r/QGIS

I am drawing polygons over a satellite image to classify forest vs non-forest. I have a raster file of polygons from the same image from 2014, and I am updating the borders of those polygons for the 2026 image. I'm completely new to QGIS, and I encountered a ton of issues last night after a couple hours of polygon editing/drawing.

1. It wouldn't let me save the layer because I had created a polygon with "unknown geometry" / a geometry type that couldn't be saved to the file. I was eventually able to find which polygon that was but I couldn't figure out how to fix it without having to redraw it entirely. Is there another way to do it without having to redraw them?

2. Often, I need to split polygons and create a new one in between. Either a) a hole inside the polygon, or b) completely dividing an existing "forest" polygon into 2 with a non-forest "corridor" between them. For a, I was using add ring, and then drawing a new polygon in that ring. I have snapping and topological editing on for reference. But that then resulted in all of those polygons being invalid and I wasn't sure why or how to fix them. For b) i haven't figured out a good way to do that yet without making everything invalid.

3. Often, when I am drawing new polygons it will then say "Add feature: The feature has been added, but at least one geometry intersected is invalid. These geometries must be manually repaired." I really don't know how to fix this or what it even means.

I tried to use Claude to figure these out + going on past threads but I couldn't figure anything out really. If anyone could help that would be much appreciated!

Was hoping someone could direct me to a source of GW maps as they cycle for a research project i’m putting together. Any help greatly appreciated.

Hi,

I am trying to reproduce the style of a map with numbered hotels and a legend listing their names.

I managed to number the symbols by using their ID with a font marker.

But the legend uses hardcoded values from the Character(s) field instead of the data defined overrides (I hardcoded 14 for Hotel d'Angleterre in the screenshot).

Is it possible to keep the flexibility of the formula or do I have to enter each value by hand? Also, how can I sort them in ascending order?

You will learn how to detect and vectorize any feature from satellite or drone imagery directly inside QGIS

• It covers : Automatic Mode: Scan an entire area with text prompts to batch-extract features in seconds
• Semi-Auto Mode: Extract single, complex objects with one click for maximum control
• Shape Regularization: Automatically square building corners and clean up polygon boundaries
• And basically just the full Workflow: Edit vertices, adjust confidence filters, and export clean layers with attribute data

We pushed a lots of updates recently so a tuto was definitely needed haha, hope it will help

The time has come to add 2 or 3 folks to the Mod Team at GIS. This is a fantastic community and technical area, and I do feel bad that r/GIS has lagged behind in features and structure. I'll take whatever portion of the blame is appropriate for that, but hopefully with a larger and more engaged team we can make some good changes.

If you think you're a fair, level-headed person who really cares about the community, I encourage you to fill out the recruitment form. I'll leave the form open for the remainder of August and come September 1st I'll begin reviewing applications and making sure that applicants have a solid history of positive engagement.

I created a new account when I was asked to become a Mod here so as to not be doxxed, and that was met with a healthy dose of trepidation. I hope the community can respect why some anonymity in a technical subreddit is a good thing, and I'll appreciate respect being given to those who join the Mod Team. Please apply with the account that you typically use to interact with r/GIS, but I understand that may not be the account that you choose to moderate under.

I'm sure there will be some questions regarding intent, and I'll do my best to respond to them in the comments as they come up. Thanks for your interest and commitment to making r/GIS a better place. Similarly, if you have thoughts on changes that you'd like to see, feel free to leave that in a comment here.

Sorry if this question is dumb, I just want an simple or long answer so I know what I'm getting into

Hey everyone, hope you're all doing well. Stuck on something and figured the community might have some insight.

Background: My colleague and I were hired to build a geographic database for a client. Project covers 7 countries and we're sitting at around 2 GB of data right now:

• Vector layers in GPKG format
• Some rasters in TIFF format
• Side note: These formats came from preprocessing the original source data so they'd work directly for what the client needs

What the client needs:

• Query layers for project planning
• Generate their own maps
• Share results online with people who don't use GIS software (big one here)

What we tried: We really liked GeoLibre at first—had good vibes about it. But then we ran into a wall. When loading multiple heavy layers that need serious rendering, the app just freezes or goes completely unresponsive. Happens especially when zooming/panning across large areas or toggling between complex vector/raster combos.

My hunch is that since GeoLibre is still actively in development, these stability issues might just come with the territory. But we need something that works reliably.

Looking for advice on: Any open source alternatives that can handle this?

• Should scale to ~2 GB without crashing/freezing
• Needs to be friendly for non-technical users (interface is key)
• Web sharing with third parties would be a plus
• We can write basic code if needed (I'm pretty basic myself but I use AI assistants, my partner doesn't code)

Also, do you guys think this is even achievable with open source software? Or are we being too optimistic about what we can pull off on our own?

Any thoughts, suggestions, or even docs/case studies would be super helpful! Thanks in advance 🙏

Hi everyone,

I'm rolling out QGIS to a few hundred Windows computers and have the base installation working silently via Intune

The part I'm stuck on is installing the required plugins without user interaction.

I need the following core/SOE plugins enabled:

• DB Manager
• Geometry Checker
• GRASS 7
• GRASS GIS Provider
• MetaSearch Catalog Client
• Offline Editing
• Processing
• Topology Checker

As well as these community plugins:

• Adjust Style
• ChangeDataSource
• Clip Multiple Layers
• Coordinate Capture
• Digitizing Tools
• GTFS Loader
• GTFS-GO
• Networks
• OSMDownloader
• QNEAT3
• Quick Attribution
• NextGIS QuickMapServices
• QuickOSM
• Search Layers
• Lat Lon Tools
• LOOM Transit Map Generator
• Maps Printer
• GTFS 2 GIS
• KML Tools
• KMZ Tools
• mmQGIS
• QGIS to Illustrator

Has anyone successfully automated plugin installation or know how I can install these remotely? I dont want to install them all one at a time for each device If I can avoid it.

Is there a supported way to pre-download and deploy the plugins, or a command-line/Python method to install them into the appropriate plugin directory?

Thanks

Hi all,

I have a spreadsheet of 200 UK addresses (Address, Town, Postcode) and I need to plot them as points on a map to allow some analysis on their proximity to flooding.

All the tutorials and plugins I have found online all focus on American addresses (i.e state, city, code). I haven't tried them yet with UK addresses so just wanted to ask if anyone had experience of doing this in the past?

Thanks.

Hello everybody, we have a project where there is a point A to point B situation, and our company has to define the best route given the topography, and if possible, other design restrictions, such as hydrology, reservation areas etc. Is there a way to do that with some specific plug-in?

Thank you in advance