Coastal Vulnerability Bathymetry Error

Hi everyone,
I was trying to test out the coastal vulnerability model but I keep running into an error regarding the bathymetry -

Could not open C:/D drive/QGIS/Trial 4\intermediate\wind_wave\Lak Bath_clipped.tif as a gdal.OF_RASTER

I do not understand what this error means. I have downloaded the bathymetry data from GEBCO and have tried extracting data from different years as well, but none seem to get past this error.
My problem is actually very similar to a problem that had occurred with user Nivedha1994 in March, however the thread did not seem to have the solution.

Any help would be much appreciated. Thanks.

InVEST-Coastal-Vulnerability-log-2021-11-22–01_41_12.txt (6.4 KB)

Hi @wenzel ,

Looking at your logfile, it looks like the actual error is a few lines up in the logging:

ERROR [errno 6] C:/D drive/QGIS/Trial 4\intermediate\wind_wave\Lak Bath_clipped.tif: File too large regarding tile size. This would result in a file with tile arrays larger than 2GB

This is a very interesting error and not one I’ve seen before! I’m not entirely sure what’s going on, but could you share your bathymetry raster and AOI with me so I can take a closer look at what’s going on? Feel free to email it to jdouglass@stanford.edu if it’s too large to share here.

Thanks!
James

Hi James,
Thanks for writing back.
I have uploaded all the files I am using for this run onto a drive folder and sent the link over to your email address.

Thanks,
Wenzel

Received!

I’m able to reproduce this error on my end, and I believe the issue here is that your AOI’s projection appears to be in units of degrees. The model requires that the projection be in meters, and the other spatial inputs will be reprojected for you to the projection of the AOI.

From the user’s guide:

Area of Interest (required). This file must be a polygon vector that has a ‘projected’ coordinate system rather than a ‘geographic’ coordinate system and the chosen coordinate system must have units of meters (the Model Resolution input value will inherit the units of this coordinate system).

So then because the model resolution input value inherits the units of the coordinate system, the bounding box is being extended by 31000 degrees on all sides! So naturally this is causing some strange behavior with the spatial library we’re using.

So the most likely solution here is to reproject your AOI to a reasonable projected coordinate system (units of meters preferred) and re-running the model.

Could you try that out and see if it resolves the issue? Please do let us know if it does not.
Thanks!
James

Hi James,
The coordinate system that I had exported all the files to was WGS84 / UTM zone 43N (EPSG:32643). In the description it did mention that the units are measured in meters, but maybe this is not the right projection to use. Is there another projection system that you would suggest for the west coast of India that might be better for this run?

Thanks,
Cheers,
Wenzel

Hi @wenzel ,

WGS84 / UTM zone 43N should be a fine projection choice. Could you make sure that you reprojected the files and didn’t just define a new projection? In QGIS for a vector this would be: Vector General -> Reproject layer. I wonder if exporting just defined a new projection system which updates the metadata but doesn’t actually transform the geometries.

Cheers,

Doug

Hi @jdouglass ,
I tried reprojecting the files. The input layers showed up as WGS84 / UTM zone 43N to begin with, but I reprojected them to the same layer again. The reprojected layers all overlap exactly with the originals. I also tried reprojecting them to EPSG 4326 and that drastically shifted the positions of the layer so I think they actually were already in the right CRS.

I tried running it again with the reprojected files, however the same error persists. Do let me know if there are any other things I could try out.

Thanking you,
Cheers,
Wenzel