Zonal statistics summarize the values of one raster within the zones of another dataset (either raster or vector) and output the results as a raster (for a single statistic) or table (for multiple statistics).

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7
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3answers
570 views

How to use ZonalStats plugin?

I am using QGIS 1.8.0 on a Windows Home Premium 7 machine. I have a single band TIFF that is 187 MB in size. My vector polygon shapefile represents a regular grid of a 147x112 36kmx36km grid cells. ...
6
votes
2answers
3k views

How to use QGIS Zonal Stats Plugin from Python Console?

I am using the Zonal Stats plugin in QGIS to extract raster statistics from overlaying polygons (I have shapefiles of species distribution and I want to extract environmental data from within each ...
5
votes
1answer
58 views

Zonal maximum at a specific location

I have 50,000 polygon shapefile, each polygon is a small community. I have a flow accumulation raster. I need to extract just the maximum cell (max flow accumulation) for each polygon. Now if I run ...
5
votes
1answer
505 views

QGis Zonal Statistics Plugin NoData included in Calculations

I have been trying to use the QGIS zonal statistics plugin. My raster has a nodata value of -99999 and all other values are positive. After computing the mean zonal statistics there are a number of ...
4
votes
2answers
1k views

Issue Trying to create Zonal Statistics using Gdal and Python.

I am trying to create zonal statistics using Python and Gdal. I have a polygon shapefile and a raster file, and in order to do so, I am using a piece of code I found in StackExchange. The raster and ...
4
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1answer
140 views

How are raster pixels determined whether they are in or out of a zone?

I just needed to confirm something that I think I already know the answer to because help pages are always unclear. I am running ArcGIS 10.2.2 and often use the Zonal Statistics and Tabulate Area ...
4
votes
2answers
843 views

Zonal statistics for millions of overlapping polygons

I am running ArcGIS 10.1 with 64-bit GP on Windows 8.1 x64. I want to calculate the zonal statistics of buffer polygons based on parcels and a kernel density raster. The 4.7 million polygons overlap ...
4
votes
1answer
53 views

Zonal statistics discrepency between Arc 10 versions

I've discovered a weird phenomenon using zonal statistics with a colleague at another office. We are attempting to use the Zonal Statistics as Table tool to sum the value of raster cells within ...
4
votes
1answer
200 views

Is there an issue with Zonal Statistics calculating wrong mean values?

I tried to solve the following issue by myself but without success. On the one hand I have a raster file which is the result of the processing "shapes to grid" tool. On the other hand I have a ...
4
votes
1answer
151 views

Any way to perform zonal statistics on column other than value or do reclass faster?

I have to perform ArcGIS zonal statistics on a raster, but the column I am interested in is not the 'value' column. Now, I can reclass the raster so that the column of interest becomes the 'value' ...
3
votes
4answers
95 views

Calculate minimum area where x% of raster value total is concentrated within polygons

I have a raster layer (chlorophyll concentration) and a layer of non-overlapping polygons (regions of the ocean). For each polygon, I'd like to calculate the area where the majority of chlorophyll is ...
3
votes
1answer
250 views

Getting Zonal Statistics of Overlapping Circles?

I have a Buildings (polygon) shp file and a DSM. what I wanted to do was to get the pixel values for all the vertices of those buildings, and find another pixel value just around those vertices (say ...
3
votes
3answers
245 views

How can I determine which raster attribute covers the highest area of a polygon?

I'm relatively new to GIS and QGIS but I have a problem that I'm not certain how to solve. I searched here for relevant information but found none. (Or, I used incorrect search terms.) My problem ...
3
votes
1answer
81 views

How to make zonal statistics model more efficient?

