Withdrawing water for agriculture is a contentious issue. Some states particularly in the west have regulations regarding withdrawing water from wells for a region. Excessive use can deplete an aquifer or lower the water table.
NPR article of overuse of groundwater by Saudi Arabian farm in Arizona
Although approximately 70 percent of the Earth is covered with water, only about 3 percent is freshwater. All of my percentages are rounded off. Precise percentages can be found in the following two sources.
Wikipedia breakdown of world's water
USGS water resource
Of the three percent freshwater, about 1.5 percent is groundwater and 1.5 percent is glacial ice and snow. About 1/10 of a percent is the world's lakes, rivers, streams, swamps, humidity. Water is a finite resource.
Some ground water is salt water. Excessive removal of freshwater along the coastline produce an encroachment of salt water into freshwater sources.
Excessive irrigation for farming causes some land to become so salty that it cannot support farming and most plant life. Minerals are dissolved in water. Repeated watering causes a buildup of minerals. Water leaves by run-off, plant use or evaporation. The minerals are left behind.
very interesting
ReplyDeleteI actually recommended your blog to another science teacher I know who's trying to teach about water consumption in class. She loved it!
ReplyDeleteI grew up with well water and we were very mindful and frugal about our water use because of it. This is a very interesting post and I really like the photography.
ReplyDeleteAh, I miss good well water. My family grew up with it, and it was so tasty! Now we live in a city, and it's not nearly as good--but some filtered water comes pretty close.
ReplyDeleteGreat post. I certainly don't know enough about all these processes, Ann.
ReplyDeleteWE also have a well on our rural property and we recently had to start drilling deeper. Water is a big issue in my part of California.
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