Class 6 Science Chapter 14 Water, Water on Earth, Water Cycle, Sources of Water (For CBSE, ICSE, IAS, NET, NRA 2022)

Glide to success with Doorsteptutor material for CBSE/Class-6 : get questions, notes, tests, video lectures and more- for all subjects of CBSE/Class-6.

Water

Introduction

  • Water is one of the natural resources that is very important for existence of live on earth.
  • Nearly 71 % of the Earth՚s surface is water.
  • Oceans hold about 96.5 % of all Earth՚s water.
  • Various uses of water:
    • Bathing
    • Washing
    • Cooking
    • Drinking
    • Irrigation
    • Industrial Purpose, etc.
  • Excess or heavy rain results in floods and can damage crops, houses, and livestock.
  • In case there is less or no rain, the areas may suffer from severe drought leading to crop failure and shortage of water.
Water May Exist in Different Forms

Sources of Water

  • Rainwater
  • Groundwater in the form of Wells and Springs
  • Surface water in the form of Sea, Oceans, Reservoirs, Rivers, Streams.

Water Cycle

  • The process of movement of water from the surface of the earth is called water cycle.
  • It may further be defined as the process of cycling of water into different forms of matter.
  • This entire cycle is controlled by the sun and is better known as the hydrological cycle.
The Hydrologic Cycle

Evaporation

  • It is the process of changing water into vapour following which the water vapour goes up into the atmosphere forming clouds.
  • Higher temperatures result in faster rate of evaporation.

Condensation

It is simply defined as the change of the physical state of matter from the gas phase into the liquid phase.

Precipitation

It is the process in which water gets released from clouds in the form of rain, snow, or hail.

Collection

The rainwater gets collected into the river, ponds, well, and back to the sea after running off to the ground.

Transpiration

It is the process in which loss of water take space from plants through numerous pores in leaves and stems.

Water Conservation

Dams

  • Dams can restrict and confine the flow of water through huge barriers.
  • Confined water can be used for generating electricity, irrigation, and agricultural purposes, etc.
  • Dams also help in controlling floods.
  • A reservoir is a dam storing water.
  • Dams can displace local tribes, deforestation and may result in the loss of biological diversity.

Water Harvesting

  • It is a process of collecting rainwater for various household purposes.
  • Also, the process of storing rainwater for future use or for recharging groundwater is known as rainwater harvesting.
  • Water for this can be obtained from various resources:
    • Excess water from rooftops
    • Seasonal flood streams
    • Watershed management, etc.
  • Water harvesting helps in mitigating droughts and floods, recharges wells, used for daily household purposes.

Drinking Water Significance

Drinking Water Significance

Developed by: