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

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4
votes
1answer
336 views

How to create a buffer on a linestring with varying or increasing/decreasing width

I want to buffer rivers/streams for a topographic map. I'm using a PostgreSQL/PostGIS database. Usually, I create buffer with ST_Buffer with a constant width. For example, the width of a river buffer ...
1
vote
1answer
120 views

What is the minimum buffer zone to get a certain amount of points within the zone?

I have one map with lines and another map with points. I want to find the distance of the buffer zone to be such so the amount of points that are in the buffer zone to reach a certain number. For ...
2
votes
1answer
329 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 ...
-1
votes
1answer
70 views

ST_buffer display creates big circle [closed]

$result = pg_query("SELECT ST_Astext(ST_Buffer(ST_GeomFromText('POINT( 80.7605 7.67833 )'),1))"); ST_buffer display creates big circle..
2
votes
1answer
168 views

Buffers with Varying Distances around a Set of Points

I have set of points in one shapefile and I have a table with a unique identifier that matches each point. I want to make a buffer around each point, according to the radius that I have specified in ...
1
vote
1answer
161 views

Buffer from Field using Different Unit

Is it possible to create a buffer polygon using an attribute field which is in different units than the feature class coordinate system? Example: I have a field that stores distances in miles (double ...
2
votes
1answer
45 views

Applying distance/area dependent procedures in geographic coordinates over large areas?

I'm currently doing some niche modelling with data in geographic coordinates spanning all of Latin America. I am using R for my analysis. Some of the tasks I have to perform are area/distance ...
1
vote
0answers
76 views

How to calculate the area of overlapping buffers within a single layer

I am very new to GIS, so don't know if this is EXTREMELY easy or impossible. I have GPS coordinates for stores (about 15000) for which I have created a buffer zone around each store location ...
1
vote
2answers
179 views

How to split a (road) buffer using the centerline?

I have a road centreline dataset which I have buffered using the road width. I used the standard QGIS buffer tool. I realise for my analysis I actually need to split the road buffer in half and ...
0
votes
1answer
120 views

WFS Filter Buffer around a point

I'm trying to make a buffer around a geometry (point/s,linestring,etc) using WFS queries without luck. This is what I've been doing: <ogc:Filter> ... <ogc:Function ...
2
votes
1answer
73 views

How to do the overlap detect for buffered lines

We have almost 50000+ lines which we want to remove a line if it is too close to the other. So we tried to do a buffer for two line, then check if the buffer area are overlapped. I wonder if there ...
0
votes
1answer
116 views

QGIS convert polyline to fixed width polygon

I have a shp file of polylines for trails, and I need to convert them all to be polygons that are 8 ft wide (4 ft from the center of each side of the polyline). I tried a following a few other posts ...
0
votes
0answers
61 views

Is it possible to use custom (non-circle) buffer shapes?

I have a shapefile containing points. I'd like to replace each point by the same shape, centered around the point, like the "Buffer" tool with shapes other than circles. How can I do that?
2
votes
1answer
248 views

How to load a memory layer into map canvas an zoom to it with pyQGIS?

I would like to load a vector memory layer into the map canvas with pyQGIS. Background is, I create a memory buffer layer around point data. While iterating the points I would like to visualize the ...
1
vote
2answers
1k views

QGIS - Continuous buffer image [Heat Map]

Is it possible to have the representation like the one the heat-map like the figure below using QGIS? The way seems to use buffer options, but I do not know how. Does exist any plugin that helps? I am ...
0
votes
0answers
75 views

v.buffer angular buffer doesn't take all the polygons into account

I am trying to create an angular buffer around building footprints with the v.buffer command (QGIS 2.2). There is no error message, but the algorithm doesn't take into account all the buildings. This ...
1
vote
2answers
132 views

Create buffer in Metres

I want to create a buffer in meters around points in Europe. But I cannot find a proper CRS for Europe that is in meters instead of degrees?
1
vote
0answers
62 views

