drawdowns in WSE

[Anonymous]

Help, am working on a model for a LOMC which means am dealing with the FEMA contractor. am having a problem with a drawdown at one of my sections that is baffling me. section is similar in geometry to upstream and downstream sections as well as roughness values and streambed elevations, but for some reason Froude is jumping up to 0.87 at this particular section. have tried everything i know to do…..thoughts??

[Anonymous]

Unsteady or steady state?

[Anonymous]

steady

[Anonymous]

Look at all variables associated with the cross sections at and around the area of interest

– contraction and expansion coefficients
– downstream reach lengths (are they correct)
– Ineffective flow areas (any there that are unnecessary?)
– ^^ That includes levees and blocked obstructions
– Cross section nomenclature, steady state 1D relies entirely on the numerical input from the user no matter how it looks in plan view

– Try running it in mixed flow conditions giving the US xs a critical depth BC
– Turn on xs direction arrows…everything going US to DS left to right?

This sounds like a simple quick error that you are possibly overlooking because youve stared at it too long. What is the US and DS Froude #’s? is 0.87 really that alarming?

[Author]

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