2. The Water Cycle The Water Cycle

4. Arguably the most important natural phenomenon on Earth, the water cycle, also known as the hydrologic cycle, describes the constant movement and endless recycling of water between the atmosphere, land surface, and under the ground. The hydrologic cycle supplies the force needed for most natural processes, thus supporting life itself.

5. The Water Molecule H20 consists of one atom of oxygen bound to two atoms of hydrogen. The water molecule has a positive charge on the side of hydrogen atoms and a negative charge on the other side. Water molecules tend to attract each other because the positive ends attract to the negative ends. H20 consists of one atom of oxygen bound to two atoms of hydrogen. The water molecule has a positive charge on the side of hydrogen atoms and a negative charge on the other side. Water molecules tend to attract each other because the positive ends attract to the negative ends.

6. Water is a “universal solvent: and wherever it goes throughout the water cycle, it takes up valuable chemicals, minerals and nutrients. Water is a “universal solvent: and wherever it goes throughout the water cycle, it takes up valuable chemicals, minerals and nutrients.

7. Condensation The change from a gas to a liquid. In the water cycle, the change from water vapor to water.

8. Condensation & Convection Warm air rises Warm air rises Air cools and can no longer hold vapor Air cools and can no longer hold vapor Process known as CONVECTION Process known as CONVECTION

9. Condensation & Cloud Formation Cooling of water vapor forms CLOUDS Cooling of water vapor forms CLOUDS Other ways clouds are formed Other ways clouds are formed Convergence Convergence Lifting of air by fronts Lifting of air by fronts

10. Precipitation

11. Snow Snow is a type of precipitation like rain but at cooler temperatures Snow is a type of precipitation like rain but at cooler temperatures Usually reaches the ground and stays Usually reaches the ground and stays Eventually melts and becomes runoff in streams Eventually melts and becomes runoff in streams

12. Rain Rain Type of precipitation during warmer weather Type of precipitation during warmer weather Occurs when clouds become too full Occurs when clouds become too full Falls to earth in the form of water and runs off to streams & rivers Falls to earth in the form of water and runs off to streams & rivers

13. Freshwater Storage Freshwater Storage Water may be stored temporarily in the ground, oceans, lakes, rivers, and ion ice caps and glaciers.

14. The world’s two main reservoirs of fresh water are the great polar ice caps, and the ground. If all of the ice in the ice caps and other glaciers melted, it would raise the sea level by about 260 ft.

15. In temperate climates, water is found in depression storage or surface water puddles, ditches, and anywhere else that runoff water can gather. This is a temporary form of storage In temperate climates, water is found in depression storage or surface water puddles, ditches, and anywhere else that runoff water can gather. This is a temporary form of storage

16. Freshwater Flow

17. A hydrologist is particularly interested in stream flow -- the 31% of precipitation which runs off into rivers, streams and lakes.

18. About 3% of this water will seep underground About 3% of this water will seep underground About 31% will run off into rivers, streams and lakes About 31% will run off into rivers, streams and lakes About 66% of the water returns to the atmosphere through evaporation and transpiration About 66% of the water returns to the atmosphere through evaporation and transpiration

19. Surface Runoff When precipitation rate exceeds infiltration rate, or when soil is saturated, water begins to move down slope on ground surface. When precipitation rate exceeds infiltration rate, or when soil is saturated, water begins to move down slope on ground surface.

20. Surface Runoff surface runoff gradually flows into gullies, streams, lakes, or rivers. Water in streams and rivers flows to the ocean, seeps into the ground, or evaporates back into the atmosphere. surface runoff gradually flows into gullies, streams, lakes, or rivers. Water in streams and rivers flows to the ocean, seeps into the ground, or evaporates back into the atmosphere.

21. Water Storage in Oceans

22. Snowmelt Runoff to Streams Precipitation falls in the form of rain and snow Precipitation falls in the form of rain and snow When the snow melts it runs into streams which eventually dump into the ocean When the snow melts it runs into streams which eventually dump into the ocean

24. Infiltration

25. -Rain water soaks into ground through soil and underlying rock layer. -Water cleaned as impurities filtered

26. -Some water remains underground as groundwater. -Some water returns to surface at springs or low spots downhill.

27. Groundwater Storage

28. -then stored underground in rock crevices and in the pores of geologic materials that make up the Earth's crust - water seeps downward underground into soil and rock crevices

29. -Water storage under the ground largely depends on the geologic features related to the types of soil and the types of rocks present at the storage locations. -underground storage occurs in the soil, in aquifers, and in the crevices of rock formations

30. Transpiration The process of evaporation from plants. Basically, plants sweating.

32. Transpiration Cont. Environmental factors that affect transpiration: Light Light Temperature Temperature Humidity Humidity Wind Wind Soil water Soil water