EQ1 - Hydrological Cycle

What type of system is the hydrological ?

Closed system . driven by solar and gravitational potential energy . No external input / output

What are the 4 stores of water

Hydrosphere

Atmosphere

Cryosphere

Lithosphere

What percentage of water stored in the hydrosphere ?

96.5%

What percentage of water is stored in atmosphere ?

0.001%

What percentage does the lithosphere and cryosphere store ?

1.7%

Define water budget

balance of water stored , entering and exiting a certain area . Assess the availability of water

Define flux

rate of flow between stores

e.g. precipitation , evapotranspiration , surface run off

Define residence time

amount of time water is typically stored

What is an oceans residence time

3500 years

What is the cryosphere’s residence time

15,000 years

What percentage of fresh water is accessible

2.5%

What percentage of water is accessible

1%

What is the main input in the cycle

precipitation ( rain/ sleet /hail '/snow )

What is the main output of the cycle

Evaporation , transpiration , discharge/channel flow

What are the 3 types of rainfall

1. Relief

2. Convectional

3. Frontal

Relief rainfall

Occurs because of landscape shape / topography

Happens due to change in air temperature

CCC

Convectional rainfall

Warmth in the air rises

Cools in atmosphere

forms cloud

Rainfall occur

Frontal rainfall

Warm air fronts meet cooler air fronts

warm air rise cool air dense false

two airs mix to form rainfall

HEAVY rainfall

7 flows of the hydrological cycle

1. Interception , plant intercepts water

2. Infiltration , soaked / absorbed

3. percolation transfer of water deep in soil / bed rock

4. Throughflow , lateral movement down slope

5. Groundwaters flow , SLOW transfer of percolated water into bedrock

6. Surface runoff , movement of water overland

7. River/channel flow , water enter channel of river

How does climate effect the drainage basin

Wet climate lots In drainage lots come out

Drier climate les IN / OUT

Change amount/type of precipitation/evaporation

Define drainage basin

area surrounding a river

How does soil effect the drainage basin

Affects different flows - surface run off

Soil absorbent affect flow

Determines infiltration rates

How does geology effect the drainage basin

Surface run off

Impacts percolation / groundwater flow rates

Impermeable rock not absorb water easily and permeable rock

Affects soil formation

How does relief effect the drainage basin

surface run off

steep slope occur quicker

amount of precipitation relief rainfall/convectional rainfall

How does vegetation effect the drainage basin

surface run off

vegetation allow to be infiltrated interception

important

How can river management disrupt the drainage basin cycle

Construction of reservoirs

Use for domestic supply

Irrigation , agriculture

How can deforestation disrupt the drainage basin cycle

Reduces evapotranspiration/transpiration

Less water into atmosphere

Increase infiltration rates , surface run off due to water log nature of soil , surplus water

How can changing land use disrupt the drainage basin cyle

Arable to pastoral farming : soil compact increase surface run off

Pastoral to arable : ploughing increases infiltration

How can urbanisation disrupt the drainage basin cycle

Impermeable surfaces

Increase surface run off

Flooding

What are the 5 components affected by human factors

Evaporation

Evapotranspiration

Surface run off

Infiltration ground water

Interception

Named example of humans disrupting drainage basin

Amazonia

Lower humidity

Less precipitation

Compact surface / soil more surface run off infiltration

Soil erosion / silt into rivers

More evaporation less transpiration

Explain a flashy hydrograph

Discharge line exponentially increase long rate of high peak discharge

Rising limb steep an falling limb

Lag time is short

Shows storm event , high rainfall , water logged

Explain a subdued hydrograph

Occur in area of less rainfall / slope

Rising limb shallow falling limb steeper

Lag time longer

Less water

Manageable drainage basin / changeable

Factors that affect shape of a flash hydrograph

1. intense storm exceed infiltration low evaporation

2. impermeable soil clay , slopes steep

3. Small basin , circular , streams flowing to main river

4. Vegetation minimal low density

5. Prior soil saturated

6. Urbanisation / concrete /deforestation

Factors that affect shape of a subdued hydrograph

1. steady rainfall

2. permeable rock

3. slopes gentle/flat

4. large drainage basin elongated few streams

5. high density vegetation

6. dry basin / water table low

7. rural low population , afforestation

Define water budget

Annual balance between inputs and outputs

What equation is used to calculate a water budget

P = E + R +/- S

Precipitation = evaporation runoff + / - storage

Defien river reigme

The annual variation of discharge in a river

what affects affect a river regime

1. size of river

2. seasons/amount of rainfall

3. temp

4. evaporation rates

5. geology

6. soil

7. vegetation

8. human activity

Amazon an example of river regime

High flow Dec-May wet season

June- Nov dry season

Human impact urbanisation / deforestation increase

Alaska example of a river regime

High flow April - August / snow melt

Low flow Sep- march / ice form

Large flow variability

Limited human impact