Spatial Analyst is a extension within ArcGIS that provides a range of spatial modeling and analysis tools.

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2
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0answers
21 views

ArcMap - proportion of polygon in lon/lat grid cells

I have a polygon representing a river basin on a 1 X 1 degree lat/lon grid. I need to create a boundary using the grid cells as the boundary to best represent the outline of the basin. I would like to ...
2
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1answer
29 views

strange banding in output raster after weighted overlay

I am trying to conduct a weighted overlay. I have two rasters, one is a continuous slope raster that I reclassified to have 6 classes (8bit signed integer), and one is an elevation raster that I also ...
0
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1answer
20 views

Error with the Contour (Spatial Analyst) tool in ArcGIS

I am having an issue with the Contour (Spatial Analyst) tool in ArcGIS. When I manually run the tool in ArcToolbox, it will sometimes say that the tool has failed, giving the following error message: ...
0
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0answers
17 views

How to reassign the values of a raster, based on the pixels of the raster beneath it?

In ArcMap 10.2.1, I have two rasters. Raster1 shows the extent of a habitat, and each pixel contains a categorical value for its land cover type (values 1-3). Raster1 has the smaller spatial extent of ...
6
votes
2answers
193 views

How to compare spatial patterns (crime cases vs population)?

I am looking for a way to statistically compare two spatial patterns in shape polygon data (not point pattern analysis). Let's say I have a city map divided in neighborhoods (barrios), in shape ...
2
votes
1answer
75 views

calculating zonal statistics of raster data in multiple overlapping zones and combining them into one table

The aim here is to calculate the max, min, mean, range, sum, count and std of raster data contained in areas delimited by polygons (much like what the Zonal Statistics as a Table tool from Spatial ...
0
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0answers
14 views

How to Krige with expectation of 0

I am trying to Krige in ArcGIS from point samples of a chemical concentration. Towards the center, most of the points are larger, and on the periphery, all of the points are 0. The generated raster ...
1
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2answers
30 views

Feature Distance for each Raster Cell

I have a polyline layer of roads and a raster of land ownership. For each raster cell I would like to calculate the distance to the nearest road. I am on ArcMap 10.2 with Spatial Analyst and 3D ...
0
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1answer
186 views

how to choose stratified random sample on multispectral image

I'd like to choose random samples from multispectral image according to each Land Cover image. The multiband image has 70 bands representing land surface temperature data from MODIS. Land cover image ...
0
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1answer
20 views

Raster data with no values (ArcGIS)

Used a DEM raster and then used the extract-by-mask feature to shrink it to the shp file I'm working with. However, when I try to get unique values, it gives me the following error message: "The ...
4
votes
1answer
5k views

Thiessen Polygon delineation within a Feature

I am trying to create Thiessen (Voronoi) polygons, based on points within a defined shapefile extent. The output should be inclusive to the feature. The output I receive now is the rectangular area ...
0
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0answers
42 views

Choosing appropriate Interpolation Tool

I am interested in doing some fairly simple interpolation work in the next few weeks using ArcGIS 10.1. However, I am unsure about which interpolation tool is most appropriate for the task at hand. ...
6
votes
3answers
4k views

Finding nearest raster cell value based on vector point?

I have two layers in ArcGIS: One is a vector point and the other is a raster layer. I want to append the value of the raster data grid to the vector point. The problem is the vector point is away from ...
3
votes
1answer
52 views

How can I create a constant slope DEM?

I wanted to create a DEM of constant slope say 1/3000. How can I proceed in ArcGIS 9.3? The area may be 1000m x 1000m or any other as per convenience.
6
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7answers
3k views

Extract raster values at points

How can I extract values from a raster by points. I prefer not in Arcgis. I prefer in Qgis or Mapwindow or other open source gis.
2
votes
1answer
66 views

Obtaining average value around polygon in raster for different cross sections?

