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Presentation on theme: "Surface Water & Groundwater & 7 TH GRADE SCIENCE BROOKVILLE INTERMEDIATE SCHOOL MS. DRAKE."— Presentation transcript:


2 Surface Water Water covers two-thirds of the planet's surface. It is essential to all forms of life and plays a vital role in the processes and functioning of the Earth's ecosystems. People all over the planet are dependent on water to grow food, generate power, cool the machines of industry, carry wastes, and much more. People use water in their personal lives for bathing and cleaning, recreating, drinking, cooking, gardening, and just for the pleasure of watching it. Water also provides habitat for fresh and salt water living resources.

3 Surface Water More than 97 percent of the Earth's water is saltwater in our oceans and salt lakes; water in icecaps/glaciers adds about 2.0 percent more. Fresh water is very limited -- water in lakes, streams, and rivers makes up less than 0.01 percent of the Earth's water. Groundwater -- fresh water under the planet's surface -- makes up another 0.6 percent. In the United States, more than 250 million people depend on the fresh water in our rivers, lakes, streams, and groundwater supplies for their drinking water.

4 Surface Water Quality Water Quality is a measure of how clean a stream's water is. Scientists take measurements of the physical and chemical condition of the water and the health of the critters that live in it. Temperature - determines the kinds of animals that can survive in a stream. Temperature also can affect the chemistry of the water. Dissolved oxygen – is how much oxygen is available in the water for fish and other aquatic organisms to breathe. Healthy waters generally have high levels of DO. Several factors can affect how much DO is in the water: temperature, the amount and speed of flowing water, the plants and algae that produce oxygen during the day and take it back in at night, pollution in the water, and the composition of the stream bottom.

5 Surface Water Quality pH – is the acidity level of water. Most waters range from 6.5 to 8.5. Changes in pH can affect how chemicals dissolve in the water and whether organisms are affected by them. High acidity can be deadly to fish and other aquatic organisms. Nutrients - The two major nutrients scientists measure are nitrogen and phosphorus. The presence of too many nutrients can hurt aquatic organisms by causing lots of algae to grow in the water. Nutrients can also affect pH, water clarity and temperature, and cause water to smell and look bad. Toxic Substances - Scientists also test for many harmful (toxic) things like metal, pesticides, and oil.

6 Surface Water Quality Turbidity - the clarity of water; how many particulates (little bitty particles of stuff) are floating around. Bacteria - Scientists sample for certain types of bacteria that are found only in the intestinal tract of animals and humans. Visual surveys - Scientists take measurements of the landscape surrounding a stream to determine things like the amount of trees and shrubs along a stream, the amount of shade that is created by trees overhanging the stream, and woody debris (sticks and leaves) in the stream. Biological sampling - taking samples of fish, plants and smaller organisms called macroinvertebrates (mack-row-in-ver-tuh-bretts). Macroinvertebrates include things like snails, worms, fly larvae, and crayfish ("crawdads").

7 Ground Water Some facts to consider... Scientists estimate groundwater accounts for more than 95% of all fresh water available for use. Approximately 50% of Americans obtain all or part of their drinking water from groundwater. Nearly 95% of rural residents rely on groundwater for their drinking supply. About half of irrigated cropland uses groundwater. Approximately one third of industrial water needs are fulfilled by using groundwater. About 40% of river flow nationwide (on average) depends on groundwater.

8 Groundwater Groundwater is the water that saturates the tiny spaces between alluvial material (sand, gravel, silt, clay) or the crevices of fractures in rocks. Aquifer : Most groundwater is found in aquifersunderground layers of porous rock saturated from above or from structures sloping toward it. Infiltration : Movement of water into and through soil.

9 Groundwater Quality Inorganic compounds, pathogens and organic compounds can negatively affect water quality. Inorganic Compounds include all compounds that do not containing carbon. Nitrates can cause problems in drinking water or marine waters. Phosphorus can reduce uses of fresh surface waters. Heavy metals include selenium, arsenic, iron, manganese, cadmium and chromium and others. Pathogens including bacteria and viruses, have been attributed for more than 50% of the waterborne disease outbreaks in the


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