The Modeling of Salt Water Intrusion
What is Salt Water Intrusion?
Salt water intrusion, or encroachment, is defined by Freeze and Cherry (1979) as the migration of salt water into fresh water aquifers under the influence of groundwater development. Salt water intrusion becomes a problem in coastal areas where fresh water aquifers are hydraulically connected with seawater. When large amounts of fresh water are withdrawn from these aquifers, hydraulic gradients encourage the flow of seawater toward the pumped well or wells. Salt water intrusion is a problem that affects coastal areas around the world. Groundwater Problems in Coastal Areas (Custodio, 1987) is an excellent reference for more information on global salt water intrusion problems, while Atkinson (1986) details salt water intrusion problems for the coastal areas of the United States.
Why is it a Problem?
The encroachment of salt water into fresh water supplies has become cause for concern within the last century as populations in coastal areas have risen sharply and placed greater demands on fresh groundwater reserves. Salt water intrusion causes many problems in these areas, perhaps the most severe being the limitation of potable drinking water. Drinking water standards established by the EPA in 1962 require that drinking water contain no more than 500 mg/L of total suspended solids (TSS), a common measure of salinity (Atkinson, 1986). Seawater contains approximately 30000 mg/L of TSS. Therefore, it is evident that even a small amount of seawater can cause drinking water problems when mixed with fresh water reserves. Also, salinity in irrigation water can be detrimental to agriculture, reducing yields and killing crops with low tolerances to salt. In some...
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...t Modeling of the Flow Through Porous Media". OWRT-C-4026(9006)(4). Office of Water Resources and Technology, U.S. Dept. of the Interior. Washington, DC. March, 1975.
Christensen, B.A., "Mathematical Methods for Analysis of Fresh Water Lenses in the Coastal Zones of the Floridian Aquifer". OWRT-A-032-FLA(1). Office of Water Research and Technology. U.S. Dept. of the Interior. Washington, DC.
Custodio, E., and Llamas, M.R. Hidrologia Subterranea. Ed. Omega, Barcelona. 1976.
Custodio, E. (prepared by). Groundwater Problems in Coastal Areas. A contribution to the International Hydrological Programme. 1987.
Freeze, R. A. and J. A. Cherry. Groundwater. Prentice Hall, Inc. 1979.
Jenkins, S. R. and R. K. Moore. "Effect of Saltwater Intrusion on Soil Erodibility of Alabama Marshlands". Water Resources Research Institute, Auburn University, Auburn, Al. 1984.
Bonnett, Gabrysch R.K. and C.W. "Land Surface Subsidence at Seabrook, TX ." US Geological Survey. Seabrook TX: Water Resources INV, 1975.
...victims of war and genocide, it is admirable to see his courage to remain engaged in service to his fellow human. With a bold, yet pragmatic vision, Orbinski is unconcerned with seemingly intractable problems of finding drugs for the poorest AIDS victims. The book illustrates his desire to get the job done without bravado and grand statements. Although the book was painful to read, it takes he reader to the extreme of human suffering. Nevertheless, it also inspires with its reflections of humanitarianism and the ingenuity brought to its implementation. It is heartening to know James Orbinski can inspire students in both the arts and sciences as they set out on their careers. Since after all he’s seen, Orbinski remain optimistic, not cynical, and committed to action. Do give this book to any students in your life, after you have read it yourself.
Typically, almost everyone in the world has taken drugs at some point in their life. Whether it be over the counter medication or prescription drugs. People get sick, they have illness, allegories, sexually transmitted diseases or other aches and pains. As you may already know, there is medication for each aforementioned problem. This is called drug use, which is using drugs for its intended purpose. However, the real dilemma happens when people began to misuse and abuse drugs.
Cystic Fibrosis (CF) is a very common, potentially life threatening condition. The disease is caused by inheritance, and affects the exocrine glands of the patient. Cystic fibrosis is found primarily among Caucasians and those of European descent. Those diagnosed with Cystic Fibrosis battle daily to perform simple tasks, such as breathing, as the mucus in their bodies thickens immensely. This mucus will potentially accumulate in the patient’s vital organs, such as the lungs, pancreas, and intestines. One can determine if he/she has cystic fibrosis by analyzing certain symptoms. Cystic Fibrosis can be diagnosed according to the symptoms the patient shows, and can be treated through specific types of treatments, such as gene therapy.
