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Showing results for tags 'hec-hms'.
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lebronkahn posted a topic in General HydrologyHi, First I want to thank you for your time in advance. Any advice on this will be appreciated as I have been stuck on this problem for weeks now. Here is the situation: I created this basin model with 101 sub-basins and 100 reaches. Pic attached: "Basin Model" (there is something wrong with the upload, I changed it to URL) I am using one plane approach. No collector and subcollector channel information. For the sub-basins, I use "SCS Curve Number" as Loss Method and "Kinematic Wave" as Transform Method; for the reaches, I use "Muskingum" Routing Method. As show in the attached: SubBasin and Reach. In Meteorology Model: Precipitation is Specified Hyetograph I followed every step of the example in the HEC guide, and the model runs and can generate results. However, I found out that, no matter how much I changed the parameters, the corresponding changes in the results were minimal. For instance, the default value I used for Length and Slope for subbasin main channels are 100ft and 0.01. After I acquired the real value through ArcGIS (much longer length and much smaller slope) and put them into the model, the results were almost the same(1855.5 CFS to 1855 CFS). I also tried change the Route Upstream for some sub-basins i.e. from No to Yes. Still minimal change. Two things noteworthy and suspicious :every time I run the model, although the process can still go through, there will be warnings: Error in computing kinematic wave for subbasin SA 064; Estimation procedure for time step size failed to converge. And this will persist for a lot of SAs (sub-basins). Couldn't find anything Google associated with this warning message. Any idea? When I print out the results, the header will show: Method: Snyder Transform. I know for a fact that I didn't use anything called Snyder. Where does this come from. Please lemme know if I need to provide more details in order for this problem to be solved. Thanks
DeniseS posted a topic in General HydrologyHello, I've been using HEC-HMS for just about two years now and I'm still learning all of the details of it. I have a detention pond which is draining 1.76 acres onto a state highway. I have put in the Elevation-Area Table in the Paired Data. There is an outlet pipe (the only outlet) of 18"; it's inlet elevation is 1278.00. I'm assuming that is the very bottom of the detention pond, because in the drawing, contours are shown for this pond starting at 1279.00. When I run the 2-year Type II SCS Storm of 3.30 inches, the following error occurs and the process is aborted: "ERROR 40254: Computed pool elevation is below minimum table value for reservoir "Detention Pond". There is also another error which follows the above error. It is ERROR 40261: Reservoir routing failed at simulation time "1 January 2000, 00:05:00" for reservoir "Detention Pond". Because I get an error relating to the time control specifications, is there not enough model time for the pool elevation to get high enough to prevent the first error from occurring? Is that what is happening? Or is it something else? This program can do so much and I'm still so very confused over half of it!! I need a one-on-one tutor to tell me, in layman's terms what all of the components are and what their methods are. Thanks for any advice! Denise
Hi folks, I am in the USA and we write our date/time in the format of "Month/Day/Year Hour:Minute:Second AM". I built an HMS model in WMS in the USA. I have imported precipitation time series and linked them to gages. I sent over the WMS files to our partners in Morocco. They open up the precipitation time series and the values are all scrambled up. My best guess is that the date/time stamp is being incorrectly interpreted as "Day/Month/Year". To test the idea, I switched my "Region and Language" setting on my computer to be "dd-MMM-yy". Sure enough, when I open up WMS and open up the files, I get the same scrambled time series. Is there a way to tell WMS to unscramble the time series? Thanks, Lisa
Hello everyone, I am new to WMS. I would like to know if it is possible to use WMS to perform real-time simulations. Both radar and gauge rainfalls are avaialbe every 10 mins. Once models (HMS, RAS, or GSSHA) are set up, I would like to have an automatic process. Thank you