Our local agency is requesting a composite q for runoff instead of a composite CN. Do Bentley products have this capability?
Hi Brian,
"Composite CN" refers to the calculation of an overall Curve Number based on multiple soil types, to describe the portion of rainfall that becomes runoff for a given catchment area. While SewerGEMS, CivilStorm and SewerCAD can use CN with the Unit Hydrograph method for example, StormCAD only uses the Rational Method, which uses a "Rational C" instead of a CN.
Can you elaborate on what you mean by "composite q"? I do not believe I have heard of this before.
Regards,
Jesse DringoliTechnical Support Manager, OpenFlowsBentley Communities Site AdministratorBentley Systems, Inc.
Is this "composite q" based on runoffs from different sub-areas of a catchment? However, it is not possible to get individual runoffs from sub-areas, unless you model each sub-area as an independent catchment with its own CN value.
Is this what you are looking for?
Yashodhan Joshi
Just wondering if stormcad/sewer gems can do a weighted q yet? As previously posted our agency requires separate runoffs for each curve number to be added together in a catchment. We are no to use a composite curve number for a catchment.
Could you provide details on what you are looking for? With further information on what this is, we can either see if there is a way to do this or be able to log a request to include this.
Scott
I agree with the others - more specifics on your requirements will help us provide an accurate answer, or define your requirements for development consideration. Which numerical solver (Rational for peak flow?), how is this weighting expected to work and which results does it apply to? Without this we can only guess as to what you need.
I am not certain at this point, but you may want to take a look at the subarea feature or consider the points in this article: Multiple CN numbers for a catchment and multiple catchments with a single outlet node