water resources (unit 6) Flashcards
How much water covers the Earth? How much is fresh water, how much fresh water is accessible?
About 71% of the Earth’s surface is covered
by water. Only about 2.5% of the Earth’s water is freshwater.
List and explain the three ways in which water is used (instream, withdrawal, and consumption).
Instream Use: Water is used without removing it from lakes and rivers. For example: fisheries, hydro-electric power plants, recreation uses.
Withdrawal Use: Water is taken from its natural source, used and returned to its natural source but not in the same condition.
Consumption Use: Water is consumed by humans and livestock, or “lost” into the atmosphere through evaporation and transpiration.
Explain the difference between surface water and groundwater.
Surface Water: This is water that is visible on the Earth’s surface in the form of rivers, lakes, ponds, streams, and oceans. It includes any water body that can be seen and is exposed to the atmosphere.
Groundwater: This is water that is stored below the Earth’s surface in underground aquifers and rock formations. It is found in the pores and spaces between soil particles and rocks.
Explain physical water pollution.
This type of pollution consists of actual physical garbage
dumped into our water. This not only contaminates the water and environment but also harms the species that live within it. Examples include floating garbage, old tires, paper, pop
cans.
Explain biological water pollution.
This is bacteria and viruses that enter lakes and rivers
from a variety of sources.
The largest source is from sewage.
Explain chemical water pollution.
The most dangerous form of pollution. These wastes are colorless, odorless and tasteless but they can be deadly. Two main sources are pesticides and herbicides.
