Monday, February 27, 2012

Depletion in the Midwest



Although not as bad as other parts of the world, the Midwest still stuffers from water depletion. The Ogalla aquifer is located partially in the Midwest, spanning eight states.
 
This aquifer (the shaded reason) is in danger of being completely depleted in only a few decades if we keep using the same amount of water that we have been. It is even a possibility that it could be depleted faster than that if we increase our water usage, which is definitely plausible. The Ogalla aquifer provides nearly all the water for residential, industrial, and agricultural use.  Irrigated agriculture provides the base of the economy for the region and it also accounts for 94% of the groundwater use. This region’s agriculture is a vital contributor to nearly one fifth of wheat, corn, and cattle produced in the United States. These provide food for animals that then support industries such as the meatpacking industry. If the Ogalla aquifer became completely depleted it would deeply affect the population and economic activity of the region.

Now let’s take a look at the effects of water depletion closer to home.

  These pictures are taken from the Ramsey County Beach near my home. I remember when the water was about 10 feet from the lifeguard’s stand. Now, you can’t even see the water line in this first picture. The second picture shows that the beach has been closed due to the low water levels and drop offs. During the summer the water is so shallow for such a long distance, it is impossible to swim at this beach. Only a few years ago the water levels were much higher. In the third picture, you can see a dock that barely reaches the water line; much of it is in weeds and what used to be underwater.

Sources:

"Ogallala Aquifer." Water Encyclopedia. Web. 23 Feb. 2012. <http://www.waterencyclopedia.com/Oc-Po/Ogallala-Aquifer.html>.
 
Peterson, Jeffrey M., Thomas L. Marsh, and Jeffery R. Williams. "Conserving the Ogallala Aquifer: Efficiency, Equity, and Moral Motives." Choices Magazine. Feb. 2003. Web. 23 Feb. 2012. <http://www.choicesmagazine.org/2003-1/2003-1-04.htm>.
 

Monday, February 20, 2012

Where is it Depleting?

          As you already know, water depletion is prevalent worldwide. Although this is a global issue, there are areas of the world that are depleting faster and at a higher rate than others.




            As you can see by this map showing the highest rates of water stress, the southwestern United States, northern Africa, and the Middle East are suffering from very high rates of water depletion.
            When it comes to freshwater specifically, two-thirds of the world's population - around 4 billion people - live in areas receiving only one-quarter of the world's annual rainfall. Much of this rainfall will run off too quickly for people in these areas to use it. Areas of the world with high water stress such as Asia are only able to get most of their freshwater during monsoon season. However, this season only lasts for about 10% of the year.  This explains part of the reason Asia has high water stress levels. When it comes to northern Africa, much of the reason for its high water stress is due to fact that what water they do have, has become polluted. In northern Africa they also do not get very much rainfall and have to resort to pumping for their water. Using wells can sometimes be too costly for this region to afford. Not only is it difficult for this region to obtain their water when they find some, but the freshwater they find is usually contaminated. Finally, the southwestern United States is suffering from high water stress levels because this area is not only highly populated, but it also uses a lot of water for agriculture and irrigation. The primary source of water for irrigation in this region is the Ogallala Aquifer. The Southern portion of the Ogallala Aquifer is thought to run out due to the low level of recharge compared to the amount of water pumped.

Sources:

Staff Writers. "Groundwater Depletion Rate Accelerating Worldwide." Terra Daily. 28 Sept. 2010. Web. 17 Feb. 2012. <http://www.terradaily.com/reports/Groundwater_Depletion_Rate_Accelerating_Worldwide_999.html>.
 
Hinrichsen, Don. "Freshwater: Lifeblood of the Planet." People and the Planet. Web. 17 Feb. 2012. <http://www.peopleandplanet.net/?lid=26385>.
 
Wheeler, Erin A., Eduardo Segarra, Phillip Johnson, David B. Willis, and Jeffrey Johnson. Aquifer Depletion and the Cost of Water Conservation: The Southern High Plains of Texas Case. Rep. Aug. 2006. Web. 17 Feb. 2012. <http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=6&ved=0CFkQFjAF&url=http%3A%2F%2Fageconsearch.umn.edu%2Fbitstream%2F25410%2F1%2Fpp060212.pdf&ei=bGpCT52vBoGe2AXx4LWUCA&usg=AFQjCNFJs016uymCqJelHUUVqFgJtrdCSA&sig2=2deK8q4rbdWNveEuPDnVhg>.
 

Wednesday, February 8, 2012

When Did it Start Depleting and Why?


