Tagged Questions

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

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2
votes
1answer
43 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
62 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
52 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
40 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
95 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
59 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
67 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
0answers
43 views

Creating multiples buffers (or rings)

I would like know how could I creat and automate with a batch multiples buffers (or rings) between two cut buffers where is crossing roads. I creat rings using the attribute table but I can't ...
0
votes
2answers
109 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
135 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 ...
1
vote
2answers
226 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
50 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
47 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
105 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
56 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
71 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
50 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
51 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
67 views

How to clip polygons within buffer using QGIS?

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
49 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
83 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
43 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
137 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
172 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
145 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 ...
3
votes
1answer
295 views

How to create multi-ring buffers automatically in QGIS?

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 ...
0
votes
0answers
56 views

Efficient manner to buffer streams with multiple attributes?

I need to buffer a very large, complex hydro vector layer based on different water quality designations and surrounding slope. Different water quality classifications have different buffer ...
2
votes
0answers
65 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
104 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 ...
3
votes
1answer
193 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
66 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
0answers
16 views

empty buffer qgis

Help! I am trying to use three buffers to select three different sets of polygons. The buffers are from a .txt file with lat and long in decimals. I made a shapefile using North America Albers (I live ...
1
vote
1answer
86 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
96 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
22 views

buffer in qgis from layer text delimited

I have a layer of polygons in British Columbia, Canada in WGS 84 which is fine. Later I created shapefile of three points (using decimals for lat and long) through the add shapefile as text delimited ...
0
votes
0answers
40 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
62 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
220 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 ...
1
vote
0answers
64 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
46 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
267 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. ...
16
votes
5answers
651 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
0answers
25 views

buffer of clusters in a sparse matrix

I work with MATLAB. I have a sparse matrix where I identified different clusters. The value within each cluster is equal, while each cluster has its own unique value. I have 0s as background (outside ...
0
votes
1answer
178 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
14 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
67 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
131 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
114 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
78 views

Analyzing Raster Data From Vector Layer Buffer

I am using QGIS 2.0. I have satellite images of night-time lights all over earth. I also have a vector shapefile of country boundaries including the largest cities on earth. I want to use buffers to ...
4
votes
1answer
154 views

How to maintain right-angles when buffering?

When buffering some polygons I am trying to avoid the curved buffered area like this: I'm trying to do thins within an FME workbench but if someone knows how its done in other software that would ...