Questions tagged [dissolve]
To merge features based on specified attributes.
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Problems with dissolved shapefiles in Google Earth Engine
I created a single dissolved polygon shapefile out of a set of smaller polygons in ArcGIS and imported it into Google Earth Engine using geemap (Python API). I wanted to extract values from every ...
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FME Form (Desktop) - Dissolver Transformer Generates Redundant Remnants
I have line geometry that I buffered with 50 feet buffer. Now I need to dissolve common boundaries for overlapped polygons, to reduce the size of the file in general.
Source lines
Buffer
"...
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1
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st_union in R creates artifacts for global data
I load this polygon data in R which global coverage.
https://drive.google.com/file/d/1E-atD4ZhbaQ8Zxv93sFgk9l_atLtG8eJ/view?usp=drive_link
It looks like this:
In QGIS I can run the dissolve function ...
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How to dissolve links and split by other links
I am trying to aggregate road network segments by intersection using QGIS.
The blue route consists of 1000 links, and I want to aggregate this route into two segments.
Ex: first and second segments ...
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Dissolve function for selected polygons in a layer in QGIS 3.3
Im using QGIS 3.3 and am trying to dissolve selected polygons in a layer. In the dissolve tool I am unable to select ' selected features only'. Even if i manually select the polygons and run the ...
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73
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Dissolve multiple overlapping polygons into one polygon covering the extent for all such instances of overlapping polygons [closed]
I have a polygon layer in which some polygons are close to one another whereas some polygons are just alone and do not have other polygons in vicinity. So I created a 10 meter buffer, I want to keep ...
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Limiting administrative shapefile to less granular level using ArcGIS Pro
I am using an administrative shapefile of Jamaica in ArcGIS Pro. I have a number of attributes at varying levels of granularity. There are 14 Parishes, 65 "Constituencies", roughly 650 "...
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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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How to speed up processing time when using geopandas dissolve() function?
I have a geodataframe with 8000 rows based on the joining and intersection of two geodataframes. One contains 8000 points and the other 12 polygons. See below the code used to join these two ...
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Dissolve multiple polygons and keeping attributes
I am new to QGIS. I have vector data with many greenspaces in a city. I want to merge neigbouring polygons. I did this using dissolve which works fine (see below, brown before dissolve, green after).
...
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Creating virtual layer with extent of features from multiple layers in QGIS
I am trying to create an atlas that shows a series of plots (polygons) along with the access routes (line features). I need to vary the extent to show the entirety of each site along with the access ...
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Creating new layer with custom regions from states boundaries in QGIS
I am trying to create a map where I can combine a layer of states boundaries and one other with custom regions (Est/West) on QGIS.
So I have tried it in different ways (union, intersection, merge ...
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188
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Dissolving overlapping multipolygon geometries into new multipolygons and keeping non-overlapping features intact
I want to merge (multi)polygon geometries any time they overlap partly or fully. For example the Dissolve function in QGIS does not fit my case, since I also want to:
Include all parts of the ...
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ET_GPBufferPolylines doesn't work
i have a problem with an ET GeoWizard function or maybe just a basic syntax problem. I need to use a script that someome else wrote and which does things that i do not completely understand ...
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73
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How can I merge polygons in QGIS by attribute only if they are adjacent?
I have a grid with 100 cells classified in deciles of a pollutant concentration. I need to merge polygons from the same decile only if they are adjacent. Someone can help me by pointing me to a ...
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Making dissolve output as temporary layer using PyQGIS
I want to dissolve my layer by using this script and it is successful, however I want my dissolved layer to be temporary, and my input as any active layer. Can someone help me?
from qgis import ...
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Error using tool dissolve
I am using the Dissolve tool to merge layer. I get the following error (translated from german):
"Object (74207) has invalid geometry and was skipped. Please correct the geometry or change the ...
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1
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117
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Geometry generator - classify objects in QGIS [closed]
How can I display objects classified/dissolved by a specific attribute (f.e. dissolving polygons by state in the attributes), by using the Gemoetry Generator?
FID
name
state
1
Peter
BB
2
Ann
MV
3
...
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1
answer
212
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Google Earth Engine: time series chart of NDVI median value for different land cover classes (ESA/WORLDCOVER/200V)
I'm trying to extract a historical series of ndvi by land cover class (in particular Trees, Shrubland and Grassland), using the ESA collection (ESA/WORLDCOVER/200V) and clipping on my study area (...
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How to dissolve touching polylines [closed]
I want to dissolve some polylines clipped in a series of polygons, but since there are different polylines in the polygons, I cannot dissolve those with the attributes of polygons. For example in the ...
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258
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GeoPandas - can't write to file because field names are tuples (AttributeError)
I have created a new shapefile by dissolving and computing centroids from an existing shapefile. I have also aggregated values of the existing shapefile to use in the new shapefile. However, when I ...
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56
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ST_Union on multiple attributes gone bad
My server runs a daily script that takes polygons and lines from a set of *.000 cells, initiated by a cronjob.
When the first step (ogr2ogr) finished I have a layer that shows the original boundries ...
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144
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Creating single polygon from overlapping ones
I would like to reduce the vertex count of a map by simplifying the overlapping polygons on each layer.
The problem is the huge map size, a whole country 1GB .MAP that depicts a whole country with a ...
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Aggregate (dissolve) polygons leaving internal lines - R
After dissolving polygons, some of the internal lines remain. It seem to be a problem common also to ther softwares (ArcGis and Qgis at least). The dissolve result is this:
To dissolve using R, I'm ...
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106
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Count amount of buildings (floating polygons) within neighbourhoods
I want to count the amount of buildings within my neighbourhoods. The dissolve function doesn't work here because the buildings are not intersecting. Does someone have a tip on how I can do this?
