1
vote
2answers
31 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
92 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
37 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. ...
0
votes
0answers
27 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 ...
16
votes
5answers
481 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
14 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 ...
1
vote
1answer
44 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 ...
2
votes
2answers
49 views

Calculating loss of value from a wind turbine on surrounding properties depending on distance

I have to evaluate where installing a turbine would be most efficient, depending on wind speed and price of properties surrounding each cell in a raster. The cost on value of properties is computed ...
2
votes
0answers
35 views

Wrong pixel sums within buffers in Esri ArcGIS 10.0

I have a raster of Zambia, 100m² resolution (about 650mb). Buffers (single) at 1,2,3,4,5,10,15,20,25,30,50 km. I'm running "zonal statistics as table" in the model builder for all buffers (actually, ...
3
votes
1answer
841 views

creating a buffer in a raster layer

I've got a raster layer separated into 3 zones, representative of marine park zones. What i'm trying to do is make it so that where zone 1 is adjacent to zone 3, there is a "buffer" between them, of ...
0
votes
1answer
348 views

ArcMap 10.1 - Tabulate Area tool “doubling up” for Overlapping Buffer Zones

This question is related to a previous question I asked: Raster Version of Spatial Join (one to many) I used the Tabulate Area tool to crosstabulate values between an overlapping "buffrast" raster ...
0
votes
1answer
208 views

Extraction of raster cell values based on 'rgeos' and 'raster' buffering approaches in R

I am trying to extract cell values from a raster that lie within a certain distance from a given location (i.e. buffering). Evaluating different approaches, I found out that applying gBuffer(..., ...
4
votes
2answers
189 views

How to extract values from intersection of different size buffers with raster?

I have a polygon shape with buffers. However, the buffers are of different size from 4m radius to 15m. In total I have 7 different buffers. I have a landcover raster and I would like to extract ...
5
votes
1answer
245 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
3answers
495 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 ...