The process of extracting geographic, statistical, geometric, or scientific information from one or more related collections of GIS features and data.

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4
votes
2answers
283 views

Identify cluster centroids

I have a data set of points which are grouped into clusters like so: I'd like to use ArcGIS or Python to create a point layer of the centroids of each cluster but I can't seem to find the right ...
0
votes
1answer
271 views

How to colour contour lines in .shp file when the lines are not meeting in QGIS?

I am doing bathymetry analysis, where I would like to color the contours one by one in the case land is rising (or sea level going down). There is a comprehensive explanation about coloring contours ...
2
votes
0answers
183 views

FME - Raster Algebra and Multicriteria Analysis

I'm trying to use FME to do some raster algebra for some Multi-Criteria Analysis. At the moment, I have three rasters, all with the same extents and resolution: Slope, Hydro, and Infrastructure Mask. ...
1
vote
1answer
153 views

How to dissolve adjacent parcels by same owner but include those parcels located across the street with the same owner?

In trying to determine the total contiguous stream length per landowner, I dissolved parcels by parcel owner name attribute and intersected these dissolved parcels with streams. However, dissolving ...
1
vote
0answers
121 views

network based interpolation methods, which one could I use?

I need to interpolate traffic data consisting in raw number of vehicles passing across certain points, where counters are. It is evident I haven't a uniform distribution of points and values about ...
0
votes
0answers
217 views

Finding shortest cumulative route (i.e. best 'hub') between networked points

How do I find the shortest cumulative route (i.e. best 'hub') between networked points? I have a dataset where some but not all of the points in the network connect to each other, however it is ...
3
votes
0answers
109 views

How to create cost surface for least cost water transport analysis?

I am working on a project to derive least cost pathways between sites by dug out canoe travel. Has anyone worked on a similar project or found a function like the Tobler hiking function that can be ...
1
vote
0answers
38 views

Analyse effect of groups on raster maps

I work with a mechanistic model that uses climate data to simulate some specific output for different time steps and spatial locations. Now I want to investigate the effect of different climate data ...
10
votes
1answer
616 views

When dealing with rasters of varying resolutions should one resample to the highest or lowest resolution?

I'm looking for recommendations on best practices for dealing with raster data layers with different resolutions and projections. The advice I've been given is to always resample to the layer with the ...
3
votes
2answers
55 views

What type of remote sensing methodology is commonly used to locate and track the movement of woodland caribou herds?

I am most curious whether it is possible to use Landsat or other freely available imagery (but info on any other method would great as well) to locate and track the movement of woodland caribou herds ...
1
vote
1answer
203 views

Calculating distance between borders when one polygon inside another polygon?

I am brand new to ArcGIS and having some trouble. I would like to calculate the distances between the border of one polygon to another polygon. However, these polygons overlap. Thus when I use the ...
1
vote
1answer
689 views

ArcGIS “Zoom to layer” scale

I'd like to quickly inspect the features in a feature class by double clicking the row in the table view and looking at the surrounding base layer. This works, but the feature fills the screen, so I ...
1
vote
1answer
114 views

How does the tolerance influence QgsGraphBuilder and tieing of points?

I am developing a script which uses OpenStreetMap data to calculate the distance (over the road network) between each building and the nearest hospital. To do this, I mainly follow the official ...
1
vote
3answers
848 views

Creating flat end type polylineline buffer in model without ArcGIS advanced

I have a polyline split into many short segments and would like to create a flat end buffer for each individual segment (not "dissolve" them all into one feature). Is there any way to do this in an ...
3
votes
2answers
850 views

Creating square buffer in qgis

How can I create a buffer with square ends along a line segment in qgis? I've buffered lines using v.buffer in the GRASS plugin, but the -c option for square ends is not exposed in that interface. ...
2
votes
0answers
100 views

Finding obstructions along a stream with LIDAR [closed]

I'm trying to find obstructions to boat traffic (downed trees, collapsed bridges, etc) along medium sized streams (5-15m across). The obstructions may or may not obstruct water flow. I have good ...
2
votes
1answer
308 views

GIS Analysis - best way to combine and display demographic data?

