a. Identify the spatial scale of the issue.
The Ogallala Aquifer covers over 225,000 miles of the Great Plains in the Midwest USA. Specifically, its area includes parts of Nebraska, Kansas, Colorado, New Mexico, South Dakota, Wyoming, Oklahoma and Texas (meteor.iastate.edu). As one of the largest groundwater deposits in the world, it provides 30% of the groundwater used for irrigation in the United States (environmental.nationalgeographic.com). With the dry climate in the Midwest, farmers have had to strictly depend on the aquifer to water their crops (washingtonpost.com). Some areas, due to their "saturated thickness and recharge rates" are less vulnerable to severe depletion, while others have already exhausted their underground supply (meteor.iastate.edu). For example, Nebraska is believed to have the most favorable recharged rate, while Texas and other southern high plains are struggling with their underground water supply (meteor.iastate.edu). Studies have shown that Kansas's water supply is dropping by 2 feet per year in some counties (washingtonpost.com), while its recharge rate is only .85 inches per year (web.mit.edu). Although the depletion of the Ogallala Aquifer only directly effects the states that sit on top of it, it also is causing a huge impact on much of the Unite States that depend on this area for their agricultural products.
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| This image shows the location of the Ogallala Aquifer as well as the the amount of depletion in meters over various areas of the aquifer. As the image depicts, the part of the aquifer in Texas has seen large amounts of depletion as well as some spots in Kansas. (http://na.unep.net/geas/getUNEPPageWithArticleIDScript.php?article_id=76) |
b. Geography associated with the problem and the ecosystems and biomes affected.
Not only is the depletion of the Ogallala Aquifer affecting the human population, but also the biomes and ecosystems in the surrounding area. The aquifer ecosystem has been largely affected by this environmental problem. The Ogallala Aquifer is home to a "wide variety of undiscovered species" (web.mit.edu). Microbes and bacteria reduce contaminants and are the primary source of energy for the ecosystem (web.mit.edu). These organisms depend on the groundwater, just as much as the aquifer depends on them. The depletion of the aquifer may lead to the loss of these species which are crucial in the health of the aquifer (web.mit.edu). Riparian ecosystems, land ecosystems found by moving bodies of water, like estuaries and wetlands, also greatly rely on the aquifer (web.mit.edu). These ecosystems, which are rich in species, depend on the aquifer for a yearlong supply of water (web.mit.edu). The loss of water and pollution of the groundwater would affect many species and drastically reduce biodiversity (web.mit.edu). Because the Ogallala Aquifer covers so much area, many of the biomes and ecosystems vary in how they have been impacted.Specifics of the Problem
a. The History
The main question most people have regarding the depletion of the Ogallala Aquifer is when this environmental issue began and why. The aquifer was overall untouched until 1910 (hrd.apec.org). Water began to be seriously removed from the aquifer beginning in the 1940s. According to many geographers, the "post-depression wartime government" of the 1940s greatly supported the implement of drilling into the practically untouched reservoir (hrd.spec.org). As drilling technology improved during this time, the government supported irrigation projects that drew from the aquifer (kerrcenter.com). Since WWII however, the reliance of the aquifer has continued to increase (kerrcenter.com). A main factor in the reliance of the aquifer is due to the recurrent droughts in the area due to climate change (meteor.istate.edu). With the prolonged dry season, farmers must rely on the aquifer to supply them with water for irrigation. The problem is continuing to worsen as the withdrawal rates of the aquifer far outweigh the recharge rates.b. Science behind the issue
The main issue facing the depletion of the Ogallala Aquifer is where it it located. The Midwest is extremely dry, so profitable agriculture can only exist with a large amount of irrigation -- supplied by the groundwater (hrd.apec.org). The most critical site of the depletion is the Texas high plains, where the withdrawal is about ten times more than the rainfall that replaces it (hrd.apec.org). Not only does the problem of depletion reside in the fact that people are extracting excessive amounts of water out annual, but many factors prevent the aquifer from recharging at the rate that it needs to be. The make up of the aquitards that supply the aquifer inhibit the aquifer from refilling at the rate that it needs to be refilled (hrd.apec.org). Also, the playa lakes that form when the Midwest gets rainfall are lined with a clay and silt bottom that prevent water from leaking into the ground and recharging the aquifer (hrd.apec.org).c. Consequences and Impact
A study done by David Stewart at Kansas State University shows that 69% of the aquifer will be depleted by 2060 (ksre.ksu.edu). If this study proves to be accurate, then the states that cover the aquifer will be seeing immense impacts in the upcoming years, as some already are. The biggest concern people have is how states' economies will be effected. Crops grown in the High Plains not only produce produce for the local people, but also provide food for livestock, which are "the primary inputs for local meat processing plants" (choicesmagazine.org). The "core" of the economy in the Midwest depends on crops and livestock, and also where most of the employment and gross output resides (choicesmagazine.org). If the Ogallala Aquifer completely dries up, the midwest states are likely to see higher food costs and "less water available" for domestic use (livescience.com). In 2011, Texas experienced a drought that cost the "$8 billion in economic losses"(livescience.com). With climate change, if droughts such as the one in Texas continue to occur and the aquifer continues to be sucked dry, economies in the Great Plains are going to suffer immensely. Not only is the depletion of the aquifer affecting people, but also the pollution of the aquifer. Pollution of the groundwater is effecting residents who depend on the aquifer for drinking water. Currently, half of the U.S. population and 97% of the rural residents in the area use the aquifer as their main source of drinking water (web.mit.edu). Currently the population levels are tolerable, but if they continue to worsen, it will affect human health and ecosystems (web.mit.edu). Industrial agriculture and the chemicals they use are contaminating the groundwater (kerrcenter.com). Nitrates in the fertilizer seep into the groundwater and can cause harm to "pregnant women and children" (kerrcenter.com). Agriculture runoff is also polluted by animal waste (kerrcenter.com). In many areas the water does not meet the EPA's "drinking water standards" (kerrcenter.com). Communities that "rely on groundwater for drinking" are required to be federally monitored, while other areas that don't greatly depend on the aquifer find the monitoring process too expensive (kerrcenter.com). The pollution of the aquifer poses great health effects.
