Quick Answer: What Does Runoff Coefficient Mean?

What happens to runoff water?

Runoff is what occurs when rain is not absorbed by the ground on which it falls and so then flows downhill.

As it does so, it will carry topsoil, nutrients, and any other water-soluble material it encounters as it flows downhill.

Eventually runoff water will drain into a stream or river..

How can we stop runoff?

Reduce impervious surfaces at home and increase the vegetated land cover of your property. Impervious surfaces include your roof, driveway, patios and lawn. Reduce rooftop runoff by directing your downspouts to vegetated areas, and not to the storm drain on your street.

What is the cause of runoff?

Runoff occurs when there is more water than land can absorb. The excess liquid flows across the surface of the land and into nearby creeks, streams, or ponds. … Glaciers, snow, and rain all contribute to this natural runoff. Runoff also occurs naturally as soil is eroded and carried to various bodies of water.

Is runoff good or bad?

Runoff is extremely important in that not only does it keep rivers and lakes full of water, but it also changes the landscape by the action of erosion. … Runoff of course occurs during storms, and much more water flows in rivers (and as runoff) during storms.

What is another word for runoff?

In this page you can discover 18 synonyms, antonyms, idiomatic expressions, and related words for runoff, like: flow, groundwater, rainfall, surplus water, spring runoff, snowmelt, siltation, aquifer, ground-water, surface-water and streamflow.

What is the meaning of runoff water?

Runoff, in hydrology, quantity of water discharged in surface streams. … Runoff also includes groundwater that is discharged into a stream; streamflow that is composed entirely of groundwater is termed base flow, or fair-weather runoff, and it occurs where a stream channel intersects the water table.

What does runoff mean?

(Entry 1 of 2) 1 : a final race, contest, or election to decide an earlier one that has not resulted in a decision in favor of any one competitor. 2 : the portion of precipitation on land that ultimately reaches streams often with dissolved or suspended material. run off.

How is peak runoff calculated?

The Rational method predicts the peak runoff according to the formula: Q=CiA, where C is a runoff coefficient, i is the rainfall intensity, and A is the subcatchment area. This formula is applicable to US or metric evaluation, as long as consistent units are employed.

What are the types of runoff?

Types of Runoff There are three major types of runoff depending on the source: surface flow, interflow, and base flow. These were discussed in Module 101 and are ex- panded upon here. Surface Flow Surface flow is water that has remained on the surface and moves as overland or channel flow.

How do you use runoff in a sentence?

runoff in a sentenceIn the spring, nearby Granite Falls roars with mountain runoff.Much of the runoff comes from farm fields in the spring.Make sure that the gutters channel the runoff to the downspouts.The two top finishers will meet in a runoff May 7.Now, no one is a cinch to reach the runoff.More items…

What is runoff coefficient used for?

Runoff coefficient is a dimensionless factor that is used to convert the rainfall amounts to runoff. It represents the integrated effect of catchment losses and hence depends upon the nature of land surface, slope, degree of saturation, and rainfall intensity.

What is rainfall runoff relationship?

the rainfall-runoff relationship for any rainstorm depends on the dynamic interaction between rain intensity, soil infiltration and surface storage. Runoff occurs whenever rain intensity exceeds the infiltration capacity of the soil, providing there are no physical obstructions to surface flow.

How do you calculate the rainfall runoff coefficient?

As explained above, the runoff coefficient from an individual rainstorm is defined as runoff divided by the corresponding rainfall both expressed as depth over catchment area (mm): Actual measurements should be carried out until a representative range is obtained.

How do humans affect runoff?

Human activities can affect runoff In addition to increasing imperviousness, removal of vegetation and soil, grading the land surface, and constructing drainage networks increase runoff volumes and shorten runoff time into streams from rainfall and snowmelt.

How do you catch runoff water?

Dig a trench. Use a shallow, gravel-filled trench to catch and slow runoff, especially at the base of a slope or alongside a driveway or patio. For slopes, consider creating a dry creek to catch, slow down and direct runoff, perhaps to a rain garden (see below).

Why is stormwater runoff bad?

Stormwater runoff can push excess sediment into rivers and streams. Sediment can block sunlight from reaching underwater grasses and suffocate shellfish. Stormwater runoff can push pesticides, leaking fuel or motor oil and other chemical contaminants into rivers and streams.

How do you calculate the runoff coefficient?

How to Calculate Runoff CoefficientThe Rational Method is used for areas less than 50 acres. … Find the appropriate values for each variable. … Calculate the value for “i.” This is a measurement of rainfall intensity. … Isolate and solve for “C.” Your altered equation should look like this: … Find a reputable runoff coefficient table (see Resources).More items…