topic Re: Statistics from Raster grids to Polyline shape file in ArcGIS Spatial Analyst Questions

Statistics from Raster grids to Polyline shape file

PawanThapa — Fri, 16 Jun 2017 17:00:20 GMT

Dear GIS experts,

I would be very thankful to receive your help/support/suggestion for solving my following problem. I'm using ArcGIS 10.1 with Spatial Analyst and 3D Analyst(no ArcInfo license) and Arcview 3x (still for many plusses).

First, I have a river network - a shape file with about 53,000 polylines for each tributaries and main river stretches over a big region. Hence at confluence point/vertex it is the end point of many poly lines upstream and starting point for one polyline downstream.

Then, I have two raster files- i) The 30m X 30m River netwok cells (actually the same shape file in grid) with each cell having the elevation value. ii) The 30m X 30m River netwok cells (actually the same shape file in grid) with each cell having the flow value.

Now what I need is -- for each polyline (river tributary) -- the product of the flow (at mid-point of the line) and elevation-difference (difference of elevation between starting and end point of the line).

I hope that I could make this my simple problem quite clear. What would be your suggestion to solve this?

Thanking you a lot!!

Re: Statistics from Raster grids to Polyline shape file

DanPatterson_Retired — Sat, 17 Jun 2017 12:11:09 GMT

Pawan

From Add Geometry Attributes you can add the coordinates of the start, end and midpoint of polyline files. From these data, you can create event layer(s) to create point data. This will allow you to collect the necessary elevation data from the DEM. Once collected, then you may have to join it back to the original lines to complete your calculations. This process is limited by your current arcmap version and license level.

Re: Statistics from Raster grids to Polyline shape file

PawanThapa — Mon, 19 Jun 2017 09:42:07 GMT

Dear Dan,

Thank you for your response/suggestion. It looksl ike there is no "Add Geometry Attributes" tool in ArcGIS 10.1 version, right? If so, isn't there any other way around that can be done with the version that I have?

Thanking you a lot!

Re: Statistics from Raster grids to Polyline shape file

DanPatterson_Retired — Mon, 19 Jun 2017 11:03:36 GMT

You can add the appropriate fields manually and do the calculations your self using the Calculate Geometry in the field calculator. For example, you can get the x and y coordinate of the first and last points of a polyline etc.

Re: Statistics from Raster grids to Polyline shape file

PawanThapa — Tue, 20 Jun 2017 08:02:21 GMT

Dear Dan,

Thank you for the suggestion. May I ask one more question.

From the 30m x 30m raster of the river network, I have some hot spots i.e. few consecutive river cells at different locations. On the other hand, I have 5 rasters (same as river network) having unique value in each of these rasters.

Now, what I need is the value of these 5 rasters at the location of the hot-spots (the identified few consecutive river cells) in a tabular form. i.e. a table which gives me the location of these hot spot cells (even one central location is ok) and the coressposnig value at these locations from the 5 rasters.

How can I do this? Your suggestion is highly appreciated.

Many Thanks!

Re: Statistics from Raster grids to Polyline shape file

DanPatterson_Retired — Tue, 20 Jun 2017 09:01:56 GMT

You have the key words... Extract Values to Points

We are beginning to stray some distance from the original question. It is best to close this off, if answered, and begin a new train of questioning in another thread.