Land and Water, Hydrological Cycle

Question 1

Hydrology

Answer 1

The movement and distribution of water

Question 2

What are the two human impacts on the hydrological cycle?

Answer 2

1. Water quantity and distribution
2. Water quality

Question 3

Why is water considered an extremely flexible and manageable resource?

Answer 3

It is both mobile and renewable. It can be stored, diverted, transported, and recycled in various ways and states

Question 4

What role does water play in the global climate system?

Answer 4

Water evaporates over tropical oceans near the Equator. Latent heat is absorbed by water molecules. This water is transported towards the poles where it condenses, releasing that latent heat

Question 5

What pathway maintains the balance between precipitation and evaporation over land and water?

Answer 5

Runoff

Question 6

Runoff

Answer 6

The flow of water across the Earth’s surface that is absorbed through soil or transported to river channels

Question 7

What are the five types of runoff?

Answer 7

1. Interception
2. Infiltration
3. Percolation
4. Throughflow
5. Overland flow (two types)

Question 8

Interception

Answer 8

Vegetation interupting the flow of water (varies between types of vegetation)

Question 9

Inflitration

Answer 9

Water transfer into soil. Is determined by hydraulic condictivity, soil porosity, cracks in soil, and antecedent moisture

Question 10

Percolation

Answer 10

The vertical movement of water through soil, continuing until an impermeable or saturated layer is met. Also influecned by relief

Question 11

Throughflow

Answer 11

The lateral, downslope flow of water that feeds into streams

Question 12

What are the two types of overland flow?

Answer 12

1. Hortonian overland flow
2. Saturated zone overland flow

Question 13

Hortonian overland flow

Answer 13

If rainfall intensity is greater than infiltration capacity, excess water is transferred downslope to the channel or infilitrates at a more permeable part of the slope

Question 14

Saturated zone overland flow

Answer 14

Occurs when saturated soil has reached its full infiltration capacity, thus causing the water table to rise to the surface. Excess water pools on the surface and is conveyed downslope

Question 15

How is discharge (stramflow) measured?

Answer 15

Q = V × A

Question 16

What do magnitude and frequency mean in the context of hydrology?

Answer 16

Magnitude: The size of the flood as measured by discharge

Frequency: How often a flood occurs as measured by recurrence intervals

Question 17

How is flow regime variablity measured?

Answer 17

Coefficient of variance

CV = Std dev of flow/ Mean flow

Question 18

Atmospheric rivers

Answer 18

Giant bands of water vapour in the atmosphere resulting in intense, sustained rainfall

Question 19

What has happened to New Zealand’s wetlands?

Answer 19

Almost all of New Zealand’s wetlands have dissapeared due to water diversion and other human activities

Question 20

What has been the consequence of wetland removal?

Answer 20

More severe floods, less infiltration of water, greater vulnerbaility to storm and flood events