Sources of Water

Questions and Answers

What are the two main categories of sources of water?

Groundwater and surface water (correct)

River water and lake water

Rainwater and seawater

Surface water and ocean water

What is an aquifer?

An underground water reservoir made of permeable rock (correct)

A type of irrigation system

A man-made reservoir

A type of surface water

Why is aquifer depletion a problem?

Because it is expensive to pump water from aquifers

Because it causes flooding

Because it takes a long time to recharge (correct)

Because it is a natural process

What can be a result of land subsidence?

Creation of dangerous sinkholes Signup and view all the answers

What is the main use of groundwater from aquifers?

Agricultural irrigation, drinking water, municipalities and commercial uses Signup and view all the answers

What is a characteristic of surface waters?

They are very dynamic systems that can move a lot of water and transport sediment and nutrients downstream Signup and view all the answers

Why is it important to consider our daily water use?

Because when multiplied by seven billion people, it amounts to a huge quantity of water Signup and view all the answers

What is responsible for the Leaning Tower of Pisa?

Extreme groundwater pumping and subsidence Signup and view all the answers

What happens when surface waters are overdrawn?

Streams, lakes, and rivers may run dry in areas that used to have plenty of water Signup and view all the answers

What is the result of massive withdrawal of water from the Aral Sea?

The sea has shrunk to one-fifth of its original volume Signup and view all the answers

Why do plants and animals in surface waters and surrounding areas struggle when water supplies change?

They are uniquely adapted to specific environmental conditions Signup and view all the answers

What happens to the salts in irrigation water?

They are left behind in the soil, causing salinization Signup and view all the answers

What is the result of excess salts in the soil?

Prevention of water uptake by plants Signup and view all the answers

What can happen to salty soils?

They affect the ecosystem and leach into groundwater supplies Signup and view all the answers

Why is irrigation a problem for both aquifers and surface waters?

It removes large amounts of water from both sources Signup and view all the answers

Study Notes

Sources of Water

Water is used for various purposes such as cleaning, drinking, agricultural irrigation, and generating electricity from hydroelectric power.
There are two main categories of water sources: groundwater (below the surface of the ground) and surface water (above ground).
Groundwater can be found just below the soil or in an aquifer, which is an underground water reservoir made of permeable rock.
Aquifers are like large spongy areas that can hold water for many years, but they do not fill quickly and can take a long time to recharge.

Removal of Groundwater

Aquifers are found all over Earth, and the water in them is removed through wells.
The water from aquifers is an important supply for agricultural irrigation, drinking water, municipalities, and commercial and industrial uses.
Aquifer depletion occurs when more water is pumped from the aquifer than is allowed to recharge, causing serious problems in the landscape.
When too much groundwater is pumped from the aquifer, the land may subside, creating sinkholes and other issues.
Other issues that may arise from aquifer depletion include less water reaching streams, rivers, and lakes, dried-up wells, a lowered water table, and saltwater entering the groundwater supply.

Removal of Surface Water

Surface waters, such as streams, lakes, and rivers, provide a necessary source of drinking water, crop irrigation, and energy.
Just like aquifers, surface waters can also be overdrawn, leading to issues such as the Colorado River no longer reaching the Gulf of California.
The Aral Sea in Central Asia is an extreme example of overdrawing surface water, resulting in a drastic decrease in volume over 40 years.
Overdrawing surface water affects not only humans but also the ecosystems these aquatic areas support, leading to habitat loss and extinction of species.

Irrigation Makes Soil Salty

Irrigation removes large amounts of water from both below and above ground, adding dissolved salts back into the soils, leading to salinization.
The water used for irrigation isn't very salty, but the concentration of salts increases as the water evaporates, leaving salts behind on the ground.
The application of fertilizers to crops adds even more salt to the soil, exacerbating the problem.
Salinized soils prevent plants from taking up water, affecting native plants, agricultural crops, and the ecosystem overall.
Excess salt may also run off into surface waters or leach into groundwater supplies, causing salinization and contamination.