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

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5
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773 views

ArcGIS Kernel Density with polyline, search radius / bandwidth calculation

I'm conducting a density analysis of a series of polylines and I'm hung up on determining an appropriate search radius. The default calculation performed by arcgis is to take the shorter dimension ...
4
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0answers
71 views

Cell Statistics standard deviation values incorrect

I'm having some issues with the Cell Statistics tool in a python script I am writing. I am using 30 years worth of global cumulative annual rainfall data as input and am getting strange values in some ...
3
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0answers
32 views

How to examine each connected pixel to select its neighbors to separate clusters?

I am trying to develop a methodology for separating pixels from one another to determine whether they belong to a city cluster or not. Starting at the center pixel of the city I want to select all ...
3
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0answers
72 views

Get counts in grid cell for multiple values

I have 500+ polygon shapefiles with nationwide coverage. Each shapefile has possible record values of 0-4. I want to get the value that intersects each grid centroid and then get a total count for ...
3
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0answers
176 views

Problem with Flow Direction in DEM

I have the following problem with Flow Direction Tool in my DEM and with such wrong calculated flow direction in the centre of DEM I am unable to delineate any watershed. What can I do?
3
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0answers
39 views

Need to run a Groundwater Analysis Based on Points to a Raster

The title sounds daunting, but this task really isn't. I have well samples over a decade in certain locations through an area. These samples contain a value of that element at that point in time. I ...
3
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0answers
71 views

Elevation interpolation along a (sewer) line

Here's what I want to do. I have a vector sewer line feature class that contaings a field for the high invert elevation and one for the low invert elevation. I can turn them into a raster no problem ...
3
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0answers
61 views

3D distance and topography

I have a set of points and want to find out the nearest distance to a water body (poly lines) taking into account the terrain and get a surface distance calculation. I understand that the way is to ...
3
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0answers
215 views

Cost Path: multiple pairs of sources and destinations

I have seen many questions related to this problem but very few answers. I am very new to scripting and using ModelBuilder, but I am trying to calculate the cost path for 200 polygons with a single ...
3
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0answers
1k views

Cause of ExecuteError: ERROR 010067 from arcpy.sa.CostPath?

By using the code below that creates least-cost paths between several polygons, I obtain this error message: ExecuteError: ERROR 010067: Error in executing grid expression. Initalization failed ...
3
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398 views

Determine 3 and 6 minute fire response times

I'm expecting to get an Excel file with data on previous fire and emergency response times. I was told it will have incident addresses and the response time for each incident (~ 12K incidents). I also ...
3
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0answers
80 views

arcpy adding time to Raster Mosiac Footprint

I am trying to create a raster mosiac for use in animating data over time. The current workflow is: Create .gdb (arcpy.CreateFileGDB_management) Create Raster Mosaic (arcpy....
3
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0answers
572 views

What is the convergence threshold for ArcGIS Iso Cluster?

The ArcGIS tool Iso Cluster Unsupervised Classification does not seem to have any documentation on the convergence threshold used in the tool. To compare, Erdas Imagine has all of the necessary ...
3
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0answers
140 views

Which geostatistical tools to use to determine surface changes over 40 years?

I have a data from the Weather station with SWEmax (snow water equivalent) collected over 40 years. I need to interpolate the data over my river's watershed and then, somehow, determine the ...
3
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0answers
912 views

Performing a Multicriteria Analysis Using Distance Along a Road Network

There is the possibility that I will be working on a project which will look at thousands of properties in a region and measure their accessibility to different services (schools, parks, hospitals, ...
3
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0answers
659 views

How to calculate Solar Radiation falling on vertical surfaces using DEMs and ArcGIS?

