The Water Cycle
|Kyle||The Water Cycle: Kyle|
Water evaporates between at the Earth's surface and leaves behind salts and other impurities. Water vapor, which is a gas, rises into the air. As water vapor rises through the atmosphere, the gas cools and condenses into drops of liquid water from the clouds. Eventually the water in the clouds falls back to Earth as rain and replenishes the earth's fresh water.
|Trevor||Surface Water (river systems and watershed): Trevor|
Surface water is fresh water on Earth's land surface. Surface water is found in lakes, rivers, streams, and wetlands. Today, most large cities depend on surface water for their water supplies. Rivers, lakes, and streams provide drinking water, water to grow crops, food such as fish and shellfish, power for industry, and means of transportation by boat. Watershed: The area of land that is drained by a river is known as a rivershed. Pollution anywhere in a watershed may end up polluting a river. The amount of water that enters a watershed varies throughout the year. Rapidly melting snow as well as spring and summer rains can dramatically increase the amount of water in a watershed. River systems: As streams and rivers move across the land, they form a flowing network of water called a river system. If a river system is viewed from above, it can look like the roots of a tree that are feeding into a trunk. Ex. Amazon river.
|Trevor||Ground Water and Aquifers: Kyle|
Most of the fresh water that is available for humans use cannot be seen- it exists underground. When it rains some of the water falls into streams , but much of the water percolates (to cause a liquid to pass through a porous body) through the soil and down into the rocks beneath. Water beneath the Earth's surface in sediment and rock formations is called groundwater. The level where the rocks and soil are saturated with water is known as the water table. In wet regions, the water table may be at the Earth's surface or in deserts where it could be 100's of meters below the surface. Aquifer: an underground formation that contains groundwater is called an aquifer. The water table forms the upper boundary of an aquifer. Most aquifers consist of materials such as rock, sand, and gravel that have a lot of spaces where water can accumulate. Ground water can dissolve rock formations like limestone and fill caves with water, which can create underground lakes. Aquifers are important to human culture.