I am currently undertaking a demographic research project for my employer. We have the data on income, age, sex, language, transport etc and I have mapped most of it and created some thematics of said ...
3
votes
1answer
149 views

Add more info in the attribute table after executing “Line intersection” in QGIS

I have executed the "Line intersection" tool on a road shapefile. This is under Vector > Analysis Tools > Line intersections. I get an output with attribute table having just two columns: type_1 ...
20
votes
4answers
3k views

What are the benefits of hexagonal sampling polygons?

I am always on the lookout for useful methods to sample or partition study areas (usually in the form of raster datasets) into smaller units. Recently, I read an ESRI blog post about a new tool for ...
-1
votes
2answers
216 views

How to get layer extension info via Arcpy

I want to get file format of a layer with using Arcpy. I am writing a tool that needs to take raster or feature extension like SHP, TIFF etc. Which functions should i use ? Note: I use ArcGIS 10
4
votes
1answer
703 views

What is the FME Equivalent to the ArcGIS Union tool?

I'm attempting to union 2 large featureclasses in ArcCatalog, QGIS, and FME. What is the transformer that would be equivalent to the ArcGIS Union tool?
2
votes
1answer
445 views

GTOPO30 Slope analysis in ArcGIS 10.1 [duplicate]

Using surface - slope analysis tool box. All values for the slope calculation are in between 80 and 89. There are no values below 80. What am I doing wrong?
2
votes
0answers
215 views

Our best table-analysis with GIS? [closed]

Sometimes I think about possible analysis using GIS models (I use QGIS 1.8), and I always think about few types of visualization techniques: demographics, traffic flows, distance ones... Thanks to ...
2
votes
1answer
114 views

How to select a part of a land cover type a certain amount of feet away from another land cover type

I have raster Landcover type Urban combined with Forest all within the county raster perimeter. I want to make a layer of only the forest cells that are more than 500 feet from an urban cell, so that ...
0
votes
0answers
256 views

Linking two Models together in ModelBuilder

I am trying to link two separate models that iterate thought two different feature classes together into one, however I am having a small issue. When I bring in the sub-model into the larger one it it ...
2
votes
1answer
151 views

Is it possible to automatically update a Buffer FeatureClass when creating new features?

Is there a way I can update the results of my Buffer analysis? I have a roads FeatureClass, and I've built a buffer for it. I will still make edits to the road FeatureClass. Let's say I add a new ...
5
votes
1answer
1k views

Split polylines at polygon boundaries in QGIS

I have a set of contour lines and a polygon set containing glaciers. Because I want the glaciers to have blue contours, I need to split the contour lines at the glacier boundaries. I can achieve this ...
3
votes
1answer
690 views

how to calculate the basin length - which point to which point and how in arcgis 9.3?

This is the area of my research.I have calculated area using area and perimeter using arcgis 9.3 for doing morphometric analysis of the area.but i dont know how to calculate the length of the basin ...
3
votes
2answers
7k views

Reading National Elevation Dataset (ArcGrid/GridFloat/IMG) with python only tools

I've found high precision elevation (1/3 - 1/9 arcsecond resolution) data from the National Elevation Dataset provided by the USGS. It comes int IMG, Arcgrid, and GridFloat formats. I know ArcGrid ...
4
votes
2answers
1k views

What are some user-friendly GIS alternatives to Alteryx and ArcGIS?

I'm posting for some inspiration. At my last workplace we used Alteryx extensively for all data analysis, pumping out shapefiles which we'd then symbolise and output maps in ArcGIS. In my new ...
6
votes
2answers
171 views

Finding lines in point patterns?

I have a point pattern (see below) in which I assume to find "significant" lines of points. However, I did not find any method that is integrated in a GIS or in R that searches for such line pattern ...
1
vote
1answer
82 views

Counting and sum by two layers

I´ve got to layers, both polygons. Layer 1 consists of propertiers, where ID is individually names. Layer 2 consists of lakes. The query I want is: Total count of squaremeters of lakes for each ...
1
vote
0answers
393 views

Calculating walking routes along a network(ArcGIS)

I've created a network consisting of footpaths, dirt tracks and junctions. I would like to calculate a route using network analysis by giving ArcMap the time and walking speed that the route should ...
2
votes
1answer
146 views

How to aggregate values multiple from multiple points along a route as an attribute of it?

