Questions tagged [qgis]

QGIS is a cross-platform GIS application licensed under the GNU General Public License.

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Filter/delete polygons if they are surrounded by other polygons

I've been looking for a method to extract polygons (here in green) witch are surrounded by other polygons (red ) in QGIS. How can I do this?
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2 votes
1 answer
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QGIS - Merging two tables and make lines

I need help with merging two table and create geometry. I have two points layer with features tables and try create polyline layer. When I create virtual layer with next querry then result is polyline ...
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3 votes
2 answers
134 views

Shapefiles won't load or load as blank [closed]

I'm brand new to QGIS and the world of geo mapping tools. I try to load a .shp file but the nothing seems to happen. The shapefile is good as it can be opened by two other users. I have tried dragging ...
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  • 31
2 votes
1 answer
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QGIS Expression: count - how to apply filter

I have a table of parcels. Each parcel can have multiple land use types (not necesarily distinct). Those are stored in another table - so in the UseType table, a parcel can show up as wineyard, ...
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1 vote
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Dataset with multiple coordinate notations (DMS, DD, etc.)

I have an original dataset in Excel form with locations given in coordinates. However, the coordinate notation is not uniform. Some are in decimal form, some in degree and minute form. How do I ...
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1 answer
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Sharing GIS data with non-GIS users [closed]

I want to visualize and share GIS data with non-GIS users within my organization. The data basis is European CO2 emissions from industrial sites from the E-PRTR, thus a point data layer that should be ...
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0 answers
16 views

Adding oblique Birds Eye View from BING

I am trying to integrate the oblique birds eye view from the bing service in QGIS. The documentation is referring to map tiles, however i don't get to load it in with the XYZ-Tiles service that is ...
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1 vote
0 answers
27 views

QGIS: Adjust line for labels at the feature end (Easy Custom Labeling)

I work on a map of overlapping public transport fare areas, e.g., Frankfurt(Oder) AB/BC, which imply different fares for using the bus. By utilising the Plugin Easy Custom Labeling I was able to ...
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NC file is not at the correct size and location

I'm trying to display on QGIS a .nc file of sea temperature of the Eastern Mediterranean, but it doesn't have the good size and isn't at the good place on the OpenStreetMap layer that is under (see ...
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1 vote
1 answer
20 views

Merge lines which has the same name ttribute and intersect in one point in QGIS

I have a polygon layer that has lines showing rivers. A river with the same name attribute might be consisted of a few lines touching each other. For example, in the image below, the river consists of ...
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  • 463
2 votes
0 answers
20 views

Statistical summary of points in a polygon (QGIS)

Is there any method for calculating the average, largest value, etc. (chosen statistic value) of points within polygons and giving the calculated value to the polygon?
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1 vote
0 answers
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how to overlap two lines in QGIS 3.10

enter image description here I am working on QGIS 3.10 and would like to overlap two lines in order to use select by location tool. I tried all the option in this tool and get just a few data selected....
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0 answers
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OD Matrice - point to point (busstop to busstop) using QNEAT3

New to Qgis. I am currently trying to establish an OD matrix from point to point. Of data I have GPS points, names and values of the busstop network. And as a secondary dataset I have starting and ...
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0 answers
15 views

Change channelnetwork for watershed basins

Currently working with QGIS 3.16 and the SAGA toolbox. I want to change the flowlines from the channelnetwork (created from channelnetwork saga tool) to fit to the lokals drainage network. Is it ...
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  • 1
0 votes
1 answer
43 views

Emulating attribute form from Esri to QGIS?

Is there a way to get the same type of attribute form of ArcMap into QGIS? In ArcMap when you select a feature you get a attribute form for that feature and when you select another feature from a ...
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2 votes
1 answer
47 views

Structure of QGIS_Processing commands

As per https://docs.qgis.org/3.22/en/docs/user_manual/processing/standalone.html?highlight=qgis_process I am trying to run the following (that works in the QGIS python console). alg_params = { ...
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  • 7,616
2 votes
1 answer
36 views

Generating discrete legend labels instead of default maximum and minimum label on single bar - QGIS 3.18 to 3.22

Question: I used a python script in QGIS 3.16 to generate a raster and subsequently a print layout with legends. I am trying to use the same script to build the print layout in QGIS 3.22. However, ...
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0 answers
30 views

Error when importing .ASC file into QGIS

I have downloaded a freely available digital terrain model from a geological survey. The file consists of a folder with .gdb files and a folder with .asc raster images. I have been unable to import ...
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1 vote
1 answer
37 views

How to sum values from multiple features with a given attribute in QGIS?

