hydrogeology
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| hydrogeology | |
|---|---|
| Name | Hydrogeology |
| Caption | Groundwater flow through porous media |
| Field | Earth science |
| Related | Geology, Hydrology, Environmental science |
hydrogeology Hydrogeology is the branch of Earth science that investigates the distribution, movement, and quality of subsurface water in porous and fractured rock. It draws on methods and institutions from United States Geological Survey, British Geological Survey, United Nations Environment Programme, World Bank, and uses tools developed in projects like National Hydrological Instrumentation Project, International Hydrological Programme, Global Water Partnership, European Geosciences Union, and International Association of Hydrogeologists. Practitioners work across settings such as Ogallala Aquifer, Nile Delta, Aral Sea region, Murray–Darling Basin, and California Central Valley.
Overview and Scope
The discipline overlaps with fields represented by organizations like Geological Society of America, American Geophysical Union, Royal Society, United Nations Educational, Scientific and Cultural Organization, and World Health Organization, and applies principles from projects such as Apollo program‑era remote sensing, Landsat imagery, Copernicus Programme data assimilation, Intergovernmental Panel on Climate Change assessments, Food and Agriculture Organization guidance, and International Atomic Energy Agency isotope tracing. Work includes assessment of groundwater resources in basins such as Amazon Basin, Ganges Basin, Yellow River Basin, Colorado River Basin, and Great Artesian Basin for stakeholders including European Commission, Asian Development Bank, African Development Bank, United Nations Development Programme, and local authorities like California Department of Water Resources.
Hydrogeologic Concepts and Terminology
Core terms originate in studies by figures and institutions like Blaise Pascal‑era hydraulics, Henry Darcy, Pierre Perrault, James Hutton, and modern syntheses from Huntington Botanical Gardens archives, with standards set by bodies including American Society for Testing and Materials, International Organization for Standardization, and United States Environmental Protection Agency. Practitioners use descriptors applied to formations such as Buntsandstein, Navajo Sandstone, Karoo Supergroup, Chalk Group, and Carboniferous Limestone and quantify parameters using methods endorsed by Society of Exploration Geophysicists, International Association of Hydrogeologists, American Water Works Association, Royal Geographical Society, and National Research Council (US). Terms include concepts like porosity, permeability, transmissivity, storativity, and potentiometric surface measured in contexts like Sedimentary Basin Analysis, Structural Geology, Tectonophysics, Volcanology, and Glaciology studies.
Groundwater Occurrence and Movement
Groundwater systems are studied in settings from crystalline shields like the Canadian Shield and Baltic Shield to sedimentary basins such as the Paris Basin, Sichuan Basin, North Sea Basin, Gulf of Mexico Basin, and volcanic provinces like Iceland and Hawaii. Flow is influenced by features mapped by surveys such as Ordnance Survey, Geological Survey of India, Geological Survey of Japan, Geological Survey of Canada, and by processes described in works like The Origin of Continents and Oceans and Principles of Geology. Movement is modeled considering recharge from rivers like the Amazon River, Mekong River, and Yangtze River, discharge to wetlands such as Okavango Delta, Everglades National Park, and Sundarbans, and interactions with coastal systems including Chesapeake Bay, Gulf of Thailand, and Bay of Bengal.
Aquifers and Aquitards
Aquifer types are exemplified by formations including the Edwards Aquifer, Floridan Aquifer, Yarragadee Aquifer, Great Artesian Basin, and fractured systems like the Scandinavian Shield and Appalachian Mountains. Confining layers occur in sequences such as the Kimmeridge Clay Formation, Oxford Clay Formation, Mercia Mudstone Group, and glacial tills studied in the context of Quaternary geology, Pleistocene glaciation, Holocene transgression, and Mississippian strata. Engineering solutions reference standards from International Commission on Large Dams, World Bank Group, United Nations Office for Disaster Risk Reduction, and notable projects like Three Gorges Dam and Hoover Dam for impacts on groundwater‑surface water exchange.
Groundwater Quality and Contamination
Issues include salinization in deltas such as Indus Delta, Nile Delta, and Ganges Delta; nitrate pollution near agricultural regions like Central Valley (California), Punjab (India), and Loire Valley; and industrial contamination exemplified by sites near Chernobyl disaster zones, Love Canal, and Minamata disease‑affected areas. Contaminants are traced using isotope methods promoted by International Atomic Energy Agency, geochemical frameworks from Geochemical Society, and remediation strategies guided by United States Environmental Protection Agency, European Environment Agency, United Nations Environment Programme, and case studies like Hanford Site and Port Hope.
Exploration, Monitoring, and Modeling
Exploration techniques employ geophysical surveys used by Schlumberger, Halliburton, and academic teams at Massachusetts Institute of Technology, Stanford University, Imperial College London, ETH Zurich, and Universidad Nacional Autónoma de México. Monitoring networks are managed by agencies such as Environment Agency (England) and Water Research Commission (South Africa), using data platforms like Global Runoff Data Centre, HydroSHEDS, GRACE satellite products, and citizen science initiatives modeled on Global Water Watch. Numerical modeling uses software stacks inspired by developments at Sandia National Laboratories, Pacific Northwest National Laboratory, Lawrence Berkeley National Laboratory, and academic codes from University of Waterloo and Colorado School of Mines.
Management, Use, and Policy
Management integrates guidance from entities such as Ramsar Convention, Convention on Biological Diversity, Sustainable Development Goals, World Health Organization, and frameworks implemented by national ministries like Ministry of Water Resources (China), Ministry of Jal Shakti (India), and United States Bureau of Reclamation. Policies address allocation in transboundary basins including Mekong River Commission, International Boundary and Water Commission, Nile Basin Initiative, Indus Water Treaty, and case law from bodies like the International Court of Justice and decisions influenced by treaties such as the Water Convention.