Network Analyst with Linear Features

Question

I want to know a network distance from a river, lake, or pond. Is this possible with network analyst?

Thanks,

RamB · Answer

Your purpose for the analysis is not very clear. For me it seems it would be better to first collect the access/entry points to the water bodies. It is not possible to reach to a water body at any point along that body for various obvious reasons. Since you are looking into network analysis, it may be appropriate to measure distances to entry point to a lake (as a recreational area), to a river ( as a swimming area) or a canal (for a evening walk) etc. In such cases, using centroid may not be a right choice.

regards,

Melinda Morang · Answer

The Network Analyst tools require points as input.  To find the network distance from a lake or river, you would want to use the OD cost matrix solver, but you can't load a polygon or line feature class for Origins or Destinations.  They have to be points.  You can convert your polygons or lines to point features by finding the centroids of those features, by using the features' nodes, by finding the intersecting points of your streets features (if they intersect at all), or by manually digitizing river/lake access points along the roads.

NicoleHanson · Answer

I did a 5 mile buffer around each of the rivers and I could extract out the roads within that buffer, but I do not have a starting point from the river out. Do I need to create nodes along the rivers and then run network analyst for new services area (miles)?

OK, if I understand you, you already have a Network Dataset of roads.  Are you wanting to do this automatically, or manually?  I don't believe that you'll need to create nodes along the rivers, unless you want to automate it.  Manually, you can select points and solve for a route.  If you check the box to accumulate the attribute of the unit you want to know, it will tell you in the NA table once it's solved.