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7thGr-Sci-Unit 12
7th Grade Science - Unit 12: Impact of Natural Events&Human Activity on Organism
Term | Definition |
---|---|
Acquifers | areas of loosely packed soil that are saturated with water and located beneath the surface. They are supplied with groundwater that comes from precipitation (rain). |
Contaminants | during rains and floods, water can transport pesticides, antifreeze, motor oil, paints and other hazardous materials, which enter the watershed, and ultimately contaminate the water. |
Deltas | large areas where soil, silt and other sediments are deposited at the mouth of a river (where the river meets the ocean) |
Groundwater | water beneath the surface of the ground |
Sediments | naturally-occurring materials that are broken down by processes of weathering and erosion and is subsequently transported by the action of fluids such as wind, water, or ice, and/or by the force of gravity acting on the particles themselves. |
Surface water | water above the ground that comes from precipitation (such as lakes,ponds, streams and oceans). It moves across transporting sediment from one place to another causing erosion and leading to deposition. |
Watershed | an area of land where the water runs off the land drains into local rivers, streams, lakes and wetlands. These areas play a vital role in preventing floods. |
Water table | an area below the surface where the ground is saturated with water. The water table rises and falls based on how much precipitation is saturated with water. It rises and falls based on how much precipitation percolates down through the soil. |
How can humans affect watersheds? | Pollutants (such as litter &oil spills) and contaminants (such as fertilizers) can end up in water supply. Also, humans can cause land subsidence. |
What can subsidence lead to? | Sinkholes |