Data Format
Data presented here is reported in dimensionless (fractional) distributions both in time and rainfall depth space. The temporal axes starts at 0.0 and ends at 1.0 with a time step of 0.01. Duration Multipliers should be used in Bentley SewerCAD to convert the dimensionless time to the desired rainstorm duration.
Quartile distributions are identified using the following notation:
- 1stQ—the first quartile time distribution
- 2ndQ—the second quartile time distribution
- 3rdQ—the third quartile time distribution
- 4thQ—the fourth quartile time distribution
Watershed area ranges are identified using the following notation:
- 00-10—point distributions (0 to 10 square miles)
- 10-50—intermediate distributions (10 to 50 square miles)
- 50-400—area distributions (50 to 400 square miles)
Exceedance probabilities are identified using the following notation:
- 50%—median distributions (for design storms)
- 10% - 90%—exceedance distributions (for analysis storms)
- 90% - 10%—exceedance distributions (for analysis storms)
Related Topics:
- Rainfall Time-Distribution Information "Rainfall Time-Distribution Information" on page 5-401
- Watershed Area
- Rainfall Duration
- Data Sources
- Bulletin 70/71 Data
- Circular 173 Data