Water Lesson 2: Physical Processes

Question 1

3 factors for rain to form?

Answer 1

-Air that is cooled to saturation point with a humidity of 100%
-Condensation nuclei, such as dust particles to facilitate the growth of water droplets in clouds
-Temperature below dew point

Question 2

Define saturation point

Answer 2

Stage at which no more of a substance can be absorbed into a vapour or dissolved into a solution

Question 3

Define dew point

Answer 3

-Dew forms as temperatures drop and objects cool down
-If the object becomes cool enough, the air around the object will also cool
-Colder air is less able to hold water vapor than warm air
-This forces water vapor in the air around cooling objects tocondense. When condensation happens, small water droplets form—dew

Question 4

Describe frontal rainfall

Answer 4

1) Warmer, lighter air is forced to rise over cold, denser air
2) Air cools as it rises and its ability to hold water vapour decreases
3) Condensation occurs and clouds and rain form

Question 5

Describe convectional rainfall

Answer 5

1) Land becomes hot, air above becomes warmer, expands and rises
2) Air cools as it rises and its ability to hold water vapour decreases
3) Condensation occurs and clouds develop
4) Air continues to rise then rain will fall

Question 6

Describe orographic rainfall

Answer 6

1) Air is forced to rise over a barrier like a mountain, it cools and condenses
2) Cloud forms and precipitation occurs
3) Leeward (downwind) slope receives little rain, which is the rain shadow effect

Question 7

Define interception

Answer 7

-Water is stored in the vegetation
-There are three types: interception loss (water retained by plants); through fall when water drops from leaves) and stem flow (when water trickles along branches/stems)

Question 8

Define infiltration

Answer 8

-Water is absorbed by the soil
-The infiltration capacity is the maximum rate at which rain can be absorbed and depends on a number of factors including the saturation level of the soil and slope angle

Question 9

Define direct runoff

Answer 9

This is water travelling over the surface of the ground

Question 10

Define saturated overland flow

Answer 10

Slower transfer which is caused by the water table rising to the surface. This is often caused by succession of winter storms

Question 11

Define through flow

Answer 11

Lateral transfer of water downslope through the soil below the surface but above the water table

Question 12

Define percolation

Answer 12

Deeper transfer of water into permeable rocks e.g. sandstone and chalk

Question 13

Define groundwater flow

Answer 13

Also known as base flow. This is the very slow transfer of percolated water through pervious or porous rock

Question 14

Name 3 outputs of water

Answer 14

Evaporation
Transpiration
Channel flow

Question 15

Define evaporation

Answer 15

Moisture is directly lost into the atmosphere from water surfaces and soil, as a result of the Sun’s heat

Question 16

Define transpiration

Answer 16

Biological process by which water is lost from plants and transferred into the atmosphere

Question 17

Define channel flow

Answer 17

Volume of water flowing within a river channel

Question 18

Factors affecting rates of evaporation and transpiration

Answer 18

Hours of sunlight
Temperature
Humidity
Wind speed
Size and depth of water
Vegetation cover
Surface colour

Question 19

Effect of temperature on EV and T

Answer 19

High temp increases KE of water - greater change of state to water vapour - increased rate

Question 20

Effect of surface colour on EV and T

Answer 20

Shorter wavelengths of light (blue end) absorb more light - darker colours absorb more - greater light intensity and greater heat increase rate