Water resources" typically refers to both fresh water and salt water, but the term
is more often associated with fresh water because it is essential for human
consumption, agriculture,……..
1-Glaciers and Ice Caps
• Volume: About 1.7% of Earth's water is stored
• in glaciers and ice caps
• Characteristics:
1-Storage of Freshwater:
Glaciers : are big sheets of ice that form on land when snow falls
and accumulates over time. As more the snow at the bottom
gets compressed and turns into ice.
• Size: Glaciers can be small or large. For example:
• Small glaciers.
• Large glaciers.
• ice Caps: huge sheet of ice that covers a large area of land are typically
found near the poles. The Greenland Ice Sheet and Antarctic Ice Sheet
are the two largest ice caps.
Note
• Glaciers and ice caps are finite resources………………….? Once they melt
completely, the water they provide may no longer be available, and the
ecosystems and human populations that depend on them would need to
find alternative sources of water.
Groundwater
• Volume: Around 1.7% of Earth's water exists as groundwater, mostly found
in underground aquifers.
How Groundwater Forms………….?
• Groundwater begins as precipitation (rain,
snow)that falls on the ground and infiltrates the
soil. Some of this water is
• absorbed by plants.
• evaporates.
• the rest seeps deeper into the earth.
filling cracks, pores, and underground formations known as aquifers.
Ground water can be divided into:
Unconfined Groundwater
- This is the water found in the shallow aquifers
- which is directly affected by the water table.
- It is easily accessible by wells
- can be recharged quickly through precipitation.
confined Groundwater
This type of groundwater is trapped between layers of impermeable
rock or clay, making it more isolated from surface water. Confined aquifers are
often under pressure and may contain older water that is not as easily renew.
importance of Groundwater:
• Drinking Water: Groundwater is a critical source of drinking water for over
2 billion people worldwide.
• Irrigation: Groundwater is extensively used for agriculture, especially in
areas with insufficient rainfall .
• Industry: Groundwater is also used in various industrial processes, such as
cooling power plants, manufacturing, and other operations requiring large
amounts of water.
Groundwater recharge is the process by which groundwater gets refilled or
renew. This happens when water from rain or surface water (like rivers or lakes)
soaks into the ground and moves down into the underground layers of water,
called aquifers.
1. The water moves down through the soil and rock layers and fills up
underground spaces or aquifers, which store water.
It depends on things like:
• The amount of rainfall (if there’s more rain, recharge happens faster).
• The type of soil and rock in the area (some soils let water soak in faster,
while others may block it).
• Surface Water
• Surface water refers to water that is found on the Earth's surface, such as
in rivers, lakes, streams, ponds, reservoirs, and wetlands.
• It is used for a variety of purposes:
• including drinking water supply, agriculture, industrial processes, and
environmental ecosystems
• Flood Control:
• Wetlands and reservoirs naturally manage water flow during heavy rainfall,
reducing flood risks and ensuring groundwater recharge.
• Ecological Importance of Surface Water:
• Aquatic Habitats:
• Lakes, rivers, and wetlands provide habitats for diverse aquatic
species, including fish, amphibians, plants, and microorganisms.
• Nutrient Cycling:
Surface water systems help cycle nutrients (like nitrogen and phosphorus)
within ecosystems, supporting plant growth and sustaining food chains
• Flood Control:
• Wetlands and reservoirs naturally manage water flow during heavy rainfall,
reducing flood risks and ensuring groundwater recharge
Note
Wetlands: act like sponges, absorbing excess water during
heavy rainfall or snowmelt. This helps prevent water from
flowing too quickly into rivers and streams, reducing the
risk of flooding downstream.
Reservoirs: created by dams, store water during
periods of heavy rainfall. By controlling the flow of
water, reservoirs can prevent rivers from
overflowing and flooding surrounding land
