Home
Back
Formula Used:
| From: | To: |
The Width of Unit Hydrograph at 50% Peak Discharge (W₅₀) represents the time duration at which the unit hydrograph's discharge equals 50% of its peak value. It is a crucial parameter in hydrological analysis for characterizing the shape and timing of runoff response.
The calculator uses the formula:
Where:
Explanation: This empirical relationship describes how the width of the unit hydrograph at half its peak discharge decreases as the discharge increases, following a power-law relationship.
Details: Calculating W₅₀ is essential for hydrological modeling, flood forecasting, and watershed management. It helps in understanding the temporal distribution of runoff and designing appropriate water management structures.
Tips: Enter the discharge value in cubic meters per second (m³/s). The value must be greater than zero for accurate calculation.
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 distributed uniformly over the drainage area for a specified duration.
Q2: Why is the 50% peak discharge width important?
A: The width at 50% peak discharge provides important information about the timing and duration of the runoff hydrograph, which is crucial for flood routing and reservoir operation studies.
Q3: What are typical values for W₅₀?
A: W₅₀ values vary significantly depending on watershed characteristics, but typically range from 1-10 mm for most hydrological applications.
Q4: Are there limitations to this formula?
A: This is an empirical relationship and may not be accurate for all watershed types. It works best for similar conditions to those for which it was developed.
Q5: How does discharge affect the width at 50% peak?
A: Higher discharge values result in narrower widths at 50% peak, following the inverse power relationship described by the formula.