Water on the land Flashcards
How many people died in the Pakistan floodings of 2010? How many were affected?
1,600 people died. 14 million were affected.
Which area in Pakistan was affected the worst during the 2010 floodings?
Swat Valley.
Why was there a slow response to the Pakistan floodings of 2010? (2 reasons)
- The global community was suffering from donor fatigue due to the recent Haiti earthquake
- The government of Pakistan had an uncoordinated response.
What are the four methods of transportation in a river?
Traction, saltation, suspension and solution.
What shape is the cross profile of the upper course?
A ‘V’ shape.
What is a drainage basin?
An area which ,if water is precipitated into, drains into a specific river.
What is a tributary?
A smaller river that joins a larger one within the same drainage basin.
What is a confluence?
The point at which two rivers join.
What is a watershed?
The boundary between two drainage basins, usually marked by highlands.
What is the source of a river?
Where a a river begins.
What is the mouth of a river?
Where a river meets with the ocean.
What is the catchment area?
The area within a drainage basin.
How do types of erosion differ in different courses?
Higher courses have more vertical erosion. Lower courses have more lateral erosion.
What is alluvium?
The sediment deposited by rivers.
What is a levee?
A bank formed by alluvium deposited through periodic flooding.
What is a delta?
When the mouth of a river deposits alluvium faster than the sea can remove it, forming a landmass.
What are the three types of delta?
- Fan-shaped: when the land around the river mouth arches and the river splits many times, creating a fan effect.
- Cuspate: the land around the mouth forms an arrow-head shape.
- Bird’s foot: The river splits on the way to the sea, each part of the river juts out into the sea, rather like a bird’s foot.
What is infiltration?
Water entering the ground.
What is surface runoff?
Water on the surface of the land.
What is afforestation?
Deliberately planting trees to decrease surface runoff.
What is a meander?
A bend in a river.
How do oxbow lakes form?
- In a meander, the river flows the fastest on the outer bend and slowest on the inner bend.
- This causes erosion in the outer bend and deposition in the inner bend.
- This exaggerates the shape of the meander until the meander connects in the middle, isolating a horseshoe shape from the current.
- This creates a straight river and a stagnant horseshoe shape, which is the oxbow lake.
What unit measures river discharge in a hydrograph?
Cumecs, or cubic metres per second.
What is lag time and how does it influence river discharge?
Lag time is how long it takes from water to end up in the rivers after being precipitated. The shorter the lag time the greater the river discharge.
