FACTOID # 20: Statistically, Delaware bears more cost of the US Military than any other state.
 
 Home   Encyclopedia   Statistics   States A-Z   Flags   Maps   FAQ   About 
   
 
WHAT'S NEW
RELATED ARTICLES
People who viewed "Hydrology" also viewed:
 

SEARCH ALL

FACTS & STATISTICS    Advanced view

Search encyclopedia, statistics and forums:

 

 

(* = Graphable)

 

 


Encyclopedia > Hydrology
Water covers 70% of the Earth's surface.
Water covers 70% of the Earth's surface.

Hydrology (from Greek: Yδωρ, hudōr, "water"; and λόγος, logos, "knowledge") is the study of the movement, distribution, and quality of water throughout the Earth, and thus addresses both the hydrologic cycle and water resources. A practitioner of hydrology is a hydrologist, working within the fields of either earth or environmental science, physical geography or civil and environmental engineering. ImageMetadata File history File links Download high resolution version (1024x512, 222 KB) Land surface, ocean color, sea ice and clouds. ... ImageMetadata File history File links Download high resolution version (1024x512, 222 KB) Land surface, ocean color, sea ice and clouds. ... Impact from a water drop causes an upward rebound jet surrounded by circular capillary waves. ... The water cycle—technically known as the hydrologic cycle—is the circulation of water within the earths hydrosphere, involving changes in the physical state of water between liquid, solid, and gas phases. ... Water resources are sources of water that are useful or potentially useful to humans. ... Earth science (also known as geoscience, the geosciences or the Earth Sciences), is an all-embracing term for the sciences related to the planet Earth. ... Environmental science is the study of the interactions among the physical, chemical and biological components of the environment; with a focus on pollution and degradation of the environment related to human activities; and the impact on biodiversity and sustainability from local and global development. ... True-color image of the Earths surface and atmosphere Physical geography (also know as geosystems or physiography) is a subfield of geography that focuses on the systematic study of patterns and processes within the hydrosphere, biosphere, atmosphere, and lithosphere. ... The Falkirk Wheel in Scotland. ... Environmental engineering[1][2] is the application of science and engineering principles to improve the environment (air, water, and/or land resources), to provide healthy water, air, and land for human habitation and for other organisms, and to remediate polluted sites. ...


Domains of hydrology include hydrometeorology, surface hydrology, hydrogeology, drainage basin management and water quality, where water plays the central role. Oceanography and meteorology are not included because water is only one of many important aspects. Hydrometeorology is a branch of meteorology and hydrology that studies the transfer of water and energy between the land surface and the lower atmosphere. ... Surface water hydrology describes the relation between rainfall and runoff, which is important for water resources for drinking water, agriculture and the environment, and for protecting and safe-guarding people against possible floods. ... Hydrogeology (hydro- meaning water, and -geology meaning the study of the Earth) is the part of hydrology that deals with the distribution and movement of groundwater in the soil and rocks of the Earths crust, (commonly in aquifers). ... This article includes a list of works cited or a list of external links, but its sources remain unclear because it lacks in-text citations. ... Water quality is the chemical and physical characterization of water. ... Thermohaline circulation Oceanography (from Ocean + Greek γράφειν = write), also called oceanology or marine science, is the branch of Earth Sciences that studies the Earths oceans and seas. ... Satellite image of Hurricane Hugo with a polar low visible at the top of the image. ...


Hydrological research is useful in that it allows us to better understand the world in which we live, and also provides insight for environmental engineering, policy and planning. Environmental engineering[1][2] is the application of science and engineering principles to improve the environment (air, water, and/or land resources), to provide healthy water, air, and land for human habitation and for other organisms, and to remediate polluted sites. ... Environmental policy refers to the laws, regulations, and other policy mechanisms concerning environmental issues and sustainability. ... Environmental planning is a relatively new field of study that aims to merge the practice of urban planning with the concerns of environmentalism. ...

Contents

History

Hydrology has been a subject of investigation and engineering for millennia. For example, in about 4000 B.C. the Nile was dammed to improve agricultural productivity of previously barren lands. Mesopotamian towns were protected from flooding with high earthen walls. Aqueducts were built by the Greeks and Romans, while the Chinese built irrigation and flood control works. The ancient Sinhalese used hydrology to build complex Irrigation Works of Ancient Sri Lanka, known for invention of the Valve Pit which allowed construction of large reservoirs, anicuts and canals which still function. The Nile (Arabic: , transliteration: , Ancient Egyptian iteru, Coptic piaro or phiaro) is a major north-flowing river in Africa, generally regarded as the longest river in the world. ... Mesopotamia refers to the region now occupied by modern Iraq, eastern Syria, southeastern Turkey, and Southwest Iran. ... This article is about the structure aqueduct, for the racecourse see Aqueduct Racetrack. ... Ancient Rome was a civilization that grew from a small agricultural community founded on the Italian Peninsula circa the 9th century BC to a massive empire straddling the Mediterranean Sea. ... This article needs to be cleaned up to conform to a higher standard of quality. ...


