1. What is Depth of Closure?

Depth of Closure for a characteristic time interval is the most landward depth seaward of which there is no significant change in bottom elevation. It represents the boundary between the active beach profile and the deeper, relatively stable offshore zone.

2. How Does the Calculator Work?

The calculator uses the Depth of Closure formula:

Where:

• \( D_c \) — Depth of Closure (m)
• \( V \) — Volume per unit Length of Shoreline (m²)
• \( W \) — Beach Width (m)
• \( B \) — Design Berm Elevation (m)

Explanation: The equation calculates the depth at which sediment transport becomes negligible by relating the sediment volume distribution to beach geometry and design elevation.

3. Importance of Depth of Closure Calculation

Details: Accurate Depth of Closure estimation is crucial for coastal engineering projects, beach nourishment planning, shoreline management, and understanding sediment transport processes in coastal environments.

4. Using the Calculator

Tips: Enter volume per unit length in square meters, beach width in meters, and design berm elevation in meters. All values must be positive numbers with appropriate precision for coastal measurements.

5. Frequently Asked Questions (FAQ)

Q1: What factors influence Depth of Closure?
A: Wave climate, sediment characteristics, tidal range, storm frequency, and duration of the observation period all influence Depth of Closure.

Q2: How is Volume per unit Length measured?
A: Typically measured through beach profile surveys where cross-sectional areas are calculated from elevation data along perpendicular transects.

Q3: What time scale does this represent?
A: Depth of Closure is typically calculated for seasonal or annual time scales, representing the maximum depth of significant sediment movement over that period.

Q4: Are there limitations to this equation?
A: The formula assumes uniform sediment distribution and may be less accurate in areas with complex bathymetry or unusual sediment transport patterns.

Q5: How does Design Berm Elevation affect the calculation?
A: The design berm elevation accounts for the vertical offset from the reference datum, ensuring the depth calculation is properly referenced to mean sea level or other appropriate datum.