# Calculating distance between points within river network using ArcGIS Pro

I have a shapefile of a river, and the coordinates of several points. I am interested in calculating the pairwise distance between each of those points along the river network.

Is there any way to do this with near table or another tool using ArcGIS Pro?

Edit: I have arcGis Pro 2.7.26828. I have tried near table and the Euclidian Distance tool. I do not have rivex.

• What have you tried? It certainly wouldn't be by a Near table (which is simple Cartesian distance). Also, please Edit to specify the exact release of Pro, and the extension you have available. Feb 23, 2021 at 23:32
• If you have access to ArcMap consider RivEX with tools specific to answering river related questions? Feb 24, 2021 at 10:30

Update: An alternative suggestion worth trying is by creating an OD Cost Matrix from your river dataset and point features. For this you do need access to the network analyst extension. This could provide you with the pairwise distance comparison you are looking for. In this case;

• Your river shapefile should be a turned into a network, by importing it into a geodatabase and network dataset
• build the network and add it to ArcGIS Pro.
• create an OD Cost Matrix analysis using the created network in ArcGIS Pro (under analysis and route tab).
• After creating the Cost Matrix, insert the point features both as Origin as well as Destination features.
• Solve/calculate the OD Cost Matrix, and the output table can be exported to Excel or any other spreadsheet tool to create a pairwise distance matrix.

Originally posted this answer, but understood later it is wrong for OP's question. It would only work if points would be along straight lines/rivers. Leaving it here as it is still useful for others to create pairwise line segments:

I would do the following:

1. If the points are already on the river (and the river is a polyline feature):
• use the "dissolve" tool to make sure that the river is merged into 1 line feature.
• Next, use the "split line at Point tool" to create independent features that are corresponding with the points. The shape length of the newly created river features determines the distance between points in meters.
• Just a tip, to make sure that the split line at point tool works as intended, I often find it easy to set a small search radius (for example 5 meters).
1. If the points are not already on the river:
• Use the Near tool to calculate the closest point of each point to the river. The input features would be the points and the near feature is the river. - Next, you can use the table to table tool to copy the point layer to a new table.
• Convert the table to points, using the make XY event layer tool (insert Near X and Near Y as respective coordinates). These places represent the closest points on the river.
• With the newly created feature layer, you would be able to calculate pairwise segments between two points on the river, using the steps I mentioned above in suggestion 1.