# What is peak discharge rate?

## What is peak discharge rate?

Peak discharge is the maximum rate of flow for a given condition and is used in the design of conservation measures. Peak discharge is also referred to as peak rate of discharge or peak rate of runoff. It is usually referred to in units of cubic feet per second, or cfs.

How do you calculate peak time?

Determine how high the projectile traveled above its initial height by using the following formula where V is the initial vertical velocity and T is the time it takes to reach its peak: Height = V * T +1/2 * -32.2 ft/s^2 *T^2 For example, if you had an initial vertical velocity of 32.14 ft/s and a time of one second.

How do you calculate discharge from rainfall data?

Find out the peak storm discharge by the Rational Method assuming that the rainfall in 5 hours is 20 cm. What will be the peak discharge if the catchment area is of clayey soil lightly covered or of steep but wooded rock? Q = 0.028 PfIcA = 0.028 x 0.10 x 0.60 x 2.98 x 80,000 = 400 cum/sec.

### What is runoff formula?

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.

How do I calculate peak hours in Excel?

The following formula can help you to count a number of peaks in a column of data directly in Excel. 1. Select a blank cell for placing the result, enter formula =SUMPRODUCT(–(B3:B17>B2:B16),–(B3:B17>B4:B18)) into the Formula Bar, then press the Enter key.

How do you calculate air time?

To define the time of flight equation, we should split the formulas into two cases:

1. Launching projectile from the ground (initial height = 0)
2. t = 2 * V₀ * sin(α) / g.
3. Launching projectile from some height (so initial height > 0)
4. t = [V₀ * sin(α) + √((V₀ * sin(α))² + 2 * g * h)] / g.

## How do you calculate water discharge?

The discharge of a stream is the product of its velocity (V – length of travel per unit of time such as feet/second) times depth of the water (D – unit of length) times width (W of the water – units of length). (Make sure all all three lengths are expressed in the same unit.)

What is the difference between peak rainfall and peak discharge?

As you can see in the graph below, the peak rainfall is the time of highest rainfall. The peak discharge is the time when the river reaches its highest flow. There is a delay because it takes time for the water to find its way to the river. This is called lag time.

How do you calculate runoff discharge?

The Rational Formula is expressed as Q = CiA where: Q =Peak rate of runoff in cubic feet per second C =Runoff coefficient, an empirical coefficient representing a relationship between rainfall and runoff.

### What is the peak discharge method of calculating runoff?

SCS PEAK DISCHARGE METHOD The peak discharge method of calculating runoff was developed by the USDA Soil Conservation Service and is contained in SCS Technical Release No. 55 (TR-55) entitled Urban Hydrology for Small Watersheds, Second Ed.; June 1986.

How is the a discharge equation developed?

A discharge equation has been developed for each flow type by combining the energy and continuity equations for the distance between an approach section up­ stream from the culvert and a terminal section within the culvert barrel.

Can the NRCS rainfall-runoff calculation be used without a hydrograph?

In such circumstances, the NRCS rainfall-runoff calculation procedure can be used to determine the required peak discharge without computing an entire runoff hydrograph.

## How do you calculate IA and P for storm of return?

Ia = initial abstraction (inch); losses before runoff begins (surface depressions, interception by leaves, evaporation, infiltration) – SCS determined the above equation for I a after numerous studies. P = precipitation (inch) for 24-hr duration storm of return period for which you are interested.