Fresh Water

Fresh Water• Most of the Earth’s fresh

water is found in moving water and in standing water.

• Rivers, streams, and springs are moving water, ponds, lakes, and swamps are standing water.

Water Cycle

• The water cycle – the movement of water from the oceans and freshwater sources to the air and land and finally back to the oceans.

• Evaporation – the process of water to gas phase.

• Condensation – the process of gas to water. Must be cooled for this to occur.

• Precipitation – water returns to the Earth in the form of rain, snow, sleet, or hail.

Where is the rest of the water?

• Groundwater – the water that remains in the ground. Eventually flows into the ocean. Some of this returns to the earth from springs

• Frozen water – Glaciers

• A. Valley glaciers – long, narrow glaciers that move downhill between mountain valleys.

• B. Continental glaciers – thick sheets of ice that covers millions of square km of the earth’s surface, moves slowly in all directions.

• C. Icebergs – Some are as large as Rhode Island

Valley and Continental Glacier

Running Water

• Surface runoff – the water that enters a river or stream after a heavy rain or spring thaw.

• Pore space – the space between particles of soil. More pore space = more water it can hold.

• Watershed – a land area in which surface runoff drains into a river or a system of rivers and streams.

Pore space

Standing Water

• Lakes – usually deep depressions in the earth’s crust filled with fresh water. Usually where glaciers once were.

• Ponds – shallow depressions with fresh water, plants usually throughout.

• Reservoirs – the most frequently used source of fresh water. Built by damming a stream or river and is protected from polluting by laws.

Lakes, Ponds, and Reservoirs

POND

LAKE

RESERVOIR

Wetlands• Wetland: land area covered with water for most of

the year, serves as a filtering system that traps pollutants, sediments and bacteria, houses birds and other wildlife

1. Bog: get their water from precipitation only, very acidic soil, grows unusual plants such as peat moss and the Venus Fly Trap

2. Marsh: form in areas with deltas, grows shallow rooted marsh grasses which aid in the deposition of silt and sand

3. Swamp: located near streams, contains shrubs and tree’s, after millions of years the decayed plant material forms coal

• Preservation of wetlands has become a global concern, between the 1700’s and the 1980’s over 50% of the USA and Europe has lost wetlands due to population growth and industry

Groundwater

• Present because the types of precipitation does not stop traveling when it hits the ground, it moves downward through the permeable areas

• Permeable: material in which the water can move quickly, sandstone has a high permeability rate

• Impermeable: water does not flow through the ground easily, clay is impermeable

Underground Zones

• When groundwater reaches a layer of impermeable rock it fills up the pore spaces above forming a zone of saturation

• Above the water filled zone is an area that is mostly dry, this drier region where the pores are filled with air is called the zone of aeration

• The area between these two zones marks the boundary where the ground is saturated and is called the water table

Water Table• When you dig in the soil and reach a point

where the hole fills with water you have located the water table

• Hills and mountains the water table is deep, valleys, marshes and swamps the water table is closer to the surface

• Deserts have a deep water table, while wet climates have it near the surface

• Water table can change depth when there are times of drought or heavy rains/snow fall or if wells are being overused

Wells• Holes drilled or dug into the water table• Aquifer: Layer of rock that allows water to pass

freely and moves sideways. Usually layers of sandstone, gravel, sand or cracked limestone

• Found when a permeable layer gets trapped in between two impermeable layers

• Is a source of groundwater for wells• Since the water moves underground over very

large distance it is vulnerable to pollution which can contaminate the whole aquifer quickly

• Artesian Well: A well from which water flows on its own without pumping

• Aquicludes: Barriers to groundwater flow

Groundwater Systems

• Springs: water discharges at the surface where aquifers and aquicludes meet

• Temperature varies from cool to hot, is generally the average annual temperature of the region

• Hot Springs: water from deep in earth has risen

• Geysers: explosive hot springs that erupt at regular intervals

Groundwater Composition

• Water can contain compounds that are not hazardous such as iron (red) or sulfur (egg smell) compounds.

• Hard Water: Water contains high concentrations of calcium, magnesium or iron, common in limestone regions. It can clog your pipes

• Soft Water: makes soap more slippery, very little minerals present

Solubility

• Solvent – the substance that does the dissolving. Water is the universal solvent.

• Solute: the substance that gets dissolved• Solution – contains two or more

substances mixed on the molecular level, one thing must be dissolved.

• Soluble – can be dissolved.• Insoluble – cannot be dissolved.

http://www.tes.co.uk/teaching-resource/Fresh-water-beneath-the-surface-of-the-earth-6286763/

I know that you can’t get much more excited!!!