What are the three main types of landscapes or topographical characteristics that describe the diversity of plains?
Plains are diverse in landscapes.
They can be:
Entirely flat
Gently rolling
Undulating (slightly wavy or uneven)
How plains are formed.
Plains are mostly formed by river systems and their tributaries.
What are the four common geographical locations where plains can be found
They can also be found as:
Lowlands within valleys
Foothills of mountains
Uplands
Coastal plains (near sea margins)
What is common type of soil typically found in plains?
Fertile
Why are plains important to people?
They are important for:
Infrastructure development, like transportation networks
Agriculture (farming)
What two main factors cause plains to have a high population density?
Their fertile soil and easy access make them densely populated.
What two major activities do plains support?
Plains support:
Urban development (cities and towns)
Agricultural activities on a large scale
What are the types of Plains
Plains are divided into different types :
- Savanna: Area between forest and grassland.
- Grassland: Has some shortage of soil and water but gets enough heat.
- Desert: Has very little soil and water but gets enough heat.
- Tundra: Too cold for plants to grow all year because there isn’t enough heat.
- Coastal plains: Flat, low-lying lands found near the sea.
Tropical Savanna
- What are savannas a combination of?
Savannas are a combination of woodland and grassland. - What kind of vegetation is found in savannas?
They have scattered trees and large areas covered with grasses. - How does the dry season affect vegetation in savannas?
The dry season limits the amount of plants and trees that can grow. - Why is savanna land mainly suitable for grazing?
Savanna land is mainly suitable for grazing because the dry season limits how much vegetation can grow, so only grasses survive well, which animals can feed on.
Temperate Grasslands
- Define Grasslands?
Grasslands are large open areas of land mainly covered with grasses instead of trees. - How tall can grasses grow in temperate grasslands?
The grasses in these areas can grow up to one metre high. - Names of grasslands around the world include:
Savannas in Central Africa - Pampas in South America
- Prairies in North America
- Steppes in Eurasia
- Downs in the UK and Australia
- Veld in South Africa
Deserts
1.Q: What are the driest places on earth?
A: Deserts are the driest places on earth.
2.Q: Why is land use in deserts very limited?
A: Because deserts have extreme dryness and very low rainfall.
3.Q: What kind of surface do deserts usually have?
A: They usually have few plants and hard, wind-blown surfaces covered with rocks and sand.
4.Q: How do desert temperatures change between day and night?
A: Deserts have a wide range of temperatures, with very high temperatures in the day and very cold temperatures at night.
5.Q: What percentage of the world’s deserts are covered by sand dunes?
A: Only about 25 percent of the world’s deserts are covered by sand dunes.
6.Q: What covers the remaining parts of deserts?
A: The remaining parts are covered by exposed rock or stone-covered plains.
Tundra
1.Q: What does the term “Tundra” refer to?
A: Tundra refers to the vast, treeless plains found in Arctic and Antarctic regions.
2.Q: What kind of climate conditions does the tundra have?
A: The tundra has frozen conditions, low temperatures, and very little precipitation.
3.Q: What type of vegetation grows in the tundra?
A: The tundra supports only sparse vegetation such as mosses and shrubs.
Coastal Plains
Q.1: What are coastal plains?
A: Coastal plains are low-lying, flat areas of land along coastlines.
Q.2: How are coastal plains formed?
A: They are formed by sediment deposited by rivers and oceans.
Q.3: What are the main features of coastal plains?
A: They are usually fertile and have diverse ecosystems shaped by interactions between land and sea.
Indus River Plain
Q.1: Through which countries does the Indus River and its tributaries flow?
A: The Indus River and its tributaries flow through :
China
India
Pakistan.
Q.2: How much sediment does the Indus River carry into the sea each year?
A: It carries about 300 million tons of sediments into the sea each year.
Q.3: How long is the Indus River?
A: The Indus River is 3,200 kilometers long.
5.Q.5: What kinds of landscapes are found in the Indus River plain?
