HEC-Georas overflow velocity mapping

[do]

Hi everybody,
I am studying hec-georas and i'm trying to run baxter river example
(one of the provided data set example)

i'm capable to import data in arcgis  and calculate inundation mapping,
but when i try to do the velocity mapping i receive an error:

computing xs transition lines and grid
overflow of an arithmetic operation

i am using argsi 10.1, hec georas 10.1 hec ras 4.1
on windows 7 x64

any suggest?
thanks for help

Dario

[JanaHnilickova]

Hey Dario!

I have the same error. Did you find any way how to solve it?

Thanks,

Jana

[JorgeHinojosa]

Hi! I know this thread is six months old but I´m having the same problem.

I am using ArcGIS 10.1, Hec-GeoRAS 10.1, after having successfully imported HEC-RAS data and drawn the water surface when trying the "Velocity Mapping" tool "Overflow of an arithmetic operation" error appears. I'm attaching a screenshot of the error.

[ATTACH=CONFIG]32111[/ATTACH]

Any one knows why is this happening?

Thx

Lucrecio

PS: For those of you in a hurry (like me) you can interpolate a raster from the velocity points layer (Using "Natural Neighbor" tool for example) and then clip it with the water surface layer. This is not correct but it will give you some idea of the velocity of the flow between cross-sections...

[JanaHnilickova]

Hey! If you use normaly as a decimal separator "," and now because of HEC-RAS you use "." then I had the same problem! After spending a lot of time I realized that when I set in my local computer settings the decimal separator as a "," before loading the velocity maps and also in the XML file I change manualy through the text editor the decimal separators from "." to "," then it works!!! just be carefull that in the first line of the XML file there must be for example like it was in my case  <?xml version="1.0"?> but with decimal separator "." . the other lines should have ","

let me know how it works...

[JorgeHinojosa]

Hi xhnij800 (or Jana?),

You where right. It is a problem with the decimal separator. It took me a while to figure out your explanation but it finally worked. In case other users have the same problem I´m going to detail the steps I took.

I am from Spain and here the decimal separator is the "," When using HEC-RAS we have to change that setting in the computer. After finishing the analysis in HEC-RAS, I generated the .sdf file [example.sdf] Then I:

1. Changed the OS decimal separator to ","


2. Opened ArcMap and converted the example.sdf to example.xml using HEC-GeoRAS


3. Layer setup, Import RAS data, Inundation Mapping (Water surface and Floodplain) and clicked on Velocity Mapping.


4. The error appears but this time click on Continue, another message appears, leave ArcMap and browse to the folder where the analysis files are saved.


5. There will be four .xml files: Parameters.xml, Parameters_P001.xml, Floodplains.xml and a copy of the example.xml file used to import RAS data.


6. With a text editor open Floodplains.xml and example.xml and replace all the "." with "," Be aware that the heading of the file must be <?xml version="1.0"?>


7. Go back to ArcMap and continue with the velocity mapping. This time it should work.

Hope this helps others.

Thank you xhnij800

[JanaHnilickova]

Hey Lucrecio,

sorry if the explanation wasn´t very clear 🙂 but I was writing in when I was in a hurry...anyway beleive me that to find out the solution took you much less time than it took me 😄

Jana