Presentation on theme: "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,"— Presentation transcript:
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
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/http://www.tes.co.uk/teaching- resource/Fresh-water-beneath-the- surface-of-the-earth-6286763/