A: The Indus River plain includes :
Deserts
Forests
Hills
Plateaus
Coastal plains
Glaciated mountain regions.
6.Q.6: Where does the Indus River begin its journey?
A: It begins in the meltwater of glaciers in the Tibetan Plateau.
7.Q.7: How far does the Indus River plunge before reaching Pakistan?
A: The river plunges nearly 3,000 metres before reaching the plains of Pakistan at Attock.
8.Q.8: In which direction does the Indus River flow after reaching Attock?
A: It flows southwards and descends slowly towards sea level.
9.Q.9: How wide is the flood plain through which the Indus River meanders (curves or bends)?
A: The flood plain is over 200 kilometers wide.
10.Q: What are the main tributaries of the Indus River?
A: The main tributaries are :
Jhelum
Chenab
Ravi
Sutlej
Beas.
11.Q: Through which region do these tributaries flow and merge?
A: They flow through Punjab, known as the land of five rivers, and then merge.
12.Q: Where do the Indus River and its tributaries finally drain?
A: They drain into the Arabian Sea near the port city of Karachi.
13.Q: What do the channels near Karachi form?
A: They form one of the significant deltas in the world.
14.Q: What is the total area covered by the Indus catchment?
A: The Indus catchment covers about 1.1 million square kilometers.
The Indus River Plains and Their Sub-Regions
The plains of the Indus River occupy most of Punjab and the central part of Sindh.
They consist of three sub-regions:
Upper indus Plain, Lower Indus Plain, Indus Daltaic Plain
Upper Indus Plain
Q1. What is the Upper Indus Plain?
A1. The Upper Indus Plain is the northern part of the Indus River Plain that stretches from the foothills of the Himalayas to Attock, near Mithankot.
Q2. Where does the Upper Indus Plain extend from and to?
A2. It extends from the foothills of the Himalayas to Attock, near Mithankot.
Q3. What is the Panjnad River system?
A3. The Panjnad River system is made up of four main rivers: the Jhelum, Chenab, Ravi, and Sutlej.
Q4. Where does the Panjnad River system join the Indus River?
A4. The Panjnad River system joins the Indus River near Mithankot.
Q5. How has most of Punjab been formed?
A5. Most of Punjab has been formed by the deposition of sediments from the Jhelum, Chenab, Ravi, and Sutlej rivers.
Q6. Why is the Upper Indus Plain very fertile?
A6. It is fertile because of the rich deposits left by the rivers and the use of canal irrigation systems.
Q7. Which main crops are grown in the Upper Indus Plain?
A7. The main crops grown are wheat, rice, cotton, and sugarcane.
Q8. What helps farming in the Upper Indus Plain?
A8. An extensive canal irrigation system supports farming in the region.
Lower Indus Plain
Q1. Where is the Lower Indus Plain located?
A1. The Lower Indus Plain lies just below the Upper Indus Plain.
Q2. Where does the Lower Indus Plain begin and end?
A2. It begins where the Upper Indus Plain ends and continues south until the Arabian Sea.
Q3. What kind of landform is the Lower Indus Plain?
A3. It is a flat alluvial plain formed by river deposits.
Q4. What problems occur in the northwest part of the Lower Indus Plain?
A4. The northwest part faces water logging and salinity problems.
Q5. What is the condition of the southeastern part of the Lower Indus Plain?
A5. The southeastern part, including Cholistan (also called the Rohri Desert), is dry and sandy.
Q6. What is a major physical feature of this region?
A6. The Rohri Ridge, made of limestone, is a major feature of the Lower Indus Plain.
Q7. Where is the Thar Desert located in relation to the Lower Indus Plain?
A7. The Thar Desert lies to the south and southeast of the Lower Indus Plain, in southern Sindh.
Q8. What type of desert is the Thar Desert?
A8. The Thar Desert is a coastal desert with rolling plains, sand dunes, and ridges.
Q9. Why is farming limited in the Thar Desert?
A9. Farming is limited because the region receives very little rainfall.