I'm working with two layers right now - a line layer called Water Lines and a polygon layer called Land Areas. The Land Areas layer has polygons in which water runoff occurs during precipitation ...
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4 votes
2 answers
74 views

Replacing column of comma separated strings of IDs with values stored in another field based on those IDs using QGIS

I have a layer with three columns: geoid: ID of each polygon (string) totpop: Total population of each polygon (integer) neigh6: Comma separated list of the IDs of polygons that neighbor that polygon ...
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0 votes
0 answers
26 views

QGIS Converting USGS GeoTIFF to Garmin CPE

I'm totally new to QGIS. I'm trying to use a USGS GeoTIFF and convert it to a KMZ via the Garmin plugin. I can load the GeoTIFF as a raster file and view it. When I run the Garmin plugin I get an ...
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0 votes
0 answers
64 views

NDVI from rescaled Landsat 8 L2 product is out of range

I need to use Landsat 8/9, level 2 products, to compute NDVI. I know that I need to scale band 4 and 5 before compute the index. Here there are the official scaling factors. So, as example, I apply ...
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1 vote
1 answer
37 views

QGIS parts to single part with a given minimal distance of the parts

Is it possible to split lines into parts and give a minimal distance for the parts to be split? I have a layer with rivers, some of them are one object, even if they are hundreds of kilometers away ...
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0 answers
25 views

One large GPX covering British isles, need to figure out how to display connections between the points which is currently proving tricky

I have a large gpx, it covers most major roads and some secondary roads of the British isles, I intend to use the coordinates to display a rudimentary road map on a device with low memory, I currently ...
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0 votes
1 answer
33 views

Creating land use layers

I have a land use layer which includes 36 different individual classes. Using the raster calculator I have been able to extract 1 of the different classes and make a new layer (landuse=[number of the ...
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4 votes
1 answer
152 views

How to get maximum possible straight + perpendicular line through polygon?

I'm trying to measure the maximum width of irregularly-shaped polygons. To me, the most logical way of doing this is to simply get the longest possible straight line through the polygon and then the ...
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1 vote
1 answer
68 views

Use QGIS `processing.run(...., alg_params)` from OSGEO4W shell in QGIS Dev 3.26

I've created a simple tool using the code from save model to automate processing. It runs as expected in the QGIS python console but does not work from osgeo4w shell. I have tried the process in https:...
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  • 7,616
1 vote
2 answers
49 views

My data is not showing when adding delimited text layer with lat/long

This is my screenshot of Data Source Manager of Delimited Text input. Sample data look fine. When I press 'Add' no data shows. World Map layer is EPSG-4326-WGS 84. I tried everything but the data ...
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3 votes
1 answer
62 views

How to remove bullet point formatting from QGIS attribute table using field calculator

I inherited a .gpkg (no CSV or shapefile) in which the attribute table has a single column containing the relevant non-spatial data. The contents (string) are set up with a <table><ul><...
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0 answers
29 views

How to export a shape to KML preserving the symbology?

I want to export a shapefile layer to KML preserving the symbology, I do it with the export option and select the KML file type but it does not save the symbology when opening it in Google Earth.
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20 views

Using topographic openness with SAGA Next gen plugin in QGIS

When using the Topographic Openness algorithm from SAGA Next Gen it does not allow me to export the layers. I have seen some solutions that suggest me to activate the module in providers in the ...
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0 answers
34 views

QGIS failing to include Authorization header (WMS layers)

QGIS 3.16.1-Hannover QGIS is attempting to authenticate with GeoServer using OAuth2. Authentication is configured as such: For WFS it works perfectly. Note that it even specifies where in the cpp ...
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0 votes
0 answers
23 views

Join raster color with point layer

I have a raster of the world considering different climatic zones. Then I have a layer with major cities worldwide. Now I want to join the information of colour into the point layer. The option of ...
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1 vote
0 answers
21 views

Assigning local CRS to space telescope imagery? [closed]

Since the new images became available from the James Webb space telescope (https://webbtelescope.org/resource-gallery/images), I want to test some of my favorite classification, segmentation, and ...
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  • 2,536
0 votes
0 answers
26 views

