tag:blogger.com,1999:blog-1675184707067447729.post4964602268711616424..comments2023-07-12T07:12:04.697-07:00Comments on The RAS Solution: 2D Troubleshooting – Fragmented InundationChris G.http://www.blogger.com/profile/00354834185663924786noreply@blogger.comBlogger15125tag:blogger.com,1999:blog-1675184707067447729.post-44183556759214410942019-03-05T07:54:40.347-08:002019-03-05T07:54:40.347-08:00Not entirely. But they have added sloping renderi...Not entirely. But they have added sloping rendering which does help a lot. Chris G.https://www.blogger.com/profile/03272464763887890080noreply@blogger.comtag:blogger.com,1999:blog-1675184707067447729.post-16530495276564292592019-03-04T09:36:24.116-08:002019-03-04T09:36:24.116-08:00Has this issue been resolved in newer versions of ...Has this issue been resolved in newer versions of HEC-RAS?Danielhttps://www.blogger.com/profile/10112041011926798243noreply@blogger.comtag:blogger.com,1999:blog-1675184707067447729.post-5167737854725068912019-02-07T11:26:03.223-08:002019-02-07T11:26:03.223-08:00a 1D reach can flow directly into a 2D area, or vi...a 1D reach can flow directly into a 2D area, or vice versa with a direct connection. A 1D reach can also flow laterally into a 2D area via a lateral structure. Chris G.https://www.blogger.com/profile/03272464763887890080noreply@blogger.comtag:blogger.com,1999:blog-1675184707067447729.post-16308844082994854712019-02-07T07:08:00.351-08:002019-02-07T07:08:00.351-08:001d/2d project. 1d can overflow directly to 2d area...1d/2d project. 1d can overflow directly to 2d area?Anonymoushttps://www.blogger.com/profile/08909487690130164177noreply@blogger.comtag:blogger.com,1999:blog-1675184707067447729.post-83927171724122253582018-08-27T10:33:38.993-07:002018-08-27T10:33:38.993-07:00Hello, we have a 2d model which is behaving rather...Hello, we have a 2d model which is behaving rather weirdly. In rasmapper, we have a profile line and when we turn on the maximum WSEL, we get a rather high WSEL of 133.6 (at the centre, its a little lower at the ends) near a connection between an upstream 2d and a 1d reach. However a time series simulation shows that the water level never goes above 132.6. In fact the profiles for all the timesteps are nice and flat and generally lower than the maximum profile. We have the same interval for mapping and hydro-graph ( 1 minute). Is the maximum profile not based on these intervals? is it based on the computation interval (in our case 5 sec). Or is this a fragmented Inundation issue?Noteswithoutemotionhttps://www.blogger.com/profile/16037830668397974731noreply@blogger.comtag:blogger.com,1999:blog-1675184707067447729.post-69473169202676184012018-06-10T06:07:06.040-07:002018-06-10T06:07:06.040-07:00can we get the measurement of inundation area from...can we get the measurement of inundation area from a 1d-2d coupled hec ras directly? or is there any other way? Thanks in advance.Angana Borahhttps://www.blogger.com/profile/03593537950102307903noreply@blogger.comtag:blogger.com,1999:blog-1675184707067447729.post-69479886264456980202017-06-06T09:36:12.571-07:002017-06-06T09:36:12.571-07:00OK thanks a lot Chris!!OK thanks a lot Chris!!Anonymoushttps://www.blogger.com/profile/02803457169765997469noreply@blogger.comtag:blogger.com,1999:blog-1675184707067447729.post-19558850348587350452017-06-06T09:33:26.513-07:002017-06-06T09:33:26.513-07:00RAS currently has no "infiltration" opti...RAS currently has no "infiltration" option for 2D areas. Therefore, when water gets into a low depression, where there is no terrain outlet, it will remain there. You can avoid it by manually filling in the terrain, or just ignore it. You can also remove the "ponds of water" from your map manually in GIS. Chris G.https://www.blogger.com/profile/03272464763887890080noreply@blogger.comtag:blogger.com,1999:blog-1675184707067447729.post-2896526644512408172017-06-06T09:22:44.880-07:002017-06-06T09:22:44.880-07:00Thanks Chris,
