NationMaster - Encyclopedia: Hydrology transport model

An hydrological transport model is a mathematical model used to simulate river or stream flow and calculate water quality parameters. These models generally came into use in the 1960s and 1970s when demand for numerical forecasting of water quality was driven by environmental legislation, and at a similar time widespread access to significant computer power became available. Much of the original model development took place in the United States and United Kingdom, but today these models are refined and used worldwide. Image File history File linksMetadata Download high resolution version (2816x2112, 1119 KB) Summary photo taken by C.Michael Hogan, who releases all rights Licensing File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Image File history File linksMetadata Download high resolution version (2816x2112, 1119 KB) Summary photo taken by C.Michael Hogan, who releases all rights Licensing File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... A mathematical model is an abstract model that uses mathematical language to describe the behaviour of a system. ... Streamflow, or channel runoff, is the flow of water in streams, rivers, and other channels, and is a major element of the water cycle. ...

There are dozens of different transport models and can be generally grouped by pollutants addressed, complexity of pollutant sources, whether the model is steady state or dynamic, and time period modeled. Another important designation is whether the model is distributed (i.e. capable of predicting multiple points within a river) or lumped. In a basic model, for example, only one pollutant might be addressed from a simple point discharge into the receiving waters. In the most complex of models, various line source inputs from surface runoff might be added to multiple point sources, treating a variety of chemicals plus sediment in a dynamic environment including vertical river stratification and interactions of pollutants with in-stream biota. In addition watershed groundwater may also be included. The model is termed "physically based" if its parameters can be measured in the field. Water pollution Water pollution is a large set of adverse effects upon water bodies (lakes, rivers, oceans, groundwater) caused by human activities. ... 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 point source may be a source of light that is treated as having no physical extension, or a source in fluid flow, or in electrostatics, or a source of pollution coming from a single cause, such as a municipal plant. ... A chemical substance is any material substance used in or obtained by a process in chemistry: A chemical compound is a substance consisting of two or more chemical elements that are chemically combined in fixed proportions. ... 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. ... Biota can refer to several things: The plant and animal life of a region; see biota (ecology) A municipality in Zaragoza, Aragon, Spain; see Biota (municipality) A superdomain in taxonomy; see Biota (taxonomy) Biota Holdings, the Australian biotech company This is a disambiguation page — a navigational aid which lists other... Watershed has more than one meaning: Look up watershed in Wiktionary, the free dictionary. ... Groundwater is water located beneath the ground surface in soil pore spaces and in the fractures of geologic formations. ...

Often models have separate modules to address individual steps in the simulation process. The most common module is a subroutine for calculation of surface runoff, allowing variation in land use type, topography, soil type, vegetative cover, precipitation and land management practice (such as the application rate of a fertilizer). The concept of hydrological modeling can be extended to other environments such as the oceans, but most commonly (and in this article) the subject of a river watershed is generally implied. In computer science, a subroutine (function, method, procedure, or subprogram) is a portion of code within a larger program, which performs a specific task and is relatively independent of the remaining code. ... Land use is the pattern of construction and activity land is used for. ... Surface of the Earth Topography, a term in geography, has come to refer to the lay of the land, or the physiogeographic characteristics of land in terms of elevation, slope, and orientation. ... Soil is the material on the surface of a lithosphere subject to weathering, and especially the earthy portion of that material. ... Vegetation is a general term for the plant life of a region; it refers to the ground cover provided by plants, and is, by far, the most abundant biotic element of the biosphere. ... spreading manure, an organic fertiliser Fertilizers or fertilisers are compounds given to plants with the intention of promoting growth; they are usually applied either via the soil, for uptake by plant roots, or by foliar feeding, for uptake through leaves. ... The worlds oceans as seen from the South Pacific Oceans (from Okeanos, Greek for river, the ancient Greeks noticed that a strong current flowed off Gibraltar, and assumed it was a great river) cover almost three quarters (71%) of the surface of the Earth, and nearly half of the...

History

In 1850, T.J. Mulvany was probably the first investigator to use mathematical modeling in a stream hydrology context, although there was no chemistry involved.^[1] By 1892 M.E. Imbeau had conceived an event model to relate runoff to peak rainfall, again still with no chemistry.^[2] Robert E. Horton’s seminal work^[3] on surface runoff along with his coupling of quantitative treatment of erosion^[4] laid the groundwork for modern chemical transport hydrology. The event model is a programming paradigm commonly used in building graphical user interfaces. ... 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. ... 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. ...

Comprehensive models

The first model to integrate all the required submodels for basin chemical hydrology was the Stanford Watershed Model (SWM).^[5] The SWMM (Storm Water Management Model), the HSPF (Hydrological Simulation Program - FORTRAN) and other modern American derivatives are successors to the SWM.

In Europe a favoured comprehensive model is the Système Hydrologique Européen (SHE),^[6]^[7] a watershed-scale physically based, spatially distributed model for water flow and sediment transport. Flow and transport processes are represented by either finite difference representations of partial differential equations or by derived empirical equations. The following principal submodels are involved: 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. ... Graph of a differential equation In mathematics, a differential equation is an equation in which the derivatives of a function appear as variables. ...

