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Shrestha

29/03/2016 14:03:39

Hello everyone,

 

I'm trying to simulate a rainfall scenario with a 2D simulation with a test version of Flood Modeller 4.1.1. My simulation runs fine and is successfully completed but when I try to load the results, I can see the available time-steps but nothing is loaded and cant see any of the results. Surprisingly, the .dat and .2dm files are only of 1 and 2 kB. What is it that I'm doing wrong here? My input dataset includes a DEM, a shapefile for rain and active area

I highly appreciate any hint/help. Thank you.

 

Cheers,

Shrestha

 

Konrad

Flood Modeller Support

29/03/2016 15:10:41

Something I forget to do occasionally is to select the model finish time (or timestep); that would certainly give the same symptoms as you see. Also check the output interval in your "Outputs" tab and that the format is set to "GRID". I assume you are running the normal [ADI] solver? (The FAST solver has different output defaults).

Have you checked through the .log file to see if anything unusual appears in there?

Konrad

Shrestha

29/03/2016 16:38:25

Hello Konrad,

Thank you for your reply.

If I forget to specify model finish time or time step, then I shouldnt be seeing the available time steps when I try to load the results, isnt it? In any case, I have a simulation time of 2.5 hours in General tab and timestep of 1 (in seconds, I guess?) in Domain=>Domain details tab. The output interval is set to 60 s in outputs tab and the format is set to GRID too. Yes, I'm running  ADI solver.

In the log file, it says:

Reading  boundary conditions ... 0  found

Applying initial conditions...No initial conditions specified - setting global depth = 0

Reading hydrology (rainfall/loss) details...
Reading rainfall area(s) from C:\Users\Rain.shp 

...

 

And at the very end,

Maximum Courant number seen:
Domain 1: .0

Run completed in 60.1 seconds
Note: No spatial diagnostics to output.

Is that something unusal there?

 

Best regards,

Shrestha

Konrad

Flood Modeller Support

29/03/2016 16:54:15

All looks fine there ... apart from a suspicious highest Cr of 0.

Next advice would be to look at the check files - a bunch of .asc files in the same folder as the results.

Specifically:

*zcen.chk.asc - ground elevations actually used by the model

*iwet.chk.asc - should have an area of 1s coincident with your active area

*hydro.chk.asc - should have an area of 1s coincident with your rainfall area

 

And what are the values you've entered for your rainfall (and how specified)? Check things like the time units, e.g. you've not specified them over a period of seconds instead of hours.

Konrad

Shrestha

29/03/2016 17:10:10

*zcen.asc - has no values at all. when I check it with ArcGIS, it shows no data.

*iwet.asc - has a value of 0 and the area is identical to the active area.

*hydro.asc - has a value of 1 and the area is identical to the rainfall area.

For rainfall, I have entered values manually, a rainfall of 120 mm/hr for 30 minutes. I have double checked the units and they are in hr and mm/hr.

Im wondering why zcen.asc has no value? The DEM loaded on Flood Modeller shows elevation values.

 

Best regards,

Shrestha

Konrad

Flood Modeller Support

30/03/2016 11:04:56

That zcen definitely shows a problem, as do the iwet=0 values (inactive cells); there's no effective computational area.

The active area looks to be defined OK as the iwet file covers the expected area.

So I'm thinking it's an issue with the topography. Is the DEM loaded into the topography section OK (domain > Domain Details > Topography)?

And does the log file report anything here, e.g.

Active Area shapefile found: ...
Computational area extents:
   Lower left coordinates        : ...
   Rotation angle                :   0.0 degrees
   Active area grid size (C x R) :    ... x     ...

...

Reading topography...
   Applying ground elevations from layer ...

 

Shrestha

31/03/2016 09:17:29

Hello Konrad,

 

thank you very much for your support. 

I think I have found the source of problem. It is the decimal separator in the topography .asc file. Here in the German speaking countries, we use a comma as a decimal separator. So, once I replaced all the commas with points, the simulation runs and produces result as expected. 

But I have a new problem now concerning coordinate system. It is strange that all my input layers are in MGI_GK_Central coord. system (for Austria). Flood Modeller however produces the output layer in some other coord. system and I cant overlap the results with my input layers now. How can I force the program to produce the results in the same coord. system as the input files? Or how can I get the input and output layers overlap each other?

One more concern about exporting the output layers: is there anyway to export the output layer (maximum depth for example) into a .tif file so that I can access it with ArcGIS or any other GIS software?

Thanks a lot in advance & wish you a nice day.

 

Best regards,

Shrestha

 

Bob

Flood Modeller Support

01/04/2016 11:44:20

Shrestha

The current release of Flood Modeller uses a UK specific projection as its default setting. However you can change this by clicking on the Start tab of the main toolbar and then going to the Info page. This gives you an option to set a different projection, i.e. your Austrian one. This may solve your problem of data not appearing in the right place (though I'm not 100% sure of this - let me know if it works for you).

Turning to your other query about exporting layers. On the results tab of the main toolbar there is a 2D flood calculator tool. This can read any selected timestep from your 2D results file (it will access any loaded in your map view or you can browse to a different 2D result). You can choose to export your data to ESRI shapefile format (these can be flood extent outlines or a grid of square polygons with depths assigned as attributes). You can also export your data to a depth grid (ASCII format). Both of these formats should be compatible with standard GIS software tools.

The 2D flood calculator tool also offers the option to convert the outline shapefile to Google Earth (kml) format.

In your post you also mentioned tiff format. There is an option on the map right-click menu to save the current view as a geo-referenced snapshot image file, although this only has the option to save to a png image format and it would be an image that includes all visible layers in the current map view. Furthermore, if you use this then you would need to first set up your map projection to the required Austrian setting beforehand to ensure the World file for the image is created correctly.

Hope this provides some useful information.

Regards

Bob

Shrestha

04/04/2016 13:33:53

Hello Bob,

 

thanks a lot for your reply.

 

I am aware of the setting the right coordinate system on the start tab and I always set it before running the simulation so that my input files are oriented correctly. I couldnt still get the output file produced by flood modeller overlap the input file. And it is strange, I just discovered that the extent of the output files are exactly 1000 times the extent of my input files. So, I suspect, somewhere again comma and point is coming into play. I couldnt figure out where?

Exporting of the output layers worked out well. But due to the fact that the output layers are in unknown coordinate system, they cant be projected and therefore appear at a wrong location when I load them in ArcGIS.

In the mean time, I am still trying to make it work. I would be glad to hear if you have any ideas about this problem.

 

Best regards,

Shrestha

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