Surface Water

Question 1

Water covers 71% of Earth’s surface and is the dominant agent governing:

Answer 1

environmental processes

Question 2

Top 3 countries with surface water:

Answer 2

1. Brazil
2. Russia
3. Canada (mostly in Arctic though)

Question 3

Water Use in Canada

Answer 3

most of our water use is for energy generation and industrial purposes: 58% thermal power gen, 18% manufacturing, 10% municipal, 8% agriculture, 4% mining

Question 4

What is the Hydrologic Cycle?

Answer 4

The transfer of water between the atmosphere, the ocean, lakes and stream and the crust (as groundwater)

Question 5

What is a stream?

Answer 5

any water that runs in a channel

Question 6

What is a river?

Answer 6

a large stream, although no specific size cut-off for a “river”

Question 7

Runoff enters channels that join other channels to form:

Answer 7

a drainage system (network of channels, sends water downhill)

Question 8

What is the watershed?

Answer 8

The total area feeding water to a stream

Question 9

First-order, second-order, third-order, fourth-order basins depend on:

Answer 9

how far from the source, first is almost the source (headwater), 1-4 is in the mountains/steep

Question 10

Drainage Patterns

Answer 10

Dendritic: looks like nerve ends
Radial: isolated high point with circular drainage, volcanoes -> stratovolcano
Trellis: parallel sheets, in Rocky mountains
Rectangular: looks like brain wrinkles

Question 11

Stream Discharge

Answer 11

The volume of water passing a point in a specific amount of time i.e m^3/s

Question 12

Stream Discharge Equation

Answer 12

• Q = AV
• Q is stream discharge
• A is the cross-sectional area of the stream channel
• V is flow velocity (the avg of velocities indicated by the arrows)

Question 13

Flow can be laminar or turbulent:

Answer 13

laminar: straight
turbulent: many different directions

Question 14

Which type of flow is likely to be most effective at transporting sediment? Why?

Answer 14

Turbulent because it uproots sediment into the water flow

Question 15

The amount of water in a river’s watershed increases:

Answer 15

downstream, with addition of tributaries

Question 16

What is the thalweg?

Answer 16

the part of the stream that has the highest flow velocity, goes the long route, carves out the deepest part (erosion), is most insulated from friction from stream bed, it moves throughout the stream

Question 17

What is the relationship b/w the water velocity and the depth?

Answer 17

Deepest goes fastest b/c protected from friction from stream bed

Question 18

Materials are carried in different ways within a stream

Answer 18

Suspended load, bed load, dissolved load

Question 19

What are the 3 types of stream channels and their shape?

Answer 19

1. Straight (self-explanatory)
2. Meandering (snaking)
3. Braided (self-explanatory)

Question 20

Braided stream type is associated with:

Answer 20

larger grain sizes and steeper slope, near headwater

Question 21

Flooding is a

Answer 21

natural process in healthy streams

Question 22

Why is there a delay between the rain event and the flood peak?

Answer 22

Floodwater comes from upstream and takes time to come downstream, farther the distance the water has to move, the longer the delay

Question 23

Streams may develop a graded profile

Answer 23

headwaters tend to be the steepest slope then flattens out, every stream tries to achieve this

Question 24

Headward erosion

Answer 24

erosion at the origin of a stream channel, which causes the origin to move back away from the direction of the stream flow, lengthening the stream channel.

Question 25

Stream piracy

Answer 25

occurs when a stream or river drainage system or watershed is diverted from its own bed, and flows instead down the bed of a neighbouring stream.

Question 26

Fluvial landscape evolution:

Answer 26

narrow V-shaped valley with enough time will turn into a floodplain

Question 27

Fluvial systems adjust to changes in Base Level:

Answer 27

any stream with enough time reaches graded profile

Question 28

Dams can cause problems

Answer 28

Creates artificial base level, now becomes new stream profile formed by sediment deposition

Question 29

What other types of problems, upstream and downstream, can be caused by construction of dams?

Answer 29

Must consider what’s underneath the reservoir, if limestone and porous then mountain can give way and create a tidal wave and kill everyone downstream

Question 30

Terrace

Answer 30

form when streams carve downward into their floodplains, leaving discontinuous remnants of older floodplain surfaces as step-like benches along the sides of the valley.

Question 31

Alluvial fan:

Answer 31

usually dry = continental, deposits sediment in fan-like way

Question 32

Delta:

Answer 32

sediment deposited when stream meets ocean and stops

Question 33

Progradation

Answer 33

growth of a river delta farther out into the sea over time

Question 34

Avulsion

Answer 34

basically switching channels b/c sediment deposit becomes high point and river goes around it

Question 35

Drainage System Maintenance is important because:

Answer 35

Need to avoid: polluted runoff and anoxic dead zones