Q10. Which crops are grown in the Thar Desert area?
A10. Crops like rice, cotton, and fruits are grown in the Thar Desert area.
The Indus Deltaic Plain
Q1. What is another name for the Indus River Delta?
A1. The Indus River Delta is also called the Deltaic Plain.
Q2. Where is the Indus River Delta located?
A2. It is located in the southern part of Pakistan, where the Indus River meets the Arabian Sea.
Q3. What kind of region is the Indus Deltaic Plain?
A3. It is a low-lying coastal region.
Q4. How much importance does the delta hold in Pakistan’s geography?
A4. It makes up a major part of Pakistan’s southern geographical area.
Q5. What special feature does the delta have?
A5. The delta has many old and new channels of the Indus River, showing how the river has changed its course several times.
Q6. In which direction has the Indus River shifted its course over time?
A6. The Indus River has shifted its position southwards several times.
Q7. Why is the Indus Deltaic Plain famous?
A7. It is famous for its mangrove forests, which are vital for the country’s marine ecology.
Q8. What is the importance of mangrove forests?
A8. Mangrove forests protect the coast and support marine life and the environment.
Q9. Into which area does the Indus Deltaic Plain extend?
A9. It extends into the Rann of Kutch, a seasonal salt marsh.
Q10. Where is the Rann of Kutch located?
A10. The Rann of Kutch lies on the border between India and Pakistan — between Gujarat (India) and Sindh (Pakistan).
| Stage | Heading | What It Explains | Relation |
|---|---|---|---|
| 1 | River erosion | River cuts and breaks the land | Starting process |
| 2 | Transporting sediment | River carries broken material | Next step after erosion |
| 3 | Transforming the land | Landforms created by erosion & deposition | End result |
| 4–7 | Catchments, Drainage, Systems, Impacts | How rivers are fed and influenced | Source and conditions |
| 8–10 | Topography, Soils, Channels | Physical factors affecting river behavior | Controls on flow |
| 11 | Velocity, Capacity, Discharge | How water moves and carries sediment | Measurement and performance of river |
River Erosion
Q1. What is river erosion?
A1. River erosion is the process by which a river wears away the land it flows over.
Q2. How does a river cause erosion?
A2. A river causes erosion through four main processes: abrasion, attrition, corrosion (solution), and hydraulic action.
Abrasion
Q3. What happens during abrasion?
A3. During abrasion, the sand, stones, and pebbles carried by the river scrape and rub against the riverbed and banks, wearing them away like sandpaper.
Q4. What materials does the river carry that cause abrasion?
A4. The river carries sand, pebbles, and small stones that grind against the river’s surface.
Attrition
Q5. What is attrition?
A5. Attrition happens when rocks and stones carried by the river crash into each other, breaking into smaller, smoother pieces.
Q6. What is formed when rocks are broken into very fine particles by attrition?
A6. Fine particles called silt are formed.
Corrosion
Q7. What is corrosion or solution?
A7. Corrosion (or solution) occurs when the river water dissolves soluble rocks and minerals like limestone and carries them away in the water.
Q8. Which types of rocks are most affected by corrosion?
A8. Soft and soluble rocks, such as limestone, are most affected.
Hydraulic Action
Q9. What is hydraulic action?
A9. Hydraulic action happens when the force of fast-flowing water pushes into cracks in the riverbanks or riverbed, breaking off pieces of rock.
Q10. How does hydraulic action change the river channel?
A10. It widens and deepens the river channel over time as pieces of rock break away.
Q11. Why are these erosion processes important?
A11. These processes shape the landscape by forming valleys, widening river channels, and creating features like waterfalls and gorges.
Transporting Sediment
When a river erodes (wears away) rocks and soil from its banks and bed, this material is called sediment. The river carries or transports this sediment as it flows.
The movement of sediment happens in two main ways:
- Bed Load:
This includes larger and heavier fragments such as pebbles, gravel, and sand.
