All Questions
1,690
questions
-1
votes
1
answer
474
views
QGIS new versions 3.28, 3.30... One part can not be selected, vertexes too, can't work with multi polygons, One part is "Hole lies outside shell"
I am currently stuck on working with polygons with QGIS versions from the new patches with the new styles (3.28, 3.30, maybe 3.26 too etc...)
When I used previous versions of QGIS, for instance 3.16 ...
- 9
1
vote
1
answer
169
views
Merging polygons with adjacent polygons using QGIS
I am using QGIS (version: 3.28) and I am looking for a way for an automatic spatial generalization of polygons:
Step: Merge adjacent polygons of same class (e.g. class "Grünfläche")
Step: ...
- 89
4
votes
3
answers
278
views
Creating ring using overlapping and fully contained polygon in QGIS
How do I use the middle polygon to cut a ring in the bigger polygon without
moving the middle polygon to another layer in QGIS 3.30?
I think there is a way to make this edit in-place without having ...
- 51
1
vote
0
answers
39
views
Georeferencing a traced polygon
As a novice, I have drawn a DXF polygon (traced from a UK Ordnance /survey map of unknown scale).
It has no geographic reference and when I import it to QGIS (with a Google Maps base layer) and save ...
- 11
0
votes
0
answers
60
views
Expression works in one QGIS project, but not another
I have an expression in a Print Layout that populates a label with an attribute, based on which polygons are selected in map view. In the QGIS project that I made, it works perfectly. I tried copying ...
- 34
4
votes
1
answer
272
views
Expression for calculating the longest edge of a polygon rectangle in QGIS
I want to be able to calculate the longest edge of a rectangle polygon to create an expression for a style.
The styled rectangles will have variable orientations, widths and lengths.
I want to use ...
- 181
2
votes
0
answers
49
views
QGIS highlighted cell issues
Does anyone know why this is occurring? I obviously want the yellow highlighted polygon boundary to be always on top. Currently, the non selected shared boundaries are rendering on top of the ...
- 21
1
vote
1
answer
180
views
Summing length of lines of a specific category from another layer in QGIS
I have a polygon layer of ski resorts call skiResorts. I have a liner layer of pistes called pistes. The pistes layer has 2 several attributes and include aa_piste_length and aa_piste_difficulty. ...
- 151
1
vote
0
answers
179
views
Polygon precision problem in QGIS
I must do some really precise GIS work.
I edited a polygon-layer, deleted two polygons, created a new one and saved the edits. Suddenly a third polygon, which I did not change, is displaced / ...
- 466
2
votes
1
answer
89
views
Add parallel lines inside an irregular polygon QGIS 3.22 [closed]
I am using QGIS 3.22.10
My end goal is to know the distance a tractor will travel all up when it is seeding an area (the irregular polygon) at 1m distance (single line seeding).
Is there an option to ...
- 99
1
vote
0
answers
146
views
When i export (save feature as) a polygon in QGIS it converts to a multipoint and multipolygon how do i stop this
Im using QGIS and I have a property boundaries .shp When I try to export this using the 'save feature as' option the resulting shpfile has missing poylgons and it has converted itself into multipoints ...
- 11
3
votes
1
answer
155
views
Clean polygons by shape type
I have a map on QGIS that looks like this:
I would like to clean the weird-looking polygons (inside a red circle for example) and keep the normal-looking ones. My initial approach was to compute the ...
- 485
2
votes
0
answers
132
views
QGIS error code, trying to split a layer [closed]
I keep getting the error code below when trying to split a polygon. There appear to be no duplicates and I have been able to spilt other layers within the same shapefile. Can anyone give me any work ...
- 21
0
votes
1
answer
375
views
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 ...
3
votes
2
answers
312
views
Splitting complex polygon in QGIS
I have a problem with a polygon in QGIS. Is a polygon that represents all street areas in a city:
And I want to slip all the area into smaller areas that represent the area of each street in the city,...
