Questions tagged [dissolve]
To merge features based on specified attributes.
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Dissolving polygons in QGIS or GRASS to new polygons of defined population sizes
I have a shapefile with 3800 polygons representing the smallest administrative areas in Ireland. Many of these, in rural areas, have tiny populations, under 100 people. In urban areas, all would have ...
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Merging/Dissolving polygons by Common Attribute Field in QGIS?
I have joined corresponding Local Enterprise Partnerships table data into a polygon shapefile containing UK Local Authorities.
How do I Dissolve or Merge the the Local Authorities polygons by ...
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4
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Unsplit/Dissolve multiple touching lines in Stream Network using ArcGIS Desktop?
I am trying to dissolve multiple lines for stream networks into individual features. The dataset contains many stream networks so a complete dissolve of the whole dataset wont do as I would like to ...
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Joining lots of small polygons to form larger polygon using PostGIS?
I have the following layer using SRID 27700 in postgis:
It's every administrative region in the UK, and (as you can see from the colour grouping) each of them has a text field specifying the county ...
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1
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Displaying categorised data using QGIS [closed]
I am using QGIS 2.16.
I have a database of 100 entries which has been categorised using a column of data that has 20 categories which essentially breaks up my map into 20 regions.
How do I create an ...
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3
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Is there a dissolve function in PostGIS other than st_union?
I'm looking for a function to dissolve shared boundaries between polygon features in a table. ST_UNION() almost does what I'm looking for, but it creates a multipolygon from all polygons in the layer ...
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2
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Styling polygon layer as dissolved with QGIS Geometry generator
The QGIS Geometry Generator seems like a nice way to keep data intact while allowing for some creative visualisations.
I have a layer of tesselating polygons that I would like to style as a continuous ...
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Dissolving overlapping polygons without common attribute in QGIS [duplicate]
In QGIS 3.20 I have clusters of overlapping polygons as shown in the image below:
My requirement is to dissolve each of these clusters into single polygons. While the "Dissolve" tool ...
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4
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Improving upon ArcGIS Buffer/Dissolve performance?
I'm wondering if anyone else has experienced significant performance penalties when using the ArcGIS buffer function with the 'dissolve' option on point features. My dataset is a shapefile of 260 ...
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2
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Batch Dissolve Polygons based on Attributes in QGIS or FWTools
I was wondering if anyone can help with batching a dissolve. I have a few hundred polygon shapefiles that I want to dissolve based on an attribute. I would like to do this in QGIS or FWTools.
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Merging adjacent polygons in shapefile that has been split at tile boundaries?
I'm currently using building data from the Ordnance Survey Vectormap District and I've noticed that a lot of building polygons are split in 2 because of the way the OS split up the shapefile.
This is ...
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2
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Dissolve polygons in QGIS (GEOS) with tolerance
I have a polygon vector layer representing the area inundated in a flood. The layer has been produced in a such a way that some of the areas are composed of multiple smaller touching polygons (see ...
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Cleaning large Shapefile using v.clean in order to dissolve features?
I'm having real problems cleaning up and reducing the size of a Shapefile which is published by the UK's Environment Agency.
It shows the extents of the LiDAR open data they publish: each polygon is ...
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2
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Cleaning polygon after using dissolve to repair geometry in QGIS?
I'm trying to obtain the boundaries of shapefile, thus to clean the inside as a matter of speaking. While I had expected that dissolve while get me a proper polygon, unfortunately it still has some ...
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geopandas dissolve overlapping polygons
Goal is to group polygon (1,2,4) and polygon (3) based on overlap. All polygons are part of the same shapefile layer.
In ArcMap I can simply do dissolve and uncheck Create multipart features.
...
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Selecting the longest connected lines from PostGIS ST_ApproximateMedialAxis
I used PostGIS ST_ApproximateMedialAxis to transform polygons representing mountain ranges into a series of lines. Now, I'd like to select only the "longest" line segment for each group, so that I ...
