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  1. Yesterday
  2. Hi speedy, it seems you need to enable the MT3DMS SSM package to enable the mixing of fluid coming from the constant conc. BCs. I would try to enable SSM and set ICBUND to -1. It should work then. Hope it helps. Michal
  3. Last week
  4. Thank you Sir now it works
  5. Long, Let me know how things go. Thanks, Chris
  6. LuboBa, Are you referring to the documentation on our wiki site? The information on our wiki site about simulating sediment transport with SRH-2D was recently added in preparation for SMS 12.2 which is currently in beta and has the sediment transport interface added. Due to this interface still being new and in beta, it is not available in the current official release of SMS (Which is SMS 12.1).
  7. Thanks, Chris. The resolution of DEM is 30m, I guess the channel bottoms are not represented in the DEM. I'll do some trial and errors. Long
  8. It sounds like the values haven't been entered as a step function. It's taking the values at the beginning of the stress period and the end of the stress period and averaging them. When you enter the values as step functions like shown in the attached image, then no averaging is done. The "Managing Transient Data" tutorial (http://aquaveo.com/software/gms-learning-tutorials) has more info.
  9. Long, I don't have any suggestions other than trying to fix the sharp transitions in channel geometry by making sure your channel cross sections represent the actual channel bathymetry. What is the resolution of the DEM you're using to extract the cross sections? Are the channel bottom elevations represented in the DEM? If not, maybe you can modify the cross sections extracted from the DEM to include an approximation of the actual channel cross section as well as the channel thalweg. If your model runs with the same cross sections assigned to the nodes of your links, this tells me that the instability is introduced from the different cross sections at each node of your stream network. You could try decreasing your number of nodes/cross sections in your model by merging the arcs in your GSSHA coverage. Alternatively, you could try making some of the cross sections closer together where there are sharp transitions, changes in slope, or abrupt changes in Manning's roughness. I think it's just a matter of trial and error from here. You could also try sending your model to Chuck Downer and see if he replies and has any input. He would be interested in getting the model working better for your case. Hopefully this helps, Chris
  10. Thanks, Chris. I tried to use the same cross section for all the channels (ensuring no transition), and the problem was perfectly solved. The model ran with no warnings or any error messages. I was just wondering if there are alternative ways to solve the 'abrupt transition' issue, cause sometimes transitions in the channels are physically present. The way I can think of would be to add a structure link in between the channels with sharp transitions. However, I'm not sure if it is entirely feasible, cause I do not really know what kind of transition does the model regard as too 'sharp' to solve. It seems that I could not locate the sharp transitions by simply looking up warning messages in the summary file, cause the nodes that broke down are not always the ones with sharp transitions. Any suggestions? Thanks, Long
  11. Naglaa, Your DEM probably has over 30 million cells, which is probably too many cells to run in TOPAZ. I'd run your model using TauDEM using the parallel processing (Use MPICH2") option. If you have a powerful computer with lots of memory and processors, that would be the best option for running TauDEM. You need to select the button to register MPIEXEC your computer if this is your first time running this option. You can select the default for the number of processors (4) or you can enter the number of processing cores on your computer, which I think is anywhere from 4 to 8 on computers nowadays. Hope this helps, Chris
  12. Hi I'm trying to comupte TOPAZ using DEM 90 m resolution for Blue Nile area which around 300000 square Km and i got this massage "wmstopaz.exe 004595c9 Unknown unknown unknown" and there is a snapshoot of error massage in the attached file Thanks Doc1.docx
  13. David, The depressions are retained on the DEM and in your model after running TOPAZ. The purpose of TOPAZ, when used with WMS, is to find the areas of high flow accumulation in your watershed. WMS can then determine stream locations from these accumulation values. TOPAZ itself does change your elevations to accomplish its purpose, but the DEM elevations in WMS are not changed. So because of this, TOPAZ may actually create areas of high flow accumulation (streams) that do not actually exist in a landscape like the one you are working on. You can always edit the streams created by WMS to more accurately represent aerial photograph or topographic map data for your area. So the answer to your question is that no, TOPAZ does not change your elevation data in WMS, but the flow accumulation values and stream network generated from running TOPAZ may not represent what actually happens in your watershed. The elevation values on your grid are changed when you run the "Clean Digital Dams" command from the GSSHA menu on your 2D Grid. This is when your depression polygons are used to define which elevation values you don't want changed. You can be certain any elevation values on your 2D Grid inside depression polygons are not changed, and you can confirm this by turning on the option to display Digital Dams in the 2D Grid display options. GSSHA takes significantly longer to run when you have lots of depressions like you have, but if this is what you're trying to do, the extra time is probably worth it to you. Hope this helps, you might want to contact Cody Alberts here at Aquaveo. He has had some experience in modeling areas with lots of depressions like yours using GSSHA. Let me know if I can help with anything else. Chris