These pieces are too heavy to be lifted by the water, so they roll, slide, or bounce along the riverbed as the water moves. - Suspended Load:
This includes smaller and lighter particles like silt and clay.
These fine materials are carried within the water, making the river look muddy or cloudy. They can stay floating in the water for a long distance before settling down.
This whole process of carrying sediments is part of the river’s natural work.
After being transported, the sediment is eventually deposited (laid down) when the river slows down, especially in flatter areas or at the river mouth.
Here are clear and simple questions and answers based on the text about Transporting Sediment:
Questions and Answers
Q1. What is sediment?
A1. Sediment is the material made up of small pieces of rocks and soil that a river wears away from its banks and bed.
Q2. How does a river transport sediment?
A2. A river transports sediment by carrying it along as it flows, either as bed load or suspended load.
Q3. What is bed load?
A3. Bed load is the heavier and larger fragments like pebbles and gravel that move by rolling, sliding, or bouncing along the riverbed.
Q4. What is suspended load?
A4. Suspended load is made up of smaller and lighter particles, such as silt and clay, that float or remain mixed in the river water.
Q5. Why does river water sometimes look muddy?
A5. River water looks muddy because of the fine particles in the suspended load that stay mixed in the water.
Q6. When is sediment deposited?
A6. Sediment is deposited when the river slows down, usually in flatter areas or where the river meets the sea.
Q7. Why can some particles travel a long distance in a river?
A7. Lighter particles can travel long distances because they are carried in suspension and do not settle quickly.
Transforming the Land
Introduction
As a river flows from its source towards where it empties into the sea or a lake, it constantly shapes and changes the land along its path. The landscape formed by the river is called a riverine landscape, and it changes from the upper course to the lower course of the river.
Q1. How does a river transform the land as it flows?
A river shapes and changes the land as it flows from its source to where it empties into the sea or a lake. It erodes rocks, carries sediments, and deposits them, creating different landforms along its course.
Q2. What is meant by a riverine landscape?
A riverine landscape refers to the landforms and features created by the action of a river, such as valleys, floodplains, meanders, and oxbow lakes.
1. The Upper Course – The Beginning of the River
a. Location and Features
- Found in hilly or mountainous regions.
- The river is narrow, fast-flowing, and steep.
- The flow is strong enough to cut through hard rocks.
b. Landforms Formed
- The river cuts a deep, narrow V-shaped valley.
- Erosion mainly happens downwards (vertical erosion).
- Steep slopes form on both sides of the valley.
c. Early Development of Floodplain
- Over time, small flat areas appear along the valley floor.
- These are the first signs of a floodplain.
- The river may begin to show small bends (meanders).
Q3. Where is the upper course of a river usually found?
It is usually found in hilly or mountainous regions.
Q4. What are the main features of the river in its upper course?
The river is narrow, flows very fast, and cuts deeply into the land due to steep slopes.
b. Landforms Formed
Q5. What kind of valley does the river form in the upper course?
The river forms a deep, narrow V-shaped valley.
Q6. What type of erosion is common in the upper course?
Vertical erosion (downward cutting) is common because the river mainly cuts down into the land.
c. Early Development of Floodplain
Q7. What changes occur over time in the upper course?
Small flat areas begin to form along the valley floor, marking the early stages of a floodplain. The river may also start forming small bends known as meanders.
2. The Middle Course – The Widening Valley
a. Changes in Flow
- The slope becomes gentler.
- The river flow slows down slightly.
- Erosion starts acting sideways rather than only downward.
b. Development of Landforms
- The valley becomes wider and flatter.
- A larger floodplain develops.
- The meanders become bigger and more distinct.
c. Deposition
- The river carries sediments and deposits them on the valley floor.
- These deposits make the surrounding land fertile.
a. Changes in Flow
Q8. How does the flow of the river change in the middle course?
The slope becomes gentler, and the river flows more slowly. Erosion becomes more sideways (lateral) rather than downward.
b. Development of Landforms
Q9. How does the shape of the valley change in the middle course?
The valley becomes wider and flatter as the river erodes sideways.
