WATER CYCLE WATER CYCLE WARM UP HTTPS WWW

WATER CYCLE

WATER CYCLE – WARM UP HTTPS: //WWW. BRAINPOP. COM/SCIENCE/EARTHSYSTEM/WA TERCYCLE/

WATER CYCLE • WATER IS AN INTEGRAL PART OF LIFE ON THIS PLANET. IT IS AN ODORLESS, TASTELESS, SUBSTANCE THAT COVERS MORE THAN THREEFOURTHS OF THE EARTH'S SURFACE. • MOST OF THE WATER ON EARTH, 97% TO BE EXACT, IS SALT WATER FOUND IN THE OCEANS. • WE CAN NOT DRINK SALT WATER OR USE IT FOR CROPS BECAUSE OF THE SALT CONTENT. WE CAN REMOVE SALT FROM OCEAN WATER, BUT THE PROCESS IS VERY EXPENSIVE.

WHY IS THE WATER CYCLE IMPORTANT? • ONLY ABOUT 3% OF EARTH'S WATER IS FRESH. • TWO PERCENT OF THE EARTH'S FRESHWATER (ABOUT 66% OF ALL FRESH WATER) IS IN SOLID FORM, FOUND IN ICE CAPS AND GLACIERS. BECAUSE IT IS FROZEN AND SO FAR AWAY, THE FRESH WATER IN ICE CAPS IS NOT AVAILABLE FOR USE BY PEOPLE OR PLANTS. • THAT LEAVES ABOUT 1% OF ALL THE EARTH'S WATER IN A FORM USEABLE TO HUMANS AND LAND ANIMALS. • THIS FRESH WATER IS FOUND IN LAKES, RIVERS, STREAMS, PONDS, AND IN THE GROUND. (A SMALL

EVAPORATION • LIQUID WATER CHANGES TO A GAS (WATER VAPOR) • TEMPERATURE IS A MAJOR FACTOR IN EVAPORATION. BOILING WATER EVAPORATES FASTER THAN COLD OR ROOM TEMPERATURE WATER. • WHEN WATER EVAPORATES, IMPURITIES ARE LEFT BEHIND. WATER GOES INTO THE ATMOSPHERE CLEANER THAN IT WAS ON EARTH!

CONDENSATION • GAS CHANGED TO LIQUID • WHEN WATER DROPLETS FORMED FROM CONDENSATION ARE SMALL, THEY REMAIN SUSPENDED IN THE ATMOSPHERE AS CLOUDS (OR FOG AT GROUND LEVEL).

PRECIPITATION • WHEN CONDITIONS (TEMP AND PRESSURE) ARE RIGHT, THE SMALL DROPLETS IN THE CLOUDS TURN INTO LARGE DROPLETS! • PRECIPITATION CAN ALSO BE

RUNOFF • WATER THAT RETURNS TO EARTH AS PRECIPITATION RUNS OFF THE SURFACE OF THE LAND FLOWS DOWN THE HILLS INTO STREAMS, RIVERS, LAKES AND PONDS. EVENTUALLY THAT WATER RETURNS TO THE OCEAN! • THE OCEAN IS WHERE A GREAT DEAL OF

INFILTRATION/PERCOLATION INFILTRATION: • RAIN WATER PUDDLES IN LOW LYING AREAS (MUD PUDDLES!) • IF THE GROUND IS NOT SATURATED, WATER SOAKS THROUGH THE SURFACE OF THE LAND! PERCOLATION: • ONCE THE WATER HAS SOAKED INTO THE SURFACE OF THE GROUND, IT BEGINS PERCOLATING (MOVING THROUGH) THE ROCK LAYERS AND SOIL! THIS NATURAL FILTERING CLEANS THE WATER!

TRANSPIRATION • PLANTS WAY OF SWEATING! • PLANTS ABSORB WATER FROM THE SOIL TO THE STEMS AND LEAVES. SOME WATER IS USED FOR PHOTOSYNTHESIS AND THE REST EVAPORATES FROM THE LEAVES. THIS ADDS TO THE WATER VAPOR IN THE AIR!