WMS:TR-55 Shallow Concentrated Flow Equation: Difference between revisions

From XMS Wiki
Jump to navigationJump to search
No edit summary
No edit summary
 
(7 intermediate revisions by 2 users not shown)
Line 1: Line 1:
After a maximum of 300 feet, sheet flow usually becomes shallow concentrated flow. The average velocity for this flow can be determined using the equations below, in which average velocity (V) is a function of watercourse slope (s) and type of channel:
After a maximum of 300 feet, sheet flow usually becomes shallow concentrated flow. The average velocity for this flow can be determined using the equations below, in which average velocity (V) is a function of watercourse slope (s) and type of channel:


For Unpaved Channels: V (ft/s) = 16.1345 (s)<sup>0.5</sup>
:For Unpaved Channels: <math>V (ft/s) = 16.1345 (s)_{0.5}</math>


For Paved Channels: V (ft/s) = 20.3282 (s)<sup>0.5</sup>
:For Paved Channels: <math>V (ft/s) = 20.3282 (s)_{0.5}</math>


Tillage can affect the direction of shallow concentrated flow. Flow may not always be directly down the watershed slope if tillage runs across the slope.  After determining average velocity, WMS uses the following equation to estimate travel time for the shallow concentrated flow segment:
Tillage can affect the direction of shallow concentrated flow. Flow may not always be directly down the watershed slope if tillage runs across the slope.  After determining average velocity, WMS uses the following equation to estimate travel time for the shallow concentrated flow segment:


: <math>T_t = \frac {L}{3600V}   </math>
: <math>T_t = \frac {L}{3600V} </math>


where:
where:


: <math>T_t </math> = travel time (hr).
: ''T<sub>t</sub>'' = Travel time (hr).
: <math>L </math> = flow path length (ft).
: ''L'' = Flow path length (ft).
: <math>V </math> = average velocity (ft/s).
: ''V'' = Average velocity (ft/s).
: <math>3600 </math> = conversion factor from seconds to hours.
: ''3600'' = Conversion factor from seconds to hours.


==Related Topics==
==Related Topics==
Line 21: Line 21:


{{WMSMain}}
{{WMSMain}}
[[Category:Equations|TR-55 Shallow]]
[[Category:TR-55|S]]

Latest revision as of 15:48, 6 December 2016

After a maximum of 300 feet, sheet flow usually becomes shallow concentrated flow. The average velocity for this flow can be determined using the equations below, in which average velocity (V) is a function of watercourse slope (s) and type of channel:

For Unpaved Channels:
For Paved Channels:

Tillage can affect the direction of shallow concentrated flow. Flow may not always be directly down the watershed slope if tillage runs across the slope. After determining average velocity, WMS uses the following equation to estimate travel time for the shallow concentrated flow segment:

where:

Tt = Travel time (hr).
L = Flow path length (ft).
V = Average velocity (ft/s).
3600 = Conversion factor from seconds to hours.

Related Topics