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

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2k views

Efficient way to handle NA values from analysis in R with Raster

I am not 100% sure if GIS is the correct stackexchange for this, but here we go. A problem I have been bested by: I have a raster layer of approximately 240 million cells. It could be a DEM or ...
3
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1answer
107 views

Elevation off Road in ArcGIS/Python

i'm using the Modelbuilder in ArcGIS 10.1 to calculate pixels depending on their slope and distance from the road. The third necessary task is to find out, if the pixel is upwards the road or ...
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2answers
1k views

Spatial Analysis - Calculate a cells elevation (height) above the nearest stream cell

I have searched for some ideas on how to formulate this analysis, but have come up short. I imagine there is a pretty straight forward answer; any help would be greatly appreciates. Data: DEM, ...
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1answer
140 views

How to choose pixel values according to each land cover class?

I would like to do following steps using two types of images (precpitation and Land cover image): select pixel values of precipitation image within each land cover classes calculate total amount of ...
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2answers
314 views

Troubleshooting why ArcGIS Model works on one PC but not another?

Do you have specific expertise you could share of examples where an ArcGIS Modelbuilder has worked on one PC but not on another? Are there any issues between different Windows versions? There is a ...
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1answer
1k views

Why does CON statement give ERROR 010240: Could not save raster dataset to (value) with output format GRID?

I am receiving the following error when trying to run the following code: import arcpy from arcpy import env from arcpy.sa import * arcpy.CheckOutExtension = "Spatial" env.workspace = ...
3
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1answer
385 views

Measuring polyline lengths running through a raster - is this possible?

I have a reclassified raster layer with 4 values and a vector layer of polylines. I would like to discover the length of the lines running through each raster value, or the percentage of the lines ...
4
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1answer
691 views

Understanding percentage drop-raster (flow direction-tool)

I'm creating a Topographic Wetness Index using a python script (http://arcscripts.esri.com/details.asp?dbid=16750) As I don't want this just to be a blackbox, I'm trying to understand the different ...
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1answer
1k views

Extracting Raster Values by Polyline End Points using ArcGIS Desktop?

I am looking for a way to extract elevations of end points for line data in ArcMap 10.2. I have a road dataset that I want to use as a Network Dataset in Network Analyst. I want to be able to set the ...
3
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1answer
943 views

PCA on correlation matrix in ArcGIS

I am trying to run a PCA on a set of normalized raster bands within ArcGIS. I would like to calculate the PCA on the correlation, not the covariance, matrix of the PCA, but Arc as far as I can tell ...
3
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0answers
60 views

How to perform euclidean distance analysis with coefficients? [closed]

I would like to perform an euclidean distance analysis in ArcGIS 10 for multi-points which represent seaports. The thing is these facilities have different capabilities for handling and i want to take ...
3
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1answer
388 views

How to best determine the future location of a Fire Station?

I have been tasked with creating a map and doing some analysis that shows the future growth (10 years) of our county. They would like to see where the future growth is likely to occur and also show ...
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1answer
212 views

Kernel Density output labeling

I have been looking for a way to try and make the output of the Kernel Density function in ArcGIS for Desktop make a little more sense to our administration. I ran the function on a sample dataset ...
6
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2answers
2k views

Is there a Focal Statistics (spatial analyst) tool in ArcGIS equivalent in QGIS?

I'm attempting to use QGIS v2.0.1 to accomplish the same tasks that I can do using ArcMap v10.1 and I'm running into some trouble finding equivalent tools. In ArcMap I am using the Focal Statistics ...
2
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2answers
69 views

Points near corner

I have a road network (lines) and some POIs (points). These POIs have the information of street name on their attribute table. I've found that some street name from the POI doesn't match with my road ...
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1answer
261 views

How can I know how many percent of area changed between 2 time step in arcgis?

I'd like to ask how to do change detection in ARCGIS? I need an image to show how many percent of area in class has been changed between 2 years? for example in output image, red is the area that has ...
0
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1answer
112 views

What tool breaks up raster cells into individual values based upon contiguity?

The green values have a COUNT attribute of 13418. I will want to use a tool that lumps the COUNT attribute and reclassifies based on values. But first it appears I will need to break up the raster ...
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706 views

Tabulate area - Spatial Analyse

I am trying to calculate the amount (sqm) of land cover types (forest, water ect.) in 1045 buffer zones, all the same size (500m in diameter).. The buffer zones are polygons and the land cover is a ...
3
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1answer
2k views

How to create mask file from shapefile using ArcGIS for Desktop?

I have a shapefile of Lakes over my study area. Each polygon has attribute information of each lake, name, shape etc. Actually I want to eliminate all lakes from analysis. In other word, I want lakes ...
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103 views

Loop - convert layer to raster coming up blank

I am looping through files, selecting out building footprints one by one and converting the selected building footprint to a raster. The script worked fine for about 2 hours this morning then stopped ...
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0answers
188 views

Is there an analog to ArcGIS' “Neighborhood Toolset > Point Statistics” for QGIS?

Quick procedural question- is it possible to create a raster with QGIS in which the raster cell value is assigned by summing the number of vector points that are within a certain radial distance of ...
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2answers
169 views

Neighborhood analysis based on occurrence of value

How can I do, either in ArcGIS, grass or another tool, the following: for each cell (pixel), if there is at least one cell with value '4' in a neighborhood of 5 cells around it, reclassify that cell ...
2
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1answer
4k views

What does “You do not have necessary license to run tool” mean when ArcGIS extension installed and activated?

