V''flo'' is a commercially available,

physics Physics is the scientific study of matter, its Elementary particle, fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. "Physical science is that department of knowledge whi ...

-based distributed

hydrologic Hydrology () is the scientific study of the movement, distribution, and management of water on Earth and other planets, including the water cycle, water resources, and drainage basin sustainability. A practitioner of hydrology is called a hydro ...

model generated b
Vieux & Associates, Inc.
V''flo'' uses radar rainfall data for

input to simulate distributed runoff. V''flo'' employs

GIS A geographic information system (GIS) consists of integrated computer hardware and software that store, manage, analyze, edit, output, and visualize geographic data. Much of this often happens within a spatial database; however, this is not ...

maps for parameterization via a desktop interface. The model is suited for

distributed Distribution may refer to: Mathematics *Distribution (mathematics), generalized functions used to formulate solutions of partial differential equations *Probability distribution, the probability of a particular value or value range of a varia ...

hydrologic forecasting in post-analysis and in continuous operations. V''flo'' output is in the form of

hydrograph A hydrograph is a graph showing the rate of flow ( discharge) versus time past a specific point in a river, channel, or conduit carrying flow. The rate of flow is typically expressed in units of cubic meters per second (m³/s) or cubic feet per ...

s at selected drainage network grids, as well as

runoff maps covering the watershed. Model applications include civil

infrastructure Infrastructure is the set of facilities and systems that serve a country, city, or other area, and encompasses the services and facilities necessary for its economy, households and firms to function. Infrastructure is composed of public and pri ...

operations and maintenance,

stormwater Stormwater, also written storm water, is water that originates from precipitation (storm), including heavy rain and meltwater from hail and snow. Stormwater can soak into the soil ( infiltrate) and become groundwater, be stored on depressed lan ...

prediction and

emergency management Emergency management (also Disaster management) is a science and a system charged with creating the framework within which communities reduce vulnerability to hazards and cope with disasters. Emergency management, despite its name, does not actu ...

, continuous and short-term surface water runoff, recharge estimation,

soil moisture Soil moisture is the water content of the soil. It can be expressed in terms of volume or weight. Soil moisture measurement can be based on ''in situ'' probes (e.g., capacitance probes, neutron probes) or remote sensing methods. Water that enters ...

monitoring,

land use Land use is an umbrella term to describe what happens on a parcel of land. It concerns the benefits derived from using the land, and also the land management actions that humans carry out there. The following categories are used for land use: fo ...

planning,

water quality Water quality refers to the chemical, physical, and biological characteristics of water based on the standards of its usage. It is most frequently used by reference to a set of standards against which compliance, generally achieved through tr ...

monitoring, and water resources management.

History

V''flo'' considers the spatial character of the

parameter A parameter (), generally, is any characteristic that can help in defining or classifying a particular system (meaning an event, project, object, situation, etc.). That is, a parameter is an element of a system that is useful, or critical, when ...

s and precipitation controlling hydrologic processes, and thus improves upon lumped representations previously used in hydrologic modeling. Historical practice has been to use lumped representations because of computational limitations or because sufficient data was not available to populate a

model database. Advances in

computation A computation is any type of arithmetic or non-arithmetic calculation that is well-defined. Common examples of computation are mathematical equation solving and the execution of computer algorithms. Mechanical or electronic devices (or, hist ...

al speed; development of high-resolution precipitation data from

radar Radar is a system that uses radio waves to determine the distance ('' ranging''), direction ( azimuth and elevation angles), and radial velocity of objects relative to the site. It is a radiodetermination method used to detect and track ...

and satellites; and availability of worldwide digital data sets and

technology makes distributed, physics-based modeling possible.ASCE, 1999, ''GIS Modules and Distributed Models of the Watershed'', Report, ASCE Task Committee, GIS Modules and Distributed Models of the Watershed, P.A. DeBarry, R.G. Quimpo, eds., American Society of Civil Engineers, Reston, VA., p. 120. V''flo'' is designed to take advantage of the spatial variability of high resolution radar rainfall input,

datasets, and hydraulic channel characteristics. Because it is

-based, it produces

s based on conservation equations and the hydraulics of the drainage network, and can be employed in locations where there are no

rain gauge A rain gauge (also known as udometer, ombrometer, pluviometer and hyetometer) is an instrument used by meteorologists and Hydrology, hydrologists to gather and measure the amount of liquid precipitation in a predefined area, over a set period of t ...

s or previous modeling studies. In addition, V''flo''’s network approach makes models scalable from upland watersheds to river basins using the same drainage network.

Formulation

V''flo'' is suited for distributed hydrologic forecasting in post-analysis and continuous operations. V''flo'' models may be

calibrated In measurement technology and metrology, calibration is the comparison of measurement values delivered by a device under test with those of a calibration standard of known accuracy. Such a standard could be another measurement device of known ...

by loading precipitation maps for historical events and comparing simulated volume/peak

s to observed hydrographs. Elevation data are taken from a

digital elevation model A digital elevation model (DEM) or digital surface model (DSM) is a 3D computer graphics representation of elevation data to represent terrain or overlaying objects, commonly of a planet, Natural satellite, moon, or asteroid. A "global DEM" refer ...

