Questions tagged [buffer]

A region enclosing a point, line, or polygon at a specified distance.

132 questions with no upvoted or accepted answers
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348 views

how to buffer a line with varying distances associated with directional quadrant with open source GIS?

I would like to buffer a set of lines with different distances to the NW, SW, SE, and NE. I have the distances stored in four attribute fields that correspond to the direction the buffer should be ...
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100 views

Variable width buffer based on axis directions in QGIS

I need to buffer a polygon with a different distance in the x and y directions. I should add that my polygon has the following properties: closed (obviously) simple (no edge crossing, no more ...
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97 views

Single Sided Buffer Error QGIS

I have delineated a shoreline and created an offset "buffer" of 75' and 250'. When projected onto the screen it appears as though a computation error has occurred and the buffers extend onto the left ...
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70 views

Creating Raster that sums up input polygons using QGIS?

I am using QGIS and I have a shapefile with buildings. From these buildings, I have built Buffer with variegating radius. The Buffer also have data about the demand for Parking spots for each building....
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195 views

Using transform function in QGIS layer geometry generator?

I'm trying to use the following expression in the geometry generator in a QGIS layer to show a 1-mi boundary around points: buffer(transform($geometry, 'EPSG:4326', 'EPSG:2877'), 5280) However, the ...
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154 views

Drawing “proportional” buffer using QGIS or GRASS?

I'm working on aquatic vegetation and have a shapefile representing floating vegetation in a lake. By some studies, we know that submerged vegetation extends for a certain extension based on floating ...
4
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326 views

How to Simulate Venn Diagram of Buffers using QGIS?

For the sake of simplicity, suppose I have only 2 points on one layer. Point A have population of 100, and point B have population of 150. I do find buffer of these 2 points and it is intersect. I ...
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1k views

Buffering a Raster with GDAL and Numpy

I am using GDAL to convert a raster dataset into a numpy.array and then using numpy to buffer the data in the raster. For example, I need to know all the regions within 100ft of a school point ...
3
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42 views

What is the name of the popular buffer algorithm?

There is a well-known algorithm that I believe is used for the "buffer" function in some GIS libraries and applications. I have a vivid memory of reading the paper that describes the algorithm and ...
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45 views

How to use the output of one run as input to the next in QGIS batch processing?

I'm trying to do a series of buffers using the processing batch interface, and I want to use the output of the first run as the input to the second (and so on). But I can only pick an existing file or ...
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92 views

Expanding polygons and clipping at midpoint?

I have several separate shapefiles with polygon features. The end goal is to maintain separate shapefiles for each polygon but form a contiguous, non-overlapping coverage for my area. Basically, I ...
3
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247 views

How to apply a rectangular buffer on spatial polygons in R/qGIS

I am trying to find a way to apply a rectangular buffer on my spatial polygon dataframe in R. At the end, I would like to be able to shrink my polygons by specified units on both sides. So far, I have ...
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76 views

How do I report area statistics for land cover classes at equal sections along a river?

I have a river outlined: Using QGIS, the Semi-automatic Classification plugin and Landsat 8 images I classified the habitats (blue=water, yellow=sand/rock...,green=vegetation/algae) inside the river ...
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254 views

Displaying symbology outside map canvas window extent?

Say we have equally distributed x,y mesh vector file. Each coordinate has a map-unit based diameter circle symbology. If we zoom into a region of the map canvas far enough, some centroids exist ...
3
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340 views

How to use buffer() in QGIS Value Relation field

When adding a point, I'd like to auto-populate one of its fields (the street address) setting it to a field in the nearest point in another layer (a layer containing all existing addresses). It ...
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32 views

Calculating variable buffers using slope between river and point 100' away using ArcGIS Pro?

I have a network of streams that I need to buffer based on a basic rule set. This buffer will depend on the slope. The slope is determined by the looking at the difference in elevation between a ...
2
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1answer
93 views

Subdividing square buffer in sub-units using QGIS?

