the hydrological cycle

• closed system

  • no external inputs or outputs of water
  • driven by solar energy and gravitational potential energy
• water stores

  • hydrosphere-oceans- 96.5%
  • cryosphere `
  • atmosphere
  • biosphere
  • lithosphere
• limited amount of water for human use

  • water with shorter residence time contains fewer pollutants= better source for humand
  • non-renewable water= water not replenished eg held in cryosphere or deep groundwater
• fluxes vary annually

  • evaporation- varies by location and season eg lots of solar radiation or large supply of water
  • condensation- depends on amount of water in atmosphere and the temp(low)
  • precipitation- main flow of water, vary seasonally due to temperature and by location eg higher in tropics
  • cryospheric process- accumulation or ablation of snow and ice- varies with temp
• • largest and most important fluc is evaporation of ocean water into atmosphere
  • smaller and less important is evap of water held in surfaces and vegetation