3
votes
1
answer
56
views
QGIS Summing attributes of polygons contained inside region polygons. Some share boundaries. Intersection gets unwanted neighbors
So I am trying to sum up populations from a census polygons layer into a region polygon layer. Now I want to sum up the total population contained in each region polygon (A & B).
Here's the ...
1
vote
1
answer
86
views
Cut out parts of raster using polygons
I am looking to cut out some areas of a large raster using polygons.
The existing clipping tools only cut the raster to the size of the polygon, but I just want to cut the areas of the polygons out of ...
- 351
-1
votes
1
answer
278
views
Create one continuous polygon from many polygons with holes in QGIS
How can I create one single continuous polygon from many polygon and the gaps will be preserved? So whole polygon will be connect into one big single polygon.
Using the dissolve tool will not connect ...
- 15
0
votes
2
answers
276
views
Filtering lines with some conditions in QGIS [closed]
I have two shape layers: a Polygon layer and a Line layer in QGIS.
I want to filter/highlight lines based on the following conditions:
Case 1: Filter/highlight lines which cross all the polygons (...
4
votes
3
answers
273
views
Changing orientation of all polygons at once with numeric value in QGIS
I want to change the orientation of the raster/polygons with a numeric value around the centroid of the total grid.
I have tried rotate($geometry, 45) in the Field Calculator but nothing happened.
- 615
2
votes
3
answers
369
views
Offset/move polygons in specific direction QGIS
I want to offset/move the polygons in the direction north-north-western direction and perform this task 3 times. I can do this manually but it would be an approximation and I want them to exactly ...
- 615
1
vote
0
answers
66
views
Georeferencing list of polygons in QGIS when CRS is unknown
I have a list of neighbourhood polygons in Casablanca, Morocco, which have an unknown CRS. Here is a link to one of the polygons: (link to a json).
I have tried several CRS in QGIS, but none of them ...
- 11
1
vote
0
answers
37
views
New Polygons vanish when ID is added [duplicate]
I am working on an old QGIS project and want to add new polygons to a layer. I have the data for the polygon in the attribute file showing an ID no and other data which also relates to other existing ...
- 11
1
vote
0
answers
49
views
QGIS3 weed tracking via polygon attributes
I have been requested to provide some information about weed distribution on a site in the form of polygons that describe land forms. I am using QGIS3 and slowly getting the hang of it, might be too ...
- 11
2
votes
1
answer
265
views
QGIS: Combine stripes of different colors on polygons
I want to create a map that shows in which country which companies (offering the same product) are active. The style of the map should be similar to this one (source):
So, if company A is red, ...
- 21
1
vote
0
answers
102
views
Encoding a Boolean raster from polygons in QGIS
Polygons become invisible when rasterised, and raster has very odd values. Can I correct this so raster has 1 for polygon and 0 for non-polygon?
I have drawn polygons over a feature for a species ...
- 63
1
vote
0
answers
100
views
Create polygons with fixed size along lines or another polygon
My task is to create layouts for the grey polygon with a rectangle covering multiple parts for the map extend. I then have to calculate the area of they grey polygon within each rectangle. My idea was ...
- 191
0
votes
1
answer
74
views
Adaptive polygon division in QGIS
Let say I have an irregular polygon layer that I want to divide into squares of fixed size (i.e. 50 x 50m). The simplest solution is to create a grid based on the polygon extension and then use the ...
- 47
-1
votes
1
answer
121
views
Importing CSV file as polygons in QGIS [closed]
I downloaded a CSV file for a city nearby. The file has columns "SHAPE_Leng", "SHAPE_Area", "lat", and "lon". I assume with represents a polygon. What are the ...
3
votes
1
answer
171
views
Dividing city into blocks (polygons) in QGIS
I'm interested in dividing a city up into distinct blocks, with the end result being polygons for the blocks. I have a polygon for the city boundary and centerlines for the city streets.
Here's a ...
- 229