Marcus Vitruvius, in the first century B.C., described a philosophical theory of the hydrologic cycle, in which precipitation falling in the mountains infiltrated the earth's surface and led to streams and springs in the lowlands. With adoption of a more scientific approach, Leonardo da Vinci and Bernard Palissy independently reached an accurate representation of the hydrologic cycle. It was not until the 17th century that hydrologic variables began to be quantified. Marcus Vitruvius Pollio (born ca. ... The Mona Lisa Leonardo di ser Piero da Vinci (April 15, 1452 – May 2, 1519) was an Italian polymath: scientist, mathematician, engineer, inventor, anatomist, painter, sculptor, architect, musician, and writer. ... Bernard Palissy. ...


Pioneers of the modern science of hydrology include Pierre Perrault, Edme Mariotte, and Edmund Halley. By measuring rainfall, runoff, and drainage area, Perrault showed that rainfall was sufficient to account for flow of the Seine. Marriotte combined velocity and river cross-section measurements to obtain discharge, again in the Seine. Halley showed that the evaporation from the Mediterranean Sea was sufficient to account for the outflow of rivers flowing into the sea. Edme Mariotte (c. ... Edmond Halley. ... The Seine (pronounced in French) is a major river of north-western France, and one of its commercial waterways. ... Composite satellite image of the Mediterranean Sea. ...


Advances in the 18th century included the Bernoulli piezometer and Bernoulli's equation, by Daniel Bernoulli, the Pitot tube, and the Chezy formula. The 19th century saw development in groundwater hydrology, including Darcy's law, the Dupuit-Thiem well formula, and Hagen-Poiseuille's capillary flow equation. In fluid dynamics, Bernoullis equation, derived by Daniel Bernoulli, describes the behavior of a fluid moving along a streamline. ... Daniel Bernoulli Daniel Bernoulli (Groningen, February 8, 1700 – Basel, March 17, 1782) was a Dutch-born mathematician who spent much of his life in Basel, Switzerland. ... A Pitot tube is a measuring instrument used to measure fluid flow. ... Darcys Law is a phenomologically derived constitutive equation that describes the flow of a fluid through a porous medium (typically water through an aquifer). ...


Rational analyses began to replace empiricism in the 20th century, while governmental agencies began their own hydrological research programs. Of particular importance were Leroy Sherman's unit hydrograph, the infiltration theory of Robert E. Horton, and C.V. Theis's equation describing well hydraulics. Robert Elmer Horton (May 18, 1875 - April 22, 1945) was an American ecologist and soil scientist, considered by many to be the father of modern hydrology. ... An Aquifer test is conducted to evaluate an aquifer by stimulating the aquifer through constant pumping, and observing the aquifers response (drawdown) in observation wells. ...


Since the 1950s, hydrology has been approached with a more theoretical basis than in the past, facilitated by advances in the physical understanding of hydrological processes and by the advent of computers and especially Geographic Information Systems (GIS). This does not cite its references or sources. ... A BlueGene supercomputer cabinet. ... A geographic information system (GIS) is a system for managing data that has a spatial specialized form of an information system. ...


Hydrologic cycle

Main article: Hydrologic cycle The water cycle—technically known as the hydrologic cycle—is the circulation of water within the earths hydrosphere, involving changes in the physical state of water between liquid, solid, and gas phases. ...


The central theme of hydrology is that water moves throughout the Earth through different pathways and at different rates. The most vivid image of this is in the evaporation of water from the ocean, which forms clouds. These clouds drift over the land and produce rain. The rainwater flows into lakes, rivers, or aquifers. The water in lakes, rivers, and aquifers then either evaporates back to the atmosphere or eventually flows back to the ocean, completing a cycle.


Branches of hydrology

Chemical hydrology is the study of the chemical characteristics of water. Chemical hydrology or hydrochemistry is the subdivion of hydrology that deals with the chemical characteristics of water. ...


Ecohydrology is the study of interactions between organisms and the hydrologic cycle. Ecohydrology is a sub-discipline of hydrology that focuses on ecological processes involved in the hydrological cycle. ...


