Question

Intersect Rivers x Contour Elevation

  • 31 March 2015
  • 5 replies
  • 2 views

hello ' m trying to make generate a point shapefile in places where the river crosses two or more times the same elevation contour 

5 replies

Badge +3
SpatialRelator with River as requestor and contours as supplier.

 

Explode "_related_candidates" and then rebuild list with Contour_ID as GroupBy.

 

Count elements of list or use a listhistogrammer. Build list for counts>1 with river_ID as GroupBy.

 

This gives the contours crossed more then once per river.

 

 

 

 
Userlevel 2
Badge +17
Hi,

 

 

If the goal is to generate point features, the following procedure may be a solution.

 

Assuming that the river lines have an attribute called "_river_name" and the contour lines have "_elevation" that stores the elevation value.

 

(1) Send all river and contour lines to a LineOnLineOverlayer together.

 

List Name: _list

 

(2) Send the resulting intersection points to a ListExploder.

 

List Attribute: _list{}

 

Accumulation Mode: Only Use Incoming List  <= important

 

(3) Send the output points to a Matcher.

 

Match Geometry: 2D

 

(4) Send the points that will be output from the SingleMatched port of the Matcher to a StatisticsCalculater.

 

Group By: _river_name, _elevation

 

Attributes to Analyze: <any>

 

Total Count Attribute: _count

 

 

The points that will be output from the Complete port of the StatisticsCalculator are the intersections between rivers and contour lines. The points will have "_river_name", "_elevation", and "_count".

 

The "_count" stores the number of intersection points between the river and the contour line.

 

 

Takashi
Badge
Hi,

 

 

Here's a sample solution using Intersector.

 

https://drive.google.com/file/d/0B9AOve1u6FfELWhoTkJfTGQ1TTg/view?usp=sharing

 

 

Regards,

 

Pierre
Userlevel 2
Badge +17
sorry, my previous solution was too redundant.

 

It's not necessary to use the ListExploder and the Matcher.

 

Just send the intersection points that are output from the Point port of the LineOnLineOverlayer to the StatisticsCalculator. 
Badge +3
After relating you have the objects related, enough info to create the interstionpoints.

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