Distribution of Water Chapter 11, Sect.1-3

Essential Question: How is water distributed throughout the earth, and how does the water cycle redistribute the water?

Water covers 71% of the Earth’s surface! In what percentage is water distributed in oceans, lakes, rivers, underground water, and ice?

Distribution of Earth’s Water 97 Percent is salt water that is found in the oceans. Only 3 percent is fresh water. Fresh water Salt water

Of the 3% that is fresh water, how much is available for human use? 76% is ice 12% is shallow groundwater 11% is deep groundwater 0.34% is in lakes and rivers 0.037% is water vapor

Water Cycle Vocabulary Evaporation (p. 379) Condensation Transpiration* Precipitation Infiltration (p. 289 in italics) Percolation (p. 309) Runoff (p. 482)

Stages of the Water Cycle: Evaporation Condensation Transpiration Precipitation

Evaporation The process by which water molecules in liquid water escape into the air as water vapor.

Evaporation

Condensation The process by which a gas, such as water vapor, changes to a liquid, such as water.

Condensation

Transpiration The process by which plants release water vapor through their leaves.

Precipitation Forms of water (rain, snow, sleet, or hail) that fall from clouds and reach Earth’s surface.

Precipitation

Runoff Water that flows over the ground’s surface rather than soaking into the ground

Runoff

Groundwater Water that fills the cracks and pores in underground soil and rock layers.

Groundwater

Permeable A characteristic of materials, such as salt and gravel, that allow water to pass easily through them

Permeable

Impermeable A characteristic of materials through which water does not easily pass, such as clay and granite

Impermeable

Aquifier An underground layer of rock or soil that holds water

Saturated Zone A layer of permeable rock or soil in which the cracks and pores are completely filled with water

Water Table The top of the saturated zone, or depth to the groundwater in an aquifer

Unsaturated Zone A layer rock or soil above the water table in which the pores contain air as well as water

Unsaturated Zone Saturated Zone

Wastewater Sewage that is treated to make it safe to return to the environment.

Conservation The process of using a resource wisely so it will not be used up.

Desalination The process of obtaining fresh water from salt water by removing the salt.