What Is A Runoff Ratio?

What is direct runoff?

Water that flows over the ground surface directly into streams, rivers, or lakes.

Also called storm runoff..

What is runoff and its types?

3 Runoff can be defined as the portion of the precipitation that makes it’s way towards rivers or oceans etc, as surface or subsurface flow. Surface runoff can be generated either by rainfall, snowfall or by the melting of snow, or glaciers. … Types of Runoff: Surface runoff/ Sub-surface runoff or Base flow.

What does a runoff include?

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 is a runoff in a river?

River runoff refers to all water that comes into a river water system from sources such as rainfall, snowmelt and groundwater.

What is runoff depth?

The volume of water that flows through a certain channel cross-section per unit of time is referred to as discharge. … The mean runoff depth at the measuring point in the receiving water results in the arithmetical mean of the values of the total runoff depth of all area units in the related catchment area.

How do you find direct runoff?

Direct Runoff Formula For a given surface area such as a roof or yard, multiply the area by the inches of rainfall and divide by 231 to obtain the runoff in gallons. The factor 231 comes from the fact that the volume of 1 gallon equals 231 cubic inches.

What is the process 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. Runoff can come from both natural processes and human activity. … Runoff also occurs naturally as soil is eroded and carried to various bodies of water.

Is runoff good or bad?

Runoff from agricultural land (and even our own yards) can carry excess nutrients, such as nitrogen and phosphorus into streams, lakes, and groundwater supplies. These excess nutrients have the potential to degrade water quality.

How do you deal with runoff water?

Consider these affordable, do-able solutions to do just that.Add plants. Incorporate plantings, especially in areas where runoff collects. … Protect trees. Like other plant roots, tree roots help absorb and filter runoff. … Break up slabs. … Go permeable. … Catch runoff. … Dig a trench. … Plant a rain garden. … Cover soil.More items…

How is runoff calculated?

To calculate the runoff from any given rainfall:Take the dimensions of the footprint of your roof and convert them to inches. (So, a 50′ x 20′ roof is 600″ x 240″.)Multiply the roof dimensions by the number of inches of rainfall. … Divide by 231 to get the number of gallons (because 1 gallon = 231 cubic inches).

What is peak runoff rate?

One of the key parameters in the design and analysis of soil and water conservation structures is the resulting peak runoff or the variations of runoff with time (hydrograph) at the watershed outlet. … The maximum flow at outlet thus attained is called peak flow of runoff.

How is drainage volume calculated?

To calculate the volume of water that needs to be stored, multiply the amount of runoff from each drainage zone by 15. The runoff for each zone was in gallons per minute. Multiplying by 15 minutes leaves you with the amount of gallons to be stored.

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 a runoff definition?

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. verb. ran off; run off; running off; runs off.

What is runoff short answer?

Runoff can be described as the part of the water cycle that flows over land as surface water instead of being absorbed into groundwater or evaporating. Runoff is that part of the precipitation, snow melt, or irrigation water that appears in uncontrolled surface streams, rivers, drains, or sewers.

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 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.