How to remove small polygons in qgis 11K subscribers 101 Sep 7, 2023 · I have a shape file with 2745 individual sites/polygons in the Philippines, each site represents a tree planting project, with relevant information (30 attributes to be precise), including the year How to remove unwanted inside area from a Polygon Shape file using QGIS?Edit Shape file in QGIS How to remove unwanted inside area from a Polygon Shape file using QGIS?Edit Shape file in QGIS Aug 26, 2022 · I'm working in QGIS. The problem is, i have multipolygon in 1 shapefile, with different fields of same value, no matter Jan 16, 2020 · I am using QGIS 3. created two overlapping polygons (yellow & green). Aug 30, 2023 · I have a large global shapefile with thousands of small gaps/sliver polygons between joined polygons (shared borders of countries). I know that Geometries are defined by „rings“ so maybe there is a way to delete „inner-rings“ in a geometry? Edit: I should mention that I need an automated process, there are roughly 250+ polygons, so now way of doing it manually. Jun 18, 2015 · Do you want to create a new small polygon inside an existing one and create a hole to the original one at the same? Like cutting cookies from dough? That can be done easily with OpenJUMP but I do not know if QGIS has a similar tool. QGIS playlist to learn QGIS with examples. For the few "islands" that remained, I did as you guys suggested and deleted anything that had a length of less than 1 meter. Like the polygons displayed here in the white space. Mar 24, 2020 · The situation is this: I need to remove the lines inside the blue polygon, I have tried with dissolve and delete holes processing tools but they didn't work. clip tool creates "difference area" (red polygon). To run the plugin once installed, go to Processing Toolbox -> Dissolve Adjacent Polygons. I've deselected every layer and these green X's and red lines persist. The adjacent polygon can be either the one with the largest or smallest area or the one sharing the largest common boundary with the polygon to be eliminated. I also have a database of observation points that I have imported into QGIS as a points layer. 1, and I am trying to fix invalid geometry in a number of polygons. QGIS - Dissolve layer to identify gaps or slivers between polygons ArcGIS 10. Mar 20, 2019 · Combines selected polygons of the input layer with certain adjacent polygons by erasing their common boundary. Example picture below with the vertices to be removed in red markings. My go-to tool for doing this is the geometry tool, simplify, in QGIS, but the problem that we always get whenever we're running the standard simplify tool in QGIS is the dreaded slivers. 18 Zurich with GRASS 7. Sometimes I can just delete the vertices and they go away, other times they cross the entire polygon and deleting any vertex meaning deforming the polygon. x - Dissolve polygon layer to identify slivers or gaps between polygons I am looking for a way to close gaps/holes in a polygon feature. Jun 6, 2022 · Remove holes from polygons in R: https://youtu. As a fairly new QGIS GIS: Merging small polygons into larger adjacent polygons using QGIS Helpful? Please support me on Patreon: / roelvandepaar With thanks & praise to God, and with thanks to the many people who have Tiny sliver polygons or gaps between polygons often result from creating new polygons without using snapping or editing shared boundaries without a topology. 18. 15 and have somehow ended up with the following on my screen. You might even look at Sep 30, 2022 · I am trying to remove vertices inside a polygon area which do not form an outside boundary to the polygon. How can you use the smaller polygon to delete a portion from the bigger one equal to its surface? Jun 20, 2023 · How to correct the topology of the lieux-dits layer by removing overlapping polygons and empty spaces between them; How to recreate a common layer consistent with the new locality layer and superimposed exactly on the locality boundaries. Jul 28, 2015 · Is there any automatic process I can make in QGIS to remove those lines inside the polygon and leave only the outer borders? I can manually delete using the "Node Tool", but I was looking for an automated solution. org. Is there a way to erase the line, boundaries, between polygons tha other polygon generalizing options with QGIS at How to smooth/generalize a polygon in qgis on sister GIS-SE site. I can identify the overlapping using the &quot;Topology Checker&quot; b The Advanced Digitizing Toolbar in QGIS is really great if you need to edit your layers in QGIS - particularly polygons. In many of the polygons I have