Water Underground Chapter 11 section 3

How does water move underground? Like surface water, underground water generally comes from precipitation. Water underground trickles down between particles of soil and through cracks and spaces in layers of rock.

Effects of Different Materials Different types of rocks and soil have different sized spaces or pores between their particles. The size of the pores between them determine how easily water moves. Permeable: materials have large and connected pores; materials such as sand and gravel allow water to pass through. Impermeable materials have few or no pores or cracks; therefore, the water cannot pass through easily. Example: clay & granite

Water Zones Top layer is called the unsaturated zone which contains air as well as water, so they are not saturated or filled with water. The top of the saturated zone is the water table. The water reaches a level where pores in the ground are saturated with water, called the saturated zone.

Bringing up Groundwater Aquifers: Any underground layer of rock or sediment that holds water is known as an aquifer. Size: small underground patch to the size of several states. Functions: drinking water, water for crops, and water for livestock. Rate of movement: depends on the slope of the aquifer and permeability of rocks.

Wells People can obtain groundwater from an aquifer by drilling a well below the water table. If the level of the aquifer drops, a well can run dry. The water table can rise after heavy rain or snow melting

Using Pumps Mechanical pumps bring up groundwater If water is pumped out too fast, we could run out.

Relying on Pressure In an artesian well, water rises because of the pressure in an aquifer. If groundwater becomes trapped between two layers of impermeable rock or sediment, the pressure sends water spurting up through the punctured hole.

Springs and Geysers Sometimes groundwater comes to the surface through natural processes. When groundwater bubbles or flows out of cracks in the rock it is called a spring. A fountain of boiling water is known as a geyser.

Effects of water use Humans can cause water shortages. Water flow can also be diverted from one area to another to support agriculture communities or a highly-populated city. The reduced flow of water in these other areas can lead to significant changes, such as loss of habitat and formation of new desert land.

Which wells end in a saturated zone? Which well(s) will not provide water?