  14. Hi Chris, Thank you for the prompt reply and detailed instructions. I've worked through most of the tutorials on WMS, but have yet to fully make connections between parts of the platform. As I mentioned in my post, we are modeling depressional storage and fill-spill processes on varied low-relief watersheds (i.e. think the prairie pothole region). I know that these depressions exist on the landscape, but am uncertain about whether they are retained in WMS when building a GSSHA model. For instance, are all depressions resolved when running TOPAZ?, and if so, does the elimination of these features show up in the model grid? How can I be certain that I am retaining depressional features on the landscape, and ensuring that GSSHA models their fill-spill processes correctly? Thanks in advance for your assistance. David
  15. SMS 12.1 seems not to be able to prepare data for sediment transport with SHR-2D. There is no way to change coverage of type to ... Sediment materials for this model. Please update documentation because I spent some time trying to simulate sediment transport until I found out that it work fine with 12.2. beta and it is probably not implemented in 12.1. Lubo
  16. Earlier
  17. David, There's not a specific tutorial that describes how to maintain depressions to WMS. But you should be able to use your polygon shapefile to define your depressions fairly easily. You need to make sure you're using the most recent version of WMS on our web site since there was a bug in a recent release of WMS. Setup your basic model, but don't run the cleandam program until you've added your depression polygons. Here is what you do (after you have defined your initial model): 1. Read your polygon shapefile using File | Open. 2. Make sure the GSSHA coverage you're using with your model is the active coverage by selecting it. Go to the GIS Module. Select Mapping | Shapes->Feature Objects. Select Yes to convert all your shapefile data to map data. Step through the wizard to convert your data. Don't worry about mapping any attributes. 3. Go to your GSSHA coverage, which should now contain your shapefile polygons. Select the select polygon tool and select all your depression polygons. Select Feature Objects | Attributes and change the polygon type to "Depression Mask". 4. You should now be able to continue building your model and run the "cleandam" program before running GSSHA. The cleandam program is accessed from the GSSHA menu in the 2D Grid module (Clean Digital Dams) or from the Hydrologic Modeling Wizard (the Clean Up Model step). There's a display option to show digital dams in the 2D Grid Data display options. The digital dams inside your depression polygons should be maintained after running cleandam and the other digital dams should be removed. There are actually some WMS tutorials on our web site that have some discussion of digital dams. A tutorial you might be interested in going through is called "Updating a GSSHA Model using the MWBM Wizard" and can be accessed by going to our tutorial page here and clicking on the Distributed Hydrology tutorial tab. I hope this helps, Chris
  18. Long, Yes, I'd say if there are sharp transitions between adjacent cross sections of your channel you could get some model stability problems. I don't know if it is feasible, but could you try changing all your channels to just use trapezoidal cross sections? Then you could work on adding the natural cross section information once you get the trapezoidal cross sections running with the OVERBANK_FLOW option. Maybe you could save your modified model to a different folder. Another thing you should check is your stream thalweg elevations in relation to your grid cell elevations that intersect your stream. The grid cell elevations should be approximately the same as your TOB elevations. You can check and edit these elevations in the WMS Map Module under the GSSHA | Smooth Stream/Pipe Arcs menu item. Check your GSSHA summary file (.sum) to see if there are any warnings you're overlooking when you run your GSSHA project. If you check these things and make sure your cross sections have fairly smooth transitions and you're still having trouble getting a stable GSSHA model, you could contact Chuck Downer. He is the main GSSHA programmer and he should be able to help you if you send him your model and the specific issue you're having. His email address is on the main gsshawiki.com page. I hope this helps, Chris
  19. Hello, I'm attempting to construct a GSSHA model of a low-relief watershed containing a significant number of natural topographic depressions. I'm uncertain about how to build and apply the depression polygon mask within WMS. I have a polygon shapefile of the depressions for this watershed. Can someone either point me in the direction of a tutorial on this process, or provide general steps within the answer to this post? Thanks, David