I've been trying for a while now to create a grid inside a square buffer, so that it can be divided into a pre-defined number of sub-units. Creating a grid that covers the whole area is not ideal ...
2
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40 views

Searching on the fly within buffer in QGIS

I am using "Unique Values" widget with "Editable" option in QGIS 2.18.3, for my "Name" field in POIs layer to eliminate spellings mistake. "Unique Values" widget fetches all the distinct values in a ...
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165 views

RasterizeLayer in GDAL Java

As per the suggestions given by Michael to one of my earlier query (URL given below), I have tried to develop a sample code to perform rasterize using GDAL Java API methods. I had written based on ...
2
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0answers
86 views

Converting single point layer to buffered raster using QGIS?

I'm trying to use the proximity tool to create a distance raster from a single vector point. I found here: Calculating distance to points in QGIS and [d-3] Create Proximity Raster. However, I couldn't ...
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102 views

QGIS - Label Rectangle/Buffer Overlapping Layer Above

When I apply a buffer or rectangle to my labels they show through the overlying layers. Is there any way to avoid this, i.e. arrange the label so it lies underneath the layers above? I'm assuming the ...
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50 views

Achieving the opposite of the shortest_line() function in QGIS?

I currently use the Geometry Generator styling on a point layer to draw the intersection between protection buffers around tree points and another polygon (say a building footprint) using the ...
2
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73 views

“two ways” Reclass QGIS

I'm a forestry technician and I've one question dealing with forest road planning... in order to calculate areas that can be cover by a specific machine (with a given work distance) I do as follow: "...
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144 views

Is there an open source library that offers geodesic buffering of large polygons?

I need to buffer some large polygons and minimize distortion. Is there an open source library that offers negative and positive geodesic buffering of large polygons? I am aware ESRI has an ...
2
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54 views

wkid error using buffer GeometryService - ArcGIS JS API 3.2

First of all, going to this url for the geometry service referenced in the documentation shows it's been deactivated so I instead chose this url - both with /GeometryServer and /GeometryServer/buffer. ...
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185 views

Flat-ended buffers on touching polygon features in QGIS?

Please note that emphasis is on POLYGON here NOT POLYLINES! I need Buffer/s on one polygon, with two touching features and straight touching parts after difference has been applied I do not want ...
2
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62 views

Buffer function crashing QGIS only on specific data set

I'm trying to run the buffer tool on a line and it keeps crashing Qgis. The line is created by merging two sets of gps point data and running points to lines with gps_date as the order. I have no ...
2
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406 views

Fixed Distance Buffer not Buffering Features with Holes

QGIS 2.18.5 I've created a viewshed over a hilly area and I would like to add a fixed distance buffer just to compensate for any underestimations from the viewshed plugin's result. This is the ...
2
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479 views

GRASS v.buffer.column and v.buffer.distance - Incomplete Output

I have tried .column and .distance buffers within QGIS and both are leaving me with incomplete results. Only a few of the features within my input file are actually being buffered. I also have both "...
2
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94 views

Automatically split line at intersection of nearby shapes/zones

I have a large dataset in QGIS with roads (blue line in picture below) and 3 type of zones (mostly rectangular areas, red and green shape in picture below). My task is to spilt to road into segments ...
2
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62 views

Creating a cumulative factor based on multiple buffers

I'm using QGIS 2.12.0 and am trying to formulate a hierarchy for the risk factor associated with footpath polygons based on their proximity to pedestrian generators and the importance factor of that ...
2
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0answers
2k views

Extract values from Rasters in R based on spatial points and spatial polygons

I am trying to extract values from a raster file using the extract command in R mentioned here: http://www.inside-r.org/packages/cran/raster/docs/extract My raster file is unprojected (WGS84 ...
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166 views

How to create buffers having regard to topography with QGIS

I want to create buffers of 25 kilometers around points in a point-shapefile with QGIS. My problem is that I don't need an air-line distance of 25 km around the points, but a "real distance" having ...
2
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213 views

ST_Buffer with segment AND endcap parameters

Making a QGis plugin that buffers a line and I want to declare a high number of segments and a flat endcap. ST_Buffer(geom, 40, 25, 'endcap=flat') This doesn't work with both parameters entered, it ...
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72 views

Distribute Hotel Beds According to Population Density in Buffers using ArcGIS for Desktop?

