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PM_2009

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About PM_2009

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  1. Hi, I realised that my model actually seems to be working like "overland_backwater": the water does not go to the stream when the water level in the stream is higher than the grid/water surface on the grid, but the water does not come out of the channel either, even if I have "allow overbank flow" chosen in the job control. Any idea if there has been this kind of problems with gssha? If this problem were be caused by too high/low channel depth, which one would be more likely to cause this kind of problem (I have tried to define the streams so that the channel bank is about at the same level as
  2. I have had the overbank flow mode on, but thanks for the answer! Do you know if it would make any difference to use ADE-PC (now using ADE) as overland flow computation method? Pirkko
  3. Hi, I have a question about relationship between the channel flow and the overland flow in GSSHA: In my simulation (overbank flow allowed) I have noticed that in a place, where water rises above the channel bank level and floods to the floodplain, the water level on the flood plain does not rise even close to the same level as the water level in the channel. The channel depth and thalweg elevations are such that the channel bank should be a few centimeters below grid elevation (but I have tried with the channel bank elevation above the grid elevation, with the same problem). The water level i
  4. Hi, is there any estimations for soil infiltration parameters (to use in GSSHA) for peat land? I have only found some values for porosity and Ks in literature. thanks! Pirkko M.
  5. Hi, I'm using GSSHA in WMS 8.2. I was wondering what happens if I connect, for example, a trapezoidal channel with depth = 1.5 m to another trapezoidal channel with depth = 1m, and then use the "smooth stream arcs" so the channels are not running uphill at any point. Does the "smooth stream arcs" actually smooth the elevations of the banks of the channels, and does this mean that if a deeper channel connects to a shallow channel, the bottom of the channel goes half a meter up in the connecting point even when "the smooth stream arcs" show that the channels are smoothed? Another question i hav
  6. hi, i'm having a problem with adding lakes and running the gshha then... Basically, the lake fills up, but then the water doesn't go out of the lake as discharge (in the end the lake is full but there is no discharge, longer total time doesn't change anything). I have tried different outlet structures, but they don't seem to make difference. (Btw, when there is a weir with a crest point elevation, is that elevation from the grid or the actual z-value i want for the crest? I assumed the latter, but tried the former too...) There is some flow out of the lake, but it's maybe a tenth of the flow i
  7. PM_2009

    Flat areas?

    Hi again, now I noticed that, after choosing "interpolate grid cell elevations to streams" box at 2D-grid creation, the 2D-grid has about 1 meter high banks around the streams (to keep the stream elevations below the grid?), and this stops the overland flow from reaching the stream and makes it pool in the places where two streams meet. Is there any way to stop this from happening, other than not choosing this interpolate grid cells- option? Related to this, is it normal that when I (before creating the 2d-grid) manually add streams to my stream network created from the TOPAZ accumulation dat
  8. PM_2009

    Flat areas?

    I used the hydrologic wizard to making interpolate the grid cell elevations to stream elevations and now water leaves as discharge, thank you, again!
  9. PM_2009

    Flat areas?

    Hi, I managed to get my GSSHA simulation run now with the diffusive wave channel routing, and the water doesn't pool on the surface. The problem is, the water seems to stay in the channels. I get the following summary file: volume of rainfall to overland: 696000.0 volume remaining on surface: 88271.4 final volume in channels (cu. m): 603714.1 volume of discharge: 5829.7 Total time is already set as 10000 minutes, so too short simulation time should not be a problem (I think?). Manning's roughness in channels is set to 0.05. I have smoothed the channels,
  10. PM_2009

    Flat areas?

    Yes, I'm using GSSHA. I'll try the hydrologic modeling wizard, thanks!
  11. PM_2009

    Flat areas?

    hi, I am modelling a watershed (with wms 8.2), using a 25 m grid DEM. The problem is that, even after removing digital dams, the water doesn't seem to leave the area. In the summary file, it says that almost all of the rain is accumulated on the surface and almost none is going out of the area as flow. When I click the "depth" on, it seems that the places the water accumulate to are not always where the TOPAZ accumulation is shown. Also, the accumulated water doesn't leave through the streams (like it does in reality) even if the stream goes through the place of accumulation. My watershed are
  12. Thank you, I used the hydrologic modeling wizard and it's working!
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