Extract Topology


The logic of your river network or "topology" needs to be extracted and stored in data structures that the algorithms that RivEX uses can read. The topology information is written to a sub-folder in the workspace.


This tool is very easy to use, simply go to RivEX Toolbox > Prepare River Network > Extract Network Topology and write to Workspace.  Select the river network which you would have typically loaded into the active map and click Run.


Depending on the size of the network RivEX can take a few minutes to build the topological information it needs.  As an example, a small network (e.g. 10,000 lines) would take less than half a minute to read and write the topology.


This is a tool you will run possibly many times as you resolve any errors you find in the network when using the quality control tools. Multiple runs of this tool and attribution will lead to redundancy in fields and its good practise to remove these. The extract topology tool has an optional parameter for you to select fields that will be deleted before the main extraction routines. This is a convenient way of keeping only the fields you need in the network.


Having extracted topology you are now ready to run the quality control tools.