I have a route network with a "Name" field that identify every route. On the other hand I have a shape file of points. Each point corresponds to the number of people using a route at a time t. I would ...
3
votes
1answer
353 views

Sensitivity analysis for coarse scale GIS epidemiological model?

I am working on an epidemiological model with disease incidence rate as dependent variable and environmental factors as independent variable. Disease data is available at county scale whereas ...
16
votes
1answer
368 views

What GIS analysis techniques were used in determining Gale Crater as the landing site for the Curiosity Rover?

What specific GIS analysis was used in determining Gale Crater as the landing site for the Curiosity Rover? I'm assuming factors such as slope, elevation, ruggedness, etc were used as well as ...
2
votes
1answer
237 views

Right raster zonal statistics for NDVI at county scale?

I am currently doing a modeling project at county scale in which I have disease rate as dependent variable and environment variables (such as temperature, NDVI and evapo-transpiration) as the ...
2
votes
2answers
394 views

SPOT NDVI time series

I have 423 spot.vgt ndvi from first April 1998 till 31 Dec 2009. I want to know how to stack these NDVI to have one image for time series analysis? Or better to ask how is it possible to analyze a ...
1
vote
0answers
268 views

Divide polygon evenly based on lines and intersection points

I have this purple polygon illustrated in the figure below. I would like to split the polygon so that each line segment (green) split the polygon evenly with the surrounding line segments. A line ...
5
votes
1answer
2k views

ArcGIS - make linear regression across multiple raster layers

I have a series of 5 rasters which represent a value for 5 consecutive years. Is there a way to create a linear regression for each cell over the 5 layers and output the slope? The result would be a ...
1
vote
1answer
449 views

Volume of Land Below Sea Level

How could one use a GIS (or other appropriate system) to calculate the change in mean ocean levels across the world if all the land below sea level were flooded (Death Valley, Caspian Depression, Afar ...
1
vote
0answers
879 views

Error #010067 when running spline interpolation

I am attempting to run a spline interpolation on a point dataset of 585 features in ArcGIS 9.3, using the spatial analyst toolbar. The dataset holds only latitude, longitude and abundance attribute ...
4
votes
0answers
2k views

Finding the “center of gravity” of multiple points where points have unequal weights [closed]

I'm trying to reduce a set of lat/lons (each with it's own weight) into one lat/lon that is the center of mass of all of the points. however when I map the results the average point falls no where ...
0
votes
1answer
335 views

Using ArcGIS 10 to find areas of overlapping use and areas with low use?

I have a spatial data set that shows areas of use (several different types of use) on the landscape. I am looking for ways to overlay these spatial use layers so that I can show where the areas of ...
1
vote
0answers
162 views

GIS Maximum area coverage problem

I want to find optimum antenna location for an area. Every antenna can cover an circular area. These areas diameter is 750meter. So how can i find minimum number of antennas and locations. NOTE: I use ...
0
votes
1answer
653 views

Nearest neighbor analysis not showing results

I'm trying to do a nearest neighbour analysis on fish shoals distribution. I go to Vector > Analysis Tools > Nearest neighbour analysis. I choose the appropriate layer and when I hit ok the black ...
4
votes
0answers
356 views

How to analyse correlations between variables and points? [closed]

I have just lost the past 8 hours on this, and literally getting nowhere - hoping someone can help before I go mad! I am trying to determine the correlation between sinkholes and a number of ...
2
votes
2answers
99 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
2answers
125 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
256 views

Python GDAL: find out spikes and pits in DEM

I'm working with on a DEM (Geotiff) in Python GDAL, and I'd like to find out the spikes or pits in my terrain. I have no idea how to proceed, does anyone have good algorithm to help me out? Thanks, eo ...