Questions tagged [analysis]

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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6
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2answers
10k views

Are GIS Analyst salaries going to always be so low? [closed]

I regularly see GIS Analyst job postings (often in very expensive cities) asking for a plethora of experience paying in the $40k - 60k a year range, many are even below $40k or $30k. Considering the ...
0
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2answers
235 views

Frequency analysis and overlay analysis

Am new to gis and I hope to find help here. I am working on a research that requires that I overlay conditions of drainage systems and quality of healthcare in a coastal state to get areas which have ...
2
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0answers
439 views

Performing Raster Algebra and Multicriteria Analysis using FME?

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. ...
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0answers
427 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 ...
1
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0answers
61 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 ...
16
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1answer
3k 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 ...
4
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2answers
101 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
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1answer
434 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
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1answer
2k 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 ...
2
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1answer
300 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
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3answers
2k 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 ...
4
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2answers
3k 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
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1answer
608 views

Combining and displaying 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 ...
4
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1answer
290 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 ...
-2
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2answers
2k views

What is Network analysis and how to find shortest path [closed]

I don't know about Network Analysis. Please any one help to understand the Network Analysis with example. General Process flow and procedure is enough to learn my self
46
votes
5answers
11k 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 ...
8
votes
1answer
3k 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
599 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
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0answers
334 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
144 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 ...
2
votes
1answer
379 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 ...
7
votes
1answer
2k 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
2k 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 don't know how to calculate the length of the basin ...
5
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3answers
3k 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
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2answers
338 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
107 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 ...
2
votes
1answer
191 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 shapefile of points. Each point corresponds to the number of people using a route at a time t. I would ...
3
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1answer
456 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 ...
18
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1answer
497 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
436 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 ...
3
votes
2answers
632 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
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0answers
392 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 ...
3
votes
2answers
1k 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
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0answers
2k 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
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0answers
5k 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
511 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
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0answers
387 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
919 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
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0answers
646 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
118 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
196 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 ...
2
votes
1answer
656 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
3
votes
2answers
521 views

Hillshade for 30m NED at continental scale

I'm new to terrain analysis. I have a 30m NED DEM (.tif) for the conterminous US. I would like to generate a nice looking hillshade for the US, but it looks bad - as in pixelated and rough (See image)....
2
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2answers
9k views

Find and list all polygons that overlap with another polygon

I am working with two polygon layers which overlap but are unrelated (one is congressional district boundaries, the other is MPO area boundaries). I would like to generate a list of all the ...
5
votes
4answers
2k views

How to computational efficiently check if there are any overlapping polygons in a group of polygons?

I need to do some processing with groups of polygons. If any of the polygons in the group overlaps other polygon the result is unpredictable and don't throw any error. So, I need to detect if there is ...
2
votes
1answer
4k views

Watershed Analysis using DEM [duplicate]

I stumbled upon your question regarding the mosaic feature in qgis, the thing is I'm also using Quantum and this is my first encounter with GIS this semester, so if you can please help me with a ...
1
vote
1answer
185 views

Basic traffic volume map [duplicate]

I'm trying to map the volume of people travelling from various cities to popular mountain towns in British Columbia. I have a CSV containing the starting point, ending point and number of travellers. ...
3
votes
6answers
457 views

GIS used to analyse micro-environment

Can anybody give me some articles or show me some link where GIS is used to analyse and manage micro-environment, such as a college campus or a small locality. I need to do a project on micro-...
1
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0answers
100 views

3D tool for a visual analysis

Given a 3D mesh I need to visualize and analyze properties and elements generated from the object such as: tensors coplanar/similar elements ( coplanar faces, aligned vertices, etc etc, 3D geometry ...
2
votes
1answer
106 views

Clipping a buffer from network analyst shapefile to a base shapefile

I have exported my polygon shapefile which I got after I ran my Network Analyst into a shapefile. It has 6 buffer zones (delimited by time in increments of 10 minutes). When I check the attribute ...