Questions tagged [qgis]
QGIS is a cross-platform GIS application licensed under the GNU General Public License.
39,752
questions
-2
votes
0
answers
9
views
I want to download Route map of Trans-Asian Highway Network
Need help in EIA Report Trans Asian Highway Network.
I want to download route map of Trans-asian Highway Network.
How can I proof the EIA Report is Correct?
Suggest me some ways and Explain how to do ...
0
votes
0
answers
34
views
Units of length
I've created a shapefile with polylines drawn. How do I measure the length of the lines. I've tried changing the units of distance (in Settings->Options->Mapping Tools->Preferred distance ...
0
votes
1
answer
27
views
Create new layer in QGIS using SQL query
This is a related question to: Speed up performance of virtual layer based on GeoPackages in QGIS
In that question, I was trying to use a virtual layer in QGIS (3.30) to add a region field to a suburb ...
- 2,465
0
votes
1
answer
17
views
Enabling render type for Mapzen Global Terrain in QGIS
I'm trying to change the color ramp on a Mapzen Global Terrain layer and only 'Singleband color data' is available in render type. 'Singleband pseudocolor' is not available. This is occurring in QGIS ...
- 3
0
votes
0
answers
12
views
Reverse linestrings, given attributes
I am working with street numbering and toponymy and I have an issue in hands: given some data provided by an Institution, i.e., points as door numbering and lines as the streets, those streets were ...
- 1
1
vote
1
answer
93
views
Delete default shadow's points in QGIS
I didn't find in QGIS documentation how to solve this and not on this site either.
I am applying a color graduation for my point layer with a simple symbology.
How to delete this shadow?
It has ...
- 75
1
vote
1
answer
24
views
Join non-spatial CSV layer with spatial shape layer, using multiple input fields
I have two separate layers i want to join in my QGIS-project based on multiple matching input fields.
One layer consists of a non-spatial CSV table, but with the matching fields: Streetname, House ...
- 13
0
votes
0
answers
29
views
Offsetting categorised symbology for features overlapping (only when features are overlapping)
I'm trying to look for a solution to a problem I am having with a polygon layer in QGIS.
I've produced a 'Boundary' layer in QGIS, such boundaries are leveled the lower levels are inside the higher ...
- 87
0
votes
0
answers
25
views
QGIS, Exporting .svg from a map, I can not produce it with as much resolution as in the main window
I am doing a PhD in wildfire modelling so that I need to deal with GIS data, mostly for visualizing purposes and data preprocessing.
I am connecting to a XYZ tiles to produce a satellite map. In ...
0
votes
0
answers
32
views
QGIS generate grid that aligns with landsat pixels
I would like to generate a grid that aligns with Landsat pixel boundaries.
I am happy to do this with Python, QGIS, or commandline tools.
Is it possible to generate one grid that aligns with all ...
- 294
1
vote
1
answer
80
views
Close a file created using GDAL
I have problems to close a file created in GDAL
I have the following code (it's a part of bigger piece of code):
driver = gdal.GetDriverByName("GTiff")
SAL01=driver. Create(Fnout1,afile....
- 13
0
votes
0
answers
16
views
Classification in QGIS with modifications in Lizmap
I'm trying to make some changes to some fields of a point layer in Lizmap. Currently the changes I make are updated in the DB.
I'm looking for a way to dynamically manage the classification done in ...
- 29
0
votes
1
answer
16
views
Creating a Weighted Map using weighted overlay method for finding shortest cost path
I have three input files as below:
Digital Elevation Model in tiff format
Drainage file in vector format (.shp) containing drainage data
Roadmap file in vector format (.shp) containing road data
I ...
1
vote
2
answers
38
views
Connecting points to the nearest K polygons in QGIS
I have a layer of point data, and a layer that contains polygons of all the lakes in a region. I am trying to find the K closest of these lakes for each point. The distance should be measured from the ...
- 11
0
votes
0
answers
33
views
What points should I add or sampling should I change to get a better georeference within QGIS?
I am working with an image that I need to georeference onto a base map. I have already added two other images to the map with minimal issues. They are not 100%, but they are good enough for this.
...
- 177
0
votes
0
answers
50
views
QGIS - Select Features by Value issues
I have a point shapefile (parent) which is related to a CSV table (child) through a one-to-many relation (Project > Properties > Relations > relationship strength: association).
When I click ...
