Final - Surface Water

Question 1

Define Wetlands

Answer 1

Land where an excess of water is the dominant factor determining the nature of the soil development and the types of animals and plant communities living at the soil surface. It spans a continuum of environments where terrestrial and aquatic systems intergrade

Question 2

Define Marshes

Answer 2

Wet most of the time. Grassy or reedy. Can be salty (tidal) or fresh. Shallow. Most common wetland in N.A.

Question 3

Define Swamps

Answer 3

Woody plants, often treed. Deeper water (>1m). Shrub and forested swamps. Nutrient rich.

Question 4

Define Bogs

Answer 4

Water from precipitation, mostly. Thick mat of vegetation (peat) rather than soil. Often acidic. Soft, spongy, organic

Question 5

Define Fens

Answer 5

Like bogs, but fed more from surface water or groundwater. More nutrients, higher pH. Often associated with glacial kettles.

Question 6

Which three countries account for the most peat stock, and therefore carbon storage of this source type?

Answer 6

1. Canada, 2. Russia, 3. Indonesia

Question 7

Which three countries account for the largest emissions from peat degradation?

Answer 7

1. Indonesia, 2. Russia, 3. China

Question 8

How much of canada is covered in peatlands?

Answer 8

12%, or 1.2 x 10^6 km2

Question 9

How much of Canada is covered in wetlands?

Answer 9

14%, or 1.4 x 10^6 km2

Question 10

How much of global wetlands occur in Canada?

Answer 10

14%

Question 11

Which provinces account for the majority of Canada’s wetlands?

Answer 11

Ontario, Yukon, Manitoba

Question 12

How many lakes are there in Canada?

Answer 12

> 32,000

Question 13

What is the largest lake in the world and how much of global lake water does it account for?

Answer 13

Lake Baikal, 20%.

Question 14

How much of Canada’s area is freshwater?

Answer 14

8.9%, 891,163km2

Question 15

What constitutes laminar flow?

Answer 15

Re less that 500

Question 16

What constitutes turbulent flow?

Answer 16

Re greater than 2000

Question 17

What factors influence river velocity change?

Answer 17

• shape of channel
• input
• surface characteristics
• slope

Question 18

What is a downfall of a stilling well?

Answer 18

Being automated, it’s subject to errors if not routinely checked

Question 19

What are three methods of measuring discharge?

Answer 19

1. Velocity-area method
2. Tracer Dilution method
3. Float measure method (surface only)

Question 20

What are two tracer dilution methods?

Answer 20

1. Constant

2. Dump

Question 21

What are some advantages/disadvantages of the tracer dilution method?

Answer 21

Advantage: useful in turbid waters where meters can be damaged
Disadvantage: must consider stagnant water, vegetation, water movement

Question 22

What two things does hydrograph character depend on?

Answer 22

1. Precipitation characteristics (magnitude, intensity, duration, distribution, phase)
2. Basin Characteristics (slope angle, slope shape, soil type, soil thickness, initial soil moisture conditions, anthropogenic impacts, basin size, basin shape)

Question 23

How are unit hydrographs used?

Answer 23

Use type of precipitation event to predict discharge/flooding conditions

Question 24

What are the three mechanisms of fluvial transport?

Answer 24

1. Advection
2. Diffusion
3. Dispersion

Question 25

Define Advection

Answer 25

Movement of tracer resulting from the current (mean flow of water)

Question 26

Define Advective Flux

Answer 26

Amount of tracer transported per unit time, per unit area perpendicular to current

Question 27

Define Diffusion

Answer 27

Tracer mixing and spreading from random molecular motion within fluid

Question 28

Define Dispersion

Answer 28

Mixing due to velocity gradients in fluid (shear dispersion)

Question 29

How can solute tracers be lost?

Answer 29

- temporary storage | - decay or sorption of solute

Question 30

What are the two methods of quantifying stream order?

Answer 30

- Strahler | - Shreve

Question 31

What 6 factors influence overland flow?

Answer 31

- Precipitation intensity - Snow melt rate - pre-existing soil saturation level - soil type (hydraulic permeability) - Ground cover - Topography/terrain characteristics

Question 32

Under what two conditions does surface runoff occur?

Answer 32

1. Infiltration excess overland flow (unsaturated soil, infiltration can't keep up) 2. Saturation excess overland flow (saturated soil, no room for infiltration)

Question 33

Define Interflow

Answer 33

Lateral movement of water through the unsaturated zone

Question 34

Define Artificial Recharge

Answer 34

Practice of artificially increasing the amount of water entering a groundwater reservoir

Question 35

What is artificial recharge used for?

Answer 35

waste disposal, secondary oil recovery, land subsidence problems, water resource management

Question 36

Define Flooding

Answer 36

a rising stage level associated with excess discharge in response to storms or seasonal melt

Question 37

Why is it useful to understand flooding?

Answer 37

- land-use planning and zoning - insurance - infrastructure design - floodplain delineation

Question 38

Define bankfull

Answer 38

threshold stage before river flows over banks

Question 39

Define mean annual flood and how often does it occur?

Answer 39

breaches channel banks onto floodplain every 2.33 yrs (P = 43%)

Question 40

What are the three methods of flood prediction?

Answer 40

1. Hydrographs 2. Recurrence Interval 3. Rational Method

Question 41

Why is BC subject to some of the largest floods in NA? (4)

Answer 41

- rain on snow melt events - autumn and winter frontal rains - spring melt or "freshet" - heavy summer rains (convectional and frontal)