I am using ArcGIS10 Area Solar Radiation tool to calculate irradiation on horizontal surfaces (building roofs) but need to do the same for vertical surfaces (building facades). Any ideas on how to do ...
2
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15 views

Determine which Polygon Attributes are the Majority Value as Defined by Second Polygon Shapefile

I need to determine the majority soil type within a series of polygons. I have data from the USDA Web Soil Survey (properly formatted and the like). I then have another shapefile with 60+ polygons ...
2
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0answers
26 views

Using “snap pour point” to find a watershed of specific area starting from a point

I am trying to find everything downhill of a certain point in order to create a watershed of a specific area. For example, say I have a point at (x,y), and I'm interested in creating a watershed ...
2
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0answers
54 views

Arcpy.sa NoData issue with saving TIFF

Similar to the poster here, I am attempting to convert numerical NoData values to actual NoData cells. The solution in the linked question doesn't work for me, however, as when I use the save method ...
2
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0answers
57 views

Spatial Analyst tools adding extra column of NoData

I've got a script tool in ArcGIS that runs Curvature and Aspect from Spatial Analyst, and the outputs of both contain an extra column. I've attempted to set the extent in the both the tool and the ...
2
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0answers
213 views

Merge Raster Layers with Raster Calculator

I am looking to merge three raster layers together, we are only allowed to use the Raster Calculator tool in Spatial Analyst, ArcToolBox. Using ArcMap 10.2
2
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0answers
30 views

Characterizing territory according to its relief using ArcGIS Desktop?

I want to characterize the territory according to its relief with ArcGis 10. I'm trying to define a wide territory by its relief, but I would like to do it in an automatic or semiautomatic form with ...
2
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0answers
339 views

Comparing two kernel density rasters for areas of interest?

The background to my question is that I have unit sales for Product A aggregated by city. I also have unit sales for Category A aggregated by city. The goal is to compare areas where Product A ...
2
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0answers
159 views

Spatial Autocorrelation tool vs. Incremental Spatial Autocorrelation

When you run the Spatial Autocorrelation (Monrans I) tool, you have the option of setting 'Conceptualization of Spatial Relationships'. This option isn't available for the Incremental Spatial ...
2
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0answers
93 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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0answers
328 views

Watershed delineation?

I'd like to delineate the catchments upstream of the sampling points. In order to do that, I have done the following: Burn the rivers into the DEM using ArcHydro>DEM Manipulation>DEM reconditioning;...
2
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0answers
282 views

How to add flow arrows to groundwater table map?

After I had created groundwater table map, I tried using 3D Analyst>Steepest Path to add groundwater flow arrows to the map. However, it didn't work. Would you please let me know how can I add these ...
2
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0answers
67 views

Copying an entire column between layers (tables)

I have a raster layer with probabilities as values and I process them using the Spatial Analyst extension. After the processing the values are modified, however I would like to also have the original ...
2
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0answers
524 views

Problems with spatial autocorrelation in Geographically Weighted Regression (GWR) analysis

I have conducted an Ordinary Least Squares (OLS) and Geographically Weighted Regression (GWR) analysis in ArcGIS where I have tried to predict biodiversity patterns in an area. When I examine the ...
2
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0answers
702 views

Question related with NDVI value on water

There is a surreal thing on my NDVI images. NDVI values on lake is ranging from -0.04 to 0.7. (The lake surrounded by forest and has freshwater). Theoretically, negative value of NDVI is correspond to ...
2
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0answers
288 views

Different results from Spatial Analyst GP Tool and Python

I am writing a script that has to subtract one raster from another. The rasters I have represent 1) Parking Lots (1 = Parking Lot, 0 = not Parking Lot) and 2) a buffer around the Parking Lot (1 = ...
2
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0answers
238 views

Limiting the maximum and minimum values of an interpolation surface tool (ArcGIS, Spline)

I've been using the spatial analyst spline tool in ArcGIS 10.1 and was wandering whether it is possible to limit the maximum and minimum values to those of the z-attribute. Currently the spline will ...
2
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0answers
219 views

ArcMAP path distance function handling of polygon and raster inputs

I am using a path distance function to calculate distances from a set of source cells on a land use raster. Unfortunately, my land use raster and my other inputs have different cell sizes. The land ...
2
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0answers
367 views

About zonal statistic function in ARCGIS

I calculated zonal statistic in Arcgis to get max/min value of each LC types. Broadly, LC image include forest, grassland, waterbody etc. But output max value of zonal statistic function give me 0.972 ...
2
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0answers
692 views

Output raster extents when using the Spatial Analyst Extract By Mask tool to clip a raster

I am using ArcGIS 9.2 and I have a simple python script that does the following : Loop over a polygon feature class (shown in red in the image below) For each record, create a feature layer to ...
2
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0answers
65 views

How do I make a path cross the most possible classes in a raster?