The war on drugs in our culture is a continuous action that is swiftly lessening our society. This has been going on for roughly 10-15 years and has yet to slow down in any way. Drugs continue to be a problem for the obvious reason that certain people abuse them in a way that can lead to ultimate harm on such a person. These drugs do not just consist of street drugs (marijuana, cocaine, ecstasy), but prescription medications as well. Although there are some instances where drugs are being used by subjects excessively, there has been medical research to prove that some of these drugs have made a successful impact on certain disorders and diseases.
However, before the specific outcomes of Congressional influence and policy impact can be evaluated it becomes important to first review the general history and current situation of drugs today. Our present drug laws were first enacted at the beginning of the century. At the time, recreational use of narcotics was not a major social issue. The first regulatory legislation was for the purpose of standardizing the manufacturing and purity of pharmaceutical products. Shortly after, the first criminal laws were enacted which addressed opium products and cocaine. Although some states had prohibited the recreational use of marijuana, there was no federal criminal legislation until 1937. By contrast, the use of alcohol and its legality was a major social issue in United States in the early 20th century. This temperance movement culminated in the prohibition of alcohol from 1920 to 1933. Recreational drug use, particularly heroin, became more prevalent among the urban poor during the early ?60s. Because of the high cost of heroin and its uncertain purity, its use was associated with crime and frequent overdoses.
The Salton Basin , a below-sea-level depression which extends on the north from Palm Springs , California, to the Gulf of California , in the south. The Salton Sea has undergone historic cycles of filling with water and later drying up. The most recent predecessor to the Sea, that being Lake Cahuilla , last filled this area between 300 to 500 years ago and at one time had a surface elevation above sea level. In 1905 the flooding of the Colorado River was accidentally diverted into the Salton though and thus the Salton Sea was born. When the Colorado River floods retreated in 1907, the surface elevation of the Salton Sea slowly began to drop until the 1930�s when agricultural drainage from the Imperial and Coachella Valleys sustained its level. Soon after , this Sea was turned into a state recreation area, wildlife refuge and a sport fishery. To this day, agricultural drainage and run-off is the major source of water inflow to the Salton Sea.
Increased sea levels can give way to a variety of problems: rapid coastal erosion, shoreline change, loss of natural protective barriers, saltwater intrusion into aquifers and surface water, changes in tidal prisms (volume of water in an inlet between high tide and low tide), and rising water tables ("Climate Change and Impacts of Sea Level Rise"). Ventura County is facing many issues with rapid coastal erosion and loss of natural protective barriers. Beach Erosion Authority for Clean Oceans and Nourishment (BEACON) conducted a study to evaluate the conditions of different beaches along the Ventura County coast (Barlow, "Coastal Erosion Problems Highlighted in New Study"). Port Hueneme’s western beaches (picture to the left) are losing three to five inches per month due to sea level rise pushing beaches farther back.
The prohibitionist national policy towards drugs in U.S has been extremely contentious in the present times. After decades of the stance that costs billions how many each year, the paltry achievements and the countless negative externalities have led to a clamor for alternative policies instead of a “War on Drugs”.
feeding off society's money, taxes and insurance. Every type of insurance goes up because of drug abuse, including auto, health and homeowners. Worst of all, the crime rate will sky rocket if we let this behavior continue. Illegal drugs and their abusers are a plague to society for many different reasons..
Drug abuse has been a hot topic for our society due to how stimulants interfere with health, prosperity, and the lives of others in all nations. All drugs have the potential to be misapplied, whether obtained by prescription, over the counter, or illegally. Drug abuse is a despicable disease that affects many helpless people. Majority of those who are beset with this disease go untreated due to health insurance companies who neglect and discriminate this issue. As an outcome of missed opportunities of treatments, abusers become homeless, very ill, or even worst, death.
Smith, Zachary A., and Grenetta Thomassey. Freshwater Issues: A Reference Handbook. Santa Barbara, CA: ABC-CLIO, 2002. Print
The use of illegal drugs in the United States and other countries around the world is one of the biggest problems in today community. Illegal drugs are drugs that are restricted by the government. Moreover, some medical drugs have chemicals that can help people with pain and stress. But when people are under the influence of illicit drugs, they can experience many side effects such as: liver cancer, heart, and brain disease. Illegal drugs are being used by many types of people around the world; they cost a large amount of money and negatively affect people both psychologically and physically.
Rogers, Peter. 2008. "Facing the Freshwater CRISIS. (Cover story)." Scientific American 299, no. 2: 46-53. Academic Search Premier, EBSCOhost (accessed November 4, 2010).