Earths water PPT#1

• The continuous movement of water from various places is called the Water Cycle or Hydrologic Cycle
• Water Cycle/Hydrologic Cycle


  1. Continuous flow of water between the atmosphere, geosphere, hydrosphere

  2. Water vapor may change its phase as it moves from one sphere to another

  3. The major source of energy is the sun

  4. No water is created nor destroyed, it just changes its form and location
• Evaporation


  • Process by which liquid water changes into water vapor
  • Water from various storages (Oceans, rivers, lakes, and soil) absorbs heat
• Each year about 500,000 km3 of water evaporates in the atmosphere, with 86% from the ocean and the remaining from other storages such as lakes, streams, and soil
• Transpiration


  Process by which plants and animals release water vapor into the atmosphere
• Evapotranspiration


  The collective water loss from an area due to evaporation and transpiration
• Condensation


  • Process by which water vapor changes into liquid water
  • When water vapor rises in the atmosphere, it expands and cools, releasing heat, and the atmosphere becomes a storage of water
• Precipitation


  • Process by which water falls to the Earth's Surface
  • Rain, snow, sleet, hail
• About 75% of all precipitation falls on Earth's oceans and the rest falls on land
• Runoff


  • Process of water flow from high elevation (mountains/land) to low elevation (ocean) due to gravity
  • Sources of runoff can either be snowmelt or liquid precipitation
• Infiltration


  • Process wherein water from land surface passes through the soil and rock
  • Can be discharged back to the surface or move deeper to the aquifer
• • Infiltration or Runoff depends on the topography, vegetation, and soil type
  • Steeper slope encourages runoff otherwise promotes infiltration
  • More plants encourages infiltration for it stops/slows down the flow of water
  • Depending on the soil type, infiltration may occur
• Water Budget


  • Accounts the supply of water and its flow on certain areas
  • Earth's water budget is balanced, but local water budgets are mostly unbalanced
• Factors affecting local water budget

  • Rate of evaporation and precipitation due to location (Climate of an area)
  • Rate of evaporation and precipitation due to seasons
  • Use of water