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
486 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. ...
5
votes
2answers
2k 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 ...
4
votes
1answer
288 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 ...
3
votes
1answer
81 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
1answer
65 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
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0answers
217 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 ...
2
votes
2answers
172 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
2answers
518 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 ...
2
votes
3answers
46 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
3answers
328 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 ...
2
votes
1answer
205 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
2answers
458 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
233 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
172 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
235 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
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0answers
35 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
60 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
91 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
40 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
58 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 ...
2
votes
0answers
337 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
231 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 ...
2
votes
4answers
1k 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 ...
1
vote
1answer
89 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
2answers
516 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
163 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
56 views

Calculating real surface area using Zonal Statistics as Table Tool?

I have a slope dataset. I have a polygon shapefile with territory within the extent of the slope map. how do I calculate the real surface area of this shapefile using the zonal statistics as table ...
1
vote
1answer
42 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, ...
1
vote
1answer
120 views

What do “count”, “mean”, and “sum” in QgsZonalStatistics mean?

I am working with Qgis and making some analytics of lightdata. I've used these commands: rasterfile = qgis.utils.iface.mapCanvas().currentLayer().source() vectorlayer = ...
1
vote
1answer
112 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 ...
1
vote
1answer
205 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
2answers
47 views

How to calculate raster class metrics by polygon zone?

I have a raster of morphology data where each bin has a code. I want to count the number of each code that fall under a polygon from another file. Zonal stats as table only gives me the min/max ...
1
vote
1answer
120 views

How to use a polygon grid to calculate statistics on line and point features

What seems a simple task but I can't find the right tool to do it. I have a polygon grid cells and say a point feature class. I want to be able to create a table that contains the grid cell ID and for ...
1
vote
1answer
350 views

identify percentage of raster cells within a polygon

As per the title I want to determine the population inside multiple polygons according to different land use zoning (High Residential, Low Residential, National Parks etc) that's in raster format. ...
1
vote
1answer
124 views

using ZonalStatisticsAsTable in python script

I use a python script in which the function ZonalStatisticsAsTable is called. In ArcGIS9.3 it all worked fine. Our company just went to ArcGIS 10.1 and now it doesn't work anymore. When looking ...
1
vote
1answer
17 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). ...
1
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0answers
62 views

Batch Zonal Statistics to Spreadsheets?

I have a pretty immense amount of Zonal Statistics as Table computations to do, and would love to find a way to grab mean and variance values from the little .dbf tables ArcGIS creates and put them ...
1
vote
0answers
66 views

Problem with polygon overlay in raster stats using gdal

I am using the raster_stats module in python to calculate the mean carbon value for different sets of polygons. Here is the code that I am using: africa_sat = ...
1
vote
0answers
42 views

I want to determine the average rainfall for a cumulative watershed, where I only have the sub-watersheds defined

I have a polygon layer with sub-catchments (sub-watersheds) and a grid of rainfall. I have used the Zonal Stats as a table to calculate the average rainfall for each sub-catchment, but I now need to ...
1
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0answers
94 views

Multiple polygons and rasters for Zonal Statistics as table in ModelBuilder

I have a large number (>17,000) of raster image files that I am creating by iteration. I also have clipped out corresponding polygon files with identical names in a separate folder (maybe not ...
1
vote
0answers
97 views

How to Iterate ModelBuilder for Zonal Statistics?

I want to use ModelBuilder to split a DEM into multiple tiles, then run the iterator on each tile made for the Zonal Statistics tool to find the highest point(s) in each tile and give these as an ...
1
vote
0answers
208 views

How to use Zonal Stats as Table tool with in-line variable substitution

I have created a model to iterate a folder of 5 shapefiles to apply the Zonal Stats as Table tool to a raster. My output table is saved as table%i% so i'm expecting it produce 5 tables (table0, ...
1
vote
0answers
78 views

Reshape Matrix and perform Zonal Statistics in Matlab

I have 2 grids: 1) n by m - at 100m 2) n*10 by m *10 - at 10m. These grids cover the same area. I have to perform zonal statistics at scale of grid no.2. Cell value of grid no.1 is cumulative for ...
1
vote
0answers
161 views

Problems running zonal statistics - not all zones represented

I have been working on a Python script to automate the steps illustrated by whuber here:Create points around the edge of viewshed results I am trying to create a horizon graph illustrating the ...
1
vote
0answers
159 views

zonal statistics in Python crashes

I have a python script that works (it's worked for several other projects in the past and it worked for my current project initially). But whenever I run it, Python crashes sporadically. It would go ...
1
vote
0answers
673 views

Raster grid for zonal statistics in R

I have two raster layer, the first one r is my zonal mask as a raster grid, and I created as: ext <-extent(Yraster) r <- raster(nrows=32,ncols=32,ext) r[] <-(1:ncell(r)) and project it ...
0
votes
2answers
29 views

Calculating Centroids with Zonal Geometry in ArcGIS

I have a shapefile containing polygons. Each polygon is defined by its postal code. I want to calculate the centroid of each polygon using Zonal Geometry. Sadly, for some polygons there are no ...
0
votes
1answer
46 views

How to use the local macro to do ZonalStatisticsAsTable in batch

I have a series of files named as 'rawfile200101', 'rawfiles200102',...,'rawfile201104'. I want to do ZonalStatisticsAsTable for each of them with names corresponding to the time of the raw files, ...
0
votes
1answer
46 views

ArcGIS10 Highest point via polygon features

I am using ArcGIS 10.0 with 3D Analyst, Spatial Analyst and Military Analyst. I feel like I am halfway to solving a problem but do not seem able to completely solve it. I have a polygon shapefile ...
0
votes
0answers
19 views

Overlaying Line (Vector) Layer on Raster Zones?

I will make my best attempt to clearly explain my problem. I am using ArcGIS 10 I have a raster layer with 3 values that make up zones. For the purpose of this example, lets say these zones are ...