Revision

Question 1

Define erosion.

Answer 1

The process of wearing away rocks and soil by wind, water, or ice.

Question 2

What is transportation in river processes?

Answer 2

The movement of sediment and materials by river currents.

Question 3

Fill in the blank: Deposition occurs when sediment is ______.

Answer 3

dropped off by the river.

Question 4

True or false: Erosion can increase river depth.

Answer 4

TRUE

Erosion deepens riverbeds, affecting flow and habitat.

Question 5

What is hydraulic action?

Answer 5

The force of moving water that erodes riverbanks and beds.

Question 6

Define abrasion.

Answer 6

Erosion caused by sediment scraping against rock surfaces.

Question 7

What is attrition?

Answer 7

The process where rocks and pebbles collide and break into smaller pieces.

Question 8

True or false: Rivers only transport sediment during floods.

Answer 8

FALSE

Rivers transport sediment continuously, not just during floods.

Question 9

What is suspension in river transport?

Answer 9

The process of fine particles being carried within the water column.

Question 10

What is the water cycle?

Answer 10

The continuous movement of water through evaporation, condensation, and precipitation.

Question 11

Fill in the blank: Evaporation is the process of water turning into ______.

Answer 11

vapor.

Question 12

True or false: Precipitation includes rain, snow, and sleet.

Answer 12

TRUE

Precipitation is any form of water falling from the atmosphere.

Question 13

Fill in the blank: Runoff occurs when water ______.

Answer 13

flows over land into rivers and lakes.

Question 14

What is condensation?

Answer 14

The process where water vapor cools and forms liquid droplets.

Question 15

What is surface runoff?

Answer 15

Water that flows over the ground surface to rivers and lakes.

Question 16

Define evapotranspiration.

Answer 16

The combined process of evaporation and plant transpiration.

Question 17

What is precipitation?

Answer 17

Any form of water, liquid or solid, that falls from the atmosphere.

Question 18

Define transpiration and infiltration.

Answer 18

Transpiration is water vapour released from plants/trees. Infiltration is water soaking into the soil from the ground surface.

Question 19

What is the difference between surface run-off and groundwater flow?

Answer 19

Surface run-off is water flowing over the land surface, while groundwater flow is water moving slowly through underground rock layers.

Question 20

Q: How do channel depth and width change from source to mouth?

Answer 20

Both increase downstream because more tributaries join the river, adding more water.

Question 21

Why does velocity increase as a river flows downstream?

Answer 21

Although the gradient becomes flatter, the channel becomes smoother, resulting in less friction with the banks and bed.

Question 22

Describe the size of bedload from the source to the mouth.

Answer 22

Bedload becomes smaller and smoother downstream due to attrition (rocks colliding and breaking).

Question 23

Q: What is solute load?

Answer 23

Material dissolved within the water flow.

Question 25

What are the two main types of rock required for a waterfall to form?

Answer 25

A layer of hard, resistant rock (like granite) lying on top of a layer of soft, less-resistant rock (like sandstone).

Question 26

Describe how a waterfall is formed.

Answer 26

The river flows over the hard rock onto the soft rock. The soft rock is eroded faster through hydraulic action (force of water) and abrasion (grinding), leading to undercutting. The hard rock becomes an overhang and eventually collapses due to gravity. The process repeats, and the waterfall moves upstream.

Question 27

What is a plunge pool and how does it form

Answer 27

A deep, turbulent pool at the base of a waterfall. It is formed by the crashing water and the erosion caused by collapsed rocks churning around.

Question 28

How does a gorge form?

Answer 28

As the waterfall retreats upstream, it leaves behind a deep, narrow, steep-sided valley, which is called a gorge.

Question 29

What are the two types of erosion and deposition found in a meander?

Answer 29

Water flows faster on the outside bend, causing erosion. Water flows slower on the inside bend, causing deposition.

Question 30

What is a "slip-off slope" and where does it form?

Answer 30

A gentle slope on the inside bend of a meander where sediment is deposited because the water velocity is slow.

Question 31

What does a storm hydrograph show?

Answer 31

It shows changes in a river’s discharge (volume of water) over time, usually after a heavy rainstorm.

Question 32

Define 'Lag Time' and 'Peak Discharge'.

Answer 32

Lag time is the delay between the peak rainfall and the peak discharge of the river. Peak discharge is the highest amount of water in the river.

Question 33

What is the difference between a "flashy" and a "gentle" hydrograph?

Answer 33

A "flashy" (steep) hydrograph has a short lag time and high peak (fast flooding), usually in urban areas or steep valleys. A "gentle" hydrograph has a long lag time and low peak, often in forested or vegetated areas.

Question 34

How does urbanisation increase flood risk?

Answer 34

Cities have impermeable surfaces like concrete and tarmac. These prevent water from soaking into the ground (infiltration), leading to increased surface run-off.

Question 35

Why does deforestation increase flooding?

Answer 35

Trees intercept rainfall, letting it evaporate or slowly reach the ground. Without trees, more rain hits the ground directly and runs quickly into rivers, decreasing lag time.

Question 36

Describe how geology affects flooding.

Answer 36

Impermeable rocks (e.g., clay, granite) do not allow water to pass through, causing surface runoff. Permeable rocks (e.g., limestone) allow water to soak in, reducing flood risk.

Question 37

Where did the worst flooding occur in Pakistan in 2022, and what was the main immediate cause?

Answer 37

Southern provinces of Sindh and Balochistan were hardest hit. The primary cause was record-breaking monsoon rains—roughly 10 times higher than usual, with some areas receiving 500% more rain than the 30-year average.

Question 38

How did climate change contribute to these floods?

Answer 38

Higher temperatures led to intense heatwaves, resulting in rapid glacial melting in the north. A warmer atmosphere meant the monsoon brought significantly more moisture, causing extreme rainfall.

Question 39

What human factors made the 2022 floods worse?

Answer 39

Poorly planned construction on floodplains, clogged drainage systems, and the removal of trees (deforestation) along the Indus River reduced the land’s ability to absorb water.

Question 40

Describe two Social impacts of the Pakistan floods.

Answer 40

Over 1,700 people died, and 33 million people were affected. Around 8 million people were displaced, losing their homes and causing a health crisis with waterborne diseases like cholera and malaria.

Question 41

What were the main Economic impacts?

Answer 41

Over US$30 billion in damages. 3.6 million acres of crops (rice, cotton) were destroyed, destroying farmers' livelihoods, killing over 700,000 livestock, and damaging thousands of miles of roads and bridges.

Question 42

What were the Environmental impacts of the pakistan 2022 flood?

Answer 42

Extensive soil erosion, damage to ecosystems like mangrove swamps, and large areas of farmland being submerged in water.