Hydrogeology is the study of the presence and movement of water in aquifers. Hydrogeology (hydro- meaning water, and -geology meaning the study of the Earth) is the part of hydrology that deals with the distribution and movement of groundwater in the soil and rocks of the Earths crust, (commonly in aquifers). ...


Hydroinformatics is the adaptation of information technology to hydrology and water resources applications. Hydroinformatics is a branch of Informatics which concentrates on the application of information and communications technologies (ICTs) in addressing the increasingly serious problems of the equitable and efficient use of water for many different purposes. ...


Hydrometeorology is the study of the transfer of water and energy between land and water body surfaces and the lower atmosphere. Hydrometeorology is a branch of meteorology and hydrology that studies the transfer of water and energy between the land surface and the lower atmosphere. ...


Isotope hydrology is the study of the isotopic signatures of water. Isotope hydrology is a fast, cheap, and reliable way to discover the age, origins, size, flow and fate of a water source for purposes of sound water-use policy, maping underground aquifers, conserving water supplies, and controling pollution. ...


Surface hydrology is the study of hydrologic processes that operate at or near the Earth's surface. Surface water hydrology describes the relation between rainfall and runoff, which is important for water resources for drinking water, agriculture and the environment, and for protecting and safe-guarding people against possible floods. ... Adjectives: Terrestrial, Terran, Telluric, Tellurian, Earthly Atmosphere Surface pressure: 101. ...


Related fields

Aquatic chemistry is the study of chemical reactions in aqueous solutions, including acid-base reactions, redox reactions, and precipitation-dissolution reactions. ... The Falkirk Wheel in Scotland. ... Climatology is the study of climate, scientifically defined as weather conditions averaged over a period of time,[1] and is a branch of the atmospheric sciences. ... Environmental engineering[1][2] is the application of science and engineering principles to improve the environment (air, water, and/or land resources), to provide healthy water, air, and land for human habitation and for other organisms, and to remediate polluted sites. ... Surface of the Earth Geomorphology is the study of landforms, including their origin and evolution, and the processes that shape them. ... Hydrography focuses on the measurement of physical characteristics of waters and marginal land. ... Hydraulic engineering is a sub-discipline of civil engineering concerned with the flow and conveyance of fluids, principally water. ... Limnology is a discipline that concerns the study of inland waters (both saline and fresh), specifically lakes, ponds and rivers (both natural and manmade), including their biological, physical, chemical, and hydrological aspects. ... Thermohaline circulation Oceanography (from Ocean + Greek γράφειν = write), also called oceanology or marine science, is the branch of Earth Sciences that studies the Earths oceans and seas. ... True-color image of the Earths surface and atmosphere Physical geography (also know as geosystems or physiography) is a subfield of geography that focuses on the systematic study of patterns and processes within the hydrosphere, biosphere, atmosphere, and lithosphere. ...

Hydrologic measurements

The movement of water through the Earth can be measured in a number of ways. This information is important for both assessing water resources and understanding the processes involved in the hydrologic cycle. Following is a list of devices used by hydrologists and what they are used to measure.

A disdrometer is an instrument used to measure the drop size distribution and velocity of falling precipitation. ... This article or section is in need of attention from an expert on the subject. ... Pan evaporation is a measurement that combines or integrates the effects of several climate elements: temperature, humidity, solar radiation, and wind. ... A double ring infiltrometer is a tool for measuring how quickly a soil can take in water, also known as the rate of infiltration into the soil. ... A piezometer is a device used for the measurement of hydraulic head of groundwater in aquifers. ... An Aquifer test is conducted to evaluate an aquifer by stimulating the aquifer through constant pumping, and observing the aquifers response (drawdown) in observation wells. ... This long range radar antenna, known as ALTAIR, is used to detect and track space objects in conjunction with ABM testing at the Ronald Reagan Test Site on the Kwajalein atoll. ... Standard Rain Gauge Tipping Bucket Rain Gauge Recorder Close up of a Tipping Bucket Rain Gauge Recorder chart A rain gauge is a type of instrument used by meteorologists and hydrologists to gather and measure the amount of liquid precipitation (as opposed to solid precipitation that is measured by a... An Earth observation satellite, ERS 2 For other uses, see Satellite (disambiguation). ... Hygrometers are instruments used for measuring humidity. ... A stream gage refers to a site along a stream where measurements of volumetric discharge (flow) are made. ... In hydrology, the discharge of a river is the volume of water transported by it in a certain amount of time. ... A tensiometer is a device used to determine soil moisture tension, an indirect measure of soil moisture content. ... This article or section does not cite its references or sources. ... In telecommunication, a time-domain reflectometer (TDR) is an electronic instrument used to characterize and locate faults in metallic cables ( twisted pair, coax). ... This article or section does not cite its references or sources. ...

