1. What is Ordinates of Unit Hydrograph?

Ordinates of Unit Hydrograph is the runoff discharge values over time after a unit input of effective rainfall. These values typically show how runoff responds and peaks after a storm event.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( U_t \) — Ordinates of Unit Hydrograph (Hour)
• \( S_t \) — S-Curve at Time 't' (Hour)
• \( S_{t-D} \) — S-Curve Addition (Hour)

Explanation: This formula calculates the ordinates of unit hydrograph by subtracting the S-curve addition from the S-curve at a specific time.

3. Importance of Unit Hydrograph Calculation

Details: Accurate unit hydrograph calculation is crucial for hydrological modeling, flood prediction, and water resource management. It helps in understanding how watersheds respond to rainfall events.

4. Using the Calculator

Tips: Enter S-Curve at Time 't' and S-Curve Addition values in hours. Both values must be non-negative numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is a unit hydrograph?
A: A unit hydrograph represents the direct runoff response of a watershed to a unit depth of excess rainfall over a specific duration.

Q2: How is the S-curve related to unit hydrographs?
A: The S-curve is the cumulative summation of unit hydrographs and represents the response to continuous rainfall at a constant rate.

Q3: What are typical applications of unit hydrographs?
A: Unit hydrographs are used in flood forecasting, stormwater management, and designing hydraulic structures.

Q4: What are the limitations of this calculation method?
A: This method assumes linearity and time-invariance, which may not hold true for all watershed conditions, especially during extreme events.

Q5: How accurate are unit hydrograph calculations?
A: Accuracy depends on the quality of input data and how well the watershed characteristics are represented in the model.