lines which do not belong there but I can not delete them as I normally delete vertices on polygons by select GIS: Removing points which fall outside of selected polygons using QGIS? Helpful? Please support me on Patreon: / roelvandepaar With thanks & praise to God, and with thanks to the many people who You can reduce the number of vertices in a polygon. clean - alternative for sliver removal - Part VII QGIS - Dissolve layer to identify gaps or slivers between polygons other polygon generalizing options with QGIS at How to smooth/generalize a polygon in qgis on sister GIS-SE site. The layer is composed of several polygons, because it includes Sardinia, Sicily, and all the tiny minor islands around. The small isolated polygons are not that important as they represent tiny values. To dissolve small polygons in a vector layer, you can use the QGIS dissolve tool in the Geoprocessing Tools menu. By extra vertices I mean vertices that lie on a straight line. Use this plugin to detect if a polygon layer has two or more features (polygons) overlapping each other. Is there any way to snap these polygons together automatically, removing all of the gaps? The only tool I'm awar Feb 27, 2015 · The polygon edges probably weren't coincident. I want to have a file that represents a residential area in a block. The dissolution is carried out into adjacent polygons of larger or smaller area, according to the option chosen by the user. We will be using the vector tool to accomplish this task. Convert layer to Line (Vector>Geometry Tools>Polygons to Lines) and then convert the new layer "Lines from Polygons" back to Polygons (Vector>Geometry Tools>Lines to Polygons) Now run v. 4 days ago · Click the Editor drop-down arrow and select Merge. Jan 4, 2024 · I would like to perform in Python, the action done by the following QGIS command: Processing Toolbox &gt; Vector Geometry &gt; Keep N Biggest Parts It removes the smallest polygons from a multipol May 29, 2016 · Do you require a dissolve type operation (i. Nov 22, 2017 · Best option I have found from looking around for same issue is. Is it possible to remove only two small regions (shown in the figure) from the whole district? When I try to find its identified features they have nothing in it, just overlay shape that I want to remove. GIS: How to delete and reconnect lines in a polygon in QGIS? Helpful? Please support me on Patreon: / roelvandepaar With thanks & praise to God, and with thanks to the many people who have made GIS: Removing overlapping polygons using QGIS Helpful? Please support me on Patreon: / roelvandepaar With thanks & praise to God, and with thanks to the many people who have made this project GIS: Filling holes in polygons automatically using QGIS Helpful? Please support me on Patreon: / roelvandepaar With thanks & praise to God, and with thanks to the many people who have made this 4 days ago · To represent the polygon boundaries concisely, the gaps between the polygons must be filled, and the polygon features merged. They are all in the same layer. Then I split it to shorter segments. 8. Dec 1, 2021 · GIS: Forcing QGIS to remove polygon borders? (2 Solutions!!) Roel Van de Paar 185K subscribers Subscribed How to Extract Smaller Areas From A larger Shapefile in QGIS Madhuraj PK 10. apply difference tool; input vector layer = original polygon layer, difference layer = clip polygon. If you zoom in you discover they are actually really narrow, linear holes in the polygon. I cannot find this functionality in QGIS. I'd like to remove them but I haven't yet found an appropriate workflow. I cannot for the life of me figure out how to delete just this small section. Feb 4, 2025 · 1 I am in QGIS, version Bratislava. Here there's a screenshot: I already tried: Delete holes (don't delete all of them) Doing Multipart to Single-parts and then delete holes Cre If you're worried about this possibility, use polygon centers that definitely lie within the polygon interiors. 84K subscribers Subscribe Jan 29, 2020 · Small gaps and errors could be addressed by using the QGIS snap geometries to layer tool or the GRASS v. Repeat Steps 6 to 9 to merge the other filled polygons with the adjacent polygons until all the gaps are filled and polygons merged. 