- 516
0
votes
1
answer
33
views
Represent linestrings with arrow direction based on origin and destination points location
I have two layers:
one linestring layer with two attribute fields that identify the codes of the origin (field A) and of the destination (field B) nodes;
one point layer with one attribute (unique ...
- 817
2
votes
3
answers
67
views
Converting a shapefile into a Power BI ready JSON file
I have a .shp file that I want to use in my Power BI dashboard, however I keep running into multiple issues. Because Power BI only accepts TopoJSON for its shape maps, I have to do some ...
1
vote
0
answers
39
views
Selecting more than one label with expression builder?
I have a layer with placenames and would like to show only a few lables like villages and not farmnames in areas where I have selcted all the Labels on the layer.
So after I have selected some labels ...
0
votes
1
answer
53
views
Cannot get line to use style file but works fine with polygons. Any idea why?
I'm using the UKHab symbology (style file downloaded from the UKHab working group). It works fine when assigned to the polygon shape file but when I try to assign the symbology to the line shapefile ...
- 1
1
vote
0
answers
29
views
QGIS - Export layer with one polygon subdivided as multiple rows to CSV
I have a GeoJSON file with quite precise boundaries of world's countries. I had to simplify it because Snowflake, where I want to keep the data, has 16MB limit and Canadian polygon is always too large....
- 291
1
vote
0
answers
39
views
Read only certain columns (read permissions) of a PostGIS database in QGIS
In our administration, each employee is given various rights to read and edit data on the PostgreSQL/PostGIS database. To view the geodata, we use QGIS. In this case there should be read permissions ...
- 351
1
vote
0
answers
32
views
Getting -inf values when calculating zonal statistics from raster layer in QGIS
I am trying to get some summary statistics from a raster layer (CRS EPSG:3035 - ETRS89-extended / LAEA Europe - Projected) of forest biomass for each polygon in a shapefile layer. I have used the ...
- 11
0
votes
0
answers
29
views
Aggregate values of a field by clusters
I want to group points by distance. I'm using the 'Group of points" in Layer Style.
I also want to sum the value of a field to the aggregate of the cluster, and I need the new cluster point to ...
0
votes
0
answers
51
views
QGIS shortest path but coordinates of another layer as intersection point [closed]
I would like to process shortest path between points A and C (point layer), as seen on screenshot, but instead of using the intersection of lines, I would like to force to get to point B.
Is it ...
- 1
4
votes
0
answers
104
views
How to change the Point Cluster circle symbol to a convex hull
I am using the expression presented by the user JGH to solve the question 'Point Clustering in QGIS, but values show a percentage and not count of points'
This shows my example:
As you can see I use ...
- 783
2
votes
1
answer
96
views
How to replicate QGIS's Identify Features functionality with ogr2ogr when downloading data from WFS endpoint?
I am working with this WFS endpoint:
https://wxs-gpu.mongeoportail.ign.fr/externe/39wtxmgtn23okfbbs1al2lz3/wfs
In QGIS, I do: Layer -> Add Layer -> Add WFS Layer..., then add the above endpoint. ...
- 1,308
0
votes
0
answers
24
views
Load CSV from SFTP
I have a CSV on our sFTP. This CSV is automatically updated every night.
I would like to add this CSV file to my QGIS project, so i can see the updated data.
But.. I've never made a connection to a ...
0
votes
0
answers
22
views
Dynamic point tracking with QGIS and Lizmap
I'm working on a vehicle tracking project and would like to use QGIS and Lizmap. The data is on a PostGIS database and comes from a web service. What interests me is how to visualize the dynamics of a ...
- 29
3
votes
0
answers
55
views
Where can I find common symbology presets for QGIS?
I am looking for a collection of basic, common styles that I can just apply in QGIS.
In ArcGIS, I am used to having a comprehensive set of common symbology options built-in, e.g. different road types, ...
- 2,062
1
vote
0
answers
30
views
How to get multiple inputs for Extract selected features processing tool in model builder
First time using QGIS modeler so i'm not familiar with it.
I want to select features from multiple layers (how many layers and what layers changes depending on the work) merge them into 1 layer (...
- 175
0
votes
0
answers
33
views
Duplicate geometry by inheriting features in QGIS
I'm working with QGIS desktop and then exporting the project to Lizmap.
What I need to do is modify the attributes of an already existing point geometry:
For example I have a point geometry with ...
- 29
-1
votes
0
answers
29
views
Identify feature not displaying info QGIS
I’m having issues with the identify feature selection on QGIS.When I click on a feature it says ‘feature could not be found’. It used to work fine. I checked that I’m in the right CRS, restarted the ...
