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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-1
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0answers
8 views

Working on query builder in QGIS?

I installed QGIS 2.16.1 and i want to work with the data using query builder. It was active and when i click it nothing pops us and now it is just deactivate. Is it related to plugin or what ?
8
votes
2answers
6k views

Creating noise maps using ArcGIS for Desktop or Open Source Desktop GIS? [on hold]

In a previous role I helped create Noise Maps for Northern England. The predicted noise levels was done using the IMMI package (which I can recommend) and the cartographic output was done in ArcMap. ...
0
votes
0answers
18 views

GRASS 7.3 r.fill.dir Does Not Create Output Raster

I am running GRASS 7.3 on Mac OS X El Capitan (2.9GHz, 8GB RAM). I have had to disable SIP in order to run it, but it works. I am hoping to perform some hydrological analyses on a few DEMs. My DEMs ...
2
votes
1answer
208 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 ...
0
votes
0answers
50 views

Finding depressions in LiDAR DTM? [duplicate]

I would like to find temporary moist areas based on terrain surface shape (depression) directly from an airborne LiDAR DTM. Could you help me to find some tools or algorithm to solve the task?
2
votes
0answers
19 views

Working with intersecting polar grids

I'm having some trouble figuring out the best way handle some GIS data. I want to analyze pollution from specific sites at specific points. I have a list of sites I'm interested in all across the ...
1
vote
1answer
21 views

Can I split my data based on the polygons in a different layer?

Carto has a built-in dataset with polygon data for UK administrative regions. I have put another layer over this, containing several thousand data points (postcodes). Is there an easy way to find out ...
1
vote
1answer
26 views

Weighted polygon-feature-classes combination/overlay analysis using ArcGIS for Desktop?

I have several (sometimes, not always overlapping) Polygon Feature Classes which are all weighted/ranked through a field from 1 to 10 (10 is best). I would like to combine/overlay these layers them, ...
2
votes
1answer
19 views

Calculating standing times

I have n objects and each object has m positions. Every position is defined by x, y (in millimeters) and a (unix) timestamp. { objId: 'a-b-c', x: 123, y: 567, date: 123456789, } Now I want ...
1
vote
1answer
176 views

Analyzing long lat location data to find locations in proximity

I am looking for a tool to analyze location data (long lat values from vehicle GPS available). The goal is to identify locations which are in close proximity (within a circle of 30-60ft) and then ...
2
votes
1answer
380 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 ...
1
vote
0answers
25 views

Analysis of concentrations

I process images of trace gases concentrations distribution over the layer of atmosphere. I need to analyse values of concentrations, rather detect so-called "background" values and "extremal" ones ...
0
votes
1answer
23 views

How to group overlapping polygon features to generate unique feature ID?

I have a group on onshore leases that are overlapping and I want to generate a field attribute so that all the polygons (or centroids of the polygons) that overlap have a unique ID so that I can ...
3
votes
2answers
53 views

How to calculate shortest distance from start to end of river?

How can I calculate the straight distance from the start to the end point of a river (red line in image)? I don't know how to do this automatically.
17
votes
2answers
246 views

Do any Basketball Coaches use GIS?

The LA Times has a leaflet map viewer app showing all 30,699 shots in Kobe Bryant's career. It seems like spatial analysis could be useful for certain coaching decisions. Are any coaches actually ...
0
votes
1answer
22 views

Add a random value of the order of 10^-2 to raster layer?

I was doing some raster analysis for smoothing in ArcGIS, one of my task is adding a random value of the order of 10^-2 to a raster layer. Does anybody know how to do it?
25
votes
4answers
4k 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 ...
2
votes
1answer
38 views

Cell-by-cell analysis of values of buildings in a city

I'm absolute new in GIS. My task is to estimate the wind energy potential in a part of a certain european city by using a given method which is based on the calculated roughness of cells of one ...
7
votes
3answers
691 views

How to get a list of adjacent lots to a road in ArcMAP and PostGIS/QGIS?