This model can analyze effects of land use and climate changes upon in-stream water quality, with consideration of groundwater interactions. Evapotranspiration (ET) is the sum of evaporation and plant transpiration. ... Look up Channel on Wiktionary, the free dictionary In general, channel refers to the path between two endpoints. ... In classical mechanics, momentum (pl. ... 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. ... Darcys Law is a phenomologically derived constitutive equation that describes the flow of a fluid through a porous medium (typically water through an aquifer). ... The law of conservation of mass/matter (The Lomonosov-Lavoisier law) states that the mass of a system of substances will remain constant, regardless of the processes acting inside the system. ... Land use is the pattern of construction and activity land is used for. ... Variations in CO2, temperature and dust from the Vostok ice core over the last 400 000 years Climate change refers to the variation in the Earths global climate or regional climates over time. ... Groundwater is water located beneath the ground surface in soil pore spaces and in the fractures of geologic formations. ...

Worldwide a number of basin models have been developed, among them RORB (Australia), Xinanjiang (China), Tank model (Japan), ARNO (Italy), TOPMODEL (Europe), UBC (Canada) and HBV (Scandanavia). However, not all these models have a chemistry component. Generally speaking, SWM, SHE and TOPMODEL have the most comprehensive stream chemistry treatment and have evolved to accommodate the latest data sources including remote sensing and geographic information system data. World map showing Europe Political map Europe is one of the seven continents of Earth which, in this case, is more a cultural and political distinction than a physiographic one, leading to various perspectives about Europes borders. ... Scandinavia is the cultural and historic region of the Scandinavian Peninsula. ... Synthetic aperture radar image of Death Valley colored using polarimetry In the broadest sense, remote sensing is the measurement or acquisition of information of an object or phenomenon, by a recording device that is not in physical or intimate contact with the object. ... A geographic information system or geographical information system (GIS) is a system for creating and managing spatial data and associated attributes. ...

Surface runoff models

A key component of a hydrological transport model is the surface runoff element, which allows assessment of sediment, fertilizer, pesticide and other chemical contaminants. Building on the work of Horton, the unit hydrograph theory was developed by Dooge in 1959.^[8] It required the presence of the National Environmental Policy Act and kindred other national legislation to provide the impetus to integrate water chemistry to hydrology model protocols. In the early 1970s the U.S. Environmental Protection Agency(EPA) began sponsoring a series of water quality models in response to the Clean Water Act. An example of these efforts was developed at the Southeast Water Laboratory,^[9] one of the first attempts to calibrate a surface runoff model with field data for a variety of chemical contaminants. Columbia River Gorge as seen from Dog Mountain, approximately 15 miles upstream from the Bonneville Dam. ... Columbia River Gorge as seen from Dog Mountain, approximately 15 miles upstream from the Bonneville Dam. ... Columbia River Gorge, Washington or North side The Columbia River (French: fleuve Columbia) is a river situated in British Columbia and the Pacific Northwest of the United States. ... 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. ... Loggers on break, c. ... 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. ... spreading manure, an organic fertiliser Fertilizers or fertilisers are compounds given to plants with the intention of promoting growth; they are usually applied either via the soil, for uptake by plant roots, or by foliar feeding, for uptake through leaves. ... A cropduster spreading pesticide. ... The National Environmental Policy Act (or, NEPA) was signed into law on January 1, 1970 by US President Richard Nixon. ... The mission of the United States Environmental Protection Agency (EPA) is to protect human health and to safeguard the natural environment: air, water, and land. ... The Clean Water Act, 33 U.S.C.A. Â§ 1251 et seq. ...

The attention given to surface runoff contaminant models has not matched the emphasis on pure hydrology models, in spite of their role in the generation of stream loading contaminant data. In the United States the EPA has had difficulty interpreting^[10] diverse proprietary contaminant models and has to develop its own models more often than conventional resource agencies, who, focused on flood forecasting, have had more of a centroid of common basin models. Look up flood in Wiktionary, the free dictionary. ...

Example applications

Liden applied the HBV model to estimate the riverine transport of three different substances, nitrogen, phosphorus and suspended sediment^[11] in four different countries: Sweden, Estonia, Bolivia and Zimbabwe. The relation between internal hydrological model variables and nutrient transport was assessed. A model for nitrogen sources was developed and analysed in comparison with a statistical method. A model for suspended sediment transport in tropical and semi-arid regions was developed and tested. It was shown that riverine total nitrogen could be well simulated in the Nordic climate and riverine suspended sediment load could be estimated fairly well in tropical and semi-arid climates. The HBV model for material transport generally estimated material transport loads well. The main conclusion of the study was that the HBV model can be used to predict material transport on the scale of the drainage basin during stationary conditions, but cannot be easily generalised to areas not specifically calibrated. General Name, Symbol, Number nitrogen, N, 7 Chemical series nonmetals Group, Period, Block 15, 2, p Appearance colorless Atomic mass 14. ... This article is about the chemical element. ... // Nutrients and the body A nutrient is any element or compound necessary for or contributing to an organisms metabolism, growth, or other functioning. ... General Name, Symbol, Number nitrogen, N, 7 Chemical series nonmetals Group, Period, Block 15, 2, p Appearance colorless Atomic mass 14. ... The tropics are the geographic region of the Earth centered on the equator and limited in latitude by the two tropics: the Tropic of Cancer in the north and the Tropic of Capricorn in the southern hemisphere. ... Semi-arid generally describes regions that receive low annual rainfall (25 to 50 cm /10 to 20 in) and generally have scrub or grass vegetation. ... Overview map of the region. ... A drainage basin is the area within the drainage basin divide (yellow outline), and drains the surface runoff and river discharge (blue lines) of a contiguous area. ...

