4.2 Warm-up Identify the stage of the water cycle represented in the picture below. Options: Infiltration, Condensation, Precipitation, Runoff, Evaporation A__________________________________. With or Against Gravity? B__________________________________. With or Against Gravity? C__________________________________. With or Against Gravity? D__________________________________. With or Against Gravity? E__________________________________. With or Against Gravity? 2) What is the difference between run-off and infiltration? 3) What is the difference between evaporation and transpiration?

EXPLORATON: If you dumped a cup of water on the ground outside of Vance, where do you think the water would go? 2

GROUNDWATER Precipitation that does not evaporate, flow into a body of water, or get taken up by organisms sinks down through the soil (infiltration) and becomes groundwater. Groundwater is held underground in aquifers.

Aquifer = a porous formation of rock, sand, or gravel that holds underground water.

Review from Rocks Unit! Porous rock : rock full of tiny holes An aquifer must have the tiny holes for the water to move thorugh the rock or soil 6

Permeability A material’s ability to let water flow. Rocks and soil which are porous are permeable Rocks and soil which are not porous are impermeaable. 7

Include: 1) Loose soil(sand) 2) Sandstone, cracked rock PERMEABLE LAYERS Include: 1) Loose soil(sand) 2) Sandstone, cracked rock 8

Include: 1) Clay(hard packed) 2) Granite IMPERMEABLE LAYERS Include: 1) Clay(hard packed) 2) Granite 9

Zone of Aeration: pore spaces are partly filled with water, partly filled with air.

Zone of Saturation: pore spaces are completely filled with water.

The water table: Top of the Zone of Saturation, line between Zone of Aeration and Zone of Saturation

1. Uncontained aquifer = can be easily recharged (refilled) by precipitation 2. contained aquifer = between two layers of impermeable rock, not easily refilled

Pollution of Groundwater Anything that if on the surface above an aquifer can be washed down into groundwater by infiltration. This may pollute the groundwater. Some pollutants include: Pesticides, herbicides, fertilizers, human and animal waste.

TAPPING INTO GROUND WATER Humans often drill wells to access the underground water in aquifers. 15

Artesian Wells Some wells at the base of sloped land areas will flow to the surface from natural pressure. These are called artesian wells. If the water flows with out drilling a well it is called a spring.

TAPPING INTO GROUND WATER Overuse of a well draws from the water table, creating a cone of depression, which makes getting water out more difficult. 17

6.2 EXIT TICKET 1) What is the porous formation that holds underground water? 2) Which zone contains pore spaces filled with air and some water? 3) Which zone contains pore spaces filled with water? 4) The top of the Zone of Saturation is called the ______ _____ 5) What do humans often drill deep into the ground to access underground water from aquifers?