Plot GIS reach bound??

[hitch24]

Dear HecRas community

I am using HecRas first time with geometry data out of GIS data. Everything is doing fine for me, except the GIS profile reach bounds.
First question: what is the profile reach bound? Watersurface? Energygrade? the width of the crossections?
When I read in the manual, I think it should be the width of the water surface, that is also the area I need for my actual project.
But when I calculate some different flows (from really low flow to high floods) the profile reach bounds to the different flows are always the same!! actually always the same width as the crossections have. So I assume, it is not the boundary to the water surface, it is rather the boundary of the geometry. Or am I wrong?
But if it is so, why I can choose in the “Plot GIS profile reach bound” menu different flows?
Is this a bug?
I really need the georeferenced boundarys of the water surface.

Thank you very much

Best regards

Chris

P.S. I have attached a printscreen from the profile bounds for a low flow and a corresponding crossection…

[xerxe2005]

Dear Chris,

I am also interrested in profile reach bounds.

I am also using not GIS data. I placed a 1:25000 map and placed the river reach on it. So I wanted to see at the end of the steady flow simulation, the reach bounds on my map.

I believe that the bounds reffer to water surface resulted on every cross section from the simulated flow.

But I am eager to know if there is anybody who has worked enough with profile reach bounds and can clarify the matter for us.



Isabela

[hitch24]

Hi Isabela

Thanks for your answer.
Now I am using GIS data and the profile bounds are still the same.
Are you sure the bounds refer to water surface?
When I measure the width of the bounds in a specific crossection and compare with the width of the watersurface in the crossection (the crossection in the attachment in my previous post) i get 29 meters bounds and 5m!!! in the crossection. The width of the crossection is exactly 29 meters.
But I need the width of the watersurface in the crossections georeferenced.

Any other suggestions?

Thank you

Greetz

Christian

[xerxe2005]

This is my map.
I have to addmit that I would very much like to understand about these reach bounds and how much can I count on their precision.
I am also interrested in the water suface levels.


xerxe2005@yahoo.co.uk

[xerxe2005]

This is my map.
I have to addmit that I would very much like to understand about these reach bounds and how much can I count on their precision.
I am also interrested in the water suface levels.


xerxe2005@yahoo.co.uk

[hitch24]

Hi Isabela

I found a solution for our problem. The profile bounds are the limits of the model or equal to the beginning and the end from the cross sections. For the water surface you have to export the results (after performing the steady simulation) in the GIS data format (under “file” and then “export GIS data”). The generated GIS file is a *.sdf file. This is a text format file which you can read with Hec-GeoRas into ArcGIS or if you don’t use GIS you can open the file with an text editor. The file format is described in the user manual in the chapter “HecRas data exchange”. For each cross section the calculated water elevation and the water surface extents are defined:
.
.

CROSS-SECTION:
STREAM ID:Ach
REACH ID:Unter
STATION:39.89998
NODE NAME:
CUT LINE:
-34230.2188294 , 246187.0531007
-34036.7924305 , 246291.742593
REACH LENGTHS:25.11,25.15,25.17
BANK POSITIONS:0.59780,0.76039
LEVEE POSITIONS:
WATER ELEVATION:676.0265,676.4125
WATER SURFACE EXTENTS:
-34110.30, 246251.96, -34085.91, 246265.16
-34110.30, 246251.96, -34085.91, 246265.16
END:
.
.
Seasons greetings ;)

Chris

[tsairi]

just one correction: if you have a levee that is not overtopped in the selected profile, the reach bound will go through the levee point, not the XS end. i think it's just like the bounding polygons created by HEC-GeoRAS