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Life Support Systems - Coggle Diagram

- - - - Less than 3% of this is freshwater. Even less than this is accessible to humans.
  - - - Less than 10% countries possess 60% of the world's available freshwater supply. America has the largest share with 45%.
    - - Channel precipitation: about 10% of fallen rain falls directly into the river channel and flowing out into the ocean.
      - Interception: Precipitation that never reached the ground because it is stopped by vegetation.
        
        Underneath the canopy of a tree, the soil tends to be drier because of interception and interception loss. There is more water under the tree trunk because of stemflow. On the edges of the canopy there are less trees to intercept it, and there is throughfall, so there is a slight increase of water in the ground.
        
        Interception storage capacity: interception loss depends on how saturated vegetation is. When vegetation surfaces are dry they can retain a lot of water. So, initially, most rainfall is intercepted. However as rain continues and the vegetation becomes saturated, intercepted water will be lost by throughfall and stemflow. Interception loss therefore depends on how long the rain lasts for (duration) and how heavy (intensity) it is.
      - Throughflow: the process of how wet leaves shed excess water on the ground surface.
      - Stemflow: Stemflow is the flow of intercepted water down he trunk/stem of a plant.
      - Interception loss: Intercepted water evaporates up into the atmosphere directly off the plant and it leaves the drainage system
        
        Higher wind speed = more evaporation = more interception loss
        
        Vegetation type affects rate of interception loss: Interception loss from trees is greater than from grassland because they have a larger surface area to intercept water. Interception loss is greater from grassland than agriculture crops.
  - - - What happens to a parcel of air that has been heated at the air's surface?
        
        The ground is heated up by the sun's energy or insolation.
        
        Parcel of warm air rises due to convection.
        
        Because the parcel of air is warmer than its surroundings it is therefore less dense and buoyant. This is atmospheric instability.
        
        The dry adiabatic lapse rate states that cooling caused by adiabatic expansion will be about 10 degrees for every 1km.
        
        As the parcel of air cools it will eventually reach its dew point (condensation point).
        
        This is the temperature at which a given concentration of water vapour in air will begin to condense. This is when condensation occurs and a cloud form.
        
        Condensation at dew point forms clouds. Water droplet coalescence occurs when small water droplets join together to form bigger droplets in the cloud. Gravity causes water droplets to fall as precipitation.
        
        As condensation occurs latent heat is given off. The air becomes saturated with water. The latent heat being given off cools the parcel of air but at a slower rate of 7 degrees for every 1km.
        
        The air will continue to rise until it becomes the same temperature as the surrounding air. At this point condensation will stop and mark the top of the cloud.
        
        Air cannot rise any further as it is the same temperature as its surroundings. The atmosphere is now stable.
    - - 3/3rds of freshwater is frozen in the ice sheets of Antarctica and Greenland.
      - Water below ground amounts to 9% of all freshwater (permeable rock)
      - The average residence time of a water molecule is 20 days.