I am running an ArcGIS for Desktop analysis where I am plotting competing hotel facilities and then distributing their beds in a 5-mile buffer around the site. I would like to distribute the beds ...
2
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76 views

Distribute population to health facilities (GP Practices)

I have been using GIS (ArcGis) for some years but I do not consider myself an expert. I am performing some analysis around GP Practices in London (UK), I would like to be able to estimate the ...
2
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117 views

Determining homogenous blocks of individual tree species in a woodland, and creating a new shapefile without blocks/polygons of < minimum area?

I'm working on a project attempting to identify suitable woodland habitat for red squirrel translocation wherein conservation efforts could be focused. Below is a small section of the map showing ...
2
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0answers
303 views

Large buffers in PostGIS (5000 km radius)

I have a number of points stored as geographies in PostGIS (version 2.0.1), and I'd like to create rather large buffers around them (with a radius of 5000+ km). However, ST_Buffer doesn't handle this ...
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0answers
204 views

How to spatial join points attributes to layer with two (or more) overlapping buffers in QGIS?

I'm working with QGIS 1.8 and I've got 3 layers : 2 points layers, and 1 layer composed of the buffers of one of the points layer. I'd like to retrieve the informations, for the point layer that isn'...
2
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0answers
570 views

Creating a Geodesic Polyline Buffer in OpenLayers

I have a feeling that the answer is going to be 'You can't do that without some very complex coding' but I thought I'd go for it anyway. I recently asked Creating Polyline Buffer in OpenLayers 2?, ...
2
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1answer
711 views

Variable buffer radius in ArcGIS JavaScript API?

I'm trying to combine the following Esri samples, to end up with the ability to create buffers based on a variable radius, that will then query data within the buffer zone. https://developers.arcgis....
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16 views

Creating buffer of points with pre-defined area?

I need to create a buffer with a predefined area, my inputs are points, at first I tried it by calculating the area that each buffer may have and then giving the radius as an input, but then I have to ...
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0answers
20 views

QGIS 3.6 QUICKOSM buildings query CRS with metre untis to create buffer

Using QGIS 3.6.2 I'm running a QUICKOSM query to find residential buildings in Scotland. I want to then put a buffer around them. The query is fine, if a little slow. The only CRS I can get to ...
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32 views

PostGIS - Get geofence polygon points within 100 metres of an existing geofence

Let's say I have a geofence polygon with the following coordinates POLYGON((-36.861986 174.726745,-36.859241 174.730442,-36.859821 174.730976,-36.862321 174.728156,-36.861986 174.726745)) I'd like ...
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21 views

Creating buffer around points (layer + map in the same PCS)?

Currently creating a map of fire stations in LA and want to create a 50-mile buffer around them. My project right now is in NAD 27 / EPSG:26799 (Projected CS). I also managed to save my shapefile with ...
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31 views

QGIS Multi distance buffer units do not align with the main layer

I have a buildings shapefile of Beijing. I know the projection WGS_1984_UTM_Zone_50N WKID: 32650 Authority: EPSG So I would like to create multi distance buffer from a central point but when I do so, ...
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0answers
69 views

Fixed distance buffer is oval in QGIS?

I want to create circles of diameter 20m in QGIS. I create a point and then use vector - geoprocessing tools - fixed distance buffer. My problem is that the size is crazy and worse, the shape is not a ...
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0answers
24 views

QGIS3 difficulty drawing 150km distance buffer and showing this on the map

I wanted to construct a 150km distance buffer around a city in North America. I changed the project co-ordinate system of the point to WGS84 Mercator North America from WGS 84 Lat/long to enable the ...
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0answers
47 views

Shoreline assesment via buffer

I've been looking around but haven't found an answer to match. I have a number of endpoint rates (EPR, I'm working on shorelines), and I want to know if it's possible to create a buffer based on the ...
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0answers
32 views

Points from polygon with buffer

How can I get points from polygon considering a buffer zone where within that buffer only one point will be generated. I have a few polygons for suitable locations. Now I want to make points from them,...