I want to create a function and possibly use Arcmap tools to create something similar to Cost Path. Instead of just choosing the LCP, it must cross through the most different integers. Let's say I ...
2
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0answers
844 views

Spatial Analyst Cell Statistics seems to give the wrong answer in ArcGIS 10.0

I have a script that calculates standard deviation for a list of grids using the Cell Statistics function in Spatial Analyst for ArcGIS 10.0 The syntax is this: stdevGrid = arcpy.sa.CellStatistics(...
1
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0answers
13 views

Interpreting output from PCA tool of ArcGIS for Desktop?

I am looking for some assistance on interpreting the output from a PCA run in Arcmap. My data is comprised of 6 raster bands representing biophysical elements in the marine environment (SST, ...
1
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0answers
15 views

Surface attribute only calculated for actual points and not interpolated

When I run the surface hillshade, slope and aspect in the Arc Toolbox using my raster surface it appears to be calculating the attribute only for the data points and not for the interpolated areas ...
1
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0answers
50 views

Thinning LiDAR points to remove redundant neighbors?

I'm trying to develop a workflow in ArcGIS with 3D Analyst or Spatial Analyst to intelligently thin a grid of spot elevation points created from a LiDAR DEM. The current point spacing is 1 meter. Some ...
1
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0answers
49 views

Getting distance from nearest stream and elevation to nearest stream?

I need to know if there are simple commands for this 2 points: the distance from the nearest stream, D [m], defined as the length of the path that hydrologically connects the location under exam to ...
1
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0answers
18 views

Reduce raster resolution and determine pixel inclusion based on % pixel overlap

I'm trying to reduce the resolution of a raster from 1m to 50m using a pixel aggregation (average) method, but I need to set a threshold for inclusion (e.g. 75% of the 1m pixels must fall within the ...
1
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0answers
24 views

Zonal Statistics error with specific dataset combination

A colleague and I are trying to use ArcGIS's Zonal Statistics As Table to calculate the mean value of a raster within the features of a polygon layer. This always results in error 999999 "error ...
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0answers
75 views

Creating Fence Diagrams from Electromagnetic (EM) Conductance Survey

I am looking for some help with creating fence diagrams in GIS for Electromagnetic Conductance surveys. I have points along a line that represent sample locations with three different depths (readings)...
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0answers
51 views

How to calculate spatial GINI coefficient for land use

I am interested in calculating an index of agricultural land inequality for Brazil. I'm thinking that a GINI coefficient would be a good approach given traditional uses of GINI. I have a data set for ...
1
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0answers
86 views

con statement outputs using arcpy.sa.Con doesn't ignore NoData

In ArcGIS 10.2, using the Con tool, I ran a conditional statement to return RasterA where RasterB value >0. That worked fine. Transferring the code into python, the statement reads something like: ...
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0answers
48 views

Zonal histogram script VALUE row suffix problem

I'm running 2 Python scripts. The first it is to apply Zonal Histogram to several rasters. The second it is for saving the Zonal Histograms to a text file. My problem is when the first script creates ...
1
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0answers
30 views

Can I interpolate but follow the trend of another surface?

I have a point data set will a fairly low sample density and a raster that should loosely correlate with the values of the points. For example, this could be elevation and temperature readings. I want ...
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0answers
44 views

How to create separate viewsheds for individual points?

I have a feature class with 3000 points. My goal is to have a viewshed, at each point, clipped to 50m and 500m buffers. I want to be able to look at the percent visible/not visible for each point. I ...
1
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0answers
54 views

Errors when using Spatial Analyst to Extract Values to Points?

I have a raster that I have classified into three slope positions and a points layer of bird nest locations. I'd like to add the layers together and use this to determine which of the three slope ...