geo - water and carbon cycle

• system is a set of steps that occur to make something happen
• positive feedback is when a change in the environment causes a change in the system that amplifies the change
• negative feedback is when the it responds to a change in the environment to restore the original condition
• water cycle is a closed system
• evaporation occurs when energy from the sun hits the surface of water/land and causes liquid to change to gas. depends on solar energy, availability of water, humidity and temperature
• condensation is as air cools its able to hold less water vapour. the dew point is the temperature at which water vapour in the air turns to liquid water, the water molecules need something to condense on. if the surface is below the dew point it will sublimate, changing from gas to solid.
• when air rises it cools, as it cools it expands (adlabatic)
• convectional is localised warm surface heats the air above. this expands, becomes less dense and rises
• frontal is masses of different temperatures and densities meet. less dense warm air rises over the denser colder air
• orographic is when air is forced over hills
• high pressure, falling air. cloudless skies, dew on the ground in winter as air is sinking, low wind speeds, calm settled weather
• low pressure, rising air. large thunderclouds, high wind speeds, unsettled rainy weather
• cryospheric process is mainly accumulation and ablation
• zone of accumulation is upper part of the glacier where inputs of snowfall exceed outputs of melting
• zone of equilibrium separates the net loss from the net growth. its position determines whether the glaciar will grow or shrink
• zone of ablation is the lower part, more is lost than gained
• flashy hydrograph, impermeable geology, steep land, blocked drains, lack of vegetation, high drainage density and circular basin base
• subdued hydrograph, permeable geology, flat relief, good drainage system, high vegetation density, elongated/long drainage basin
• P = Q + E +/- change in storage

  Precipitation

  Q-runoff

  Evapotranspiration
• soil moisture recharge is soil water store will begin to fill agains
• soil moisture utilisation is when evapotranspiration exceeds precipitation- water store is used by plants
• soil moisture deficit us a deficit of soil water, plants will wilt
• soil moisture surplus is soil that has been filled as precipitation is greater than evapotranspiratiob
• water abstraction can cause sea water intrusion, impacts water stores, flows of water and subsidence
• deforestation short term impacts = no interception (increase in runoff), soil erosion, flooding and contamination
• deforestation long term impacts - no evapotranspiration, less convectional condensation and drought
• subsurface drainage removes excess water from the soil profile, through a network of pipes (tiles). main aim is to control the water table to fit the ideal growing conditions
• irrigation is human activity of controlling the amount of water to land to help production of crops
• eutrophication is excessive richness of nutrients in a lake or other body of water, frequently due to runoff from the land, which causes a dense growth of plant life. this process may result in oxygen depletion of the water body after the growth of surface algae blooms