Q10. What happens to the floodplain and meanders in this stage?
The floodplain develops further, and meanders become larger and more noticeable.
c. Deposition
Q11. What happens to the sediments carried by the river in the middle course?
The river deposits sediments on the valley floor, making the nearby land fertile and suitable for agriculture.
3. The Lower Course – The Final Stage
a. Landscape Features
- The land is almost flat.
- The river channel is broad and winding.
- The floodplain becomes very wide and well developed.
b. Processes and Landforms
- The river flow is slow, so deposition is more common than erosion.
- Large meanders are clearly visible.
- Over time, meanders may become so curved that parts of the river are cut off, forming oxbow lakes.
c. Evidence of River Changes
- The presence of oxbow lakes shows that the river’s course has changed over time.
Q12. How is the land in the lower course different from the upper course?
The land is flat, the river is broad and winding, and the floodplain is wide and well developed.
b. Processes and Landforms
Q13. What process is more common in the lower course—erosion or deposition?
Deposition is more common because the river’s flow is slower.
Q14. What major landforms are seen in the lower course?
Large meanders and oxbow lakes are common in this stage.
Q15. How are oxbow lakes formed?
When a meander becomes very curved, the river may cut through it and form a new, straighter channel. The curved section that gets cut off becomes an oxbow lake.
c. Evidence of River Changes
Q16. What do oxbow lakes show about the river’s history?
The presence of oxbow lakes shows that the river’s course has shifted and changed over time.
2.4 Riverine Landform
Is the land in the upper course flat or steep?
Its steep
What effect does the strong water flow have on the riverbed?
Because of this strong flow, the river cuts into the ground quickly.
What does the fast water crash the stones against?
Fast water crashes stones against each other and the riverbed.
Why does the river valley become V-shaped?
The river cuts downward more than sideways.
Over time this creates a V shaped valley.
Define Rapid
Sometimes the slope becomes even steeper.
The water becomes faster and more rough.
This part of the river is called a rapid.
Under what conditions does a waterfall form
A waterfall forms when the river drops over a vertical edge.
This usually happens in a narrow and deep channel.
What effect does hard rock have on the rate of erosion in waterfall?
Hard rock slows erosion.
What changes the shape of a waterfall?
Water movement still erodes the softer rock underneath, which changes the shape of the waterfall.
What can lift land upwards and its effects?
Forces inside the Earth can lift land upward.
This changes how the river cuts the land.
Effect of speed of uplift?
If uplift is slow or fast, the river landforms adjust to these changes.
In which part of river the land becomes flatter?
In the lower part of a river, the land becomes flatter.
What is the effect of flatter land on river?
Because the land is flatter, the river slows down.
Effect of slower water?
Slower water leads to more deposition, which means the river drops the material it was carrying.
What is a flood plain?
A flood plain is a flat area on both sides of the river.
Describe flood plain formation?
It is wide and stretches from the river banks outward.
What happen to flood plains in rains?
It becomes covered with water when the river rises during heavy rain.
During floods what does river carries? what change the shape of flood plain?
During floods, the river carries and deposits large amounts of material on this flat land.
These deposits slowly change the shape of the flood plain.
During floods, what spreads out over flood plain?
During floods, water spreads out over the flood plain.
What happens when a river’s water spreads out and slows down, and what landform is created by the resulting deposition?
The water slows down quickly when it spreads out.
Because the water slows, heavier material is dropped close to the river channel.
This repeated deposition builds raised ridges along the river.
What are Levees?
These raised ridges are called natural levees.
How are braided channels formed?
A river forms braided channels when it becomes filled with too much sediment.
Because of this heavy load, the river cannot carry everything smoothly.
The river then splits into several small channels.
What are meanders?
Meanders are repeated curves in the river channel.
What causes a river to form meanders?
They form when moving water erodes the outer banks and widens the valley.
What happens to the outer bank when water moves around a bend?
The outer bank is eroded by the flowing water.
