EARTH’S WATER SUPPLY

UNDERGROUND WATER Water Table: The upper surface of the groundwater zone Groundwater Zone: The area where water fills the space between the soil and cracks in rocks Aquifer- An underground fresh water reservoir

SOME QUICK FACTS 70% of the Earth’s surface is covered with water 97% of Earth’s water is salt, 3% is fresh Salinity is the amount of salt that is dissolved in water

Rising and Falling Water Table If more water leaves a watershed before it can recharge its volume, the underground freshwater reservoirs will lessen, deceasing the water table. Too much rain can cause the water table to fill to quickly causing ground water to surface and lead to flooding.

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NATURAL WATER TABLE CHANGES Natural events include flooding, drought, and earthquakes.

Rise and Fall of Water Table Earthquake Drought Flooding water table can drop as much as 1 m and less water from wells. Less water to collect from rivers and lakes and water table drops Heavy rain, snow and ice jams can cause flooding

Human Causes of Changes in the Water Table Some human activities also cause changes to the water table and it is often overuse or misuse of water.

1. Overuse of Wells Over drilling of wells by people in the country and tapping into aquifers. During a very dry summer or a winter with very little snow, less water sinks into the ground and collects in aquifers.

Farming and Industry Rely on water and operate near lakes and rivers They use water and discharge it back with harmful polluting chemicals.

Water Diversion and Export Bottled water removes water from our water supply. Companies take water from springs, aquifers, glaciers, and municipal water treatment systems. Taking too much too fast can lower our water supply

Quiz Time https://sciencesource.pearsoncanada.ca/quizzes/quiz2_11_01SeUUP.htm

Homework P.310-316 Questions 1-5