- 1
0
votes
0
answers
29
views
Error when cropping a layer mask (raster)
I'm trying to crop an image using the mask layer to make a slope map and relief analysis, but every time I try, these errors appear, as shown in the images below.
0
votes
1
answer
61
views
Creating an automatic page size inQGIS Print-Layout with a pre-defined scale
How can QGIS Print-Layout with a given scale (eg 1:50000) create an automatic page size and layout equal to the coverage of the selected map layers?
I tried it in the page properties, it didn't help:
...
- 99
0
votes
0
answers
21
views
QGIS - Processing framework - QgsProcessingParameterFeatureSource type
I use QGIS to build a script with processing framework. In processing toolbox menu I wan't to "filter" data with data types. I can filter point/line/polygon vector layer but how can I filter ...
- 1,566
0
votes
1
answer
52
views
How to change vertex order to a polyline in QGIS?
I'm trying to change the vertex order of a polyline in QGIS.
I have an existing polyline that's closed (last vertex = first vertex).
The starting point of this polyline is in a totally casual position....
- 1
1
vote
1
answer
50
views
Import tiles OpenStreetMap QGIS [closed]
I have a map in QGIS that is supposed to have multiple layers, a custom made map, and a google street/openstreetmap layer.
The layers somehow don't work, and so I decided to make a new connection. I ...
- 11
0
votes
1
answer
35
views
Identify feature issue [closed]
When I click to identify a feature it comes up with 'no features found at this position'. It was working fine before so I think it's something to do with the settings. I installed the latest version ...
0
votes
0
answers
20
views
Result of merge in QGIS is image that doesn't contains all the merged raster
I'm trying to merge ~10 rasters that I have on qgis. Each raster has 2 bands.The rasters overlap each other, and their no-data value is -9999.
This is how all the rasters look like before merging (the ...
- 1,967
0
votes
1
answer
59
views
Joint feature QGIS 1 a N
I have 3 tables, a linear table of sections, a non geometric table of bus lines, and a intermediate table between both, with relations N:M. In the intermediate table I have the ID of sections table ...
1
vote
1
answer
44
views
How to change the layout DPI for PDF export in QGIS
I am working with QGIS 3.28.4. I have set the export resolution to 300dpi in the layout properties but when I export the layout as a PDF it gets exported at 72dpi. If I export it as png it gets ...
- 11
1
vote
1
answer
56
views
Drawing lat, lon grid over UTM project not working in QGIS 3.32
Goal
I want to draw both an UTM coordinate grid as well as a geographic coordinates grid (lat, lon) on a map in the QGIS print layout window as shown here.
Setup
GeoTIFF layers with tfw files as .zip ...
0
votes
0
answers
21
views
Plotted data in Python and plotted data in QGIS is different
I'm currently working with a raster dataset containing U.S. land cover data and a vector dataset containing building footprints within a specific state. When I attempt to plot two buildings that ...
0
votes
0
answers
7
views
QGIS 3.26 Layer from Image server disappears after panning/zooming
I've connected to an ARCGIS Image server using the ArcGIS ImageServer Connector plugin on QGIS 3.26
As soon as I pan/zoom the image disappears in the viewer and never returns. I've tried using QGIS 3....
- 53
0
votes
0
answers
29
views
Cluster points based on a maximum distance to each cluster's center
I have a layer of buildings (points). I would like cluster as many of them as I can around a common point in space in such a way that all the members of each cluster have a maximum distance of 100 m ...
0
votes
0
answers
12
views
Batch process automatic filling of two columns
I would like to automatically fill two columns in my batch process. Column 3 is to be numbered consecutively with "fid_". Column 5 is to be numbered consecutively with "fid_Mi_". ...
- 1
0
votes
0
answers
54
views
How to use an Excel file (.xlsx) in QGIS
So I have an Excel file where I want to use built in Excel features such as restrict data type in columns etc. but I want to use QGIS to display the data.
I know that I can change it to a CSV file ...
- 1,984
0
votes
0
answers
40
views
Calculation of LST overestimates values
I am trying to retrieve LST from Landsat 8 data, after writing my script, it shows very good results until I estimate the emissivity of my study area, but when I run the following part,
var LST = ...
- 1
0
votes
1
answer
30
views
Extract climate data
I need Qgis to extract climate data informations which are layered into the maps. Moreoever, I got exact geospatial plot-information for all of the plots.
So lets say I got in QGIS a map with 2500 ...
