Water+on+the+Move

By: Connor W & Tarik M  As we learned in earlier chapters that impermeable substances allow no water to go through. Instead water runs off of these impermeable things. Substances such as cotton and soil are called porous. Porous objects absorb water that stays on top of them. When the land becomes dry after a rain storm the water either evaporates (turns into a gas) or runs off of the impermeable land into a river or stream. After the water gets in the river it travels in only one direction which is downstream. Downstream is the way all water travels because it is lower ground and the water comes from upstream. Just like how downstream is lower ground upstream is higher ground.

A flood plain is practically where all the water goes after a flood. This is both good and bad because of sediment. Sediment helps the land after a flood because it carries many nutrients. Also sediment is very important in dry places such as Egypt because it can revitalize the land. One of the main reasons there are floods are because of run-off. Trees absorb much of the run-off, but because humans have been cutting down trees more run-off water goes into the river. This causes more destruction to homes, but on the other hand more sediment helps vitalize the land.

Run-off can be very dangerous as it can collect many pesticides and put them in the river. These pesticides can affect fish and other sea animals in negative ways. Pesticides can affect animals by killing and poisoning them. Also, it disrupts the circle of life so if a fish is toxic and a bird eats it the toxic will enter the bird. The run-off that travels through cities can pick up more than just pesticides they can pick-up other chemicals too. Although affecting fish is not the only thing that is dangerous about run-off.

Experiments Definitions Take The Test

References

Clancy, Christina. //SciencePower8//. Toronto: McGraw-Hill Ryerson, 1999. 312-323. Print. Helfrich, Louis. "Pesticides and Aquatic Animals: A Guide to Reducing Impacts on Aquatic Systems." //Virginia Cooperative Extension//. N.p., n.d. Web. 22 May 2012. "Revitalization." //http://www.thefreedictionary.com/revitalization//. N.p., n.d. Web. 31 May 2012.