3. Alternatively is there is a different way to easily produce the outline of the polygons? Feb 7, 2023 · "Learn the process of digitizing in QGIS, including how to create polyggon features, convert points, lines, or raster data into polygon data, buffer points or lines, and edit polygon vertices. Another possibility is to intersect the state and county layers and discard any small-area bits, then query what's left. be/8qb0jhFgZOQThis method remove holes which a Sep 23, 2019 · I am looking for an efficient method to edit and remove the space between multipart polygons in QGIS 3. Select attribute field to dissolve based on, set any advanced options as needed, choose the output file location, and run the tool. Select the big polygon and use the Cookie cut tool Draw the inner polygon and it will be cut out from the big polygon automatically. I have digitized 1600+ polygon boundaries that now have sliver polygons, gaps, and overlaps which I've confirmed via GIS: Removing lines from inside polygon in QGIS Helpful? Please support me on Patreon: / roelvandepaar With thanks & praise to God, and with thanks to the many people who have made this project This video shows how to iteratively clean-up vectorized layers. I have polygons that look like this. I cannot "undo" to remove them. Feb 5, 2025 · I want to delete small areas from my layer (Polygon). The split adds some points (as shown in figure) too near to each other. Attention! Aug 12, 2024 · To dissolve small polygons in a vector layer, you can use the QGIS dissolve tool in the Geoprocessing Tools menu. Nov 18, 2021 · I want to remove it and when I go down in toggle editing, delete part it removes the whole district. So Aug 18, 2020 · I have a vector layer being rendered in QGIS. Instead, you can merge the vertical streets with a neighbouring large polygon using "Vector / Geoprocessing tools / Eliminate sliver polygons", saving the result to a new file. Larger gaps might be addressed by creating a "background" polygon which is used in symmetrical difference to create "fill" polys to add to your layer and then use the Eliminate tool to add them to abutting polys. Sep 28, 2016 · Simply deleting the features won't help, since the polygons will leave holes behind, as you have already noticed. 18 to 3. 7. I have downloaded administrative boundaries from www. Full playlist : • QGIS Vector more In this video, we'll be learning how to Dissolve polygon features in QGIS. I'm a bit stumped as to why this is occurring. Mar 30, 2019 · Using QGIS v 3. clean for "Polygons from lines" and choose the cleaning tool "rmarea" and set the Threshold to something that works depending on smallest polygon Mar 25, 2022 · I need to fill/delete the lines inside the polygon. It will open popup where check the checkbox of selected features only. This polygon (orange) surrounds a road, but also has a sliver going straight across. Also It should be linked to a condition. be/iPiieHqWOIQRemove holes from polygons in QGIS: https://youtu. GRASS is the ideal tool for this: being a topological GIS, adjacency and correctness are preserved even at very high simplification levels. However, I want to get rid of the sliver that is connected to "proper" polygons as well. Then, I want to remove the small islands and keep only the mainland. We'll remove the duplicates from the attribute table as well as rem My pervious polygon crosses a small section of a drive way that I want to delete. This video is designed for beginners who are looking to Feb 23, 2016 · In order to delete separate polygons, you will need to convert this to singleparts by using the Multipart to Singleparts tool: Vector > Geometry Tools > Multipart to Singleparts. Please write it in the comments, if you have any advice to improve my tutorials o Aug 25, 2020 · QGIS has a few tools from Geology Checker to Snap Data to Snap lines to make your data cleaner. Sep 17, 2019 · I'm a regular user of the 'Eliminate Sliver Polygons' tool in QGIS. I know I can creating a separate layer and manually digitize the area, but there are many of such polygons. This is often much faster than tracing when adding polygons etc. I want to absorb these into the large polygon around the pixel (polygon). Step 2: Next select Vector -> Geoprocessing Tools -> Dissolve option. This comprehensive guide will help you to digitize your maps and bring your spatial data into the digital world. I want to delete various features in the layer. 