Water the elixir of Water the elixir of lifelife

• In our solar system water in the liquid form only found in earth

• 2/3 of the earth is covered by water• When we look at the earth it is

looks like a blue ball , so it is called blue planet or watery planet

• 97% of the water on the earth is saline

• Pure water contains only 3 % , out of which 2.67 cannot be utilized directly

Blue planetBlue planet

• The amount of water can be directly used is only 0.33%• Total quantity of water on the earth

is around 1386 lakh cubic metre• Saline water found in ocean, • Pure water found in river lake etc• It found in gases manner in the

atmosphere

Saline water

lake

• Total volume of water on the earth is almost constant

• From sea, lake, and from plants get heated up by sun and finally evaporates and condensed, as a result precipitation takes place

• Thus water is always in cyclical movement and it is called water cycle, due to this process the amount water remains constant

cyclical movementcyclical movement

• Largest amount of pure water found in polar ice blocks• % of pure water found in river

and lakes are 0.26 and 0.0006• Atmosphere contains about

0.04 %• 2.5 % of pure water found totally

on the earth

Ice cubesIce cubes

Surface water• Rivers are the major agent of surface water• Land use of the area is largely determine by the

amount of water flowing through• River origin from the mountain where dense

forest can be found where water flow throughout the year

• If river originates from slopes where plantation or mixed crops can be seen and the river will be less flow in summer

Rivers are the major agent of surface waterRivers are the major agent of surface water

• Rivers can be divided into two basis on their flow

• Perennial rivers and Perennial rivers and • Non perennial riversNon perennial rivers• Rivers that flows throughout the year called

Perennial rivers• Rain fall and melting of snow are the major

source of these river• Indus ,Ganges Brahmaputra are examples

• Some perennial rivers are depend solely on rain , which take its origin near the equator , where there is rain fall in almost days in year.• Amazon, Nile and Congo are examples• The only river which cross the equator

twice is the Congo, this perennial river originates from the forest of Africa

• All the rivers except Himalayan rivers in India have lean flow during summer and regular flow during monsoon

• Some part of the area water seeps into the earth, some area water dries up quickly but not in paddy fields• Factors which influence rate of seeping are• Different in the composition of soil particles• Topography of the land• Presence of organic matter

• When the water filters from the top soil inward is called infiltration, if it filters down due to gravitational pull and become underground water it is called percolation

• Water filters through the crack of rocks also

• There difference in rate of percolation, depending on the composition of soil

•Water infiltrates and get collected in rock layers these are called aquifers• These collected water finally

reach into the rivers and ponds as underground water