WMS:Eagleson Lag Time Equation: Difference between revisions

From XMS Wiki
Jump to navigationJump to search
No edit summary
No edit summary
 
Line 5: Line 5:
where:
where:


''T<sub>LAG</sub>'' = watershed lag time in hours.
:''T<sub>LAG</sub>'' = watershed lag time in hours.


''L'' = maximum flow length in miles.
:''L'' = maximum flow length in miles.


''L<sub>ca</sub>'' = length to the centroid in miles.
:''L<sub>ca</sub>'' = length to the centroid in miles.
 
''S'' = weighted average slope of the maximum flow path in ft/mile.


:''S'' = weighted average slope of the maximum flow path in ft/mile.


The typical characteristics of watersheds for which the Eagleson method was applied include the following:
The typical characteristics of watersheds for which the Eagleson method was applied include the following:

Latest revision as of 15:12, 29 September 2017

Eagleson’s method (1962) for computing lag time in completely storm-sewered watersheds is given as follows:

where:

TLAG = watershed lag time in hours.
L = maximum flow length in miles.
Lca = length to the centroid in miles.
S = weighted average slope of the maximum flow path in ft/mile.

The typical characteristics of watersheds for which the Eagleson method was applied include the following:

  • Areas from 0.22 to 7.5 square miles.
  • L from 1 to 7 miles.
  • Lca from 0.3 to 3 miles.
  • S from 6 to 20 ft/mile.
  • Impervious cover from 33 to 83 percent.


Related Topics