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

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4answers
1k views

How to buffer in pyQGIS?

I'm looking for some examples to do simple python scripts in QGIS. How would I do a buffer analysis on a dataset? I can't seem to find much in the manual and QGIS python that quite matches the Esri ...
5
votes
3answers
1k views

Dissolving polygons by attribute and in a certain distance (ArcGIS)

in a FeatureClass I have a lot of polygons which contain attributes of different landuse-types. Now I am trying to dissolve those polygons of the same landuse-type, but only if the distance between ...
3
votes
1answer
479 views

FME remove polygon holes of under size ### sqft and chop the ends off

Quetion #1 I have a wokspace that takes the latest version of my data and creates buffers and then merges those to one polygon. When 2 buffer polygons are near each other and close to create a hole. I ...
5
votes
1answer
347 views

How can I create a pollutant dispersion raster in QGIS?

As my previous questions have indicated, I am working on an air quality problem where I have a dataset of industrial emissions that consists of a location (long, lat), and an annual volume of ...
5
votes
1answer
151 views

How do I find location of minimum value within a buffer (around a point)

I have a digital elevation model (DEM) with a point location defined. I want to locate the lowest height values at a set distance from this point. I envisaged creating a buffer around the point ...
5
votes
3answers
634 views

Is it possible, in QGIS, to create buffers with a set radius, but with individual values taken from the attribute table?

I am looking to create an output that consists of an 11KM buffer around a number of discrete points, where the buffer has a value defined by a column in the data sets attribute table. Is this ...
0
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2answers
293 views

QGIS regular points around each polygon in a layer (vs ALL polygons)

I have a number of buffered points (some where polygons intersect & are dissolved. I'd like to create regular spaced points grid around EACH polygon -- not ALL polygons. When I do Vector -> ...
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vote
1answer
761 views

create buffer around locator-derived point

I am trying to create a buffer around a point derived from a locator search, using this example: http://help.arcgis.com/en/webapi/javascript/arcgis/help/jssamples_start.htm ..but I am getting no ...
5
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2answers
200 views

Using newly created features in the next part of a python script

Good Afternoon I am trying to write a python script which buffers a large number of features from a geodatabase (but not all) and then dissolves the newly created buffer shapefiles together. ...
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vote
1answer
232 views

How to fit a polygon to a “best buffer” about a reference geometry in it?

If I have a polygonal geometry gbase, like a street (a rectangular strip), and a reference geometry gref, like a central line of gbase. The question is what is the function (here named BestBuffer) ...
5
votes
1answer
214 views

What is the width of the beach of a little island polygon?

This is a "classic" problem, that have no practical utility (see note-1 for applications), but illustrate another GIS problems... We can do some approximations to modeling the situation, the real ...
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vote
3answers
681 views

In ArcMap, what is the difference between Copy Parallel and Buffer?

To build an offset of a linear feature in ArcMap, what is the difference between Copy Parallel and Buffer? In terms of the resulting features and their linear differences from the source linear ...
2
votes
1answer
284 views

Python add-in won't buffer from output layer

I have a simple add-in script for Arcmap 10.1 to create a toolbar, select a layer from a drop down list of the current layers in the project, buffer that layer four-miles, then use the resulting ...
2
votes
1answer
503 views

Geotools // buffer using different CRS

I'm currently having a problem with Geotools. I try to generate a buffer (in meter using Lambert 72) on a map that has WGS84 as it's coordinatesystem. (problem is a bit like this one: ...
7
votes
3answers
523 views

Is there a st_buffer inverse function, that returns a width estimation?

