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 ?
Heavy metals in surface runoff have a number of sources: construction sites, roofing, abrasion of automobile tyres, abrasion and corrosion of brake pads and other vehicle details, and combustion of fuel (Gobel et al.
About 20% of the rain on conventionally tilled fields was lost in surface runoff, compared with only 12% from the strip-tilled fields.
The researchers also found that the benefits of strip tillage, with respect to erosion and surface runoff reduction, are enhanced with cover crops.
The impact energy can cause sealing in the superficial layer of uncovered soils, with consequent reduction in infiltration capacity and increase in surface runoff and its transport capacity (Sidiras & Rotjh, 1987).
2% increase in the surface runoff and water yield respectively, expansion of forests areas from 46% to 66% indicated 9.
In horticulture plantation, agricultural land and degraded forest the infiltration is very less, and surface runoff will be more and join to the stream at the base that may cause top-soil loss.
The reasons the strips can return so many benefits are manifold, but, in part, deep-rooted native perennials add organic matter to soils, prevent surface runoff, and result in better water retention and filtration.
The northern Ogallala, found near the surface in Nebraska, is replenished by surface runoff from rivers originating in the Rockies.
Leachate and surface runoff leaving intensively managed pasture systems typically have elevated concentrations of N (Ledgard et al.
The tanks will serve as an underground floodwater storage system, capable of holding surface runoff from up to 3.
The curve number was then used as input parameter in runoff estimation method to compute the surface runoff potential for different combination of landcover and Hydrological Soil Groups (HSG) in the study area, which helped in the results to identifying the potential sites for rainwater harvesting.
On Earth, tree-like channels of this kind are usually formed by surface runoff after significant rainfall, or when snow or ice melts.