How to Buffer with Dissolve ALL on very large polyline dataset? [duplicate]

So I have a fairly large polyline network covering a decent chunk of North America, containing just shy of 900,000 table records. I want to do some very simple "GIS 101" kind of processing to it -- I ...
0
votes
1answer
78 views

Using the buffer tool in ArcGIS 10

I have a map that has a 12 mile buffer round it already. I have created a buffer inside the original 12 mile line (using a negative value of 9). Is it possible however to stipulate that the new buffer ...
0
votes
1answer
88 views

Generating buffers in a automate way

I would like to creat buffers in a automate form and no matter the way (e.g. script, batches and etc) I am asking if anybody here knows how to do it or if are there scripts ready to do it. My ...
2
votes
2answers
525 views

Sql Query for percent of buffer filled with objects

Hi I am trying to write a query to find the percentage of a buffer polygon (Called 250_Buffer) that is filled with or contains other polygons in another layer (Called Development) any help that you ...
-1
votes
1answer
65 views

Esri ArcGIS 10 - using ArcPy to select buffer line by length

I created a buffer, then converted polygon to line (around a city block). I want to select the internal line. I'm thinking since there is no uniform way that ArcGIS labels the interior or exterior ...
11
votes
5answers
8k views

Performing a reverse clip in ArcMap?

Is there a way to perform a 'reverse' of the clip function in ArcMap, I'm not exactly sure how to explain this so here's a diagram:
0
votes
1answer
205 views

batch buffer with different distances with python 2.7 in arcgis 10.1

I am trying to write a "smart" way in Python to process multiple buffer to lines, polygons and points with different distances. I use Python and ArcMap 10.1. I can figure out to separate lines, ...
2
votes
1answer
330 views

Large Dataset Buffer Help

Using ArcGIS 10.1. I have a large polygon feature class (130,000 records). I need to do an inside/outside buffer (+5 then -5 to fill in some gaps)... the process takes so long, I'm looking for a way ...
5
votes
4answers
2k views

How to improve upon ArcGIS Buffer/Dissolve performance?

I'm wondering if anyone else has experienced significant performance penalties when using the ArcGIS buffer function with the 'dissolve' option on point features. My dataset is a shapefile of 260 ...
7
votes
1answer
673 views

Is there a significantly faster way to buffer than arcmap? [duplicate]

I hope this question is appropriate here and I apologize if it is more of a discussion question than a specific technical problem. I have to buffer 150,000 polygons for a real estate project. While ...
2
votes
1answer
281 views

How to Buffer based on SQL expression?

Is there any way to optimize this code? It creates two buffer feature classes based on two different fields in the shapefile attribute table import arcpy from arcpy import env ## Set Workspace ...
0
votes
1answer
770 views

Geodjango: Using Lat / Lon to Buffer from Point

I want to have a radius based distance search. To do this, I want to create a buffer around a point object so that I can filter objects that are inside this buffer, a method that I learned based on a ...
1
vote
2answers
337 views

QGIS radius buffer question, can it be more circular?

Conundrum for the day, When I request a radius buffer in QGIS (Dufor). my buffer comes out as a 20-sided polygon rather than a true "circle". This has lead to some missed blocks when clipping ...
1
vote
1answer
89 views

How to extract information from a buffer in ArcMap

I have a buffer in ArcMap 10 extending from a polyline, with numerous 5 km intervals (multiple buffer tool). I also have many layers already in raster format in ArcMap, including slope angle, geology, ...
0
votes
1answer
89 views

USGS Earthquake GPS Metadata: Buffer Zones & Python

I'm making a python web crawler that gets USGS earthquake GPS data, and I'm wondering how I should process the latitude longitude pairs to see if it falls within a specified radius of a specified GPS ...
0
votes
1answer
61 views

Summing the number of intersections with a separate buffer layer

I have dabbled with ArcGIS and QGIS a bit, and I consider myself a self-taught beginner with a whole lot to learn. So, I have two layers: 1) census blocks, and 2) point data. My goal is to calculate ...
2
votes
2answers
113 views

What's the use of the buffer function in field calculator?