When you supply a geometry g1 and a width w to the standard OGC function ST_Buffer, it returns a new geometry g2, g2 = ST_Buffer(g1,w) This question is about the inverse: a function where you ...
10
votes
2answers
1k views

How to buffer a line with different distances for left/right sides

How can I buffer a line in QGIS using one attribute for the left side of the line and one attribute for the right side of the line? I am trying to buffer a river with its bank width, which is ...
0
votes
1answer
529 views

How can I make a buffer with xxx meter by NetTopologySuite

I am very new in NetTopologySuite, I work with the coordinatesystem in WGS84 by lon/lat, with the NetTopologySuite. I found the Buffer function to create a buffer with a distance, but how can I make a ...
5
votes
2answers
601 views

memory issue when trying to buffer/union large dataset using postgis

I am trying to generated a dissolved buffer of a large point dataset (Ideally 29 million points - Address data in Great-Britain, but I receive the data by chunks of 1 million points, so these could be ...
6
votes
1answer
347 views

How to generate non-merging buffers in QGIS?

I'm using QGIS to construct some fixed width buffers from a coastline shapefile. Is there a way to easily handle overlaps/ median lines? (I'm not sure if there's a particular term or phrase I should ...
0
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1answer
200 views

Buffer and Intersect differences

“What is the difference between ‘Select by location using a buffer or intersection’ and the ‘Buffer’ or ‘Intersect’ Analysis tools?
2
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0answers
321 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 a question on how to create a Polyline Buffer ...
3
votes
2answers
3k views

Creating a Polyline Buffer in OpenLayers

I was wondering if there was a way to create a buffer around a polyline feature in OpenLayers. I have created a tool that allows the user to draw a circle buffer zone of whatever size and style they ...
3
votes
1answer
2k views

How to create a polygon (fixed width buffer) around a polygon in QGIS?

I have created a polygon in QGIS (in this case it describes a country's maritime baseline). I need to create a second polygon whose boundary is a fixed distance from the original polygon. (in this ...
4
votes
3answers
337 views

Buffering with physical barrier using ArcGIS for Desktop?

I don't think it is possible, but I'm looking for a way to stop my buffer at a certain physical barrier. For example, I have point near a river and I'm creating a buffer around my point that is ...
3
votes
1answer
297 views

How to calculate buffer surface that falls within another layer's borders

The image below shows what two selected layers. One contains a series of borders, and the other a series of buffers. I am trying to obtain the buffered surface within each of the borders in the ...
4
votes
1answer
247 views

Surface covered by buffers in QGIS

In QGIS, I have plotted buffers around points. I would like to calculate the area which falls under buffers without over counting due to buffer overlaps. Is there a quick and easy way to do this?
7
votes
2answers
820 views

Growing a PostGIS geometry by a percentage

I'm looking for a way to add a buffer around a PostGIS geometry, but the size of the buffer should depend on size of the geometry. That is, I want each geometry to be enlargened by, say, 5%. The idea ...
1
vote
1answer
390 views

how can i use flat buffer for polygon?

i'd like to create flat buffer in a polygon shapefile .i try to use buffer tool in ArcGIS 9.3 but i could'nt select "flat" option in endtype combobox because the input feature is polygon .how can i ...
12
votes
4answers
9k views

Creating square buffer around point feature using ArcGIS for Desktop?

I would like to create a square buffer from a point feature but I do not understand the code that goes into it. Similar questions have been asked on the forums.esri website but that was over 10 ...
2
votes
2answers
1k views

polygons won't buffer in ArcMap

I have been trying to buffer 15 polygons (-15m) in ArcMap. I did a batch buffer and 13 polygons worked fine, the other 2 have not buffered, an error occurs: WARNING 000117: Warning empty output ...
5
votes
1answer
430 views

What is the unit of measurement for buffer calculation?

What is the unit of measurement used by Geometry class for it's buffer calculation ? Api doc currently defines it as " distance - the width of the buffer (may be positive, negative or 0)" I need to ...
2
votes
1answer
226 views

Query for segments at same place and time in PostGIS

A newbie-question: I've imported the segments of several GPX-Tracks in a PostGIS-Table. Now I'm looking for a query that returns all segments that: are spatially overlapping (within a specific ...
13
votes
2answers
720 views

ArcGIS Buffer accuracy problem

world, once again I encounter something very strange with ArcGIS. I perform a buffer analysis on one side of a polyline. There seems to be a serious accuracy problem and I can't figure out what the ...
2
votes
1answer
157 views