Larger Consequences
a. Are there other cases of this same problem/issue in different locations?
Yes. There are two main types of aquifers, replenishable and nonreplenishable. Both are found throughout the world, and water issues occur with both. But, nonreplenishable aquifers (also called fossil aquifers) were filled over long periods of time in history, and recharge at extremely slow rates, as compared to replenishable aquifers, which recharge fairly quickly, but were not filled largely by historical water aggregation. Thus, since the Ogallala Aquifer recharges at such a slow rate (compared to the rate of withdrawal), it falls into the "nonreplenishable category."b. Are there global consequences to this issue?
As mentioned above, both types of aquifers are found throughout the world. The deep aquifer under the Northern Chinese plains is an example of a replenishable aquifer, and the Saudi aquifer represents an example of a nonreplenishable one, the latter being more threatened since conditions in the area are too dry to allow for conventional rainwater farming. In the Saudi aquifer, the groundwater does not recharge, or does so extremely slowly, since the average yearly rainfall is only a few inches. And, as in many other cases, excessive withdrawal of water from coastal aquifers often leads to saltwater intrusion; since Saudi Arabia is bordered by water on two sides, saltwater intrusion often leads to contamination of even the water that is yet to be withdrawn.
In the Northern Plain Chinese aquifer, the water level is currently falling at a rate of just under 10 feet per year. In fact, aquifer withdrawal in the Northern Plains has been so drastic that Chinese officials have devised plans to transfer water from the South to the North via enormous pipelines. But, with China's ever rising population, even this new transfer system will not be enough to provide sufficient water. As it is today, China's dramatic population growth has been ultimately made possible by use of the Northern Plains aquifer, and without it, no matter what system of transfer the government devises, continued growth (at least at the same rate) will be impossible.
Aquifer depletion is a worldwide issue, and one that certainly calls for quick remediation in the near future. The Ogallala aquifer is just another example, though the effects of its depletion will be felt disproportionately in the US. Indeed, the Ogallala "supports nearly 1/5 of the wheat, corn, cotton, and cattle produced in the United States." It also "supplies approximately 30% of the nation's irrigation water." Thus, the effects of this relatively localized problem will be felt throughout the United States if we fail to either find alternative (or supplementary) sources of water or adopt more effective methods of water conservation.
Solutions
a. What are the potential solutions to this issue, and how realistic are they?
As mentioned above, there are two possible ways to mitigate this issue: either find alternative water sources, or change the way we (both citizens and farmers) use water. But, given the historical lack of rainfall in the High Plains (ie, the Dust Bowl), and the lack of water bodies nearby, the latter is the more practical solution for the time being. Eventually, though, since the Ogallala aquifer is essentially a nonrenewable resource, we will have to find alternative water sources.
Since irrigation for farming represents "94% of the groundwater use [in the area]," it is largely up to farmers to do what they can to protect this ever dwindling water source. Perhaps the most effective way to continue use at our current rate would be for farmers to control the amount of water lost to evaporation. For example, when irrigating during the heat of the day, water loss due to evaporation can be nearly 30%, whereas watering at dusk or dawn yields losses of only around 15%. This rate could be even further reduced to roughly 5% if farmers ceased flood irrigation and began drip irrigation, a method of irrigation which delivers water directly to the roots of plants via pipes.
Using drip irrigation would be extremely effective in helping farmers conserve water, but the technology is expensive and would require government subsidies to farmers. However, in the long run, these subsidies would pay for themselves by helping to prevent water crises in the future. Of course, the only permanently effective solution would be to limit the rate of water withdrawal to the rate of natural recharge. Unfortunately though, the aquifer's rate of recharge is so slow that implementing this solution would lead to food and water shortages throughout the nation.
Hence, there are strategies to more effectively use the limited resources provided to us by the Ogallala aquifer. But, it's safe to say that one of the biggest challenges to the implementation of these strategies is that many farmers are simply not educated on how to efficiently use water. So, the ultimate solution is to educate farmers, both on the extent of the depletion of the aquifer, and on how they can modify their practices to ensure the maintenance of this crucial water source.
b. Identify and describe any organizations that are acting to address the issue.
The Department of Agriculture's Natural Resources Conservation Service spearheaded the "Ogallala Aquifer Initiative," which aims to "reduce aquifer water use, improve water quality and enhance the economic viability of croplands and rangelands in [the affected areas]." The NRCS has some 25 smaller organizations on board with the Initiative, including organizations from every state directly affected by the aquifer's depletion.
c. Have these solutions been applied with any success?
Unfortunately, many of these solutions have not been applied yet, for a variety of reasons. Primarily, as mentioned above, many farmers are uneducated when it comes to the extent of the issue or how they can contribute. Another issue is that many of the technologies that would help conserve the water are expensive, or hard to get, and thus, the government would either need to subsidize or require the purchase of these technologies (which, of course, it has yet to do). Finally, the government needs to establish an organization to oversee and ensure judicious use of the aquifer, because effectively applying these solutions means that ALL farmers must adopt them. Unfortunately, since this issue does not affect us today, many politicians fail to address it, instead focusing on "current" issues. If this trend continues, we will face food shortages to an extent we have not seen for many years.
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