is this due to a missing component...Thanks Chris, <br /><br />is this due to a missing component for the subsurface flow drainage? where could i find a bit more information regarding this? Until now we are just ignoring this "problem" but for further work, like publishing etc., it will be nice to have a reference to justify that we ignore this water. Also is there any way to avoid this? <br /><br />thanks again!! :)Anonymoushttps://www.blogger.com/profile/02803457169765997469noreply@blogger.comtag:blogger.com,1999:blog-1675184707067447729.post-34690102356081419202017-06-06T09:09:03.002-07:002017-06-06T09:09:03.002-07:00That is a different thing altogether. If you have...That is a different thing altogether. If you have depressions in your terrain, and water can get there, it will stay there.Chris G.https://www.blogger.com/profile/03272464763887890080noreply@blogger.comtag:blogger.com,1999:blog-1675184707067447729.post-43778232608177964042017-06-06T05:32:16.043-07:002017-06-06T05:32:16.043-07:00Hello Chris,
Does this applies also when we have...Hello Chris, <br /><br />Does this applies also when we have a river with islands and the water seems to remain in small depressions inside the island? Or is there any other reason? Thanks a lot! Anonymoushttps://www.blogger.com/profile/02803457169765997469noreply@blogger.comtag:blogger.com,1999:blog-1675184707067447729.post-23380658150839112962015-04-22T07:52:38.657-07:002015-04-22T07:52:38.657-07:00Are the stages the same also?Are the stages the same also?Chris G.https://www.blogger.com/profile/03272464763887890080noreply@blogger.comtag:blogger.com,1999:blog-1675184707067447729.post-69137131536599879232015-04-22T07:13:50.603-07:002015-04-22T07:13:50.603-07:00Hello Sir,
I am trying to see the extent of w...Hello Sir,<br /> I am trying to see the extent of water at different discharge values in HEC RAS 4.1, but I am getting the same extent for different discharge values. Please help me resolving this problem.Anonymoushttps://www.blogger.com/profile/06106056067682379233noreply@blogger.comtag:blogger.com,1999:blog-1675184707067447729.post-66150742151649492432015-02-20T11:26:23.529-08:002015-02-20T11:26:23.529-08:00Hi Vern-
I think by saying it's purely a grap...Hi Vern-<br /><br />I think by saying it's purely a graphical issue may have been an over-simplification on my part. You are correct that the face hydraulics are based on the upper (higher water surface) cell's elevation. So in a sense, that can be a small amount of error introduced-small especially in typical overbank terrain (i.e. not too steep). However, the point I was trying to make was that the momentum equation and continuity equation are solved over the length between cell centers, so in that regard, a hydraulic gradient is realized between the two cell centers, even though the hydraulic parameters are based on the higher of the two neighboring cell's water surface elevations. Nevertheless, your point is a good one, in that smaller cells should be used when modeling steep streams/terrain in 2D. Thanks for pointing that out. I will edit this post to be more clear about this issue.Chris G.https://www.blogger.com/profile/03272464763887890080noreply@blogger.comtag:blogger.com,1999:blog-1675184707067447729.post-54740490583079601172015-02-20T09:59:15.074-08:002015-02-20T09:59:15.074-08:00Chris - Are you sure the problem is only graphical...Chris - Are you sure the problem is only graphical? I have not seen the Hydraulic Reference Manual chapter on 2D, but I understood from Gary that the Cell volume and the Face hydraulics are computed from the upper cell center elevation. If that is true, then the hydraulics are based on the histogram, stair-step, water surface as you show as Mapped WSEL, above. Generally, it would not be worth while to model steep streams in 2D, and if you do, you should use very small Cells to minimize the errors. VernAnonymousnoreply@blogger.com