I have elevation data in a raster, river (blue line) and the flooded area (black polygon) as shown in the image below: I want to find the water depth in the flooded area (inside the black polygon). ...
1
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0answers
27 views

Trying to combine 29 zip code service areas into 10 or fewer service areas

I am tasked with coming up with 10 or fewer zip code service areas based on 29 pre-existing zip code service areas. The zip codes cover 5 counties and many service areas, obviously, overlap. The ...
1
vote
1answer
36 views

Why is my spatial join count 0 in ArcGIS Desktop?

In arcMap, I have a list of locations with lat/long. From a previous post, I learned about the Spatial Join tool to determine the amount of joins that I have. I tried to use the tool with my states ...
5
votes
1answer
91 views

Can 2D polygon be used as hard breakline for terrain?

I've been working with TINs for years and have only ever been satisfied when using 3D polylines for breaklines. I am currently transitioning to using terrains and after reading the documentation in ...
3
votes
1answer
144 views

How to calculate the distance of sites to riverways

How do you calculate the distance of about 10 sites scattered across a region to bodies of water (rivers and lakes) using ArcGIS 10.1? I have the lat/lon coordinates of the 10 sites as a point ...
0
votes
1answer
449 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
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0answers
54 views

What is GDAL equivalent to ArcGIS Lookup (Spatial Analyst) tool?

I use the Lookup (Spatial Analyst) tool to create several raster layers from a combined raster layer. I know ArcPy can do the same thing. However, I would like to know whether GDAL (or another ...
1
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0answers
56 views

How to extract NetCDF raster values to time enabled shapefiles?

Does anyone know a good way to extract NetCDF raster values to each data point from a time enabled shapefile at the correct time? I have tried using a python script tool and a loop that steps ...
0
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1answer
71 views

Extracting NetCDF raster values to time enabled shapefiles - what's wrong with my python script?

I'm trying to make a python script tool that extracts the values from a NetCDF raster to each data point from a time enabled shapefile at the correct time. My NetCDF raster consists of monthly sea ...
1
vote
1answer
91 views

3D Analyst - Point File Information - pt_spacing definition?

I can't find any definition of the outputs of the Point File Information tool, specifically the pt_spacing field. Is this the average distance between points, or the average number of points per ...
1
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3answers
7k views

How to calculate Raster Area per Polygon?

In ArcMap, I have a raster file that contains 6 classes of landcover and a shapefile that is the census data (OA boundaries and their population). I want the area of each class in each OA? For ...
5
votes
2answers
42 views

Compare slopes between adjoining line segments

Using a DEM, I assigned slope values to individual segments in a street network feature class. In some areas the slope values seem suspect, such as where a highway overpasses a local road. Is there a ...
1
vote
1answer
207 views

Converting Heatmap into Grid of Points to regenerate less accurate Heatmap?

Question: How do you take a heatmap generated using a GIS software (arcgis, qgis...) and convert it into a uniform grid array of points which can be used to regenerate the heatmap (although with ...
3
votes
2answers
147 views

Is r.cost equivalent to diffusion interpolation with barriers?

I want to perform interpolation using cost distances rather than euclidean distances similar to Greenberg et al. (2011). In that paper they use r.cost in GRASS to compute cost distances for each ...
9
votes
3answers
608 views

Creating raster by randomly choosing cell value from multiple overlapping rasters?

I'm using ArcGIS Desktop 10 with its Spatial Analyst extension. How do I combine multiple rasters into one, always choosing randomly from the values of overlapping cells? I have an image that may ...
1
vote
2answers
86 views

Using Spatial Analyst Sample tool

I have a bunch of rasters and a point file. I need the information from ll the raster files to be added to my points. My usual workflow is to use the Spatial Analyst sample tool. It works fine and ...
0
votes
1answer
22 views

Contouring surface with barriers?

I'm using ArcGIS Desktop 9.3, and I want to contour a surface with barriers. Every time the result is a polyline contour shape file which covers only a part of the surface not the whole surface. ...
4
votes
1answer
415 views

Statistical analyses for survey against raster?

I am somewhat of a newbie to geostatistical analyses, but pretty familiar with GIS and remote sensing packages. I was wondering if anyone had suggestions on appropriate geostatistical analyses for a ...
0
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1answer
164 views

How to modify 2 raster images to have the same resolution?