. A vector channel representation is employed. Parameterization utilizes digital data sets at any resolution, including

LIDAR Lidar (, also LIDAR, an acronym of "light detection and ranging" or "laser imaging, detection, and ranging") is a method for determining ranging, ranges by targeting an object or a surface with a laser and measuring the time for the reflected li ...

terrain data and other digital maps of impervious area, soils, and land use/cover. V''flo'' is developed to utilize multi-sensor inputs from

, satellites,

s, or model forecasts. The kinematic wave analogy is used to represent hydraulic conditions in a

watershed Watershed may refer to: Hydrology * Drainage divide, the line that separates neighbouring drainage basins * Drainage basin, an area of land where surface water converges (North American usage) Music * Watershed Music Festival, an annual country ...

Specific simulation options

*Rainfall input ** Radar-rainfall: UF,

ASCII ASCII ( ), an acronym for American Standard Code for Information Interchange, is a character encoding standard for representing a particular set of 95 (English language focused) printable character, printable and 33 control character, control c ...

NEXRAD NEXRAD or Nexrad (Next-Generation Radar) is a network of 159 high-resolution S-band pulse-Doppler radar, Doppler weather radars operated by the National Weather Service (NWS), an agency of the National Oceanic and Atmospheric Administration (NOAA) ...

Level II, CSV **Satellite data **

Rain gauge A rain gauge (also known as udometer, ombrometer, pluviometer and hyetometer) is an instrument used by meteorologists and Hydrology, hydrologists to gather and measure the amount of liquid precipitation in a predefined area, over a set period of t ...

s, Barnes objective analysis **Quantitative precipitation estimates from model forecasts **Multi-sensor precipitation estimates *

Evapotranspiration Evapotranspiration (ET) refers to the combined processes which move water from the Earth's surface (open water and ice surfaces, bare soil and vegetation) into the Atmosphere of Earth, atmosphere. It covers both water evaporation (movement of w ...

Snowmelt In hydrology, snowmelt is surface runoff produced from melting snow. It can also be used to describe the period or season during which such runoff is produced. Water produced by snowmelt is an important part of the annual water cycle in many part ...

Sensitivity analysis Sensitivity analysis is the study of how the uncertainty in the output of a mathematical model or system (numerical or otherwise) can be divided and allocated to different sources of uncertainty in its inputs. This involves estimating sensitivity ...

*Inundation mapping * Infiltration **Enhanced Green-Ampt infiltration module with initial saturation calibration factor (slider), saturated hydraulic conductivity, wetting front suction, effective porosity, and soil depth **Abstraction and impervious area parameters with

import/export *Overland flow **Manning's equation *Channel flow **Kinematic Wave Analogy **Modified Puls **Observed flow **Looped rating curve modification (Jones method) **Rating curves and cross sections for complex hydraulics *Flood watch points *Design storms, SCS, user generated

Applications

*Continuous and short-term surface water runoff *Stormwater prediction and management *

Flash flood A flash flood is a rapid flooding of low-lying areas: washes, rivers, dry lakes and depressions. It may be caused by heavy rain associated with a severe thunderstorm, hurricane, or tropical storm, or by meltwater from ice and snow. Flash f ...

forecasting *Operational flood alert *Flood event reconstruction *Design Storm development *Recharge estimation *Soil moisture monitoring *

Hydrology Hydrology () is the scientific study of the movement, distribution, and management of water on Earth and other planets, including the water cycle, water resources, and drainage basin sustainability. A practitioner of hydrology is called a hydro ...

and

Hydraulics Hydraulics () is a technology and applied science using engineering, chemistry, and other sciences involving the mechanical properties and use of liquids. At a very basic level, hydraulics is the liquid counterpart of pneumatics, which concer ...

studies *

Land use Land use is an umbrella term to describe what happens on a parcel of land. It concerns the benefits derived from using the land, and also the land management actions that humans carry out there. The following categories are used for land use: fo ...

planning scenarios *

Water quality Water quality refers to the chemical, physical, and biological characteristics of water based on the standards of its usage. It is most frequently used by reference to a set of standards against which compliance, generally achieved through tr ...

studies *

Hydropower Hydropower (from Ancient Greek -, "water"), also known as water power or water energy, is the use of falling or fast-running water to Electricity generation, produce electricity or to power machines. This is achieved by energy transformation, ...

management *

education *

Hydrologic Hydrology () is the scientific study of the movement, distribution, and management of water on Earth and other planets, including the water cycle, water resources, and drainage basin sustainability. A practitioner of hydrology is called a hydro ...

research

References

{{Reflist Integrated hydrologic modelling Hydrology models Environmental engineering Stormwater management Hydraulic engineering Water resources management Finite element software Computer-aided engineering software Finite element method Applied mathematics Mathematical modeling Radar meteorology