0. results of applying clip polygon with difference tool to each of the original polygons. They were created incidentally because in the original, multi-feature vector, adjacent polygons which should have been flush with each other actually had a tiny amount of space separating them, but Nov 27, 2016 · 4 I want to delete isolated polygons (only polygons not adjacent to other polygons) smaller than a specified area. Is there a tool in QGIS available to do this? Aug 21, 2017 · 1 I have a river network, extracted from a DEM. This video will provide a step-by-step tutorial on how to extract or separate a specific polygon from a shapefile using QGIS. How to remove polygon/point/line from a QGIS layer? Dec 8, 2021 · I have a large GeoDataFrame with over 1 million polygons. Along with the contours I need, there are thousands of small geometries and points that I need to delete. Here's some clumsier ideas. clean tool. The other vertices must r I have transformed a . I joined the shapefiles using the sf R package, and have attempted to resolve the issue using R as well as QGIS. clean - alternative for sliver removal - Part VII Apr 4, 2012 · Hi all. Aug 24, 2021 · I saw Deleting sliver polygons after difference operation in QGIS? and got rid of the sliver polygons that are not connected to bigger polygons (black lines and the small polgon on the house). 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). dxf-file into a polygon shapefile. I would like to know if there is a solu Step 1: Now hold command key (mac) or contrl key (windows) to select all the polygons/features you want to merge. Do you ever need to remove a hole from a polygon layer in QGIS? If you do, this video shows you a simple method for doing it. I've tried using reshape tool and edit vertices tool but these only move the polygon not delete the section. Jul 30, 2019 · This is what I'm working on: How can I remove the parts of the land cover map that is outside the Baao map? I can't use the filter function since the land cover map does not have location data: Mar 13, 2012 · I'm new at this, a novice at best. If there are just remnant vertices because the lines over and underlapped, you can manually select those vertices and delete them. When using the vertices tool the lines don't show and sep Oct 23, 2025 · Many tools do this in a very rough way, and miss the adjacency and sometimes the topological correctness of polygons. We go through the command to apply the following operations- Filter polygons smaller than 100 How to Merge Multiple Vector Polygons/features into one Polygon on QGIS Spatial Data Hub 1. In this video we look at how split a polygon into two separate polygons or I have QGIS 3. I'm currently deleting each node by selecting the node through node tool and then pressing the delete b Feb 28, 2022 · In a polygon dataset, I have several thousands of features that have gaps mostly at the corner zones (see below). Dec 6, 2022 · I have converted a raster to shapefile (polygonize) in QGIS and now have some areas that are salt and pepper with small points. We will be using the geoprocessing tools in QGIS to do this. After dissolving a few polygons I got some unrequired lines inside one of the polygons that I couldn't delete. remove all polygons < X area)? Jul 7, 2023 · I have got a number of polygons within a single larger polygon. I'm using QGIS 1. Wh Mar 22, 2018 · 8 Is there a way batch remove or delete null geometries from hundreds of small polygon vector files in QGIS, while saving the new clean file to their original directories? I can't check for and fix geometry errors individually but I'm happy to give up some precision / data integrity / knowledge for a method that saves time. hope this helps:) GIS: How to remove thin lines and small points from qgis raster? Helpful? Please support me on Patreon: / roelvandepaar With thanks & praise to God, and with thanks to the many people who have Jun 7, 2019 · I have files that representes individual houses and blocks. Simplification reduces the complexity of the polygon by removing unnecessary Sep 10, 2020 · I have tried "delete holes" however QGIS does recognise the lines as holes. 🔽 CONTACTS 🔽W E B 👉 https://webstor Jan 6, 2017 · I have a polygon shapefile with holes (representing Islands and Rivers) within it as seen below: I need an automated way to fill the polygon in QGIS as seen below: That is remove all Islands and divisions within and outside the polygon. You may also like full tutorial how create custom GeoJSON from shapefiles using QGIS. 4. Convert lines back to polygons I get the following results. I can do a select analysis - area less than, but that removes ALL small polygons. 1. Jan 17, 2024 · This algorithm takes a polygon layer and removes holes in polygons. 4 and the 'Eliminate Sliver Polygons' tool isn't available. 10 I want to clip (remove) the polygon areas (yellow) in one layer from a larger polygon in another layer (gray). Zoomed out, it looks like there are lines in the middle of the polygon. Several of the polygons have very thin gaps created by the bounding line of the polygon and they do not penetrate the entire width of the polygons - see the attached picture: I have tried several methods to remove these with no success. I created a polygon layer of evenly spaced squares (see below). 