I just purchased ArcGIS for Home Use 10.2 and installed and activated the extensions with the codes I received from Esri. The ArcGIS Administrator says Yes for Installed and Authorized, and even has ...
3
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2answers
120 views

how to change the pixel value to zero when it corresponds to a slope above 15%

i have a landuse raster data and raster data containing slopes in percentage. i want to assign pixel value as zero which corresponds to slope more than 15%. i tried using 'extract by mask' but i'm ...
3
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1answer
573 views

How to exclude stations from IDW interpolation?

I have the following problem: I need to calculate an average precipitation amount on a catchment using an IDW interpolation. The interpolation is performed in a loop since each precipitation station ...
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1answer
2k views

How to change the pixel value of a raster dataset which overlaps a polygon featured shapefile in ArcGIS

I have a raster data of 1992 and a 'shapefile' of Los Angeles county. I want to reclassify the pixel value of the raster data set to 'no data' or zero in the region where the raster and the ...
2
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1answer
623 views

How can I define hierarchical levels in eCognition

I'd like to define classes with 2 levels. Firstly I'm gonna classify some broad classes such as forest, grassland in a level 1. Furthermore, I'd like to classify these classes into some sub-classes ...
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0answers
65 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 ...
3
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1answer
177 views

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

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
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3answers
729 views

What DEMs does QGIS support? + DEM data sample

I am working on QGIS rasters. I want to know about DEM file formats supported by QGIS. I know that QGIS can read the GDAL supported formats. but what is GDAL supported format ? Does QGIS support the ...
5
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1answer
107 views

Can I “stack” semivariogram data?

I have several synoptic measurements (every few months) of a gravity field I would like to interpolate by kriging. Each group of measurements comprises about 45 measurement locations, and spatial ...
2
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0answers
517 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 ...
4
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1answer
2k views

How to reclassify raster inside polygon mask, leaving values outside as they are?

I am in the final stages of a landcover classification and need to reclassify thematic raster values that are inside different polygon masks, while leaving the values outside as they are. Can I do ...
2
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1answer
97 views

Examining the covariance between biodiversity and other variables

I have som problems with an analysis and would be very grateful for any answers or suggestion. The background is: - I want to examine the covariance between ecosystem services in an area. I don´t ...
2
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0answers
685 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 ...
5
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1answer
464 views

Tabulate Area ArcGIS

I am trying to work out the relationship between the 'processing cell size' and the result from Tabulate Areas. If one uses the same as the raster cell size, and this is the same for both rasters, the ...
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1answer
47 views

What is the meaning of “MULTIPOLYGON EMPTY” Message?

I am trying to run ST_Intersection function. SELECT ST_AsText(ST_Intersection(ST_Point(42.729123082000058,-96.619302355999992), ST_Point(42.72899715300008,-96.619410439999967))) FROM clu_08aug; I am ...
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1answer
365 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 ...
2
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1answer
1k views

Using Regression Trees in ArcGIS

I have a follow up question to Statistical analyses for survey against raster? I have a very similar problem as the initial poster David. I am creating a multivariate model from raster data in order ...
0
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1answer
245 views

What Z-factor to set in Curvature (spatial analyst)?

I'm making a slope curvature map, my DTM is 5*5 meters cells, in a meter grid projection. The elevation is in meters asl. When using the Curvature tool for different units of measure, the Z-factor has ...
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0answers
701 views

How to Smooth Polygons after converting DEM using Raster to Polygon?

I have a DEM SRTM that I classify using Spatial Analyst Tools > Reclass > Reclassify. The result is box shaped so I go to Layer Properties > Display and choose cubic convolution. The result is ...
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1answer
473 views

Overland flow modeling Help

I would like to determine the surface flow network, this based on the spatial analysis of DEM data and the creation of separate layers for surface ponds and preferential surface flow pathways. More ...
7
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1answer
655 views

How to find nearest neighbors of polylines?

I have a shapefile containing irregularly placed polylines (i.e., survey routes). Following the general idea of a paper I read, I would like to use tessellation to identify the neighbors for each ...
7
votes
3answers
352 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 ...
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0answers
328 views

How to calculate Gradient from DEM?

I have a digital elevation model for a catchment area and I would like to calculate the gradient by cells. Is that possible and does anybody know the steps?
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0answers
47 views

Problem in analyzing data in a stream segment

I have to find out the head difference along the stream segment. For that I used Spatial Analyst Tool>Extraction>Sample. With that I got the elevation values in points. But after doing so, i found ...
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2answers
421 views

Site Selection using Spatial Analyst

How can I select a recreation site location based on the criterion that it should AT LEAST be 500 m from a river (shapefile) and AT MOST 15000 m from the same river using Spatial Analyst Extension? ...
2
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3answers
3k views

How to perform a view shed analysis?

I want to run a viewshed analysis on a site I am interested in. I have the relevant elevation raster (taken from the OS UK, which is in the ASCII format) and a point feature class from the lat/lon ...
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2answers
272 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
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1answer
499 views

Where can I get documentation for Netezza Spatial Functions

I am looking for some documentation or manual or reference guide for Netezza Spatial Functions. Any idea where can I get the same. Thank you. Dharmesh