  20. Hello !!!!! I am making a simulation of a tracer test with three injection wells (north) and one pumping well (south). On the injection wells we have injected the salt and water for 16 hours and then successively water for two months. After 16 hours of injection (the initial concentration was 330g/l), we started to pump almost the same amount of water injected on the north on the same time span. we have found the Kx values that match the arrival times of the breakthrough curve at the observation points, according to the pathlines. The problem is that I am getting Nacl concentrations that are too high compared with the values I have measured (calculated from the electric conductivity at the observation point converted in Nacl concentration). The aquifer thickness is about 30 meters. My question is, according to the above mentioned; is there any way to reduce the concentration at the observation well (40 meters downgradient of the injection well). There should be no adsorption or other phenomena within the aquifer, or at least we expect that. The concentrations should be around 10mg/l, however, the concentrations I am getting are around 1800mg/L * could it be possible to use double density approach to solve that problem? * RT3D gave me better results than MT3D, setting in both cases NO reaction (tracer transport), but setting in the CHEMICAL REACTION PACKAGE A value for the Linear isotherm a first sorption value of 1e-3, could that value influence a lot? Thanks a lot for your reply and possible suggestions Alexxander
  21. The way it currently works is as intended. For shapefiles, exported points are those that aren't associated with an arc. Nodes are exported with the arcs. It is possible to get at the X, Y, and Z values along with stage and elevation by right clicking on the coverage, selecting Attribute Table, changing the Feature type to Nodes and then turning on Show coordinates. Then the X, Y, and Z values could be copied along with stage and elevation by clicking in a cell and typing control-A to select all, and control-C to copy.
  22. Thanks Alan, the nightly build solved the issue.
  23. I am using SFR package. In transient state, I have 18 stress period and assigned all hydraulic parameters to each stream according to stress periods. But when I Map the stream conceptual layer to MODFLOW and check the SFR window from MODFLOW|Optional Packages|Stream Flow Routing, I found the flow data as average of input inflow data in consecutive stress periods. Values from attribute table should match the values in SFR package window, which is not the case here. I would be grateful if you could help me in this regard. Thank you.
  24. Hi Chris, This is exactly what I'm asking. Thanks! I'm currently trying to simulate extreme flood events using GSSHA. I tried not to turn on OVERBANK_FLOW, cause the simulation just cost too much time to finish. However, if I did not turn on OVERBANK_FLOW option, the model crashed at certain nodes, and I got the error message as "The channel routing time step is getting really small less than 1/1000 of a second. Reduce the model time step by a factor of 2 and try again. Program stopped." I know there might be some abrupt transitions of flow volume around the nodes, due to which the model stability could not be satisfied by reducing time steps. The time step is 1s for my case. I then tried to reduce the time step to 0.5s. The new simulation passed the crashing nodes of the 1-second simulation, but crashed over other nodes anyway. I'm using the natural channels (cross sections extracted from DEM). I know there might be sharp longitudinal transitions of cross sections over the channels, but not quite sure if this would crash the model. Any suggestions? Thanks, Long
  25. The problem has been fixed and will be in the nightly update as well as the next release of 10.2. We have also added a test to verify that the fix stays fixed.
  26. This looks like a bug. I am currently putting in a fix and adding a test so we will know if it breaks again.
  27. i really like the tutorials of GMS, but you should put more information regarding the time steps for transport models. which is not very well explained if you want to decide the output time stes you should put in the column Max trans steps,( in the figure i used 120) and all the time i had a results of only 27 tstress periods, at least that numbre should be 400 or 500, in my case i have got a stress period each day, as i wanted, the model worked in maybe 30 minutes but the output times were as I wanted 120 , 1 every day to see the plume evolution once a day, dont forget to leave the column trans.step size =0 so mt3dms decides according to your output time
  28. Hi, When i customize the variogram for the pilot points of the HK-field in the nsmc I and II tutorials, and also in my own models, I encounter the problem showed in the attached figure. It seems like the whole field is generated from only one point and not all available ones. I also edited the already set up variogram in the tutorials, and then changed back to its original form and still got the same problem. Any ideas on how to solve this issue? Kind regards, Jonas
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