7K views 2 years ago removing holes from polygons in ArcGIS • Eliminating/ removing holes in polygons in more In polygon vector layers it is not unusual to find overlapped areas and gaps, especially if they were digitized without using the snapping or other editing t Feb 21, 2016 · Remove islands and completely surrounded polygons after polygonization with QGIS Ask Question Asked 10 years, 1 month ago Modified 9 years, 9 months ago The plugin dissolves polygons whose area falls below a user-defined threshold. Is there a way to erase the line, boundaries, between polygons tha QGIS - Fill gaps and slivers between polygons - v. com/help/l) CC BY-SA. Unless zoomed in these extensions appear as dangles but when zoomed right A subreddit for discussion and all things QGIS - A Free and Open Source Geographic Information System. In the Merge dialog box, click the existing polygon feature and click OK to view the merged polygons. 16. It creates a new vector layer in which polygons with holes have been replaced by polygons with only their external ring. g. maximum area, distance between borderlines? I want to delete/fill holes that a very &quot;thin&quot;/sm Aug 26, 2015 · 6 If the number of polygons is relatively smaller and you prefer to keep the more detailed boundary I would probably make it semi-automatic way as following: remove the overlaps of less detailed polygon with Clipper plugin - you select more detailed polygon and use clipper which will remove all overlaps of other polygons. In this case, the plugin can dissect the overlaps into separate features and dissolve those features into the neighboring feature, with three options: largest area, smallest area or largest common boundary. The video May 17, 2024 · 24 To not have overlapping polygons/features, I normally use one or more polygons to clip/shape other polygons. This process is known as simplifying or generalizing a polygon. Either using QGIS/ArcGIS or gdal python / ogr. I simply want to select a large number of points on a single polygon and delete them. gadm. I have digitized 1600+ polygon boundaries that now have sliver polygons, gaps, and overlaps which I've confirmed via GIS: Removing lines from inside polygon in QGIS Helpful? Please support me on Patreon: / roelvandepaar With thanks & praise to God, and with thanks to the many people who have made this project Dec 28, 2020 · I extracted vertices using 'Extract vertices' in Processing Tool. That's simple. Deleting small areas from polygon in QGIS I hope you found a solution that worked for you :) The Content is licensed under (https://meta. You can select the problematic polygons and merge them to adjacent polygons based on a common boundary or area propotion. @Andrew suggested that I associate each line with adjacent polygon but I do not know how to do it in QGIS. The "mainland" polygon has a hole in correspondence of San Marino. May 14, 2021 · I would like to simplify the raster by grouping large groups of pixels and removing very small 'islands' of pixels. I can use "Points along geometries" and pinpoint where these useless points are, but I can't seem to figure out how to delete them from the original layer. merge smaller polygons with larger polygons) or a simple select (e. Parts of the smaller polygons go out from under the larger one, and I want to delete the parts of the smaller polygons, that go outsi Sep 16, 2015 · Removing small areas from raster layer using QGIS? Ask Question Asked 10 years, 2 months ago Modified 3 years, 9 months ago Sep 6, 2019 · How to remove sliver polygons in QGIS? dev via the OSGEO installer, see qgis homepage) is a new function in the vector menu called “Eliminate sliver polygons”, which exactly does what you want. I am currently working on merging polygons on a geologic map together and I am finding that when I merge them together I get these lines sticking around. I have a big, detailed layer of polygons that represents Italy. e. The Advanced Digitizing Toolbar in QGIS is really great if you need to edit your layers in QGIS - particularly polygons. Aug 19, 2021 · I'm using QGIS 2. 