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I'm using ArcGIS 10.2 Desktop and I need to trace downstream on a river network from a Discharge point to another point where the river intersects polygons of interest. The distance from each discharge point to the nearest point of intersection (with the polygon of interest) is an important element that I need to know.

I am using a geometric network and my question is how do I go about doing this process? I've looked at flags and barriers but distance doesn't seem to be included when looking at geometric networks as opposed to Network Datasets such as roads etc. I'm not sure how to mark the first point of interaction a river has with the area of interest. I've been able to dissolve my geometric layer so that I'm left with just the sections of river concerned with each discharge point.

I need to be able to say that from Discharge Point A, here is a list (say 5km's downstream of it) of all the receptors (my areas of interest which are either lines or polygons) it interacts with.

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    Are you asking can a geometric network be used for downstream tracing? If so, then yes... What you have written is more of a statement rather than a question, so not sure what you are asking? – Hornbydd Jul 1 '15 at 16:02
  • I'm really sorry for wording the question incorrectly! Yes I am using a geometric network and my question is how do I go about doing this process? I've looked at flags and barriers but distance doesn't seem to be included when looking at geometric networks as opposed to Network Datasets such as roads etc. I'm not sure how to mark the first point of interaction a river has with the area of interest. I've been able to dissolve my geometric layer so that I'm left with just the sections of river concerned with each discharge point. – Sheftee Jul 6 '15 at 11:03
  • I need to be able to say that from Discharge Point A, here is a list (say 5km's downstream of it) of all the receptors (my areas of interest which are either lines or polygons) it interacts with. I'm sorry if my explanation is a bit confusing! – Sheftee Jul 6 '15 at 11:07
  • I think gis SE etiquette is to amend your original question with the extra information you have just given in your comments. This will attract a better response and remove the unclear tag on your question. – Hornbydd Jul 6 '15 at 11:41
  • Okay I've edited the original question now too, thanks for letting me know, I appreciate it. – Sheftee Jul 6 '15 at 12:49
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First you have to do a trace downstream from the discharge point. Make sure the return result of the trace is set to be a selection set. After this trace you have a set of selected river features.

Then you must convert your polygon layer to a line layer using "Polygon To Line" tool.

Then you have to use the Intersect tool to intersect the selected rivers with your linear layer derived from your polygon layer (polygon of interest). By doing so you will get a point dataset which is the intersections river with those polygons.

Finally measure the distance between the intersection point and the discharge point either using measure tool or a geoprocessing tool.

If you want to do this processing in batch mode, then you have to create model and link all the tools together.

  • Thank you so much for you reply, it was very helpful. (I had lost my log in details for this website so my apologies for the extremely late reply). Could I ask is there any way to automate the measuring aspect of this task? For instance I'd like to set up a model linking all of the tools as you suggested however I need a way to input differing distances so from 500m, 1km, 1.5km, 2km etc. instead of manually measuring. Thanks again. – Sheftee Apr 10 '18 at 13:21

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