<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META content="text/html; charset=us-ascii" http-equiv=Content-Type>
<META name=GENERATOR content="MSHTML 11.00.9600.19597"></HEAD>
<BODY>
<DIV><FONT color=#000080 size=2 face=Arial><SPAN class=706372501-31032020>Hi
all,</SPAN></FONT></DIV>
<DIV><FONT color=#000080 size=2 face=Arial><SPAN
class=706372501-31032020></SPAN></FONT> </DIV>
<DIV><FONT size=2><FONT face=Arial><FONT color=#000080><SPAN
class=706372501-31032020>I am working on a PostGIS polygon (parcel) layer where
I need to merge adjacent parcels of the same land use.In between the parcels
there are roads (that I would want to get rid of) by merging them to
the adjacent land use area they share the longest common boundary with.
</SPAN></FONT></FONT></FONT></DIV>
<DIV><FONT size=2><FONT face=Arial><FONT color=#000080><SPAN
class=706372501-31032020></SPAN></FONT></FONT></FONT> </DIV>
<DIV><FONT size=2><FONT face=Arial><FONT color=#000080><SPAN
class=706372501-31032020>One complication of this is that </SPAN>t<SPAN
class=706372501-31032020>he roads </SPAN><SPAN class=706372501-31032020>often
stretch past the edges of neighboring parcels making in difficult to merge them
(in a query) to the land use without producing a long
(former road) area 'sticking' out. The following graphs
show what I am trying to accomplish :</SPAN></FONT></FONT></FONT></DIV>
<DIV><FONT color=#000080 size=2 face=Arial><SPAN class=706372501-31032020>Graph
1 ( <A
href="https://github.com/karstenv/postgis_processing/blob/master/parcel_layer1.png">https://github.com/karstenv/postgis_processing/blob/master/parcel_layer1.png</A> )
shows a typical parcel example with land uses 1 (yellow), 2 (blue)
and 3 (orange) and a road in between in beige (light yellow).
Adjacent parcels can be merged alter for the three land uses when they are
touching. However, first I would like to split the road ( in order
to later merge that area their adjacent land use as
well).</SPAN></FONT></DIV>
<DIV><FONT color=#000080 size=2 face=Arial><SPAN
class=706372501-31032020></SPAN></FONT> </DIV>
<DIV><FONT color=#000080 size=2 face=Arial><SPAN class=706372501-31032020>My
question here is about the splitting (not the merging part of this work flow):
<BR>Does anyone have any hints /ideas how one can extend (all)
the parcel boundaries (or any way to create a lines similar to a
line between points 1 and 2) in order to cut roads so that I could merge
them in a meaningful way to the adjacent respective land uses ( see as an
example of such a line in red line in graph 2: <A
href="https://github.com/karstenv/postgis_processing/blob/master/parcel_layer2.png">https://github.com/karstenv/postgis_processing/blob/master/parcel_layer2.png</A> )
? <BR>This split is necessary as otherwise I could still merge the road to
either land use but it would 'stick' as a long shape way beyond the actual land
use area . The ideal final result (after cutting and then merging) I am after
should like in graph 3 ( <A
href="https://github.com/karstenv/postgis_processing/blob/master/parcel_layer3.png">https://github.com/karstenv/postgis_processing/blob/master/parcel_layer3.png</A> ).</SPAN></FONT></DIV>
<DIV><SPAN style="FONT-SIZE: 11pt; FONT-FAMILY: 'Verdana','sans-serif'"><SPAN
class=706372501-31032020><BR><FONT color=#000080 size=2
face=Arial>Cheers</FONT></SPAN></SPAN></DIV>
<DIV><SPAN style="FONT-SIZE: 11pt; FONT-FAMILY: 'Verdana','sans-serif'"><SPAN
class=706372501-31032020></SPAN><FONT color=#000080 size=2
face=Arial>Karsten</FONT> </SPAN></DIV></BODY></HTML>