Overlapping buffers - Doublecount points that fall within 2 or more buffers

I want to analyze crime around certain types of stores in a city. I made buffers around the stores and I need to a) select and extract crimes that occurred within those buffers, and b) join the two ...
4
votes
1answer
2k views

Best way to get Convex Hull/Boundary of millions of points

I've been trying to do some point analysis on some xyz data, I'm at the point where I've decided it is best to produce a boundary of my xyz files and put this with the metadata for each survey. Now ...
2
votes
1answer
229 views

how to extract overlap from non-dissolved buffer zones in qgis 1.7.4

I have a shapefile with the inventory of all limetree in a region. I made a buffer around each tree. So, the place where buffers overlap each other is the best place to put beehives. Is there a way ...
3
votes
2answers
2k views

ArcGIS 10: How to clip point buffer to features in another layer?

I'm on a steep learnig curve here, so aplogies if my question is a one-banana problem. In ArcGIS 10 I have a contour layer that was generated from an ESR ASCII raster file (batyhmetry of the South ...
8
votes
2answers
2k views

Creating “Inner Buffer” using ArcGIS for Desktop?

I am currently searching for how to create an "Inner Buffer" in ArcGIS for Desktop? I have a lot of polygons (houses) in one feature class, and one big polygon (in another feature class). I want so ...
3
votes
1answer
911 views

How to obtain statistics within a Buffer/Catchment in MapInfo?

I need to calculate the population statistics within a 10 minute drivetime catchment from a point and within 1 Km Buffer from a point in MapInfo, how can I do that can someone please elaborate? I have ...
5
votes
2answers
715 views

Create a polyline buffer with Arcpy

I'm trying to write a python script with ArcPy that draws arcs and I've achieved something with creating a buffer and then clipping it with a bounding box so I only keep the length I need (I thought ...
5
votes
1answer
284 views

Geodesic buffers for polygons

How can I create geodesic buffers around polygons? I'm on 9.3.1 ArcMap, but I need a programatic solution. IBUfferConstruction only does geodesic buffers for points. What are my options?
7
votes
1answer
4k views

Understanding QGIS buffer tool units?

I have been trying to figure this out for a couple weeks now and have had no luck getting the buffer tool to accept anything but degrees as units of measure. I have found lots of stuff saying the ...
3
votes
2answers
821 views

Generate non-overlapping shapes from a buffer

I have a collection of points, and I need to generate shapes around these points. Let's assume that these points are locations of offices and that the shapes are the 'area of responsibility' around ...
3
votes
3answers
1k views

Is it possible to create multiple buffers using QGIS?

I'm new to QGIS and have no programming skills, is there an easy/uncomplicated way to create multiple buffers around a line feature.
0
votes
1answer
290 views

Generate a report or table for buffer zone

I have a polygon feature class. I create a buffer for this feature with a distance being 2 km.Now the buffer output intersect with features of the original polygon.So say for instance from the orginal ...
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vote
2answers
247 views

Buffer point dataset based on compared value

I am creating polygons from the dissolved buffers of points and need to control the dissolve process. In the model the first stage is to assign high/med/blackspot using the following f2='ERROR' def ...
3
votes
1answer
289 views

ArcMap: extracting overlapped buffers

I have a set of points in ArcMap which I create a buffer for each point. Then I use intersect to extract the overlapping buffers. The result is something like this: The lighter color are the ...
2
votes
2answers
158 views

After two buffers operations (+/-), why is the result file bigger than the original?

First file ( .shp ) had 1000KB, after 2buffers ( buffers on polygon, 1st buffer +100, 2nd buffer -100 ( small things near polygon should be removed )) in quantum gis file grown to 1500KB, and after ...
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vote
1answer
503 views

Converting distance between nautical miles and degrees

This is such a basic question that I'm kinda of embarassed. Here is the situation: We have a certain funcionality developed that: Will check for a tolerance value (this input is given by the user ...
0
votes
2answers
521 views

How to remove overlapping buffer in QGIS?

I wanna know how to do this in QGIS: I've tried many ways, but still can't find the right solution.