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

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2
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1answer
165 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
147 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 ...
4
votes
3answers
226 views

How to compute the outline of multiple tracks?

I have multiple gps tracks with depth data gathered from the lake. The tracks are overlapping/intersecting. I want to get an outline polygon. I have a multi-line shp. I've tried to diffuse it in qgis ...
2
votes
1answer
44 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
72 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
175 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
112 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
71 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
108 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
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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?
0
votes
0answers
72 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
3answers
120 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?
0
votes
1answer
77 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
86 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 ...
0
votes
2answers
216 views

isolated polygons selection (not donuts)

I'm exploring a few different options for this process and I'm unsure what would be most effective. I'm trying to find all isolated, non-intercepting polygons in the same layer (not to merge). Most ...
2
votes
1answer
185 views

How to creat multiple rings between two circular buffers?

I am working with mathematical-ecological modeling and I am also a new user of QGIS Software. First I am creating 3 circular buffers with same center (shape center) covering a region with roads (shape ...
2
votes
2answers
509 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 ...
0
votes
1answer
56 views

Find Minimum Value of Point within a buffer output as a point file

I have a series of 30m buffers along a polyline (river). Within each buffer I have a series of points each point represents a 10m x 10m cell with an elevation value known as "Elev". I want to find ...
-1
votes
1answer
64 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 ...
0
votes
1answer
200 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, ...
1
vote
0answers
61 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 ...
1
vote
2answers
293 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 ...
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 ...
1
vote
1answer
86 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, ...
1
vote
0answers
130 views

How to clip polygons within buffer using QGIS? [closed]

I am trying to do the clip operation with polygons in the buffer, so far I'm getting no results. It is working for points in the buffer. Am I doing anything wrong? Basicly I'd like to include ...
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
110 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 ...
1
vote
2answers
47 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 ...
4
votes
3answers
164 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 ...
2
votes
1answer
297 views

How to create multiple buffers around line at equal intervals without typing in every value?

I have a line in ArcMap 10.2, and want to create lines to the right of it at 100 m, 200 m, 300 m etc. up until 1.7 km. Obviously typing in these values under 'multiple ring buffers' will take too much ...
7
votes
1answer
246 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 ...
4
votes
0answers
433 views

How to create multi-ring buffers automatically in QGIS? [duplicate]

I'm wondering if anyone knows of a tool or plugin for QGIS that allows for multi-ring buffers. I've found a post about doing multiple buffers one by one, but was hoping there was a way to do this all ...
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
180 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 ...
4
votes
1answer
319 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 ...
0
votes
1answer
157 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 ...
1
vote
1answer
128 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
286 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 ...
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 ...
0
votes
1answer
161 views

Intersecting Overlapping Polygons Individually in ArcGIS

Map Layers: -Census Tract Shape File w/Population Data -Set of Store Locations with 5 Mile Buffers (Significant Overlap Between Buffers) I have create feature layers for both and I am trying to ...
0
votes
2answers
665 views

Calculate sum of points within buffer (ArcMap)

I've created buffers around home origins and am looking to calculate the sum of shapefiles (in this case crime) within each buffer. How would I go about doing this? I want to know how many crimes are ...
2
votes
0answers
103 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
0answers
69 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 ...
3
votes
2answers
574 views

Creating square buffer in qgis

How can I create a buffer with square ends along a line segment in qgis? I've buffered lines using v.buffer in the GRASS plugin, but the -c option for square ends is not exposed in that interface. ...
21
votes
6answers
1k views

How to buffer raster pixels by their values?

The pixels to the left represent tree locations and their associated crown radii (i.e. pixel values ranging from 2 - 5). I would like to buffer these raster pixels by their crown radius value. The ...
0
votes
1answer
497 views

Units of gBuffer from rgeos package

I have this polygon: library(maptools); library(sp) setwd(system.file("shapes", package="maptools")) columbus <- readShapeSpatial("columbus.shp") proj4string(columbus) <- CRS("+proj=longlat ...
2
votes
0answers
15 views

Eliminating/minimizing distortion in 200 NM EEZ buffers [duplicate]

I frequently need to calculate buffers of 200 nautical miles from country or baseline polygons in order to map maritime Exclusive Economic Zones (EEZs). However, I've noticed that when generating the ...
1
vote
1answer
95 views

Is there a tool to buffer features with more than one distance value in GRASS GIS?

I´m looking for a tool like Multiple-Ring-Buffer in ArcGIS, but for GRASS GIS to be able to buffer with different distances but only having to start the process once.
0
votes
0answers
209 views

Why does ArcGIS 10 Buffer not provide accurate geodesic buffer?

I created a shapefile following these criteria as recommended for Performing Geodesic Buffering: The input feature class must be a point or multipoint dataset. (shapefile is a point) The input ...
0
votes
2answers
140 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 ...