5 installed on my 64bit Windows machine. It is also very important that they QGIS - Delete holes - Remove gaps or holes inside polygons after dissolving the layer Bhaskar Reddy Pulsani 5. Slivers and gaps keep your dataset from forming a continuous fabric and should be identified and fixed as appropriate. remove all polygons < X area)? Aug 12, 2024 · Quick answer summary: How do I dissolve polygons in QGIS? To dissolve small polygons in a vector layer, you can use the QGIS dissolve tool in the Geoprocessing Tools menu. It is slightly better than before but still I get areas outside original polygons (see white areas in the picture below). I have a polygon layer in which some shapes have a very narrow extension that i would like to remove. #qgis #gis In this video we will see how to detect and correct the geometry of overlapping polygons in the same layer. Wanna brag? Show us your stuff. This article touches on Geometry Checker. Some of them are partially overlapped. In this video we look at how to simp Subscribed 17 3. I've just switched from 2. I am still trying to complete simplifying polygons process. stackexchange. using qgis 2. Dec 11, 2020 · I have a shapefile with buildings defined as polygons. Deleting the vertices 1 In QGIS 3. I managed to create a feature layer using[Select Attribute]. 10. I have alr Most map data sourced from third parties contains features and information outside of your area of interest - here's how to quickly and easily clean it up! Do you ever need to remove a hole from a polygon layer in QGIS? If you do, this video shows you a simple method for doing it. Any ideas and thoughts to delete the holes? Aug 31, 2020 · Not only did that eliminate over 900k small polygons, but it also nicely smoothed out the line without giving up too much accuracy. Here is what I'd like to achieve in QGIS. I have tried the dissolve and delete holes tools, but did not work for me. It is fine of this makes my polygon incomplete, that doesn't matter. I'd like to exclude all the observation points that fall outside my region of interest (the polygon). The highlighted polygon is overlapped by the adjacent (west/left) polygon with a straight edge. How to use a polygon as a mask to delete portions from another polygon? Let's say you have a big polygon, and a smaller one over the bigger one. I have an example below which should hopefully be clear: Multipart polygon Final result I kn How about: buffer the lines with a small positive buffer buffer these buffers with an even smaller negative buffer to make polygon "islands" that are close to the vector lines use "keep n biggest parts" (n = the number of longer lines you want/expect to end up with) so you only keep the largest buffer "islands" use the remaining buffer polygon layer to clip the vector lines so you lose all of My pervious polygon crosses a small section of a drive way that I want to delete. QGIS is also showing the output as one large polygon too. . Is there a processing tool to remove the overlapping part of polygons? It does not matter which polygon gets clipped. Try it out! What are slivers in GIS? Sliver polygons are a small area formed Dec 14, 2023 · Is there an option in QGIS to fill holes in polygons automatically by setting parameters e. If there is a very small but complete gap between them you've created multipart polygons. 5K subscribers Subscribe Mar 24, 2021 · I am looking for a QGIS tool that would allow me to remove extra vertices on a line or segment of a polygon. Aug 3, 2025 · 4 I have a polygon that is my region of interest. I wonder how I should remove those small lines and simplify the segments? GIS: How can I remove the gap between two polygon boundaries in QGIS? Helpful? Please support me on Patreon: / roelvandepaar With thanks & praise to God, and with thanks to the many people who Nov 5, 2021 · 2 I am working in QGIS 3 and I have a shape file containing many polygons. What I want to leave is at the beginning and the end of the l How about: buffer the lines with a small positive buffer buffer these buffers with an even smaller negative buffer to make polygon "islands" that are close to the vector lines use "keep n biggest parts" (n = the number of longer lines you want/expect to end up with) so you only keep the largest buffer "islands" use the remaining buffer polygon layer to clip the vector lines so you lose all of In this tutorial, we'll go over the steps on how to remove duplicate records using QGIS. The user can also choose an adjacency by common largest border. Is this possible? This is an easy way to dissolve touching polygons and split them afterwards. You need to fill that gap before merging to get rid of the "line". QGIS - Fill gaps and slivers between polygons - v. Got a problem? See what the community thinks. This article provides two workarounds to fill the gaps between polygons, using the Autocomplete Polygon tool, or the Union tool, in ArcGIS Pro. But so many unnecessary vertices extracted, so I want to remove them. In this video we look at how to add holes to polygons, how to add islands Jul 17, 2022 · I have a polygon shapefile.