WaterCycleReview.ppt Civil Engineering Notes
- 1. Water Cycle Bell Work: Where does the water cycle get its energy from?
- 2. What is the water cycle? • The water cycle describes the existence and movement of water on, in, and above the Earth. • Water is always in motion • Water is always changing states –Liquid –Solid –gas
- 3. Hydrologic Cycle • The water cycle can also be called the Hydrologic Cycle… WHY? • Since the water cycle is truly a "cycle," there is no beginning or end. • Water can change states among liquid, vapor, and ice at various places in the water cycle • These processes have been happening over millions of years. • The water in the apple you ate yesterday may have fallen as rain half-way around the world last year or could have been used 100 million years ago by Mama Dinosaur to give her baby a bath.
- 4. Components of the Water Cycle • Water storage in oceans • Evaporation • Sublimation • Evaporation • Water in the atmosphere • Condensation • Precipitation • Water storage in ice and snow • Snowmelt runoff to streams • Surface runoff • Stream flow • Freshwater storage • Infiltration • Ground-water storage • Ground-water discharge • Springs
- 5. Water storage • 96.5% of the water on earth is in the oceans • 3.5% of the water on earth is fresh • 90% of the evaporated water contained in the water cycle came from the ocean • Ice caps and glaciers
- 7. Evaporation • Evaporation is when the sun heats up water in rivers or lakes or the ocean and turns it into vapor or steam. • The water vapor, or steam, leaves the river, lake or ocean and goes into the air. • 90% comes from oceans, seas, lakes and rivers • 10% comes from plants: transpiration • Humidity • Evaporation removes heat from the environment: HOW?? • Once evaporated, a water molecule spend about 10 days in the air.
- 10. Sublimation • Sublimation: The change of snow or ice to water vapor without melting • Solid gas • High amounts of energy is needed….Where would this energy come from??? • South side of Mt. Everest: – Low temperatures – Strong winds – Intense sunlight – Low air pressure
- 11. Transpiration • Transpiration is the process by which plants lose water out of their leaves. • Transpiration gives evaporation a bit of a hand in getting the water vapor back up into the air • Moisture is carried through plants from roots to small pores on the underside of the leaves, where it changes to vapor and is released to the atmosphere. • A large oak tree can transpire 40,000 gallons of water a year. • Factors that effect Transpiration: – Temperature – Relative humidity – Wind and air movement – Soil-moisture availability – Types of plants
- 13. Water in the atmosphere • The atmosphere always contains water • Tiny water particles are too small to see UNLESS…. • Clouds • Superhighway used to move water around the globe
- 14. Condensation • Condensation: Water vapor in the air gets cold and changes back into liquid, forming clouds. • Responsible for the formation of CLOUDS • Vapor liquid • Condensation is the opposite of evaporation • Fog • Moisture on your windows or drink – Water vapor in the warm air, turns back into liquid when it touches the cold glass
- 17. Precipitation • Precipitation: Occurs when so much water has condensed that the air cannot hold it anymore. • The clouds get heavy and water falls back to the earth in the form of rain, hail, sleet or snow • Millions of cloud droplets are required to make a single raindrop
- 18. Precipitation Rates Vary by location
- 19. Surface Runoff • Surface Runoff: Occurs as precipitation travels over the soil surface to the nearest stream channel. • Run over the soil and collect in the oceans, lakes or rivers where the cycle starts • Ground saturation • Flash flood • Deposition can happen during this time….What was that?? • Dangerous time for pollution to occur
- 21. A watershed is an area of land where all of the water that falls in it and drains off of it goes into the same place.
- 22. Groundwater • A portion of the water that falls as precipitation can infiltrate (seeps into) the subsurface soil and rock. • Used by plants and burrowing animals • Keeps soil cool during the summer
- 24. Water Table • The top of the surface where ground water occurs is called the water table
- 25. Aquifer • An underground layer of water-bearing porous stone, earth, or gravel