In the following map, I have: A line / road layer A parcel / lot layer The Task: Find and count the list of lots adjacent to the road with their types (parcel_type is a field in the parcel layer)...
0
votes
2answers
82 views

QGIS NDVI Spatial Analysis

I have an NDVI raster that I would like to reclassify into some arbitrary bins i.e. all values between 0 - 0.2, 0.2 - 0.4 etc. for spatial analysis. Could anyone advise how to: 1) reclassify a ...
0
votes
1answer
55 views

Nearest Neighbour analysis between points in 2 tables utilizing with distances set along specific polyline roads

I'm trying to do a Nearest Neighbor analysis between points in 2 tables utilizing with distances set along specific polyline road files I have. I am attempting to determine the most cost effective way ...
0
votes
1answer
21 views

Is there any water quality toollbox which can be used in water quality analysis [closed]

I just start my job in water quality analysis,I wonder that do we have any toolbox to do water quality analysis in GIS
4
votes
1answer
53 views

The source of and possible solutions for DEM anomalies?

I am working with a DSM (Digital Surface Model) created using stereo-paired spot 6/7 satellite imagery. This DSM, and metrics derived from it will be used to create a Predictive Ecosystem Map (PEM). ...
3
votes
1answer
114 views

Counting polygons in one layer that are overlapping/touching/contained in each polygon in separate layer of contiguous polygons using QGIS?

I have a layer of contiguous (pink) polygons (UK Parliamentary constitutencies) and a separate layer containing (blue) polygons representing protected nature areas (Natura 2000 areas): Each ...
3
votes
1answer
43 views

Distance matrix tool, how to include distances at 0 metres?

I have used the Vector -> Analysis Tools -> Distance matrix to merge two datasets by the closest points. But in my output csv file, the points that match exactly, or that has 0 metres between them ...
1
vote
1answer
33 views

QGIS: Distance Matrix tool omitting some points in output table. (qGIS 2.10.1-Pisa)

I have used the Analysis Tools -> Distance matrix to merge two datasets by the closest points. But in my output csv file, some of my points are left out. In the original datasets, none of these points ...
4
votes
3answers
2k views

Summing attributes intersected by under a radius

Apologies - new user. I am working with QGIS on Mac OS X and with shapefiles downloaded from the US Census Bureau that show population data by state and by county. How do I: select certain points (...
1
vote
1answer
110 views

Slope analysis of DEM in QGIS?

I have very strange problem with the raster analysis. I have a DEM as a Geo tiff and I do a slope analysis in QGIS. I've done this many times and everything was ok but this time I received reversed ...
0
votes
0answers
50 views

Modeling Gun Safety

I am attempting to wrap my head around a modeling workflow for gun safety. I have been tasked with developing a model that would identify locations where discharging a firearm would result in the ...
4
votes
2answers
191 views

Finding tight corners on roads using ArcGIS Desktop?

Problem: How can I pinpoint tight corners on a road dataset that might cause longer/larger vehicles difficulty in driving around. Assumptions: Ignore turns into junctions. Just interested in ...
16
votes
1answer
381 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 ...
5
votes
1answer
196 views

Dividing polyline layer in clusters with specific requirements in ArcGIS for Desktop?

For my work in ArcGIS 10.2 for Desktop I need to divide line layers into clusters/groups. Currently I am doing this manually, but I like to automate this. The line layers can consist of 50 up to 2500 ...
11
votes
2answers
3k views

How to calculate average slope in a grid?

This is actually a two part question: Which methods are there to calculate average slope by unit (say km²) for a given area? Are there any special requirements on the data - like additional ...
0
votes
0answers
35 views

Analysing TMS / WMS usage and performance

to tune my webservices, I like to know, if there are existing anlysis tools to measure spatial requests (similar like Piwik does for web requests). There is Maptiks as service, but I'm looking for an ...
0
votes
0answers
49 views

Missing data in exercise in training manual? (Qgis training manual 2.6)

I'm following the Qgis training manual 2.6. The step 7.4.1.2 (according to http://docs.qgis.org/2.8/en/docs/training_manual/vector_analysis/spatial_statistics.html )doesn't generate a new SHP with ...
1
vote
2answers
62 views

How to set independent path in QgsOverlayAnalyzer >> intersection statement using Python?

