The Hydrosphere Flashcards
What are the different stages of the water cycle?
Evaporation
- Part of evapotranspiration
- Where moisture is lost to the atmosphere due to air or heat movements
Transpiration
- Part of evapotranspiration
- Where water is lost from the leaves of plants
Condensation
- Where water changes from a gaseous form to a liquid form due to cool temperatures
- Can only occur if there is a solid for moisture to be deposited on e.g. dust particles
- Dew point is the temperature at which air needs to be cooled at before it comes saturated
- Sublimation is when dew point is below freezing and the water vapour turns into snow and frost
Precipitation
- When large masses of moist air are rapidly cooled beyond dew point
- Water droplets are formed and are dropped when too heavy to be supported
Run Off
- Where water follows a steep gradient
Infiltration
- Where water passes through soil
Recall facts about the sources of water and their amounts.
2.65% of water on earth is fresh water
- Plants - 0.001%
- Atmosphere - 0.01%
- Rivers, lakes and marshes - 0.02%
- Groundwater - 0.61%
- Ice caps and glaciers - 2.14%
- Ocean water - 97.2%
Total supply of water - 1 385 000 000 km^3
97% is salty and oceanic
1% fresh water in lakes, rivers and underground reserves
2% snow and ice
0.001% atmosphere
How does runoff and topography affect the water cycle?
- Runoff pools the water together. This can create mass flooding.
- Topography mainly plays a vital role in orographic rainfall.
How does insolation affect the water cycle?
- The exposure of sunlight will affect the rate at which water evaporates and transpires.
- Cooler areas will cause condensation and precipitation.
How does ocean currents affect the water cycle?
- Affects how much moisture in the air.
- Cold currents will be more rainy - less moisture.
- Warm currents will have more energy - more moisture.
How does glaciation affect the water cycle?
- Freezes and stores water away from the water cycle
- Can store water for as long as 1000 years
- Moves rocks and affects landscapes
How does gravity affect the water cycle?
- Precipitation occurs when water water droplets are too heavy to be supported by the atmosphere
- Runoffs, topography
What are the different types of floods?
Slow-onset flood
- Develops over a series of days and can last for weeks
Rapid-onset flood
- Occurs very quickly
- Mountain headwater areas are more prone
- May last one or two days
Flash-floods
- Occurs when intense storms deposit a large amount of water in a brief period of time
- Little warning and can reach peak in a matter of minutes
Define drought.
- Prolonged periods of below average rainfall
- More likely to occur in areas of a low average rainfall
- Contributes to land degradation - wind erosion - desertification
Describe the different spacial factors that affect the distribution of fresh water.
- How large land masses are and their location to the equator affects how much water is available
- Topography directly links with this
- large land masses one or near the equator would be generally drier and more humid
- Dry areas of the world will have less water compared to their wetter counterparts
- River systems will transport and distribute water
- Lakes will collect water
- Ice caps can store water for hundreds or thousands of years
What is the El Niño, “Little Boy”?
- Starts around November-January
- Rain and flooding along Pacific coast
- warm water disrupts food chains
- Tornadoes and thunderstorms in southern US
- Fewer than normal hurricanes in Atlantic
- Drier conditions
- Extensive warming of central and eastern Pacific
- Focus of convection moves from Australia/Indonesia region to central tropical Pacific Ocean
- Weaker easterly trade winds
- Identified with low (negative) values of SOI (Southern Oscillation Index)
What is the La Niña, “Little Girl”?
- AKA El Viejo “Old Man” or Anti ENSCO event (anti-El Nino- Southern Oscillation)
- Snow and rain on west coast
- Unusually cold weather in Alaska and warm weather in USA
- Drought in South West
- Higher than normal hurricanes in Atlantic
- Cooler ocean temperatures across central and eastern tropical Pacific Ocean
- Increased convection/cloudiness over tropical Australia, Papua New Guinea and Indonesia
- Stronger easterly trade winds
- High (positive) SOI values
How do warm and cold ocean currents affect rainfall, climate and location?
Warm ocean currents
- Bring higher and more frequent bouts of precipitation
- Forms climates that are warmer and wetter
- Located from the equator
Cold ocean currents
- Generally drier weather conditions
- Most of the world’s deserts are formed because of these
- Based from the poles
What are the effects of glaciation on the land, its effect on sea levels and precipitation and what can it form or lead to?
Land
- move rocks through sublimation
- create a variety of land forms: moraines, crevasses, valleys, cirques etc.
- extremely erosive
Sea levels and precipitation
- Reduce and withhold water from the water cycle
- Water as a solid is less dense - it floats on liquid water. However, once it melts …
- Glaciers
- Ice caps
- Sea ice
- Icebergs
NEED RESEARCH
Temporal rainfall changes over long, medium and short term
Long term rainfall
- very wet and very dry cycle
- wetting and drying season
Medium term rainfall
- balanced
Short term rainfall
- frequent but short periods of precipitation
- drier location