Hydrologic prediction

Observations of hydrologic processes are used to make predictions of the future behaviour of hydrologic systems (water flow, water quality). One of the major current concerns in hydrologic research is the Prediction in Ungauged Basins (PUB), i.e. in basins where no or only very few data exist. Prediction of future events is an ancient human wish. ...


Statistical hydrology

By analysing the statistical properties of hydrologic records, such as rainfall or river flow, hydrologists can estimate future hydrologic phenomena. This, however, assumes the characteristics of the processes remain unchanged. A graph of a Normal bell curve showing statistics used in educational assessment and comparing various grading methods. ...


These estimates are important for engineers and economists so that proper risk analysis can be performed to influence investment decisions in future infrastructure and to determine the yield reliability characteristics of water supply systems. Statistical information is utilised to formulate operating rules for large dams forming part of systems which include agricultural, industrial and residential demands. Engineering is the application of scientific and technical knowledge to solve human problems. ... Economists are scholars conducting research in the field of economics. ... Risk analysis is a technique to identify and assess factors that may jeopardize the success of a project or achieving a goal. ... A residential area is a type of land use where the predominant use is residential. ...


See: return period. A return period also known as a recurrence interval is an estimate of the liklihood of a flood or river discharge flow of a certain size. ...


Hydrologic modeling

Hydrologic models are simplified, conceptual representations of a part of the hydrologic cycle. They are primarily used for hydrologic prediction and for understanding hydrologic processes. Two major types of hydrologic models can be distinguished:

  • Models based on process descriptions. These models try to represent the physical processes observed in the real world. Typically, such models contain representations of surface runoff, subsurface flow, evapotranspiration, and channel flow, but they can be far more complicated. These models are known as deterministic hydrology models. Deterministic hydrology models can be subdivided into single-event models and continuous simulation models.

Recent research in hydrologic modeling tries to have a more global approach to the understanding of the behaviour of hydrologic systems to make better predictions and to face the major challenges in water resources management. Black box is technical jargon for a device or system or object when it is viewed primarily in terms of its input and output characteristics. ... In meteorology, precipitation is any kind of water that falls from the sky as part of the weather. ... Run-off or runoff may refer to one of the following. ... Generally, regression is related to moving backwards, and the opposite of progression. ... A transfer function is a mathematical representation of the relation between the input and output of a linear time-invariant system. ... A neural network is an interconnected group of neurons. ... System identification is a general term to describe mathematical tools and algorithms that build dynamical models from measured data. ... Runoff flowing into a stormwater drain Surface runoff is water, from rain, snowmelt, or other sources, that flows over the land surface, and is a major component of the water cycle[1][2]. Runoff that occurs on surfaces before reaching a channel is also called overland flow. ... Subsurface flow is the flow of water beneath ground surface in hydrology. ... Evapotranspiration (ET) is the sum of evaporation and plant transpiration. ... The Manning formula is an empirical formula for open channel flow, or flow driven by gravity. ... In hydrology, behavioral modeling is a modeling approach that focuses on the dynamic behavior of environmental systems resulting from coupled biotic and abiotic processes, feedback and evolutionary mechanisms. ...


Hydrologic transport

See main article: Hydrologic transport model

Water movement is a significant means by which other material, such as soil or pollutants, are transported from place to place. Initial input to receiving waters may arise from a point source discharge or a line source or area source, such as surface runoff. Since the 1960s rather complex mathematical models have been developed, facilitated by the availability of high speed computers. The most common pollutant classes analyzed are nutrients, pesticides, total dissolved solids and sediment. River in Madagascar relatively free of sediment load An hydrological transport model is a mathematical model used to simulate river or stream flow and calculate water quality parameters. ... It has been suggested that this article or section be merged with Point source (sound), Point source (light), Point source (heat), Point source (radio) and Point source (fluid) (Discuss) A point source of pollution is a single identifiable localized source of air, water, thermal, noise or light pollution. ... North-South Expressway in Malaysia; a roadway can be considered as a line source of air and noise pollution and need not be a straight line. ... Area sources emit a substance or radiation from a specified area. ... Runoff flowing into a stormwater drain Surface runoff is water, from rain, snowmelt, or other sources, that flows over the land surface, and is a major component of the water cycle[1][2]. Runoff that occurs on surfaces before reaching a channel is also called overland flow. ... A mathematical model is an abstract model that uses mathematical language to describe the behaviour of a system. ... A nutrient is either a chemical element or compound used in an organisms metabolism or physiology. ... A cropduster spreading pesticide. ... Bottled mineral water usually contains higher TDS levels than tap water Total dissolved solids is an expression for the combined content of all inorganic and organic substances contained in a liquid which are present in a molecular, ionized or micro-granular (colloidal sol) suspended form. ... Sediment is any particulate matter that can be transported by fluid flow and which eventually is deposited as a layer of solid particles on the bed or bottom of a body of water or other liquid. ...