I have data for 2 rasters images that have different resolutions: z downloaded from trmm An MSAVI2 output image. For calculating the correlation between them, the data has to be in the same ...
2
votes
2answers
43 views

How do I create zones using location features? [closed]

I have a list of rock art sites with a recording of every image within each site. For example, Site 1 has 4 kudu, 1 lion, 3 males and a locust; Site 2 has 2 leopards, 1 elephant and 3 giraffes; Site 3 ...
3
votes
1answer
466 views

How does cost allocation work?

Why, when I use the cost allocation function of Spatial Analyst, is space not allocated in all input source locations (as shown in image below)? In particular, the input raster has 18 spots while the ...
1
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0answers
21 views

ExtractByMask with one mask and multiple layers ArcMap

I have a multiple cost distance rasters and multiple feature layers. I need to find and join the feature layers (or associated shapefiles) that lie within a threshold of costs on the cost rasters. For ...
1
vote
1answer
26 views

Aggregate the raster from the Combine Tool in Spatial Analyst--->Local

I have a raster file created through the Combine tool (Spatial Analyst--->Local). The attribute table is showed below. Its resolution is roughly 10m. I would like to aggregate it to 50m with each ...
13
votes
3answers
1k views

How does Nearest Neighbor Image Resampling work in ArcGIS?

I am trying to understand how nearest neighbor for the resampling of Image datasets works in ArcGIS. The output raster cell value is the value of the closest cell value in the input raster: In this ...
3
votes
1answer
205 views

Can ArcGIS handle missing values to create a contour map?

I am trying to create a contour map for a waterbody. It turns out that in several locations there is no data. I just don't want to use the missing values as zero in ArcGIS because it would create ...
3
votes
2answers
246 views

scratch files left behind by arcpy.sa.Con

I have a Con() statement that creates two "extra" scratch files during it's processing, but that do not get cleaned up once the operation is over and the output is saved. r=arcpy.sa.Con(elv, ...
0
votes
1answer
39 views

Z values all equal 0

I have just posted a similar question, but I solved part of it, however it has now lead to a new problem. I have a point layer, and have got the x,y and z coordinates from 'extract values to ...
1
vote
2answers
74 views

Open source, Python option for Arcpy's Con tool?

I'm wondering if there is a method to perform a function similar to Arc's Con tool, using open source options in python. I have two rasters, one that shows locations of clouds and the other is just a ...
1
vote
1answer
60 views

'Sample' tool in ArcGIS 10.1 not working

I am trying to use the spatial analyst tool 'sample' to extract data from several layers. I have double checked and the input location raster is in the same format and cell size as the input raster, ...
2
votes
1answer
229 views

Multiprocessing issues with ArcPy

I am using ArcGIS 'watershed' routine in a script which makes use of multiprocessing. This works fine, but during execution I get the message: Unable to remove directory. Possible causes: 1- Not ...
3
votes
1answer
34 views

Can't save result of “Extract Values to Points (Spatial Analyst)” inside the working feature dataset!

I have a file geodatabase in which I have a feature dataset. I have some feature classes inside the feature dataset. I wonder why when I attempt to save the result of Extract Values to Points (Spatial ...
0
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2answers
60 views

Identifying clusters of points within a given distance

So I have a database of lats/longs representing incidents occurring on or near roadways. My goal is to identify the street block areas with the highest number of incidents in the database. I don't ...
5
votes
1answer
2k views

How to calculate stream order for vector data without a DEM?

I have a shapefile which contains the streams that were digitized from a satellite Image. I would like to calculate the stream order for this data. The data does not exactly match the DEM that I have, ...
1
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1answer
298 views

GWR Result Issues

I am working with GWR to identify if there are any relationships between 'extreme' events and disease incidence. The use of GWR has been employed because I am working in a region where local ...
17
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6answers
6k views

Ways to Speed Up Python Scripts Running As ArcGIS Tools

This is a pretty general question. I just wondering what tips and tricks GIS programmers have used to speed up arcpy scripts that you import into the toolbox and run. I work most everyday writing ...