Hydrologists study water and the water cycle. They study the movement, distribution, and other properties of water, and they analyze how these influence the surrounding environment. They use their expertise to solve problems concerning water quality and availability, for example.
Hydrologists typically do the following:
Hydrologists use remote sensing equipment to collect data. They or technicians whom they supervise usually install and maintain this equipment.
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. Some of the most common specialties are:
Groundwater hydrologists study the water below the Earth's surface. They decide the best locations for wells and the amount of water that should be pumped. They are often consulted about the best places to build waste disposal sites to ensure that the waste does not contaminate the groundwater.
Hydrometeorologists study the relationship between surface waters and water in the atmosphere. For example, to predict and prepare for droughts, they study how much rain or snow a particular area gets and how that evaporates.
Surface water hydrologists study water from above ground sources such as streams, lakes, and snow packs. They may predict future water levels and usage to help reservoir managers decide when to release or store water. They also produce flood forecasts and help develop flood management plans.
Some people with a hydrology background become professors or teachers. For more information, see the profile on postsecondary teachers.
Cement masons pour, smooth, and finish concrete floors, sidewalks, roads, and curbs. Using a cement mixture, terrazzo workers create durable and decorative surfaces for floors and stairways.
Cement masons typically do the following:
Terrazzo workers typically do the following (in addition to what cement masons do):
Concrete is one of the most common and durable materials used in construction. Once set, concrete--a mixture of cement, sand, gravel, and water--becomes the foundation for everything from decorative patios and floors to huge dams or miles of roadways.
The following are types of cement masons and terrazzo workers:
Cement masons and concrete finishers place and finish concrete. They may color concrete surfaces, expose aggregate (small stones) in walls and sidewalks, or make concrete beams, columns, and panels.
Throughout the process of pouring, leveling, and finishing concrete, cement masons must monitor how the wind, heat, or cold affects the curing of the concrete. They must have a thorough knowledge of the characteristics of concrete so that, by using sight and touch, they can determine what is happening to the concrete and take measures to prevent defects.
Terrazzo workers and finishers create decorative walkways, floors, patios, and panels. Although much of the preliminary work in pouring, leveling, and finishing concrete is similar to that of cement masons, terrazzo workers create more decorative finishes by blending a fine marble chip into the cement, which is often colored. Once the terrazzo is thoroughly set, workers correct any depressions or imperfections with a grinder to create a smooth, uniform finish.
Janitors and building cleaners keep many types of buildings clean, orderly, and in good condition.
Janitors and building cleaners typically do the following:
Janitors and building cleaning workers keep office buildings, schools, hospitals, retail stores, hotels, and other places clean, sanitary, and in good condition. Some do only cleaning, while others have a wide range of duties.
In addition to keeping the inside of buildings clean and orderly, some janitors and building cleaners work outdoors, mowing lawns, sweeping walkways, or shoveling snow. Some janitors also monitor the heating and cooling system, ensuring that it functions properly.
Janitors and building cleaners use many tools and equipment. Simple cleaning tools may include mops, brooms, rakes, and shovels. Other tools may include snowblowers and floor buffers.
Some janitors may be responsible for repairing small problems with electricity or plumbing, such as leaky faucets.
Construction equipment operators drive, maneuver, or control the heavy machinery used to construct roads, bridges, buildings, and other structures.
Construction equipment operators typically do the following:
Construction equipment operators use machinery to move construction materials, earth, and other heavy materials at construction sites and mines. They operate equipment that clears and grades land to prepare it for construction of roads, bridges, and buildings, as well as airport runways, power generation facilities, dams, levees, and other structures.
The following are types of construction equipment operators:
Operating engineers and other construction equipment operators work with one or several types of power construction equipment. They may operate excavation and loading machines equipped with scoops, shovels, or buckets that dig sand, gravel, earth, or similar materials. In addition to operating the familiar bulldozer, they operate trench excavators, road graders, and similar equipment. Sometimes, they may drive and control industrial trucks or tractors equipped with forklifts or booms for lifting materials. They also may operate and maintain air compressors, pumps, and other power equipment at construction sites.
Paving and surfacing equipment operators control the machines that spread and level asphalt or spread and smooth concrete for roadways or other structures. Paving and surfacing equipment operators may specialize further:
Piledriver operators use large machines mounted on skids, barges, or cranes to hammer piles into the ground. Piles are long, heavy beams of wood or steel driven into the ground to support retaining walls, bridges, piers, or building foundations. Some piledriver operators work on offshore oil rigs.
Some workers operate cranes to move construction materials. For more information on these workers, see the profile on material moving machine operators.
Heating, air conditioning, and refrigeration mechanics and installers--often referred to as HVACR technicians--work on heating, ventilation, cooling, and refrigeration systems that control the air quality in many types of buildings.
Heating, air conditioning, and refrigeration mechanics and installers typically do the following:
Heating and air conditioning systems control the temperature, humidity, and overall air quality in homes, businesses, and other buildings. By providing a climate controlled environment, refrigeration systems make it possible to store and transport food, medicine, and other perishable items.
Although trained to do all three, HVACR technicians sometimes work strictly with heating, air conditioning, or refrigeration systems. They also may specialize in certain types of HVACR equipment, such as water-based heating systems, solar panels, or commercial refrigeration.
Depending on the task, HVACR technicians use many different tools. For example, they often use screwdrivers, wrenches, pipe cutters and other basic handtools when installing systems. To test or install complex system components, technicians may use more sophisticated tools, such as carbon monoxide testers, voltmeters, combustion analyzers, and acetylene torches.
When working on air conditioning and refrigeration systems, technicians must follow government regulations regarding the conservation, recovery, and recycling of refrigerants. This often entails proper handling and disposal of fluids.
Some HVACR technicians sell service contracts to their clients, providing regular maintenance of heating and cooling systems.
Other craft workers sometimes help install or repair cooling and heating systems. For example, on a large air conditioning installation job, especially one in which workers are covered by union contracts, ductwork might be done by sheet metal workers and duct installers, or electrical work by electricians. In addition, home appliance repairers usually service window air conditioners and household refrigerators. For more information on these occupations, see the profiles on sheet metal workers, electricians, or home appliance repairers.