I've made this model, to assess some 500-600 rasters for one area, and spit out one huge table. So far, when testing it with 20-30 rasters as inputs it works, but now that I put in the full amount its ...
3
votes
3answers
1k views

How to get count of non-NA raster cells within polygon using R

I've been running into all sorts of issues using ArcGIS ZonalStats and thought R could be a great way. Saying that I'm fairly new to R, but got a coding background. The situation is that I have ...
3
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0answers
109 views

Zonal Histogram Output Problems - No values associated with the habitat type

I have a outline of some islands (shapefile or raster) and GAP landcover data (raster). I am trying to use Zonal Histogram to create a file with a histogram of the habitat types in each island. Each ...
3
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0answers
496 views

Extract values from raster based on weighted average area using polygon grid

EDIT: I am using Armap 10 sp 5 I have found similar questions but they were either unanswered or somewhat different to what I am asking. I have a raster with cell values 1-5 and a polygon shape file ...
3
votes
1answer
131 views

Tabulate Area using GDAL and Numpy

How could I perform a Tabulate Area using GDAL and Numpy? I am trying to summarize how many pixels of each class in a Landcover raster are within each polygon of a Census Blocks shapefile. I've ...
3
votes
4answers
3k views

How to read this data file and convert it to raster format for analysis?

I am trying to introduce the 5 degree dataset from here http://www.cru.uea.ac.uk/cru/data/precip/ (it is the first link). And once I introduce it to GIS to use it as a raster input to calculate zonal ...
2
votes
2answers
441 views

How to Calculate Custom Zonal Statistics?

I have a vector polygon shapefile outlining counties for which I have a raster of nighttime-luminosity data. I've been able to compute Zonal Statistics in ArcGIS 10.0 using Zonal Statistics as Table ...
2
votes
1answer
160 views

Find local maxima with variable window search using ArcGIS Desktop?

I would like to find local maxima in different zones of raster file. I got five zones (zone 1, 2,3,4,5) and would like to find local maxima with different window search for each zone in arcgis ...
2
votes
1answer
199 views

Right raster zonal statistics for NDVI at county scale?

I am currently doing a modeling project at county scale in which I have disease rate as dependent variable and environment variables (such as temperature, NDVI and evapo-transpiration) as the ...
2
votes
1answer
113 views

Monthly weather averages using NCEP/NCAR Reanalysis data

I'm a political science grad student and I've recently (and probably foolishly) committed to dipping my feet into GIS. Right now I need to build a table that has monthly precipitation and temperature ...
2
votes
1answer
92 views

Issues with PyQGIS while running a QgsZonalStatistics script

I have experienced a very bizarre issue with my PyQgis code. I simply want to load a raster and a vector layer to do zonal statistics, the first part works perfectly but for the zonal statistic I have ...
2
votes
1answer
109 views

Intersect shapefile with raster, then determine proportion of each raster value?

Using the arcpy module in Python, I want to find the proportion of each pixel value within the boundary of an overlaying polygon. (The polygon is in a shapefile.) For example, there are 10 possible ...
2
votes
3answers
160 views

Zonal Statistics as Table Tool

I have a slope dataset. I have a polygon shapefile with territory within the extent of the slope map. I have to calculate the real surface area of this shapefile using the zonal statistics as table ...
2
votes
1answer
105 views

How to loop qgis:zonalstatistics using Python?

I'm looking for some Python + QGIS foo for the following: import processing for i in range (1,20): processing.runalg("qgis:zonalstatistics", "/folder/input/raster.tif",%i, ...
2
votes
1answer
286 views

Error 010240 with ZonalStatistics

I have a code that calculates the sum of water recharge for a pixel for a 9 year period (This piece of code works fine, just thought I would show how it is made just in case. The values range from 0 ...
2
votes
1answer
45 views

Can I use TIFF files for zonal statistics in QGIS or ARCGIS?

I am completing a remote sensing paper and am doing most of the work in PCI Geomatica, where I have 2 separate files. One from running a texture analysis algorithm containing 6 band layers from a ...
2
votes
1answer
200 views

Export “Zonal Statistics As Table” output in Modelbuilder

I have an extremely simple model that takes as input a shapefile for zones along with a value raster. All the model does is produce a table of my desired zonal statistic for each zone (the mean). ...
2
votes
2answers
2k views

Iterate through multiple Raster files and compute statistics using Zonal Statistics

I have a large number of raster images. What I'd like to do is to compute statistics on different sections of these raster files using a polygon. I think everyone is suggesting Zonal statistics. ...
2
votes
2answers
351 views

Tabulate Area crashes Python and ArcGIS

I have a script that runs Tabulate Area on a single feature class multiple times with different rasters. In total Tabulate Area runs 5 times. 2 of the input rasters are provided as arguments to the ...
2
votes
1answer
325 views