I'm trying to find out how the buffer command in the filed calculator works. I tried to create a new field to my point shapefile (integer) with the following: buffer ($geometry, 100) but no ...
4
votes
3answers
169 views

How to shrink polygon on two sides?

I have a polygon which I know is a rectangle, although it may be at any orientation: I want to shrink this polygon by a third of the width from two sides, so that I just get the strip in the middle ...
1
vote
2answers
48 views

Creating Many Uneven Buffers

Qgis 2.2, Windows 7 I am looking to create buffers around city lights (the raster). Currently, I have simple polygon buffers around the point layer (oecdminusa), but this is not accurately capturing ...
7
votes
1answer
256 views

How can I conduct Geographically Weighted Analysis using an exponential decay function?

I have some points (representing 30 study sites) and I want to calculate the weighted mean of several variables (landscape layers) using a negative exponential decay (weights function) to give more ...
2
votes
0answers
174 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 ...
5
votes
1answer
2k views

Why are my buffers not circular?

I would like to select areas under a particular circular radius in QGis. I believe this is accomplished with the buffer tool, but when I specify the radius the area is not circular. How to make it ...
2
votes
0answers
80 views

Zonal Statistics Freezing QGIS 2.2

Running on Windows; 8gb memory, 500gb HD, i5 cpu; Raster file: 250mb I am having a problem with zonal statistics advancing past 17%. I am trying to run statistics on a crop grown in certain counties. ...
2
votes
1answer
185 views

Problem with matching a buffer in Openlayers and the same buffer in PostGIS query

I am using a buffer tool to create a buffer on my base map in Openlayers. In addition to creating and visualizing this buffer, I pass the center point and radius to a query. The query collects all ...
0
votes
1answer
163 views

Remove buffers of overlapping buffers

I work with ArcMap 10.2 and would like to remove buffers of the overlapping buffers, but not all overlapping buffers. So for example: I would like to remove the buffer in the middle and remain the ...
0
votes
2answers
148 views

Low resolution raster conversions to vector yielding millions of single pixel polygons. Trying to merge all directly adjacent polygons

I'm trying to scan plain pdf maps containing color-coded geographic regions and convert them into undifferentiated (I don't actually need them to contain any attribute data) overlays. My workflow is ...
1
vote
1answer
133 views

Select point with highest value within a buffer

I work with ArcMap 10.2.1 and I created buffers around points. Some buffers contain many points and others just one. I would like to select one point for each buffer, but the points can represent ...
2
votes
1answer
301 views

Remove overlapping buffers

I have put a buffer around points from a point data set. But some buffers overlap each other. Now I would like to remove all the buffers (from the data set) which overlap another buffer. Does ...
2
votes
3answers
1k views

How to find most common classification within buffers?

I have a point shapefile that identifies the location of incinerators in England and an output area classification shapefile. I have created a buffer for all the points in the shapefile because i ...
0
votes
0answers
54 views

how to mark certain distance alongside a coastline and saved as kml to import to google earth?

Hi all I would like to mark the region of 200 nautical miles away from the coastline, how can i do this? Thanks in advanced...i already try the buffering function on qgis but dont know how to create a ...
2
votes
0answers
111 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 ...
0
votes
4answers
346 views

Buffer in QGIS/R is 650-670 m wide instead of 500 m

I am trying to make a 500 m buffer for my polyline layer. Unexpectedly, I receive buffer varying from 650 to 670 m, depending on location. As many resources recommend to use UTM before making a ...
0
votes
0answers
72 views

Zonal statistics won't work after re-projecting vector layer

I have qgis 2.0. I want to analyze raster information within a buffer of 30 miles around a vector layer of cities across the world. However, both the raster and the vector are in WGS84. I have no ...