            The depletion of water was first noticed in the mid-1900s. In 1972, the Yellow River in China failed to reach the sea for the first time and this problem is only getting worse. The glaciers that replenish the river are depleting significantly. Ever since the mid-1900s, researchers have begun to notice the amount of drilling and usage has increased and consequently, our water levels have been decreasing. Water tables around the world are falling 3-10 feet per year.
            The cause for this depletion stems from many different problems. For instance, farmers need to irrigate their fields, but this irrigation uses an enormous amount of water. The world’s agriculture uses 70% of our freshwater, but if farmers cut down on their irrigation we will be in danger of a food shortage. This is because 40% of the world’s grain is produced on irrigated land; it takes 1,000 tons of water to produce one ton of grain. According to the Earth Policy Institute, “roughly 160 million tons of the world’s grain supply is now being produced by over-pumping. “ That brings me to my next point; aquifers are being over-pumped and drilled deeper each year to supply the amount needed for irrigation and domestic use. According to the U.S. Geologic Survey, “If water is withdrawn from the ground at a faster rate that it is replenished by precipitation infiltration and seepage from streams, then the water table can become lower. The impact on the level of the water table can be short-lived or last for decades, and the water level can fall a small amount or many hundreds of feet.” Not only are aquifers being depleted for the use of irrigation, but residential overuse of water can also affect water levels. Even though only 10% of freshwater is used for residential use, we overuse our water constantly. Showers account for 20% of indoor use, and how many of you know you take a very long shower or could at least cut down on the time? In fact, there are many ways for us to cut down on water usage at home. Just think, the consumption of water is doubling every 20 years - more than twice the rate of increase in population. Also, water can be overused by what some think of as trivial reasons, such as watering a golf course. It takes 2.5 billion gallons of water per day to irrigate the world’s golf courses. It would take 2.5 billion gallons of water per day to support 4.7 billion people at the UN daily minimum. That kind of makes you think, doesn’t it?
            Finally, credited as the number one cause of freshwater shortage and water depletion is global warming. It has been said by some scientists that a rise in average temperature in mountainous regions can alter the precipitation amount of rain/snow. This change means more flooding and more runoff during the rainy season, but also less water held as snow and ice in the mountains for use in the dry season. Snow/ice masses are now shrinking at an incredible rate. Many rivers across the world originate from these masses.

Sources:

"The Water Cycle: Groundwater Storage." USGS. 27 Dec. 2011. Web. 08 Feb. 2012. <http://ga.water.usgs.gov/edu/watercyclegwstorage.html>.
 
"Problem: Freshwater and Oceans in Danger." Web Of Creation. Web. 8 Feb. 2012. <http://www.webofcreation.org/Earth%20Problems/water.htm>.
 
"Groundwater." ENVIS Centre in Biogeochemistry. Web. 08 Feb. 2012. <http://jnuenvis.nic.in/subject/freshwater/groundwater.htm>.
 
Shepard, Kenton. "Groundwater Depletion." Peak to Prairie Inspection Service. Web. 08 Feb. 2012. <http://www.peaktoprairie.com/?D=192>.

Wednesday, February 1, 2012

Where is Our Water and How Do We Get It?


            Many of you know, approximately 70% of the Earth is covered in water. However, less than 1% of that water is fresh water. Like the saying goes,

“Water, water everywhere, nor any drop to drink.” –Samuel Coleridge

            Our fresh water supply is very limited and most of the 1% we have is contained in groundwater. The small amount of fresh water that is left is found in rivers and lakes. The majority of Earth’s water belongs to seas and oceans, while another portion of it is found in glaciers and permafrost. Distribution of groundwater across the globe can be explained in three categories, regions with the most, least, and moderate amounts of groundwater. Europe takes the title of the region with the most groundwater. The United States, parts of South America and Australia have a moderate, yet sufficient amount of groundwater. That leaves the rest of the world with the least amount of groundwater, with Africa and the Middle East struggling the most.

            There are many different ways in which we acquire the water we use every day. For instance, one way we get our water is from dams that have collected water that has drained down from hilltops and mountains, or “catchment” areas. This water comes in the form of precipitation and is eventually transported to reservoirs where it is then pumped to cities and water towers to be distributed throughout the city. Another way we obtain our fresh water is from aquifers deep underground. These aquifers are accessed by drilling wells above the location of the water. Some wells are able to flow on their own, but most have to be pumped using an energy source such as electricity. Not all wells are pumped using mechanical energy though. In most third world countries, wells are dug near villages and must be hand pumped. Villages depend on these wells, as they are usually their only source of fresh water because most of their other water sources are deeply contaminated. This idea of drilling into aquifers is one of the most popular ways to access fresh water. However, as fresh water depletes, wells need to be drilled deeper and deeper, which only causes depletion to worsen. 

If you'd like to learn more about Earth's water, where it is stored, and how it is accessed... click here.

Sources:

"Where Is Earth's Water Located?" USGS Georgia Water Science Center. Web. 01 Feb. 2012. <http://ga.water.usgs.gov/edu/earthwherewater.html>.

"What on Earth Do You Know About Water?" US Environmental Protection Agency. Web. 01 Feb. 2012. <http://www.epa.gov/gmpo/edresources/water_5.html>.

"Origin and Quantity of Groundwater on the Earth." Water Treatment and Purification. Web. 01 Feb. 2012. <http://www.lenntech.com/groundwater/origin.htm>.

"Catchments." Shoalhaven Water. Web. 01 Feb. 2012. <http://shoalwater.nsw.gov.au/education/catchments.htm>.

"How Does Your Water Get to Your Taps?" The Water Guide. Web. 01 Feb. 2012. <http://www.water-guide.org.uk/science.html>.

"How Do We Get Water Out of the Ground?" Tech Alive Home Page. Web. 01 Feb. 2012. <http://techalive.mtu.edu/meec/module06/Wells.htm>.