CH 9: Water Resources

aquifer

permeable layers of rock and sediment that contain groundwater

unconfined aquifer

an aquifer made of porous rock covered by soil, which water can easily flow into and out of (recharges faster)

confined aquifer

an aquifer surrounded by a layer of impermeable rock or clay that impedes water flow (recharges extremely slow)

water table

the uppermost level at which the water in a given area fully saturates rock or soil

groundwater recharge

a process by which water percolates through the soil and works its way into an aquifer

springs

natural sources of water formed when water from an aquifer percolates up to the ground surface

artesian wells

wells created by drilling a hole into a confined aquifer

cone of depression

an area from which the groundwater has been rapidly withdrawn (could make it so other wells also go dry)

saltwater intrusion

an infiltration of salt water in an area where groundwater pressure has been reduced from extensive drilling of wells

oligotrophic

when a body of water has a low level of productivity as a result of low amounts of nutrients in the water (very clear water)

mesotrophic

when a body of water has moderate levels of productivity (still pretty clear)

eutrophic

when a body of water becomes rich in nutrients and has a very high level of productivity, algae grows on the top layer and blocks sunlight from many of the plants in the body of water and animals. causes many dead zones

impermeable surfaces

pavements or buildings that do not allow water penetration (in cities it can cause a lot of flooding)

levee

an enlarged bank built up on each side of a river to prevent flooding

dike

structures built to prevent ocean waters from flooding adjacent land

dam

a barrier that runs across a river or stream to control the flow of water

reservoir

a body of water created by blocking the natural flow of a waterway

fish ladder

stair-like structures that allow migrating fish to get around a dam

aqueducts

canals or ditches used to carry water from one location to another

desalination

the process of removing the salt from salt water

Explain the difference between a confined and an unconfined aquifer.

A confined aquifer has impermeable layers around it that doesn't let water in, it also takes 10,000-20,000 years to recharge. An unconfined aquifer can easily have water flow in and recharges faster.

What is saltwater intrusion and what causes this problem?

Saltwater intrusion is when too much fresh water is drawn out from the ground near the coast, so the pressure keeping the saltwater out lowers and saltwater infiltrates the fresh water.

Describe the causes and effects of a eutrophic body of water.

Eutrophic bodies of water are highly productive because of their high levels of phosphorus and nitrogen. One of the causes is fecal waste or runoff from farms containing fertilizer. The algae that grows on the surface of the water blocks the other organis

Describe the ecological benefits of freshwater wetlands.

Freshwater wetlands absorb and store the excess water from heavy rainfall and help to reduce the likeliness of a flood.

Describe some human activities that have impacted flooding.

Some human activities that impacted flooding include dams, that create a reservoir that can flood nearby lands. Also, impermeable surfaces (such as cities) cause flooding because the water has nowhere to go.

Describe both the benefits and consequences of dams.

Dams can cause a lot of flooding as well as the killing of millions of fish that can't migrate. Although, they can create a lot of energy with the water that passes through it and can help the lands that have less water on them now.

What are the three major users of water and what percentage of water is used for each?

Agriculture uses 70% of water, industry uses 20% and households use around 10% of water.