What is the synthetic unit hydrograph?
A synthetic unit hydrograph retains all the features of the unit hydrograph, but does not require rainfall-runoff data. A synthetic unit hydrograph is derived from theory and experience, and its purpose is to simulate basin diffusion by estimating the basin lag based on a certain formula or procedure.
What is Muskingum routing method?
The Muskingum method is a hydrological flow routing model with lumped parameters, which describes the transformation of discharge waves in a river bed using two equations. These equations are applied within a river reach between two cross sections of a river.
What is S curve method?
S –curve method works for any duration. The first step is to add a series of UH’s of duration D, each lagged by time period D, This corresponds to the runoff hydrograph from a continuous rainfall excess intensity of 1/D inches/hour.
What is runoff equation?
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.
How do you calculate discharge from runoff?
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 rational formula?
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.
How do you calculate a hyetograph?
4. Convert to a hydrograph
- Multiply the rainfall excess by the catchment area (converts rainfall to a volume)
- Divide by the time step (to calculate volume per unit time)
- Ensure flow is allocated to the correct time step – the rainfall during a time step produces the instantaneous flow at the end of the time step.
In what way are all the precipitations measured?
In what way are all the precipitations measured? Explanation: All forms of precipitation are measured on the basis of vertical depth of water which would accumulate on the level surface if all the precipitation remained where it fell. The rainfall is usually measured with rain gauges.