International Error Messages

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Joined: Thu May 28, 2020 1:30 pm

International Error Messages

Post by farkasal » Thu Jun 25, 2020 2:08 pm


I'm attempting to use i-Tree Hydro for a location near Toronto, Ontario, Canada. I chose Erie, NY as our base location and used the Erie Intl. Airport weather station for a 2009 simulation. I inputted my own DEM file. After trying to move on from step 2 to step 3, I received two error messages:

"Error reading location data" and "Object reference not set to an instance of an object". How can I fix both of these?

I initially had a Canadian location selected as the base location and changed it to a US location (I saw this in another forum question) and still got the same message.
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Joined: Wed Sep 18, 2019 10:26 am

Re: International Error Messages

Post by James.Kruegler » Fri Jun 26, 2020 11:48 am

Hi farkasal,

To start, I would like to to clarify your US reference location. Although there is an Erie County in NY, I am struggling to find a NY city named Erie. Is it possible you meant Erie, PA? There is an Erie Intl. Airport here as well.

Your first error message indicates Hydro was attempting to access location data for somewhere outside the US, even after you changed your location to Erie. The second error message is more generic, but generally it suggests the model was calling upon some kind of variable that it expected was already established, but in fact was not.

It is possible both of these errors would be cleared up if you started over with a new project and .iHydro file, this time selecting Erie as your location from the beginning. If the errors persist, I would suggest using the Sample project for troubleshooting by slowly adding elements of your project, proceeding through all four Hydro steps, and noting when/if errors appear. For example, you could try this sequence after opening up the Sample Project:

1. Run the Sample project without any changes
2. Try #1, but now with your DEM
3. Try #2, but now also with your location and weather station
4. Try #3, but now also with your simulation period (you will be prompted to re-select your weather station so Hydro loads the correct weather data)
5. Try #4, now also with any other values unique to your project (land cover, hydrologic parameters, etc.)

If you make it through this sequence without any errors, at the very least you will have a project that runs the simulation you were looking for.
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