The United States EPA developed the DSSAM Model to analyze water quality impacts from land use and wastewater management decisions in the Truckee River basin, an area which include the cities of Reno and Sparks, Nevada as well as the Lake Tahoe basin. The model^[12] satisfactorily predicted nutrient, sediment and dissolved oxygen parameters in the river. It is based on a pollutant loading metric called "Total Daily Maximum Load" (TDML). The success of this model contributed to the EPA’s commitment to the use of the underlying TDML protocol in EPA’s national policy for management of many river systems in the United States.^[13] Lake Tahoe Picture taken from near the top of the Heavenly Ski Resort Tram on May 13, 2003. ... Lake Tahoe Picture taken from near the top of the Heavenly Ski Resort Tram on May 13, 2003. ... Lake Tahoe Emerald Bay State Park Lake Tahoe is a freshwater lake in the Sierra Nevada, on the border between the U.S. states of California and Nevada, near Carson City. ... The headwaters of a river are small streams that create it. ... The Truckee River is a river, 140 mi (225 km) long, in northern California and northern Nevada in the United States. ... Lake Tahoe, headwater sub-basin of the Truckee River watershed The DSSAM Model (Dynamic Stream Simulation and Assessment. ... Water pollution Water pollution is a large set of adverse effects upon water bodies (lakes, rivers, oceans, groundwater) caused by human activities. ... Land use is the pattern of construction and activity land is used for. ... Wastewater is any water that has been adversely affected in quality by anthropogenic influence. ... The Truckee River is a river, 140 mi (225 km) long, in northern California and northern Nevada in the United States. ... Places Reno, Nevada Reno, Pennsylvania Reno, Lamar County, Texas Reno, Parker County, Texas A valley in Italy Other Uses Reno, a Turk from the popular videogame and CG movie by Square-Enix, Final Fantasy VII. Reno a 1939 film A band named Reno Reno is a drug Reno 911! - A... Sparks is a city located in Washoe County, Nevada. ... Lake Tahoe Emerald Bay State Park Lake Tahoe is a freshwater lake in the Sierra Nevada, on the border between the U.S. states of California and Nevada, near Carson City. ... In mathematics a metric or distance is a function which assigns a distance to elements of a set. ...

The DSSAM Model is constructed to allow dynamic decay of most pollutants; for example, total nitrogen and phosphorus are allowed to be consumed by benthic algae in each time step, and the algal communities are given a separate population dynamic in each river reach (e.g. based upon river temperature). Regarding stormwater runoff in Washoe County, the specific elements within a new xeriscape ordinance were analyzed for efficacy using the model. For the varied agricultural uses in the watershed, the model was run to understand the principal sources of impact, and management practices were developed to reduce in-river pollution. Use of the model has specifically been conducted to analyze survival of two endangered species found in the Truckee River and Pyramid Lake: the Cui-ui sucker fish and the Lahontan cutthroat trout. This article or section contains information that has not been verified and thus might not be reliable. ... A seaweed (Laurencia) up close: the branches are multicellular and only about 1 mm thick. ... Washoe County is a county located in the state of Nevada. ... Xeriscaping, a word coined by combining xeros (Greek for dry) with landscaping, is a water-conservative approach to landscaping. ... The endangered Sea Otter An endangered species is a population of organisms (usually a taxonomic species), which is either (a) so few in number or (b) threatened by changing environmental or predation parameters that it is at risk of becoming extinct. ... The Truckee River is a river, 140 mi (225 km) long, in northern California and northern Nevada in the United States. ... Pyramid Lake as seen from the Pah Rah Range Pyramid Lake from space, September 1994 Pyramid Lake and its environs Numaga chief of the Paiutes during the Pyramid Lake Paiute War. ... Binomial name Chasmistes cujus Cope, 1883 The Cui-ui (Chasmistes Cujus) is a large sucker fish which is endemic to Pyramid Lake in northwestern Nevada. ... The Catostomidae, also known as the sucker fish is part of the order Cypriniformes. ... Lahontan Cutthroat Trout (Oncorhynchus clarki henshawi) is the state fish of Nevada. ...

Contents

History

Comprehensive models

Surface runoff models

Example applications

See also

References

External links

Contents

History GA_googleFillSlot("encyclopedia_square");

Comprehensive models

Surface runoff models

Example applications

See also

References

External links

History