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Merging adjacent lines in QGIS
In QGIS, I want to merge features lines that same attribute value and are adjacent. What characterizes a line to be adjacent to another is the final vertex of a line to be coincident with the initial ...
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Merging lines with same name and intersect each other?
I have shp file with 50k lines (roads).
Many roads have same name like 'high road' . some of them are the same road (they intersect each other) and some are located in different places of the city.
I ...
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5
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Why is the Dissolve Tool not working?
I'm still having trouble with the dissolve tool and I've tried all of the solutions offered here including moving the process from the background and repairing the geography. I've also tried amending ...
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QChainage doesn't place points evenly along dissolved lines
I am trying to add mile markers to interstate centerline data. I've tried both the native dissolve tool (which freezes QGis) and SAGA line dissolve to create one continuous line. When I run the ...
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ArcGIS Desktop tool that does for records in a table what "Dissolve" does for features?
I have a data table that I need to trim down, merging records which have the same value in an ID field and performing a couple math operations on various other fields (summing, averaging). The ...
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Deleting 'garbage' nodes after polygon dissolve [duplicate]
I work with QGIS 2.10.1 on Windows 7 (x64). I have dissolved polygons from an attribute value and the polygons geometries being not perfectly joined together, I get some 'garbage' nodes I need to ...
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PostGIS Dissolve/Union close polygons
I have approximately 1 million polygons that have been split by lines. However, this has caused one half of a polygon to be separated by approximately 50cm from its other half.
After doing a lot of ...
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Dissolving shapefile but retaining a list of original attribute value in QGIS
How can I dissolve a polygon layer in QGIS based on a single attribute but keep all (or some) other attributes at the same time? This is how I want to retain fields:
There are at least two fields I ...
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Dissolving shapefile but retain attribute fields using ArcGIS Desktop?
Is there any way to dissolve shapefile but keep attributes fields in the same time?
This is how I want to retain fields:
There are two fields I want to conserve in a shapefile. The first column is ...
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2
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Combining adjacent polygons sharing similar trait into single polygon using ArcGIS Desktop?
I have a large dataset of habitat classes which I have further simplified down into my own unique classes.
However, it resulted in there being habitats adjacent to each other with the same forest ...
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8
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4
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Dissolve in ArcMap gives ERROR 999999
The Dissolve tool is not working for me when I use ArcGIS Desktop 10 to dissolve a shapefile.
It says:
ERROR 999999: Error executing function.
It works perfectly when I use version 9.3.
Any help?
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answer
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Dissolve only overlapping polygons in R
I have a spatialpolygons-dataframe in R that contains overlapping polygon features. I would like to dissolve only the overlapping features into separate polygon features (one feature per par of ...
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Dissolving polygons fails on computers with small amount of RAM
When I'm trying to dissolve a polygon through an arcpy script the operation fails with the 999999 error on computers with small amount of RAM [~3 GB] (known issue).
Unfortunately neither:
arcpy....
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"Singleparts to multipart" vs. "Dissolve"
It seems to me that the vector tools "Singleparts to multipart" and "Dissolve" do the same things. Can someone confirm this, please? Or do I overlook something?
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Merging polygons only if three or more are on top of each other in QGIS
I am working on a layer with many polygons (circles). I would like to create a polygon containing only the areas where 3 or more circles overlap (in my example there would be only 1 area in the east). ...
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1
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Dissolve (merge) polygons QGIS based on attribute values only when are adjacent
I am a fairly new user of QGIS having a question regarding dissolve functionality.
I am working with the NUTS-2 shapefiles provided by EU, which I have imported in QGIS. I have created a new layer ...
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1
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Dissolving reprojected features split into two parts by international dateline (180 degrees) in QGIS
I am trying to view the World EEZ polygon from Marine Regions.org, but centered on the Pacific Ocean.
To centre the EEZ map on the Pacific ocean I followed these steps. The custom CRS from this ...
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votes
3
answers
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Combining rows in attribute table using ArcMap
I have an attribute table with three columns "FID" "Shape" and "Class"
All records have the same shape (polygon). Each record has its own FID. I have three classes, "...
