a patch and a whole city is a dot. A shaded soil or a shaded population class is one value spread across an area far larger than anything it actually describes, so nothing on these sheets can be read down to a district, a village or a field.

The dated lines of the monsoon maps are normal dates, meaning usual ones, and they say when the wind is expected rather than when it came in any particular year. Nor do these maps carry amounts: they show where the rain-bearing winds go, not how much rain fell; where a mineral is worked, not how much is taken from it; where people are counted, not how they live. ## 5.12 Check Your Concepts

A distance of 6 cm is measured between two points on a map of India drawn to a scale of 1:20,000,000. Work out the ground distance between them in kilometres, showing every step of the arithmetic and stating the unit at each stage.
Map 5.5 and Map 5.6 both carry dates. Explain what each set of dates records, and then use them to say why the rains last for a shorter part of the year in the north-west of the country than in the south.
The north east monsoon blows outward from the land towards the seas, yet the Southern Coromandel Coast receives rain from it. Using the direction of the arrows on Map 5.6, explain how this happens.
Map 5.10 shades each state according to its total population. Explain why a state shaded in the highest class is not necessarily the most densely populated, and state one thing this map cannot tell you about how people are spread inside a state.
On the outline map of India:
1. Draw, name and number the Indian Standard Meridian.
2. Mark and name the Karakoram Range.
3. Mark and name the Karakoram Pass.
4. Shade and name a region with alluvial soil along the western coast.
5. Mark and name the winds that bring rain to West Bengal in summer.
On the outline map of India:
1. Shade and label the Chota Nagpur Plateau.
2. Shade and name the gulf between Sri Lanka and India.
3. Mark and name the Gangetic Plains.
4. Shade and label an area with red soil.
5. Mark and name the Jharia coal field.
On the outline map of India:
1. Draw, name and number the latitude marking the northern limit of the sun’s apparent movement.
2. Shade and name Wular Lake.
3. Mark and name the Aravalli Mountains.
4. Shade and name a region with black soil.
5. Shade and name a densely populated state in South India.
6. Mark and name the winds which bring rain in winter to the Coromandel Coast.
On the outline map of India:
1. Mark and name the Great Indian Desert.
2. Mark and name the Konkan plains.
3. Shade and name an offshore oilfield.
4. Mark and name the highest mountain peak of India.
5. Mark and name two rivers in India draining into the Arabian Sea.
6. Mark and name the Palk Strait.