IAH members range from students and those early in their careers, right through to those who have have spent their entire professional lives working as hydrogeologists, or in jobs relating to groundwater. The association facilitates information sharing through its national chapters groups , specialist networks and commissions, through meetings and events, and more. You are welcome to find out more about our association, its efforts, and if you work or plan to work in the field of groundwater, to participate.
Information for students, hydrogeologists and other groundwater-related professionals, career development. International Association of Hydrogeologists. Join Login. Search for:. They also use sophisticated computer programs to analyze and model data. They use sophisticated laboratory equipment to analyze chemical samples collected in the field. Hydrologists work closely with engineers , scientists , and public officials to study and manage the water supply.
For example, they work with policy makers to develop water conservation plans and with biologists to monitor marine wildlife. Most hydrologists specialize in a specific water source or a certain aspect of the water cycle, such as the evaporation of water from lakes and streams. Hydrologists have distinct personalities. If the reservoir also is used for recreation or for generation of hydroelectric power , those requirements must be considered.
Decisions must be coordinated with other reservoir managers along the river. Hydrologists collect the necessary information, enter it into a computer, and run computer models to predict the results under various operating strategies. On the basis of these studies, reservoir managers can make the best decision for those involved. The availability of surface water for swimming, drinking, industrial or other uses sometimes is restricted because of pollution. Pollution can be merely an unsightly and inconvenient nuisance, or it can be an invisible, but deadly, threat to the health of people, plants and animals.
Hydrologists assist public health officials in monitoring public water supplies to ensure that health standards are met. When pollution is discovered, environmental engineers work with hydrologists in devising the necessary sampling program. Water quality in estuaries, streams, rivers and lakes must be monitored, and the health of fish, plants and wildlife along their stretches surveyed.
Related work concerns acid rain and its effects on aquatic life, and the behavior of toxic metals and organic chemicals in aquatic environments. Hydrologic and water quality mathematical models are developed and used by hydrologists for planning and management and predicting water quality effects of changed conditions. Simple analyses such as pH , turbidity , and oxygen content may be done by hydrologists in the field.
Other chemical analyses require more sophisticated laboratory equipment. In the past, municipal and industrial sewage was a major source of pollution for streams and lakes. Such wastes often received only minimal treatment, or raw wastes were dumped into rivers. Today, we are more aware of the consequences of such actions, and billions of dollars must be invested in pollution-control equipment to protect the waters of the earth.
Other sources of pollution are more difficult to identify and control. These include road deicing salts, storm runoff from urban areas and farmland, and erosion from construction sites. Groundwater , pumped from beneath the earth's surface, is often cheaper, more convenient and less vulnerable to pollution than surface water. Therefore, it is commonly used for public water supplies. Groundwater provides the largest source of usable water storage in the United States.
Underground reservoirs contain far more water than the capacity of all surface reservoirs and lakes, including the Great Lakes. In some areas, ground water may be the only option. Some municipalities survive solely on groundwater. Hydrologists estimate the volume of water stored underground by measuring water levels in local wells and by examining geologic records from well-drilling to determine the extent, depth and thickness of water-bearing sediments and rocks.
Before an investment is made in full-sized wells , hydrologists may supervise the drilling of test wells. They note the depths at which water is encountered and collect samples of soils, rock and water for laboratory analyses.
They may run a variety of geophysical tests on the completed hole, keeping and accurate log of their observations and test results. Hydrologists determine the most efficient pumping rate by monitoring the extent that water levels drop in the pumped well and in its nearest neighbors. Pumping the well too fast could cause it to go dry or could interfere with neighboring wells. Along the coast, overpumping can cause saltwater intrusion. By plotting and analyzing these data, hydrologists can estimate the maximum and optimum yields of the well.
Polluted groundwater is less visible, but more insidious and difficult to clean up, than pollution in rivers and lakes. Ground water pollution most often results from improper disposal of wastes on land.
Major sources include industrial and household chemicals and garbage landfills, industrial waste lagoons, tailings and process wastewater from mines, oil field brine pits, leaking underground oil storage tanks and pipelines, sewage sludge and septic systems. Hydrologists provide guidance in the location of monitoring wells around waste disposal sites and sample them at regular intervals to determine if undesirable leachate — contaminated water containing toxic or hazardous chemicals — is reaching the ground water.
In polluted areas, hydrologists may collect soil and water samples to identify the type and extent of contamination. The chemical data then are plotted on a map to show the size and direction of waste movement. In complex situations, computer modeling of water flow and waste migration provides guidance for a clean-up program.
In extreme cases, remedial actions may require excavation of the polluted soil. Today, most people and industries realize that the amount of money invested in prevention is far less than that of cleanup. Hydrologists often are consulted for selection of proper sites for new waste disposal facilities.
The danger of pollution is minimized by locating wells in areas of deep ground water and impermeable soils. Other practices include lining the bottom of a landfill with watertight materials, collecting any leachate with drains, and keeping the landfill surface covered as much as possible.
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