Applications of hydrology

Note: The Water Balance method is a winding mechanism used in mining In hydrology, the water balance is an equation which describes how water can be accounted for within a drainage basin. ... Picture of flooding in Amphoe Sena, Ayutthaya Province, Thailand. ... Rockslide redirects here. ... A drought is a period of time when there is not enough water to support agricultural, urban, human, or environmental water needs. ... High-altitude aerial view of irrigation in the Heart of the Sahara ( ) Irrigation is the replacement or supplementation of rainfall with water from another source in order to grow crops or plants. ... Catastrophe modeling (also known as cat modeling) is the process of using computer-assisted calculations to estimate the losses that could be sustained by a portfolio of properties due to a catastrophic event such as a hurricane or earthquake. ... Drinking water Mineral Water Drinking water is water that is intended to be ingested by humans. ... DAMS is a racing team from France, involved in many areas of motorsports. ... A water supply system provides water to the locations that need it. ... Hydraulic turbine and electrical generator. ... A log bridge in the French Alps near Vallorcine. ... Sewers transport wastewater from buildings to treatment facilities. ... Please wikify (format) this article or section as suggested in the Guide to layout and the Manual of Style. ... Surface of the Earth Geomorphology is the study of landforms, including their origin and evolution, and the processes that shape them. ... Severe soil erosion in a wheat field near Washington State University, USA. For erosion as an operation of Mathematical morphology, see Erosion (morphology) Erosion is displacement of solids (soil, mud, rock and other particles) by the agents of ocean currents, wind, water, or ice by downward or down-slope movement... Sedimentation describes the motion of particles in solutions or suspensions in response to an external force such as gravity, centrifugal force or electric force. ... Water resources are sources of water that are useful or potentially useful to humans. ... It has been suggested that Pollutant be merged into this article or section. ...

References

  • Introduction to Hydrology, 4e. Viessman and Lewis, 1996. ISBN 0-673-99337-X
  • Handbook of Hydrology. ISBN 0-07-039732-5
  • Encyclopedia of Hydrological Sciences. ISBN 0-471-49103-9

External links - Hydro Wikis

  • The Experimental Hydrology Wiki
  • The Wiki about how to choose an uncertainty method for hydrologic and hydraulic modelling
  • The distributed hydrologic modeling Wiki

Other external links

General subfields within the earth sciences
Atmospheric sciences | Geodesy | Geology | Geophysics | Glaciology
Hydrology | Oceanography | Soil science
Physical geography
v  d  e
Biogeography · Climatology & paleoclimatology · Coastal/Marine studies · Geodesy · Geomorphology · Glaciology · Hydrology & Hydrography · Landscape ecology · Limnology · Oceanography · Palaeogeography · Pedology · Quaternary Studies

  Results from FactBites:
 
DEQ - Introduction to Hydrology (2243 words)
Hydrology has evolved as a science in response to the need to understand the complex water systems of the earth and help solve water problems.
Hydrology is the science that encompasses the occurrence, distribution, movement and properties of the waters of the earth and their relationship with the environment within each phase of the hydrologic cycle.
The hydrologic cycle is a continuous process by which water is purified by evaporation and transported from the earth's surface (including the oceans) to the atmosphere and back to the land and oceans.
Hydrology - MSN Encarta (863 words)
Hydrology, scientific study of the waters of the Earth, including their occurrence, distribution in space and time, and their relation to people and the natural environment.
Hydrology studies all aspects of the movement of water on the surface of the Earth and within the underlying soil and rocks.
Hydrology overlaps with the scientific study of water in the oceans and atmosphere, but these are primarily the responsibility of oceanography and meteorology.
  More results at FactBites »

 
 

COMMENTARY     


Share your thoughts, questions and commentary here
Your name
Your comments

Want to know more?
Search encyclopedia, statistics and forums:

 


Press Releases |  Feeds | Contact
The Wikipedia article included on this page is licensed under the GFDL.
Images may be subject to relevant owners' copyright.
All other elements are (c) copyright NationMaster.com 2003-5. All Rights Reserved.
Usage implies agreement with terms, 1022, m