Hydrograph Convolution Calculator

Calculate runoff hydrographs using unit hydrograph convolution. Applies the principle of superposition to combine rainfall increments with unit hydrograph response per NRCS NEH Part 630.

Hydrograph Convolution

For educational purposes only. Not a substitute for professional engineering judgment.

Input Parameters

Calculation Mode

Choose convolution or unit hydrograph generation

Mode

Select calculation type

Watershed Parameters

Basic watershed characteristics

Drainage Area

sq mi

Contributing watershed area

Time Step

minutes

Computation interval

Unit Hydrograph

Enter UH ordinates as comma-separated values

UH Ordinates

10 ordinates parsed

Unit hydrograph discharge values (cfs)

UH Depth

Depth represented by unit hydrograph

Excess Rainfall

Enter rainfall increments as comma-separated values

Rainfall Increments

4 increments, Total: 2.50 in

Excess rainfall per time step (in)

Base Flow

cfs

Constant base flow to add