Hi,
I am importing pipe from a shapefile and pipes are crossing each other without being connected. The source file is obviously not created to that effect and was probably only for visual purposes.
Inside WaterGEMS there is a function where one can "Split" the pipe and connect it to nodes.
Is there a way in which model builder can do these automatically or does this have to be corrected in the source file?
Regards,
Rossouw
The best long term solution is to fix the GIS. Otherwise this problem will keep repeating itself. The basic law of modeling is "Garbage In - Garbage Out". If the GIS department is not getting connectivity right. they are pretty worthless.
A lot depends on how many of these intersections are wrong. If it's only few, you can fix them in the model and tell the GIS team to fix them in the GIS. If there are thousands, you need to fire the GIS supervisor. Building a GIS without thinking about how you will the information is a serious offense. To find such problems, use Analysis > Navigator > Network Review > Crossing Pipes. It will give you a complete list of intersections you need to review.
Hello Rossouw,
Batch pipe split tool is used to fix nodes that overlay a pipe instead of connecting to it, which happens in case of Modelbuilder data import.
ModelBuilder will not split pipes that happen to intersect. ModelBuilder will create a junction at the end of the pipe that touches the other pipe, but will not split it.
You can either use Batch pipe split tool in such cases or if possible you can correct the source file to make sure to snap all the lines(pipes) to end points. If you snap the lines to mid-points when Modelbuilder builds your network it will create a junction on the end point of a pipe that is attached to the mid-point of the other pipe, but the pipe won't be attached.
Using batch pipe split to fix nodes that overlay a pipe instead of connecting to it
Preparing GIS data for use in the hydraulics and hydrology products
Sushma Choure
Bentley Technical Suppport
Answer Verified By: Rossouw Boshoff
Thanks, That makes sense.
Hi Tom, Haha yes I agree, in this case, it is second hand CAD layout drawings (which we converted to GIS hoping to be more forgiving in modelbuilder) . I suppose the intended purpose was not for modelbuilding but the drawing was not created with good drawing standards nonetheless.
In my experience it is more important for the WaterGems model to be correct than the GIS. With this in mind, import the initial GIS shapefiles into WaterGems, then fix all the connectivity issues within WaterGems (this can be a long, tedious process - ask me how I know). This is the only way I know of to assure that your model is properly connected.
After you get your model piping and valves all connected properly, export these files back to shapefile format and give them to the GIS department and tell them to use these.
For future revisions to the piping system I have found that it is better to make the changes within WaterGems (I use WaterCad, but Gems is a superset of Cad), then export these to shapefiles, then give them to the GIS dept.
Doing it this way assures that you always have a properly connected model that will run. It's more work for you, but in the long run you have more confidence that your model is topologically correct.
And the GIS people will probably thank you.