QGIS 3.10 Selecting unclassified road line (One layer) that miss survey data (another layer)

I am working on QGIS3.10 and ArcPro. My goal is to select all the Unclassified road that do not have any scheme. For that I need to overlap the two layers (Unclassified road network and schemes) ...
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-2 votes
0 answers
24 views

Assigning geolocation to shapefile [duplicate]

I received shapefiles from the Senegalese city (probably a conversion from AutoCAD) not georeferenced. What can be done to solve this problem ?
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0 votes
0 answers
18 views

Symbology of a point layer on attributes of a child layer

I have created a project in which I want to monitor technical systems. The systems are serviced at different annual intervals. I have created a point layer that shows the plant locations and contains ...
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  • 1
0 votes
0 answers
23 views

Changing spatial resolution of raster layer using QGIS

I'm working with the Hansen forest loss year data from Global forest watch (which is 30m per pixel) as part of my MSc thesis to look at deforestation risk of palm oil. All I want to do is to change ...
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  • 1
0 votes
0 answers
13 views

How to convert mask in netCDF to one polygon shp, with QGIS/GDAL polygonize or python?

I made a 0-1 mask in netCDF, with coordinates lat lon. The mask itself looks like: 0 0 0 0 0 0 0 0 0 0 1 1 1 0 0 0 0 1 1 1 1 1 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 I have succeeded to read it, ...
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1 vote
0 answers
15 views

Disable option "open output file after running algorithm"

Whenever I run a model in QGIS there is a dialog box asking for the set parameters. There the option "open output file after running algorithm" is always checked. is there a setting to have ...
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0 votes
0 answers
32 views

Create a QgsProject without opening it

I could find a method to do that. Suppose you have a list of QGIS project paths and you want to get the project information, like the loaded layers, canvas extent, etc from the project. I thought the ...
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  • 2,682
1 vote
1 answer
31 views

Correct way to use DROP TABLE on SpatiaLite in PyQGIS

I try to delete a table in an SpatiaLite database using PyQGIS. The table is deleted, but still shown in the browser panel. I'm using the following code: query = "DROP TABLE table_name;" ...
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  • 298
0 votes
1 answer
48 views

Dividing a roadnetwork into intersections in QGIS

I have a shapefile showing New Zealand's road network, and I need to break up roads at their intersections for my analysis but I haven't been able to do so. So far I've tried Vector>Analysis Tools&...
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1 vote
0 answers
20 views

How to combine different azimuth hillshades (e.g 45°,315°) extracted from the same DEM using QGIS?

I've a DEM from which I created duplicates that have different azimuthal values on hillshades. I would like to see the possibility of combining different azimuths (e.g 0°, 45° and 315°) in a single ...
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1 vote
2 answers
28 views

Showing vector various feature (location) in QGIS layer menu

In QGIS (I'm using 3.16), I would like to know how to display, in the layer menu, the many feature/location included in a vector file (KML) My KML vector includes 15 features (polygons), but ...
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  • 91
1 vote
0 answers
31 views

QGIS Check parent layer name

I have a no-geometry layer 'pictures' linked to several different parent layers. This means the project can have multiple photos attached to a point and all the photos for the project can be viewed at ...
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  • 63
3 votes
1 answer
46 views

QGIS - list with clear name colours

One may use data defined override in order to set symbol colours. The expression editor says, the expected format would be string [r,g,b,a] as int 0-255 or #AARRGGBB as hex or color as color's name ...
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  • 13.2k
-2 votes
1 answer
41 views

Basemap (OSM Standard) is not showing upon export [closed]

My base map of the UK is there when adding everything else and showing when I am in the preview section of the export page, but when I do export it using qgis2web - Create web map, either on Leaflet ...
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  • 1
3 votes
2 answers
137 views

Incremented index on a split polyline in QGIS

I would like to use a function like SAGA LINE-POLYGON INTERSECTION in QGIS, that splits a polyline into several polylines at every intersection of another layer of polygons. I would like the polylines ...
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  • 816
1 vote
1 answer
51 views

Creating enclosed polygon using QGIS

I have a pole data connected to houses. I wanted to create an enclosed polygon with the pole and all its corresponding demand points. How can I do this? Input Output I am using QGIS.
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