Hydrological cycle

Question 1

Interception

Answer 1

The CAPTURE AND STORAGE of precipitation by vegetation such that it doesn’t directly fall to the ground. The water may then be evaporated or absorbed by the plant (interception loss) or reach the ground ans throughfall or stemflow.

Question 2

Surface storage

Answer 2

Water that hasn’t infiltrated the surface and is stored either as temporary features or permanent.

Question 3

Soil moisture storage

Answer 3

Water stored in the subsurface soil horizons above the water table

Question 4

Groundwater storage

Answer 4

Percolated water which is held in aquifers in the phreatic zone, and recycles every 20,000 years.

Question 5

Hortonian overland flow

Answer 5

Movement of water along the surface when rainfall exceeds the infiltration capacity of the soil, due to intensity , antecedent events or impermeability.

Question 6

Saturated overland flow

Answer 6

Water moving along a slope due to all the pore spaces in the soil already being totally filled with water.

Question 7

Percolation

Answer 7

The downward movement of infiltrated water due to gravity through joints and pores of rock

Question 8

Groundwater flow

Answer 8

Water flows from the phreatic zone under gravity and hydrostatic pressure towards a river channel.

Question 9

Base flow

Answer 9

Discharge into a stream from a groundwater store, sustaining flow between rainfall events. Fairly constant but increases following rainfall.

Question 10

Groundwater recharge

Answer 10

Water that has soaked into the ground and moved through pores and fractures in the soil and rock to the water table to fill up previously depleted groundwater stores. Occurs when precipitation exceeds evapotransporation and water percolates downwards to the aquifer.

Question 11

Spring

Answer 11

Flows of water where the water table intersects with the surface.

Question 12

Evapotranspitation (EVT)

Answer 12

Combination of moisture loss due to evaporation and transpiration from the stomata of vegetation.

Question 13

Evaporation

Answer 13

Process whereby a liquid changes state into a gas with sufficient heat, creating water vapour.

Question 14

Transpiration

Answer 14

The movement of water within plants and its loss as vapour through the stomata to the atmosphere.

Question 15

Water table

Answer 15

The upper level of the phreatic zone, with its location varying seasonally depending on precipitation levels.

Question 16

Phreatic zone

Answer 16

Permanently saturated zone within solid rocks and sediments.

Question 17

Aeration zone

Answer 17

Zone under the surface that is seasonally wetted and dries out above the water table.

Question 18

Aquifers

Answer 18

Rocks that contain significant quantities of water, permeable rocks such as sandstones and limestones.

Question 19

Porosity

Answer 19

The proportion of pore space relative to solid material and therefore ability to hold water.

Question 20

Permeability

Answer 20

The rate and ease at which water may be transmitted within a rock or pass through it.

Question 21

Antecedent moisture

Answer 21

Moisture that is retained in the soil after a period of rainfall.

Question 22

Infiltration capacity

Answer 22

The maximum rate at which rain can be absorbed by a soil in a given condition.