Chapter 9 - WaterChapter 9 - Water
Water Cycle
Water Budget
The World’s Water• Oceans, lakes, rivers,
groundwater, atmosphere, living things, glaciers, and more…
• Water is measured by volume. “How much space it takes up.”
• 97 % is in the oceans
The World’s Water• Less than 3% is fresh!!!
–2/3 is frozen in ice caps
–Rest is fresh (usable) water
–Works out to be less than 1/2 of 1%
OCEANS 97.2%
ICE CAPS 2%
GROUNDWATER 0.78%
LAKES 0.013%SOIL 0.006%
ATMOSPHERE 0.0007%RUNNING 0.0002%
BIOSPHERE 0.0001%
Where is the fresh water?Where is the fresh water?
• TinyTiny part is flowing on the surface of Earth (rivers, streams)
• 100 times that is stored in lakes, swamps, etc.
• 50 times that is stored in the ground as groundwater.
Water CycleWater Cycle• Again like all matter, water is
recycled.
• Simple water cycle (Magnificent 7):Evaporation-liquid to gas Transpiration-liquid to gas in plants
Sublimation-solid to gas
Water CycleWater CycleCondensation–Gas to liquid-clouds
Precipitation-gas to liquid/solid
Runoff-running water on surface
Groundwater-soil moisture, water underground
Water BudgetWater Budget•Compares the input (water you get) and output (water you use) of water in a specific region.
Water BudgetWater Budget• Controlled by many different
climate climate factors
–Air temperature
–Humidity (Season Extremes)
–Rainfall amount
–Soil Type
Water Budget Graphs• A comparison between
Moisture supply (precip) and Moisture demand (evap)
• A water budget has 4 parts: usage, recharge, surplus,
and deficit
Water Budget Graphs• Usage – When plants,
humans, sun is taking water out of the system.
• Recharge - When the ground water is being filled back up
Water Budget GraphsWater Budget Graphs• Surplus - Rainfall is greater than
the need. Soil is moist.
• Deficit - Need for moisture is greater than the rainfall coming into the system. Soil is dry
Rocks Holding Water??Rocks Holding Water??
Porosity – Volume of space in between rocks/soil that can hold water
Permeability – The rate at which water can pass through the pore spaces of rock/soil
Rocks Holding Water??Rocks Holding Water??
Rocks Holding Water??Rocks Holding Water??
• Impermeable – Water cannot pass through the pore space.
• Capillary – Ability of water to “stick” to its surroundings by its surface tension
Rocks Holding Water??Rocks Holding Water??
Water TableWater Table
Water TableWater Table• Ground becomes saturated with
water. This is the ground water that we have been talking about.
• Water Table – The top portion of the “zone of groundwater saturation”
Water TableWater Table• Zone of Aeration – Water and
air mixed with the rocks and soil• Capillary fringe – Border
between air/water and just water. Right above the water table (pg. 154)
• Zone of Saturation – Just water in the soil and no air
Wells and SpringsWells and Springs• Ordinary well - A hole dug or
drilled down below the water table. ( water must be pumped out)
• Spring - Place where the water table is at the surface.
• Artesian well - A well that is pressurized. (water will not have to be pumped out)
AquifersAquifers• Are permeable materials that contain and
carry groundwater–Best are - Sand, gravel, and porous
sandstone
Link to Page About Water Resources
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