5.2A - Hydrological Cycle

Question 1

What is hydrological cycle

Answer 1

linked processes:
- inputs (precipitation patterns and types: orographic, frontal, convectional);
- flows (interception, infiltration, direct runoff, saturated overland flow, throughflow, percolation, groundwater flow)
- outputs (evaporation, transpiration and channel flow).
- inpu

Question 2

What is the effect of form and amount of inputs

Answer 2

• Form: rain, snow or hail. Clearly, with snow, entry of water into the drainage system will be delayed.
• Amount: this will affect the amount of water in the drainage basin and the fluxes within it

Question 3

What is the the effect of seasonality and distribution on drainage basins

Answer 3

• Intensity: the greater the intensity, the greater the likelihood of flooding.
• Seasonality: this is likely to result in the drainage basin system operating at different flow levels at different times of the year.

Question 4

What is the effect of distribution on drainage basin

Answer 4

Distribution: this is significant in very large drainage basins, such as the Nile and the Ganges, where tributaries start in different climate zones.

Question 5

What are the seven types of flows

Answer 5

(interception, infiltration, direct runoff, saturated overland flow, throughflow, percolation, groundwater flow)

Question 6

Define interception

Answer 6

the retention of water by plants and soils which is subsequently evaporated or absorbed by the vegetation

Question 7

Define inflitration

Answer 7

the process by which water soaks into, or is absorbed by, the soil.

Question 8

Define percolation

Answer 8

similar to infiltration, but a deeper transfer of water into permeable rocks.

Question 9

Define throughflow

Answer 9

the lateral transfer of water downslope through the soil

Question 10

Define groundwater flow

Answer 10

the very slow transfer of percolated water through pervious (permeable) or porous rocks

Question 11

define surface run off

Answer 11

the movement of water that is unconfined by a channel across the surface of the ground. A.k.a. overland flow

Question 12

Define river or channel flow

Answer 12

takes over as soon as the water enters a river or stream; the flow is confined within a channel

Question 13

State three types of outputs

Answer 13

Evaporation, transpiration and discharge

Question 14

Define evaporation

Answer 14

the process by which moisture is lost directly into the atmosphere from water surfaces, soil and rock

Question 15

Define transpiration

Answer 15

the biological process by which water is lost from plants through minute pores and transferred to the atmosphere

Question 16

Define discharge

Answer 16

Discharge (channel flow): into another, larger drainage basin, a lake or the sea

Question 17

define orographic

Answer 17

• Orographic precipitation occurs when moist air is forced upwards by terrain
• aka relief rainfall

Question 18

define frontal

Answer 18

Frontal rainfall occurs when warm air is forced to rise over cold air. The moisture in the warm air condenses as it cools which causes clouds and rain

Question 19

Define conventional

Answer 19

Convectional rainfall occurs when the sun’s energy heats the surface of the Earth, causing water to evaporate to form water vapou