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

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6
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1answer
324 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
229 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 ...
0
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0answers
142 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?
1
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0answers
36 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 ...
0
votes
2answers
156 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
votes
3answers
1k 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 ...
0
votes
2answers
193 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
1answer
348 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
1
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0answers
235 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, ...
2
votes
1answer
521 views

Better way to get raster values for a large number of point features?

I have several projects with tree point features (SpecialStatusSpeciesPoint) that contain up to 2,000,000 records. I am trying to record tree height (Hgt) and base elevation (BaseElev) values, based ...
2
votes
1answer
268 views

Are there Open Source alternatives to ArcGIS Aggregate and Extract Value to Points?

I am looking for some kind of Open source GIS library which can perform spatial analytic functions same as ArcGIS. My use case is : I am processing GeoTIFF file provided by USGS and performing ...
1
vote
2answers
328 views

How to create a raster (topo to raster) with non-rectangular shape?

I'm using Arcmap 10, I need to create a raster from contour lines. These contour lines were clipped out with a certain shape with the purpose to modify them only within that shape and then create the ...
0
votes
1answer
97 views

How to make a new raster out of two other rasters [duplicate]

I have two raster images, one is the Corine Land Cover for the year 2000 and another one which is the anthropogenic effect on land. The first image reclassified in 9 categories: Artificial surfaces ...
1
vote
0answers
147 views

ArcGIS Spatial Analyst “Sample” returns Null values

Using "sample" to join raster values onto point data, some of my points get assigned a Null raster value. The raster does not contain Null values and definitely looks like it has a value at the ...
4
votes
1answer
212 views

Shortest raster path

I am trying to create a path from the blue square to all the green dots. The blue square represents an existing road and the green dots represent centroids of forest stands. The total path distance ...
3
votes
2answers
304 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, ...
2
votes
2answers
714 views

Arcmap 10 restrict Flow Accumulation

I am working with the Flow Accumulation tool in ArcMap 10's spatial analyst hydrology tools. This tool calculates the total number of raster cells that flow into a given cell. However, for my ...
1
vote
1answer
311 views

How to run a shortest path analysis for DEM-derived streams and pour points?

I have a .shp for streams and another for pour points. Those features were extracted from a DEM by using the Hydrology package from the Spatial Analyst Tools of ArcGIS 10. I want to know the distance ...
1
vote
1answer
71 views

Near / Near Table creates -1 values

I have two feature classes. Point feature of hand-sampled GPS locations Line feature of terrace walls digitized from aerial photograph. Because of the less than perfect ways I generated these ...
0
votes
1answer
375 views

How to run a ZTV (ZVI) on ESRI ArcGIS 10 for a 3m high object?

What tool in the spatial toolbox would you use to run a ZTV (ZVI)? or is there a better way of carrying this type of query out using Arc? Also what other information would I need to do this type of ...
3
votes
0answers
168 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 ...
1
vote
1answer
549 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 ...
2
votes
3answers
2k views

How can I reclassify a raster to floating point values?

I have a raster of landuse values that I need to reclassify into pollution concentration values. I have the pollution values in a separate table. They are decimal values (ex. 0.0056), and my landuse ...
1
vote
0answers
198 views

How to create backlink raster for Cost Distance tool?

I have two polygon shapefiles and one cost surface. I need to estimate accessibility to these two sets of destinations. The part that I don't understand is whether I have to use an output backlink ...
2
votes
2answers
275 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
0answers
128 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
2answers
75 views

Solar analysis; Are there any issues with splitting large DEM

I am trying to run Solar analysis in ArcGIS and it is an enormous DEM of a very mountainous region. I'm obviously going to have to split the DEM, but I was wondering if there are any issues with ...
0
votes
1answer
85 views

territory analysis

I want to determine the territories in which customers to a bank has the shortest path. It can be done with desktop software packages or programming if it is needed. Does anybody has idea on how to ...
1
vote
1answer
107 views

Global DEM and country borders

I am trying to split up the world into 2 categories based on elevation (below 2000m and above 2000m) while still including a country identifier. So in the end, I would like to have 2 types of units ...
0
votes
0answers
49 views

How specify a corridor minwidth?

I’m trying to make a corridor between two substations with ArcGIS, a macro corridor and a micro corridor. I have two questions in this respect and would be grateful for your suggestions. a) How can ...
1
vote
0answers
135 views

ArcHydro: Flow Accumulation 863988034 Cells

I've been using Arc Hydro for the last 7 years to determine catchment characteristics. I'm currently setting up a new model to determine structure locations along a proposed railway alignment. This is ...
1
vote
0answers
223 views

How to compare outputs of erosion from ArcSWAT and RUSLE from ArcGIS?