What type of land is meandering more common in?
areas where rivers flow over flat land.
What features inside the river channel help form meanders?
Deep pools and shallow riffles
How does water behave when it moves past a riffle?
The water is pushed toward the outside bank.
How does a river undercut the outside bank?
The strong flow cuts into the outside bank.
What happens to the meander when the outside bank is eroded?
The meander moves outward.
What is a point bar?
A point bar is a buildup of deposits on the inside of the loop.
How does a point bar form inside a meander loop?
It forms as sediment collects on the inside of the meander.
What happens to meander loops as they grow larger?
The meander loops grow until the channels almost meet.
What event increases the amount and speed of river water?
Floods increase the amount and speed of water.
How can a river cut across the narrow neck between two meanders?
The strong floodwater may cut straight across the narrow neck.
What are the old sections of the former channel called?
They are called cut offs or oxbow lakes.
What is an oxbow lake?
How does an oxbow lake change over time?
It slowly fills with sediment.
What does an oxbow lake become after it fills with sediment?
It becomes a waterhole.
DELTAS
What is a delta?
A delta is a landform that develops at the mouth of a river.
What happens to the speed of a river when it reaches the sea or lake?
The river’s speed drops.
How does the drop in speed affect the sediment load?
The river cannot carry all its sediment, so the sediment is deposited near the mouth.
How does a delta form over time?
Sediment builds up over time, creating a delta.
What factors influence the type of delta that develops?
Wave action, currents, and tides affect the type of delta formed.
Why do some rivers not form deltas?
Rivers on coasts with a large tidal range do not form deltas.
How do such rivers enter the sea instead?
They enter the sea through an estuary.
Which significant delta is found in Pakistan?
The Indus River Delta.
Where does the Indus River Delta meet the sea?
It meets the Arabian Sea.
Why is the Indus Delta important for the environment?
It supports many habitats like mangroves, tidal flats, and lagoons, and protects the coastline.
Write about Importance of rivers as per Pakistan’s environment, economy and daily life.
- Rivers support Pakistan’s environment, economy and daily life.
- Dams on rivers like the Indus and Jhelum produce electricity.
- Canals carry river water to homes, cities and industries.
- The Indus River provides most of the irrigation water for farming.
- The Indus Delta has wetlands and marshes that support many plants and animals.
- Rivers help move heat and moisture, which affects climate and weather.
- Rivers support fishing and fish farming with species such as catfish, carp and trout.
- Floodplain soil becomes fertile when rivers leave fine sediment, which helps crops grow.
How humans change the shape and path of a river to control water flow and reduce flooding.
- Humans straighten the river or dig a new channel to help the water flow quickly.
- In cities, they widen the river and cover its sides with concrete so it can hold more water.
- They build levees along the sides to keep the water from spilling out.
- They create basins to store extra water during heavy rain.
- They remove sediment bars and small islands so the river does not damage its banks.
Example of heavily modified river
London’s River Lea is an example of a heavily modified river.
What steps should be taken to protect rivers from damage, pollution and reduced water flow?
– Earth moving machines should be controlled because they can damage riverbeds and banks and increase sediment.
• Soil erosion areas must be found and fixed to stop more soil from entering the river.
• Any obstacles blocking the flow should be removed.
• Pollutants like sewage, industrial waste, farm chemicals and salty water must be treated before reaching the river.
• Water use for farming and cities should be managed carefully.
• Enough environmental flow should be kept so the river can support its natural processes.
• Farmland near rivers should be managed to stop polluted water from entering the river.
What are the right and wrong ways of managing rainwater and household water to protect the environment?
• Direct rooftop rainwater into gardens and use plants that need less water.
• Wash cars at proper car wash stations and keep harmful waste out of drains.
• Build rain gardens and wetlands to clean stormwater.
• Avoid sending rooftop rainwater into street drains.
• Do not overuse herbicides and fertilizers.
• Do not wash cars on driveways where chemicals can enter drains.
• Stop untreated stormwater from flowing into rivers.