OK Peter -- I've looked at our curves again and familiarized myself with the definition of 'mass curve' and you've nailed it. Thank you! I was given the set of points from our State, so I will have to think about how to 'smooth' them.
Peter,
Thanks for the explanation. I will have to go back into the project and see what exactly I have. You are talking about the mass curve, and I am talking about a distribution. I will go back into the project later and check.
Peter,
If I'm understanding you right, I think I tried that. I was using a rainfall distribution that only had a data point every 6 hours. I went back and interpolated between these points to create data points every 15 minutes. Is this what you're suggesting? I am wondering if the program...
I'm using HEC-1. I did a hydrograph time step of 15 minutes. Is there another place to specify the OUTPUT time step? I ran it again with a time step of 3 minutes (the shortest I could do, since HEC-1 limits you to 2000 ordinates), and got the same result.
Does anyone have any ideas on why the recession limb of this hydrograph would be stairstepping like this?
I have run several different storms on this watershed (6 hour 100 year, 24 hour 100 year, 6 hour Probable Max. Precip. adjusted for our location, and 72 Probable Max Precip. adjusted for...
Remind me which files I need to include in order to email a HEC-RAS project. I am thinking I need to include
.prj
.p
.f (the one specified in the .p file)
.g (the one specified in the .p file)
Should I delete the extra "Geom File=", "Plan File=", etc. lines out of my .prj?
Cross-posted from water distribution:
Does anyone have any tips for keeping your work logical when you are troubleshooting a model? When I am doing this, I'll change something here, change something there, try this, try that. I've tried making lists of what I changed, saving a new version of...
Does anyone have any tips for keeping your work logical when you are troubleshooting a model? When I am doing this, I'll change something here, change something there, try this, try that. I've tried making lists of what I changed, saving a new version of the model if I make a really...
I don't need to design the pipe, as it is already part of the system. I wanted to see how it affects or is affected by the pressurized system that it ties into.
We have a pipe running from a spring to a water tank in our water distribution system. This pipe is not flowing full. It is my understanding that EPANET cannot model this situation. Is there a way to work around this within EPANET? If not, what is the best (free) program to use instead? SWMMM?
Thanks Drew. I ran a simple HMS model using the two methods, and method 1 was less conservative. I am reviewing a drainage report where they used Method 1. From your explanation, it makes sense why it would be less conservative.
Also, the 30 was just an example. I thought of that when I...
Using the SCS CN Method in HEC-HMS:
Are both of these correct to model a developed area?
1 - compute the CN of the basin in the undeveloped state and input this into the 'CN' field. Compute the percent impervious in the developed state and enter this in the 'percent impervious' field. Run the...
I am doing a spillway analysis for a small pond/dam. The spillway is a 24-inch pipe. I understand how I would calculate the rating curve if it was a short culvert with a known tailwater (or range of tailwater levels). What if the spillway pipe extends thousands of feet before it gets to an...
