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

learn more… | top users | synonyms

5
votes
0answers
796 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
votes
0answers
73 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
votes
0answers
40 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
votes
0answers
70 views

Arcpy code only works when run in two chunks, not as one piece

I have a weird thing happening with my script. When I copy/paste it into the python cmd line within ArcMap, I get error messages. However, if I run the first part, then copy in the very last line by ...
3
votes
0answers
78 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
votes
0answers
184 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
votes
0answers
41 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
votes
0answers
74 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
votes
0answers
63 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
votes
0answers
220 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
votes
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
votes
0answers
414 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
votes
0answers
82 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
votes
0answers
580 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
votes
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
votes
0answers
929 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
votes
0answers
665 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
votes
0answers
32 views

Pixel based Regression

I have 80 .tif files, and each pixel value represents NDVI. The whole stack of images is a time-series. I want to run a regression for each pixel using NDVI and time. I have tried to approach this ...
2
votes
0answers
18 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
votes
0answers
28 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
votes
0answers
58 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
votes
0answers
58 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
votes
0answers
221 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
votes
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
votes
0answers
350 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
votes
0answers
166 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
votes
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
votes
0answers
337 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
votes
0answers
300 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
votes
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
votes
0answers
536 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
votes
0answers
719 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
votes
0answers
295 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
votes
0answers
245 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
votes
0answers
221 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
votes
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
votes
0answers
703 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
votes
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
votes
0answers
856 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
vote
0answers
14 views

Delineate Built-Up Areas not working

I have been experimenting with the Delineate Built-Up Areas tool in ArcToolbox and have been unable to get it to properly work. The tool works properly without giving error messages, however I get an ...
1
vote
0answers
11 views

How to change the raster cell values where they overlap with the cells of another raster?

I have a raster that I'm trying to edit by changing the value of select cells (those that overlap with the cells of another raster). For some context, what I'm trying to do is create a Distance to ...
1
vote
0answers
64 views

Performing Viewshed Analysis in ArcGIS?

I have a series of observation points with heights specified within a long-integer type field. Points and DEM are in the same coordinate system. When I run the Spatial Analyst - Viewshed tool, the ...
1
vote
0answers
21 views

Extracting pixels with value in one raster but NoData in other raster?

I have two raster A and B, and they are representing the info for Florida. Ideally A and B should have same coverage. However, due to some data processing issue, B's boundary is a bit smaller than A's....
1
vote
0answers
21 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
vote
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
vote
0answers
54 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
vote
0answers
56 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
vote
0answers
19 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
vote
0answers
25 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 ...
1
vote
0answers
81 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)...