How to set independent path in QgsOverlayAnalyzer >> intersection statement using Python? QgsOverlayAnalyzer.intersection(QgsVectorLayer, QgsVectorLayer, QString, bool onlySelectedFeatures=False, ...
0
votes
1answer
35 views

Does ArcGIS Online include High Speed Rail in its network analysis?

I'd like to run an OD Matrix using network analyst in Europe and Asia to study high speed rail. Does ArcGIS online include HSR (such as the AVE in Spain or the TGV in France) in its analysis?
1
vote
1answer
327 views

Batch frequency of point groups to single table in ArcGIS Desktop? [duplicate]

I'm new in the GIS world. I have a bunch of points (around 40,000), which are split in categories (1 to 9) and have a field which specifies their membership to a polygon (~50) (e.g, 30, which would ...
2
votes
1answer
188 views

Arcpy Intersect analysis function returns an error when using certain types of strings for input

In an arcpy for the intersect_analysis function, certain syntax works and others don't. What is the reason for this? Works: arcpy.Intersect_analysis("'D:\\Program Files (x86)\\ArcGIS\\data\\uscities....
3
votes
2answers
140 views

Which SRIDs to use for what tasks?

I try to understand the idea behind the different Spatial Reference Identifiers. I understand that the different SRIDs identify different projection views on the earth and that they are important for ...
-3
votes
1answer
66 views

How to determine how many times an area was burnt? [duplicate]

In arcgis I want to find from various forests fires shp files how many times parts of a particular forest were burnt during the last 70 years. Is there a way to count overlapping polygons?
0
votes
2answers
36 views

Visually identifying areas where older poles predominate?

I have a dataset of 300,000 poles including a number of attributes including pole age. What I'd like to do, ideally, is be able to distinguish areas that have more old poles. Unfortunately I can't ...
1
vote
0answers
70 views

Calculating spread of invasive species using ArcGIS for Desktop?

I have ArcGIS Desktop Advanced and so far have completed the following; Used Supervised classification on a satellite image to identify the invasive species with field verification. I have converted ...
1
vote
1answer
64 views

Identify nodes in GRASS

Apologies if this is a really basic question but I have been unable to sort this out: How do I identify nodes in GRASS? Specifically, I am running a Salesman analysis and get the following error ...
1
vote
2answers
851 views

How can I calculate how many of a certain feature lie within my various buffer rings?

I am using ArcMap and I have a series of real estate parcels mapped along with a series of wind turbines. I have created multiple buffer rings around each real estate parcel with distances (0.5, 1, 1....
1
vote
1answer
271 views

How to read GeoCSV with OGR?

I have a GeoCSV file which stores the geometry in a WKT formatted cell following this recommendation: "identifier","date","geom","value" "Dgf01","15.04.2013","POINT (52.404869 13.147457)","285" "...
3
votes
2answers
7k views

How do you use GIS to detect percentage of Land Use Change

I am a student in GIS I have a dissertation about land use change. I have questions about using ArcMap 10 for this aim, how can using GIS to detect the percentage of land use change. For example we ...
4
votes
2answers
3k views

Where can I download a free dataset containing major ports across the world?

I am working on an analysis and would like to incorporate major maritime ports from across the world. Some initial searching turned up a dataset produced by General Dynamics, however it will be ...
0
votes
0answers
44 views

Aggregate polygons based upon adjacency to an acreage threshold

I work as a forester. I have a feature class of approximately 750 polygons that range in size from a few acres to more than 250 acres. I would like to combine these polygons based upon their proximity ...
9
votes
1answer
362 views

PostGIS polygon edge analysis (orientation, edge length)

I am rather new to the world of GIS and especially PostGIS, so please excuse me if the answer seems evident... I would like to do analysis on a number of buildings. One thing I am interested in is ...