drainage basin

mesotrophic lake

estuary

source zone

Estuary

Lake

Pond

River

Wetlands

To conserve water

To allow uptake of CO2 from the atmosphere

To carry soil minerals into the leaves

To prevent leaves from overheating

To promote gas exchange with the environment

An aquifer that is surrounded by an impermeable bedrock or clay

An aquifer that is sealed off by manmade efforts (e.g. concrete) to limit percolation of water

An aquifer where percolation occurs, but only upward toward above-ground sources

An aquifer that has been contaminated by pollutants or pathogens and must be sealed off through manmade efforts to prevent contamination to other water tables through percolation

An aquifer that can only be recharged by precipitation

Insufficient precipitation and soil that lacked a healthy root system

A market that lessened demand for cultivation and insufficient rainfall

Over-dependence on chemical fertilizer and failure to mulch regularly

The soil was lacking a healthy root system and producing more food than the ecosystem could support

Over-dependence on chemical fertilizer and insufficient rainfall

A newly formed glacial lake

A river that runs through a fertile, heavily-cultivated delta

A lake that is located in a geographically mountainous area where clear-cutting is pervasive

The rivers and freshwater lakes on and nearby Mount St. Helens shortly after the 1980 volcanic eruption

A swamp-wetland ecosystem with a healthy population of aquatic vegetation

An unconfined aquifer is more likely to contain pathogens and pollutants.

An unconfined aquifer can be exhausted faster than a confined aquifer.

Sulfur deposits (which taste horrible) are more common in unconfined aquifers.

There are few sources for an unconfined aquifer to recharge and it is very easy to pump out more water than what replenishes the table naturally.

An unconfined aquifer is usually further below ground and can be very expensive to drill into and pump water out of the well.