Water cycle

• The hydrosphere associates with ice and liquid states for example lakes and rivers
• The cryosphere refers to water in the form of ice on earth.
• The lithosphere associates with the solid outer parts of the earth (crust and upper mantle) portions of the earth including rocks and soil.
• A water cycle is the continuous movement of water from the ocean to the atmosphere to the land and back to the ocean.
• The water system is a closed system, there is a fixed amount of water on the earth and atmosphere and water can exist as a solid, liquid and gas so is interchangeable.
• Oceanic water contains dissolved salts. The pH has fallen which is linked to the increase in atmospheric carbon.
• The five parts of the cryospheric water are sea ice, ice sheets, ice caps, alpine glaciers and permafrost.
• Sea ice forms when water in oceans are cooled to temperatures below frozen.
• Ice sheets form in areas where snow that falls in winter does not melt entirely over the summer. Over time the snow thickens and denses. They contain enormous quantities of water.
• Ice caps are thick layers of ice on land, usually found in mountainous areas and tend to be dome shaped.
• Alpine glaciers are thick masses of ice found in deep valleys which can also be used as reservoirs.
• Permafrost is soil and rock that is underground that remains frozen for at least two consecutive years, found beneath ice free regions of the Antarctic continent. The melting releases large amounts of carbon dioxide and methane.
• The four sections of terrestrial water are surface, ground, soil and biological water.
• Surface water is free flowing water of rivers and water of ponds and lakes.
• Ground water collects underground in the pores in rocks and is recharged from and eventually flows to the surface.
• Soil water is held together with air in unsaturated weathered layers of the earth. This process effects run off potential and is key for evaporation and transpiration.
• Biological water - water stored in all the biomass. Trees take in water via their roots and lost via transpiration through the stomata which helps regulate climate.
• Atmospheric water

  • water vapour absorbs, reflects and scatters incoming solar radiation keeping the correct temperature.
  • Cold air cannot hold as much water vapour than warm air
  • the poles = quite dry
  • tropics = very humid.
  • Increase in water vapour in atmosphere = increased atmospheric temperature
• Positive feedback is where the changes work to reinforce the direction o change. Makes the problem worse
• Negative feedback is where the changes work to counter the change. Makes the problem better.
• dynamic equilibrium is when the system has equal inputs and outputs
• Sublimation is the transfer from a solid to a gas
• Desublimation is the change from gas to solid
• There are three types of rain; relief, convectional & frontal
• A drainage basin is an open system which is an area of land drained by a single stream
• Water shed is the boundary and divides one river basin from it's neighbour
• A tributary is a small stream or river that flows into a larger river
• A confluence is where two rivers meet
• A source is where the river begins
• The mouth is where as river meets the sea/lake
• The river basin is the area drained by its river and tributaries
• water table - the debt at which soil pore spaces become completely saturated with water
• Leaf drip is water dripping off the leaves to the ground surface
• Stem flow is the process that directs precipitation down plant branches and stems
• Channel fall is precipitation directly entering the river channel
• Soil water is water stored in the soil above the water table
• What changes the magnitude of stores?

  urbanisation

  deforestation

  farming

  storms

  seasonal change
• Precipitation = total run off + evapotranspiration +/- storage
• River discharge = cross sectional area x rivers mean velocity
• Lag time is the time taken from peak rainfall to peak flow