Water

• Distribution of Water Bodies
  • Earth's surface: 71% water, 29% land
  • Distribution ratio: 97.3% oceans (saline), 2.7% fresh water
  • Fresh water breakdown:
    • Ice-caps: 2.0%
    • Groundwater: 0.68%
    • Fresh water lakes: 0.009%
    • Inland seas & salt lakes: 0.009%
    • Atmosphere: 0.0019%
    • Rivers: 0.0001%
  • Salinity: Amount of salt in grams per 1,000 grams of water (Average ocean salinity is 35 parts per thousand)
• Water Cycle
  • Continuous movement of water among oceans, atmosphere, and land
  • Key processes:
    • Evaporation: Sun heats water, turning it into water vapor
    • Condensation: Vapor cools and changes into water droplets (clouds)
    • Precipitation: Falling of moisture as rain, snow, or sleet
    • Transpiration: Release of water vapor by plants
• Ocean Circulation
  • Movement of ocean water distinctly different from calm lakes/ponds
  • Waves:
    • Rise and fall of water on the surface
    • Caused by winds pushing the surface
    • Extreme events: Tsunamis (huge tidal waves caused by earthquakes/volcanic eruptions)
  • Tides:
    • Rhythmic rise and fall of ocean water twice a day
    • Caused by the gravitational pull of the Sun and the Moon
    • Types: Spring tides (high range) and Neap tides (low range)
  • Ocean Currents:
    • Streams of water flowing constantly on the ocean surface in definite directions
    • Types:
      • Warm currents: Originate near the equator (e.g., Gulf Stream)
      • Cold currents: Originate from polar areas (e.g., Labrador Current)
    • Importance: Influences temperature and provides best fishing grounds where warm and cold currents meet
• Conservation of Water
  • Need: Scarcity of clean water due to population growth, urbanization, and pollution
  • Methods:
    • Rainwater harvesting
    • Efficient irrigation methods like drip irrigation
    • Preventing industrial and domestic water pollution
    • Turning off taps when not in use