Zonal Statistics-Weighting

I have a raster file on precipitation and I want to create zonal statistics as a table using a shape file wiht boundaries of countries across the world. However it appears that I need to take into ...
2
votes
1answer
375 views

joining a table from zonal statistics as table with a layer, problem with reserved names

I have a raster file (percentage of total forest killed) and a shapefile with polygons (municipalities). I thought as a first step I would like to find out which municipality shows the greatest ...
2
votes
0answers
30 views

Zonal statistics error: 0-d arrays can't be indexed

How can I fix the error 0-d arrays can't be indexed? This message appears after the tentative to use the algorithm Qgis Zonal Statistics. Detail: the algorithm worked very well several times and then ...
2
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0answers
15 views

Remote sensing Classification and texture analysis compared with QGIS zonal statistics

Some back round: Using Geomatica to analyse suburban spectral signature in Las Vegas. Ran a texture analysis on all band images. Combined texture bands with original image bands to run an unsupervised ...
2
votes
0answers
62 views

Zonal computations: computing raster pixel counts within polygons using GDAL versus rasterstats

I'm computing some zonal statistics, and was comparing the results obtained using the GDAL cookbook example code here with the rasterstats zonal_stats function. I want to compute the mean value per ...
2
votes
1answer
71 views

Memory issues with zonal statistics

I have got a memory issue due to the use of the zonal statistics command into a loop. It seems that after using the ZS command QGIS stores some information in the RAM (cache memory?). It is not ...
2
votes
0answers
61 views

Does converting polygon to raster generate more accurate results from the Zonal Statistics in Arcgis 10.2

I have heard the following for Arcgis 9.1 and wonder whether it is still an issue in Arcgis 10.2. If so, should I convert the polygon into raster before dissolve or convert the dissolved polygon ...
2
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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
0answers
257 views

Zonal Statistics using Gdal and Python

I recently came across a loop_zonal_stats function by @ustroetz found here: Issue Trying to create Zonal Statistics using Gdal and Python.. I am using a (single) polygon shapefile and a raster file to ...
2
votes
0answers
51 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, ...
2
votes
0answers
533 views

How to Calculate Utilization Distribution Overlap Index (UDOI) in ArcGIS

I'm interested in calculating the overlap of home ranges (=utilization distributions in my case) of a bird species using sighting coordinates. This article introduced UDOI as the best index for such ...
2
votes
0answers
319 views

How to use GRIB data in ArcGIS? (Zonal Stat as Table)

I am trying to calculate zonal stats as table with a python script for 45 .grib files from the ERA-40 Monthly Mean of Daily Mean database (http://data-portal.ecmwf.int/data/d/era40_moda/) for certain ...
1
vote
1answer
60 views

Overwrite option on a standalone ZonalStatisticsAsTable using ArcPy

How can I code an "overwrite option" on a standalone ZonalStatisticsAsTable using ArcPy? I don't see any overwrite option from a Esri example. # Execute ZonalStatisticsAsTable outZSaT = ...
1
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2answers
1k views

What to do when raster cell size is larger than zonal vector feature in order to collect statistics?

I am trying to extract the mean cell values for a raster dataset based on a survey grid polygon feature using ArcINFO 10.1. The cell size of the raster dataset is about 4 times the size of the survey ...
1
vote
1answer
314 views

How to create graph out of two layers using ArcGIS 10.1 for Desktop?

I would like to create a graph of two layers I have. on one hand its the land price of a certain area and on the other a layer with a crime rate. first of all, the layer with the land prices doesnt ...
1
vote
1answer
280 views

ArcGIS TabulateArea() :: Recommend Ratio of Zone Area to Value Raster Cell Size?

Any recommended ratio of zone area / raster cell size when running small input zones with ArcGIS Tabulate Area Tools? Esri mentions: If the zone input is a feature dataset with relatively small ...
1
vote
1answer
404 views

Is there a way to perform zonal statistics-like operations with feature zone data without doing feature-to-raster transformation?

I want to use zonal statistics on Chinese counties (which can be very small) from a fairly coarse (0.5 degree) raster grid. The problem with zonal statistics is that it returns a much smaller number ...
1
vote
1answer
25 views

Querying Raster Dataset by Location to Study Area

I have downloaded a very handy raster dataset generated by the Nature Conservancy for identifying terrestrial habitat cover types in the north east. Link to the project info and a link containing a ...