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How to use the dissolve function to create multiple dissolved polygons at once
I had a village level shapefile. I selected villages using the "select by attribute" function to group them into electoral units (labelled as GP in attribute table)
I wanted to use the ...
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1
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256
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How to dissolve two geodataframes, using multiple columns to group by
I want to dissolve a dataframe grouped by two columns. However, in the documentation of the Dissolve function only one column is provided:
GeoDataFrame.dissolve(by=None, aggfunc='first', as_index=True,...
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179
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Preserving None values in GeoPandas when dissolving (by="id", aggfunc="first", as_index=False)
If I dissolve two geometries with the same id and tell to aggregate the other attributes from the first geometry, I get the attributes values from the second geometry because the first is None.
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119
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Seeking PostGIS equivalent of Geopandas dissolve method
Suppose I have a multiline string feature that I have brought into PostgreSQL as a table called nld_table with the following columns: 'SystemID', 'SystemName', 'Location', 'Accred', 'NLD_Access', '...
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406
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QGIS Calculate Percentage Area of Grid Cell
I'm trying to use QGIS to calculate the area of each grid cell that has been deforested.
To do so, I have tried the following:
Create Grid to create a 30km x 30km square grid
Add Deforestation Layer (...
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301
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Dissolve multiple layers
I want to dissolve over 100 shapefiles into same attributes to eliminate number of features. I was going to merge all the polygon first then dissolve it, but each layer has 10,000 to over 50,000 ...
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668
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Removing partly overlapping lines within the same feature
I have several layers which have features with several parts. These parts are often overlapping however and as a result the Length of the feature is often not correct when I calculate it using $length....
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2
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428
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Merging/Dissolving multiple layers in QGIS Virtual Layer
I have several polygon layers that I would like to merge and dissolve within a virtual layer in QGIS. So that any changes made to the individual layers will automatically update in the merged/...
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117
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Dissolve a intersection along id and keep only features of the bigger area QGIS
In QGIS I'm trying to dissolve an intersection and keep only the features with the bigger area [blue arrow] (compared with other features with same id [red box]). I'm interested in keeping other ...
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2
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482
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Combining non-contiguous polygons in ArcGIS Pro
I am trying to combine non-contiguous polygons that are close but not touching one shape. As if you were to draw a line around these five parts connecting them into one. Originally these were part of ...
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446
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How to merge the attributes of point shapefile in QGIS
I am trying to make wind map in QGIS, where I used vector point shapefile.
Because I have two different shapefiles I first merged them:
Then I Dissolve it where I choose two attributes to dissolved:
...
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96
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Dissolving features based on another layer in QGIS
I have two layers, see image below:
Yellow: the ground where people can build;
Red: existing buildings.
Create a shapefile of all grounds where >50% of the grounds are free.
In order to do this, ...
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1
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33
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Does a tool exist to merge multiple things in a table at once? [closed]
Is there a tool that can merge specific things in a table at once?
The problem I currently have is that I have about 110 different features in a table and all of them have another entry with the same ...
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0
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129
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Why does Dissolve tool create little holes in the resulting polygon?
I tried to dissolve a couple of polygons and found out that it creates little holes in the Polygon
(see: QGIS Dissolving and holes). I knew how to 'fill' the holes (with v.clean) but I am wondering ...
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215
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Merging features of the same class in QGIS
I am running with a problem that I want to merge all the features of the same vector class into one attribute. Below the green layer is the forest layer that has more than 11 thousand features, I want ...
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Merging multiple intersecting/overlapping polygons in QGIS [duplicate]
Is there a way in QGIS to select multiple polygons and merge only the ones that intersect/overlap with each other? As in the example bellow only those appointed would merge, becoming each a single ...
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Dissolving polygon on QGIS
I have a grid of polygons as in the figure below;
I need to dissolve the polygons into a single feature. I used the Dissolve tool on QGIS without specifying any dissolve field. The QGIS result is ...
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QGIS: Dissolve adjacent small polygons
Does anybody know a solution for this qgis task?
I have a polygon layer with many small and bigger polygons. I would like to merge/dissolve the polygons smaller than 100 m² with directly adjacent (...
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122
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Unable to aggregate line segments while summing values
I've a layer with multilines, overlapping to a various degrees. I need to merge/dissolve them "downwards" while summing their values for the overlapping segments.
I made it to "Union&...
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225
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Multiple Unions & Dissolve for Buffers
I'm a new user of QGIS 3.10.4.
I need to create contours on maps using buffer, union and dissolve functions in QGIS. The buffers will be from multiple points.
Is there any way I can unionize and ...
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QGIS Union is slow. How to speed up or which alternative to use, creating the same output?
I have two polygon layers which I want to union. One layer (1) is just one big feature, the other (2) contains 250’000+ features. Layer 1 was created this way: Several polygons --> fix geometry --&...
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3
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Eliminate polygons using attributes in ArcGIS Pro
I've done an intersect of two polygon feature classes: one of neighborhoods and one with census block groups. I'm now trying to figure out how to merge the polygons smaller than a certain area with ...
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782
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GeoPandas Eliminate polygons (select by attribute)
I have a large GeoDataFrame with over 1 million polygons. Many of these polygons are of a small size and I want to merge them to one of the neighboring polygons (to the one with the greater area). I ...
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564
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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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152
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Exporting joined attribute table features gives wrong number of records using ArcMap
I work in ArcMap 10.8.1.
I have a feature class of ~40k records of road segments. I dissolved the segments using a field containing numbername of the roads. This created a feature class of ~10k ...
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