rainfall and interception

Question 1

precipitation

Answer 1

All liquid or solid phase aqueous particles that originate in the atmosphere and fall to the earth’s surface, measured above the canopy.

Question 2

conditions needed for cloud formation

Answer 2

vertical movement of air (for cooling and condensation)

air cools when it rises due to the dew point temp forming clouds.

Question 3

convectional air lifting

Answer 3

❑The warm air is a result of a heated surface of the earth.
❑ Convective rainfalls are of high intensity and are referred to as heavy rain or rainstorm.
❑ Usually they are of short duration and limited spatial extension.

Question 4

Frontal air lifting

Answer 4

✓ Cyclonic precipitation is usually linked to front systems.
✓ Accounts for the largest percentage of the total annual precipitation in temperate latitudes.
✓ Compared to convective rainfalls, the mean spatial extension and duration are significantly higher (continuous precipitation).

Question 5

Orographic air lifting

Answer 5

Occurs when air is forced to rise because of the physical presence of elevated land.

Question 6

rain shadow example

Answer 6

Death Valley, a desert in the U.S. states of California and Nevada, is so hot and dry because it is in the rain shadow of the Sierra Nevada mountain range, blocking the moist air coming in from the Pacific Ocean.

Question 7

British rain gauge network

Answer 7

• Almost 30% automatic gauges (TBRs)
• Majority of remainder daily read storage gauges
• 5 inch (127mm) diameter storage gauges still a standard because of long historical record
• 59 rain-gauges with 100+ year record
• Over 1,500 rain gauges with 30+ year record
• Over 14,000 closed gauges in the archive

Question 8

Global distribution of precipitation is influenced by the…

Answer 8

(1) general circulation of the atmosphere (large scale air movement),
(2) proximity to large bodies of water,
(3) topography. Precipitation is most abundant where air rises, and least abundant where it sinks. It also tends to be greater near oceans and lakes, and in higher elevations.

Question 9

Remote sensing

Answer 9

They provide a spatial resolution of areal precipitation to an extent impossible to achieve by point measurements due to the extreme spatial variability of rainfall.

• Radar precipitation measurement (bouncing radar off raindrops)
• Satellite (global coverage)

Question 10

interception.

Answer 10

Interception is the part of the rainfall that is intercepted by vegetative substances (the canopy) and which subsequently evaporates.

Interception can amount up to 15–50% of precipitation, which is a significant part of the water balance.

Question 11

Factors affecting interception

Answer 11

Meteorological parameters
Wind speed, promotes interception loss by evaporation.
duration
, height,
intensity and temporal distribution of precipitation,
wind, h2o delivered too quickly for plants to accommodate
radiation,
intensity of potential evaporation

Question 11

Characteristics of vegetation

Answer 11

type and age of vegetation, percentage of tree top coverage, seasonal development.

Interception loss of deciduous temperate forest is generally lower than for coniferous forest