Water Cycle & Groundwater Notes
Water can be all 3 states of matter – solid, liquid, gas
Percentages of water on Earth:
75% of earth is covered with water, of that:
97.2% salt water
2% frozen in glaciers
0.6% deep underground
0.1998% surface water
0.01 in atmosphere
Water in ground water is 50 times more than all the lakes and rivers combined!
Water is the universal solvent - it can dissolve anything
It is a polar molecule - A molecule whose atoms have a slight negative and positive electric charge
Hydrosphere: the sphere of water that surrounds the earth, including the water in the atmosphere, groundwater,
running water, lakes, oceans and glaciers.
Water cycle: the movement of water from one part of the hydrosphere to another.
Evaporation: heat from the sun causes water to change into a gas called water vapor; energy is absorbed BY
THE WATER , evaporation is a COOLING process (area evaporated from cools)
Transpiration: process where water moves up through a plant, eventually exiting through tiny holes in the
leaves (Evapotranspiration: combination of evaporation and transpiration)
(Sublimation - conversion from solid to gas, w/o liquid stage; process of snow and ice changing water vapor w/o
first melting into water)
Condensation: water vapor changing into liquid in the atmosphere to form clouds; energy is released BY THE
WATER, condensation is a WARMING process, area condensed onto warms.
(Deposition - opposite of sublimation;, where water vapor changes directly into ice—such a snowflakes and frost)
Precipitation: condensed water falling to the ground as rain, snow, sleet, or hail.
Runoff: water that neither soaks into the ground nor evaporates, but instead flows across Earth’s surface and
eventually into streams, lakes, or oceans.
Groundwater: water that soaks into the ground and collects in the pore spaces between particles of rock and soil
Water budget: income and spending of water for a region. (expected income vs. expenditures)
Extra moisture is stored in the soil – stored between the grains + Recharge
Continued rainfall – soil becomes saturated, water table rises,
Surplus = rainfall is greater than the need and soil water storage is full
Too little moisture - time of soil ‘usage’
Deficit = need for moisture is greater than the rainfall and the soil water storage is gone.
Porosity: the percentage of a material’s volume that is pore space, how much water that rock or soil can hold
Permeable: describes rock or soil that has connecting pores that allow water to pass through easily
Capillary: rate at which water is pulled upward from the water table into pore spaces by capillary action (the
larger the pore space the poorer the capillary action)
Impermeable: rock or soil that has very small pores, preventing water from passing through
Aquifer: layer of permeable rock that has connecting pores and transmits water freely
Zone of Saturation: area where all the pores in a rock are completely filled with water, usually near the ground
surface
Zone of Aeration: area where the pores are filled with air, usually near the ground surface
Water Table: top of the zone of saturation
Artesian Well: well in which water under natural pressure rises to the surface without being pumped
Spring: point at which that water table meets Earth’s surface, causing water to flow from the ground
Hot spring: spring of warm groundwater, caused when the water is heated by rocks that contact magma under
Earth’s surface
Geyser: hot spring of groundwater that erupts periodically, shooting water and steam into the air
Cave: large underground opening formed when groundwater gradually dissolves rock
Karst Topography: regions characterized by sins, sinkhole ponds, lost rivers and underground drainage.