Surface Runoff

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surface runoff

[′sər·fəs ′rən‚ȯf]
(hydrology)
Runoff that moves over the soil surface to the nearest surface stream.

Surface runoff

The precipitation, snow melt, or irrigation water in excess of what can infiltrate the soil surface and be stored in small surface depressions; a major transporter of non-point-source pollutants in rivers, streams and lakes.

Surface Runoff

 

movement of water across the earth’s surface owing to the force of gravity. A distinction is made between sheet flow and channel flow. Sheet flow is made up of rain and meltwater and moves down slopes, without fixed channels. Channel flow occurs in definite linear directions, in the channels of rivers and bottoms of ravines and gulleys. Subterranean water and groundwater sometimes also form part of channel flow.

Surface runoff is described by the volume of water flowing across a surface (the modulus of runoff) and is expressed either as l/sec/km2 or as a depth in mm per year or some other period. In the USSR, the lowest modulus of runoff— in the arid regions of the Middle Asian plain— is 0–1 l/sec/km2, while the highest goes up to 125 l/sec/km2, in the mountains of the Western Caucasus. Surface runoff varies over time. The average annual modulus of runoff in the Vorskla River basin is 2.1 l/sec/km2, but the maximum figure, during spring high water, is 220 l/sec/km2. In the Primor’e, where the modulus of average runoff is 8-15 l/sec/km2, the maximum modulus of direct runoff reaches 600–700 l/sec/km2, and sometimes even more than 1,000 l/sec/km2.

K. G. TIKHOTSKII

References in periodicals archive ?
When selecting a runoff model, the user should generally select the model that best suits the purpose.
By combining the power of the hydrodynamic, transport and sediment models, and with outputs from a catchment runoff model (see story on page 23), Bell and Amghar have shown that large plumes of suspended sediments enter Moreton Bay primarily from the Brisbane River, but also from the Caboolture, Pine and Logan Rivers.
Snowmelt Runoff Model (SRM) used the temperature as a key index for Degree Day Factor (DDF).
2001), a reasonably general runoff model, and parameter values for a wide range of soil types, are needed.
To rectify this, two sub-productive area floods were simulated as effective area (86/10 kilometers) that is very close to the measured runoff model results.
The WEAP rainfall runoff model requires data on soil, land use, climate, etc.
His Snowmelt Runoff Model (SRM) uses climate-change algorithms, imagery of snowpacks from National Aeronautics and Space Administration satellites, and data from ground-based SNOTEL sensors in 11 western states to measure water levels.
Rango does these predictions using the Snowmelt Runoff Model (SRM), which he developed in the 1970s.
The thermal urban runoff model was developed and tested in Dane County specifically for the purpose of assessing a development project's thermal impact on the cold-water stream into which it drains in order to design and implement effective temperature reduction practices.
The snowmelt runoff season starts around April 1st and may not end until sometime in August," says Rango, whose research includes running ARS' Snowmelt Runoff Model (SRM) to study and forecast snowmelt in mountain regions of both the western and eastern United States.