Bdale Envir Ch 14 – Water Resources and Water Pollution
Intro is a water wars story about Nile River
Nile essential to life in Egypt, but Ethiopia plans to divert water
shows the region, rivers
Quote indicates “spreading scarcity of fresh water facing the world in this new millennium”
14-1 – Water’s importance and unique properties
This IS the water planet…..70% water.
Many organisms, including people, are 50-65% water.
There are a number of unique properties that are listed:
Exists over a wide range of temperature
High heat capacity moderates earth’s temp fluctuations
Water has tremendous dissolving power
Unique property of density decrease upon freezing (ice floats)
14-2 - supply, renewal, and use
just a tiny fraction of planet’s water is available as fresh water
97.4% is in ocean
2.59% is in ice caps & glaciers
0.01% is available for soil moisture, GW, lakes/streams
analogy – if there were100 liters (26 gallons) total of water on the planet, only 2.5 teaspoons would be usable fresh water
luckily, fresh water is continuously recycled through the hydro cycle, so fresh water is continuously being pulled out of the ocean and returning to Earth.
But GW acts like a non-renewable resource if we pull it out of the ground faster than it recharges
(Show an example problem…)