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In ArcMap (ArcGis 10.1) I'm trying to find a way to fill a polygon with a symbol in different orientations. Is it possible?
Example: look at the red semicircles, I would like to do something like that.
In case it's not: is it possible to associate the rotation of a polygon feature's fill to value in Attribute Table like I can do for points?
Example: rotation of a point feature depending on a column in Attribute Table. Is it possibile to do the same for polygons?
Yes, it's possible to fill a polygon with symbols on an angle. It cannot be done with Marker symbol type, only with Picture symbol type.
Even with Picture it applies to the symbol as a whole, meaning you'd need to symbolize on your rotation field and set each one to the angle you want - the angle cannot be read automatically from a field (so far as I know).
The most interesting ideas I found were at http://mappingcenter.esri.com/index.cfm?fa=ask.answers&q=878
That's not so easy as a fill symbol--you could convert the fill symbols of your landslide layer to representations and then individually rotate the arrow markers within those fill symbols (that might get really tedious).
If you've got an elevation dataset you could do the following:
Use the Aspect tool in either the Spatial or 3D Analyst extensions. That will produce an output raster with values that represent downhill azimuths. (This assumes that gravity is in play in the sense that flow movement is being derived from an after the fact elevation dataset where downhill movement is assumed to be the path of least resistance.)
The idea here is to produce a point dataset from the Aspect raster. But, depending on your map scale you will likely need to reduce the resolution of the Aspect raster before using the Raster to Point tool. To do that use the Aggregate tool in the Spatial Anaylst.
Once you have an acceptable outcome from the Raster to Point tool for your map scale (density of points is not too dense or too sparse), then I would add a Short Integer field to the point dataset to have a value of 0 for outside the landslide areas, or 1 for inside the landslide areas. First calculate all values to 0, and then use Select by Location to select the points inside your landslide areas and calculate that field's value to 1. That will allow you optionally include (via definition query) or symbolize differently the points outside the landslide areas.
This will result in a more regularly spaced look, like the bottommost of your scans.
Another option, particularly, if you want a more hand rendered look (like the uppermost of your attached scans), you could hand-digitize flow lines and then use cartographic representations on those. We explain how to set up that kind of symbology on the Mapping Center blog when talking about symbolizing one-way streets. You could control the spacing and offsets of each flowline's symbol, creating a similarly expressive effect as shown in your attachments.
Use quantities/graduated colors.
Its rather tedious work but it should work.
As a result you should get a pretty good approximation of your map.