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Concatenate fields on a Dissolve
I have a feature class that that I would like to dissolve. Upon the dissolve, I would like to concatenate a comment field, which is a text field. How can I do this? Conceptual idea below:
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Dissolving line segments in QGIS if they touch and fall within same class?
I have line segments that have the following 3 attributes (Class, start_point, end_point).
I would like to merge/dissolve line segments that fall within the same class if they intersect (touch).
i.e. ...
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3
votes
1
answer
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QGIS 2.4.0: dissolve tool renders artifacts / errors
The dissolve tool (vector>geoprocessing tools>dissolve) renders some artifacts on shapes with high number of polygons. I’m using a shapefile with 3222 polygons and I’m trying to dissolve it using the ...
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1
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Using shapely unary_union() function to union polylines in ArcGIS Pro not behaving
I am developing an ArcGIS Pro 3.1.0 toolbox (atbx) and one of the tools I'm creating is selecting a set of polylines (which are river centrelines) and merging them into a single long polyline. ...
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1
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How to dissolve naturalearth vectordata with gdal?
I'm trying to use the workflow described by @aflaciano at How to render area that crosses 180°? I did the following:
downloaded and installed gdal-111-1600-x64-core.msi from here on my Windows 7 ...
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Merging adjacent polygons to one which sum of attribute values of adjacent ones is between 1000 and 2000?
I have a huge number of polygons that contain attribute field that represent number of offices inside each polygon. Now I want to merge all adjacent polygons which count (sum) of offices values is ...
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Dissolving not based on attribute in GeoPandas
I would like to dissolve a shapefile regardless of attribute content using geopandas. The regular dissolve can be accomplished with something like this:
import geopandas
all = geopandas.read_file(r'...
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How to achieve equivalent to Dissolve from ArcGIS for Desktop using ST_Union?
I am trying to achieve an equivalent to the Dissolve tool from ArcGIS for Desktop using ST_Union from PostGIS but it seems I am not getting expected result.
I have one table which has certain ...
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Merging adjacent polygons using ArcGIS Desktop?
I want to use ArcGIS Desktop to merge adjacent polygons with each other.
There is no common field between the polygons and hence the Dissolve tool is not the ideal solution. The polygons that I want ...
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How to dissolve overlapping polygons?
I have a query regarding the dissolving of polygon features in ArcGIS 9.3. I only have the bare-bones license and an extremely basic knowledge of VB.
I have a large shapefile with around 4500 polygons ...
user1762
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votes
1
answer
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Dissolve overlapping polygons according to percent overlap using PostGIS?
I have a shapefile with convex hull polygons, all in the same layer/shapefile. Some of the polygons overlap (not duplicate polygons). I would like to dissolve/union the polygons which overlap with ...
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How to create point labels from midpoints of road polylines in QGIS?
I have a road polyline layer (singlepart ie has several features per road, grouped by an id field), and i want to (after merging the parts) find the mid point of the resulting lines. This is for roads ...
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Removing lines from inside polygon in QGIS
Through a "dissolve" process in QGIS, I achieved some defective polygons generated after dissolve process that have some fails, like these in the screenshot:
Is there any automatic process I can make ...
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Using Dissolve and Multipart to Singlepart in QGIS?
I started with a network of polylines.
In QGIS I used dissolve to 'merge' all lines according to an attribute value. This did exactly that, but included non-connecting lines which I don't want. I ...
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2
answers
1k
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Rendering polygons ordered by size in QGIS
How can I merge shapefiles in a special order in QGIS?
What I have and what I need to be merged in that order:
What happens when using merge by MMQGIS:
As u can see not usable at all. Attributes are ...
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1
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Dissolving featurecollection in google earth engine?
Here is the link to my GEE code:
https://code.earthengine.google.com/99b494aacf00df398e0e710ec02c13e8
Here is the code (DMDP is an asset and to see it please follow the link):
Map.centerObject(...
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