Hydrology

Water is among the most important resources on our planet. Without it, life would not exist. Hydrologists study how water moves across and through Earth’s crust. They study how rain, snow, and other forms of precipitation impact river flows or groundwater levels and how surface water and groundwater evaporate back into the atmosphere or eventually reach the oceans. Hydrologists analyze how water influences the surrounding environment and how changes to the environment influence the quality and quantity of water. Hydrologists use their expertise to solve problems concerning water quality and availability and assist in water conservation.[1] The work they do is very important for environmental preservation; for example, they may project water shortages, analyze the quality of potential water sources, or monitor the inflow and outflow of reservoirs. Some hydrologists forecast and help to prepare a region for conditions such as flooding, snowmelt, drought, and the formation and melting of river ice. Hydrologists often serve as consultants to scientists, engineers, developers, and governing bodies.[2]

Hydrologic Cycle

One crucial concept in hydrology is the hydrologic cycle. The hydrologic cycle involves the continuous circulation of water in the Earth-Atmosphere system. At its core, the water cycle is the motion of the water from the ground to the atmosphere and back again.[3] Of the many processes involved in the hydrologic cycle, the most important are:

• evaporation
• transpiration
• condensation
• precipitation
• runoff

The hydrologic cycle starts when water evaporates and moves as water vapor into the atmosphere. Then, the water falls back to the planet’s surface to the oceans and land masses. Once back on Earth, the water may be frozen into icebergs or captured by oceans and rivers. It may soak into the soil, where it can make its way to groundwater reserves or be sucked up by the roots of plants. Human activities—ranging from the operation of a manufacturing plant to the irrigation of a home garden—affect the hydrologic cycle, as well as the availability and quality of water resources.[4]

Groundwater Hydrologists

Groundwater hydrologists study the water below Earth’s surface. Groundwater hydrologists sample and measure properties of water, analyze environmental data, collect samples for analysis, forecast the future water supply, and prepare reports. Some groundwater hydrologists look at water supply to decide on locations for digging wells or pumping.[5] Others focus on groundwater cleanup from contamination. They often help determine the locations of new waste disposal sites to prevent groundwater contamination.[6]

Surface Water Hydrologists

Surface water hydrologists study above-ground water sources such as streams, lakes, and glaciers. Surface water hydrology includes the study of surface water movement and the distribution of surface water in space and time. Of particular interest is the variability in water quantity and flow within a year and between years.[7] Surface water hydrologists work with usage and precipitation data to estimate water levels in reservoirs. Their estimates help reservoir managers make decisions about storing and releasing water to meet demand. They also create flood forecasts and help develop flood management plans.[8]

Hydrogeologists

Hydrogeologists are a type of environmental geologist that study how water interacts with the natural environment of rocks and soils. People with these qualifications can carry out one of two jobs, but sometimes will be expert in both. The first role is that of environmental geographer. They study the relationship between water and rocks and soil as a natural process. Their data will help other experts understand such environmental processes as glaciation, river formation and movement, flood and other natural disaster risk and long-term environmental processes. They help us understand the world around us in terms of the relationship between water and dry land. They will look equally at data collected from the field, GIS analysis and old maps. The second role of a hydrogeologist is to ensure that water supplies remain safe and healthy. Some rock and soils contain contaminants that are harmful to human health. It is their job to identify and mitigate them. Most of these will be naturally occurring contaminants, but they may also be the result of pollutants. They may provide expert analysis in litigation against the businesses responsible should a court case be necessary.[9]

They may also be involved in environmental planning. The amount of waste that we produce requires space to put them. Hydrogeologists will look at the underlying soil and geology of proposed sites to ensure that pollution risks are low (for example subterranean rivers or lakes that flow into domestic water supplies). Land use planners will often consult hydrologists and hydrogeologists. They differ from hydrologists in that these professionals study surface water rather than how water changes the environment.[10]

Hydrometeorologists mainly study both the atmospheric and terrestrial phases of the hydrological cycle, with emphasis on the interrelationship between them (e.g. the transfers of water and energy between the land surface and the lower atmosphere). Accordingly, the science of hydrometeorology bridges across both hydrology and meteorology. For example, hydrometeorologists are interested in the study of natural hazards of hydrometeorological origin and the mitigation of their effects. Among these hazards are the results of natural processes or phenomena of atmospheric, hydrological or oceanographic nature, such as floods, tropical cyclones, drought and desertification, and the potential impacts of land-cover change and changing climate. Major and important processes of interest to hydrometeorologists are precipitation and evapotranspiration, and also how the land surface partitions energy into different components (sensible, latent, ground heat flux) and how this then affects the overlying atmosphere.[11]

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Citations

1. Hydrologists, Occupational Outlook Handbook, U.S. Bureau of Labor Statistics.
2. Hydrologist, Purdue University.
3. The Hydrologic Cycle, NOAA
4. What is a Hydrologist?, Grand Canyon University.
5. Groundwater Hydrologist, Powerful Geography.
6. What is a Hydrologist?, EnvironmentalScience.org.
7. Surface Water Hydrology, Regional Aquatics Monitoring Program.
8. What is a Hydrologist?, EnvironmentalScience.org.
9. Hydrogeology, University of Michigan.
10. Hydrogeology, University of Michigan.
11. Atmospheric Science-Meteorology, Hydrology, and Hydrometeorology, University of Arizona.