I calculated water erosion in ArcSWAT and I also calculated erosion by RUSLE http://35.8.121.139/rusle/ equation in ArcGIS. Now I need to compare these two (from ArcSWAT I used SYLD- assumed ...
4
votes
1answer
338 views

How to calculate the volume of several DEMs to obtain elevation and volume changes?

I am trying to calculate the volume of several DEMs in order to obtain elevation and volume changes. I have pixels of 1x1 each one associated to an elevation. I used several methods but non of them ...
2
votes
1answer
195 views

Error while using raster calculator in model builder

I am trying to use the model builder for the RUSLE Model. Well this is how the model looks like: So in the raster calculator I have a formula which also involves the rasters generated in the model. ...
2
votes
2answers
496 views

What tool would you use to “clip” a vector line file to a vector polygon file?

I am trying to select the use of a large vector line file within only the parameter of a vector polygon file to do spatial analysis. It would be the same thing as using the extract> clip tool under ...
2
votes
0answers
205 views

ArcGIS Raster Calculator VS QGIS Raster Calculator [closed]

Are there any major differences between ArcGIS Raster Calculator and QGIS Raster Calculator?
1
vote
0answers
189 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 ...
3
votes
1answer
441 views

Why is my simple arcpy script failing? (sets raster cell value to null if below threshold value, ArcGIS 10.1)

As mentioned in the title, simple script to set null cell values below three standard deviations beyond the mean: import arcpy, sys, os #Accept input and output raster inRas = sys.argv[1] outRas = ...
1
vote
0answers
88 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 ...
0
votes
1answer
208 views

Error while creating a slope [duplicate]

I have a elevation raster (1 arc second) downloaded from USGS site. Before adding it to ArcMap I changed the display units to meters.The projection system for this raster is GCS_1983. When I use the ...
1
vote
2answers
383 views

Round Raster to next higher or lower int

I am using ArcGIS 10.1. I am searching for a solution to calculate a raster. The values are like: 0.2 0.6 5.3 i.e. How can I now get 0.2 as 0 and 0.6 to 1 and 5.3 to 5? In the end integer numbers. ...
6
votes
2answers
333 views

What do ArcGIS regression analysis warnings 000853, 000916 & 000981 mean?

I'm trying to do regression analysis using a shapefile which contains dependent variable (NDVI) and explanatory variable (prec) in ArcGIS. First, I run GWR analysis and then run spatial ...
2
votes
1answer
256 views

Nearest Neighbor Focal Statistics and Map Algebra

I would like to use a nearest-neighbor type analysis to iterate over a raster. The nearest neighbor analysis will give a cell value of 1 IF AND ONLY IF the cell being analyzed has a cell value larger ...
0
votes
1answer
129 views

Elevation Drop Along a Stream [duplicate]

Previous discussion In reference to a previous discussion, suppose I want to cut the stream every 100 m and find the elevation drop every 100 m. How can I do this?
1
vote
0answers
57 views

Is there any method to analyze data from fire protection events? [closed]

I want to analyze data from events in fire protection a create some illustration of maps. In short: my task is to find methods for data visualization. Data are represented by point layer (each event ...
4
votes
1answer
354 views

Which flow routing algorithms does ArcGis support?

Other than standard D8 are there support for multiple flow algorithms like FD8, DEMON, Dinfinity etc?
1
vote
2answers
1k views

“Extract by Mask” changing raster pixel values…or not?

I am using ArcMap 10.0 and am confused by my Extract by Mask output rasters. I hope to eliminate the black background from three Landsat ER Mapper images so that I can mosaic them. Originally I ...
1
vote
1answer
199 views

IDW: Default Maximum Distance and Coincident Points

The ArcGIS Help file says the Default Maximum Distance, when using the Variable Search Radius in IDW, is the extent's diagonal, however, no value is automatically filled in the corresponding box after ...
1
vote
2answers
245 views

How can i use field of view in ArcGIS?

The field of view analysis in GIS is a polygon file that shows the portions of an area that are visible versus no visible across a terrain starting from a given point. see this Link How can I use ...
1
vote
1answer
189 views

How to estimate flow paths between contaminant sources and catchment offtake (exposure point) at catchment?

I am trying to estimate flow paths between contaminant sources and the catchment offtake (exposure point) at the catchment. Can anybody give me some help in how to proceed?