2
votes
0answers
6 views

Best tool for interactively determining upslope and downslope areas on a DEM

I know SAGA GIS can be used to interactively generate maps of upslope and downslope areas for a cell within a DEM, but the output is pretty ugly. An upslope area is defined as all cells (for a ...
5
votes
0answers
38 views

How do ESRI and QGIS calculate scale values of geographic projections?

Does anyone know how (from which location) scale values are calculated in ESRI products and QGIS for geographic projections? The only thing I've noticed is that QGIS is changing scales when you pan ...
3
votes
2answers
182 views

How to calculate the square root of a feature attribute?

I have a polygon shapefile with over 16k features. Each has an attribute (Double, Precision(10) Scale (2)) that I am trying to calculate the square root of, and store in new field. Is there a tool, ...
1
vote
0answers
39 views

Scaling features based on an attribute

I would like to scale polygon features by a specific factor I have calculated for each feature in a feature class. I know of the Scale tool, however it only allows for manual entry of a scale factor ...
3
votes
2answers
57 views

Correlation between a raster and a point dataset

I have an interpolated surface (in raster form) with temperature values and I also have the measurements of temperature in certain locations that belong to the same region (with the raster). I want to ...
4
votes
1answer
110 views

Can ArcGIS ModelBuilder be exported to Python and run in QGIS?

Is it possible to construct a geoalgorithm on the ArcMap modelbuilder, export this entire algorithm to python syntax (without having ANY knowledge of python) and then import this algorithm to QGIS and ...
0
votes
0answers
27 views

Graphical Modeler Equivalent in Arcmap? [duplicate]

Is there a similar interface as the QGIS Graphical Modeler in Arcmap for geoalgorithm development? If so can one develop a sequence in Arcmap and open it in QGIS? I would prefer using an 'Arcmap ...
2
votes
1answer
40 views

Conditional Statements in QGIS raster calculator?

What is the equivalent statement of the following expression in the QGIS raster calculator? Con(((Abs("DEM" - "FSMin") > 120) | (Abs("DEM" - "FSMax") > 120)), 1, 0) I have no problem ...
0
votes
0answers
31 views

Exporting feature class from gdb crashes ArcCatalog

I'm trying to export a polygon feature class from a file geodatabase created and managed using ArcCatalog. When I click "export" a dialog window pops up, then another that says script error, then ...
1
vote
1answer
47 views

Shapefile not projecting correctly [duplicate]

I am still new to this, so I apologise if I don't make a lot of sense! I am using QGIS 2.4.0 Chugiak. I am working on a project set to the GDA94/MGA Zone 50 coordinate system with 'on the fly ...
1
vote
0answers
31 views

Way to split and create buffer space between polygons in QGIS or ArcMap

After performing a feature extraction of rooftops, some of my buildings have been joined together as one polygon. I want to split these large polygons so that each new division is only covering one ...
3
votes
1answer
95 views

Benchmarking QGIS and ArcGIS for Desktop speed for “significant buffer on very large shapefiles”?

I am a newcomer to the world of GIS. I realized that QGIS was relatively similar to ArcGIS for Desktop. I would like to know if the two programs are comparable in terms of computational speed. For ...
2
votes
1answer
63 views

How to do a “fuzzy” intersection?

I have two layers that look like this: I want the intersection (or whatever the correct term may be) to look like this where the output polygons are the same as the original base layer, just with ...
0
votes
1answer
53 views

Creating a new shapefile based on an existing problematic shapefile

I have a large floodplain shapefile and would like to create a new shapefile based on coverage. I'm having major problems with the original (intersections and other errors) which I've been unable to ...
0
votes
1answer
56 views

Determining direction of longest segment of polygon?

I have a shapefile with 9000 agriculture fields and what I like to do is to determine for each field (=each polygon) the direction of the longest segment. For instance, the selected polygon in the ...
0
votes
0answers
28 views

How to select duplicate polygons? [duplicate]

Although it may seem this has been answered before, there doesn't seem to be a solution. I am trying to simply select duplicate polygons. I don't want to delete them or anything like that. I need ...
6
votes
1answer
94 views

How to replicate QGIS vector smoothing effect in ArcGIS for Desktop?

You can see from the screenshots that QGIS has, in my opinion, much more pleasant on-screen rendering of vector features. I assume there is some sort of smoothing algorithm used in QGIS. Is there a ...
3
votes
1answer
77 views

Cropping or removing borders (not NoData) from multiple scanned and georeferenced maps (ArcMap or QGIS)

I have several hundred scanned maps in TIFF format, each correctly georeferenced and forming a large grid of images. The problem is that the border for each map is present - a white band, with a black ...
1
vote
1answer
61 views

Help choosing an appropriate GIS solution for the following question [closed]

I am currently researching for an appropriate GIS solution. My requirements are pretty simple: Ability to create circles, symbols or diagrams with transparancy tied to their geographical location ...
2
votes
1answer
92 views

Calculating the fractal dimension of a line segment

I have a shp file with hundreds of features that represent clipped segments of coastline. Each segment is made up of many vertices (dozens, perhaps even hundreds). (FYI, the segments were created by ...
2
votes
2answers
129 views

How to determine which polygons, if any, points fall within?

I am a amateur at GIS and need some help. I have a group of shapefiles of various areas and an Excel spreadsheet of addresses I have geocoded to points. I want to determine whether each point falls ...
2
votes
2answers
58 views

Display two-dimensional color gradient for two different quantities

I have two overlapping raster layers. One contains quantity A from 0 to 100, and the other contains quantity B from 0 to 100. I'd like to create a map displaying both sets of data at once based on a ...
0
votes
2answers
71 views

Any clue how to read a .style (ArcGIS) file in Python, for converting into another platform-specific format? [duplicate]

The problem I am face with is that I have all my data as shapefiles but my organization works with only 1 ArcGIS license. Migrating to QGIS to prominent amount of work, I need to convert my ArcGIS ...
1
vote
0answers
61 views

Selecting only parallel lines along a center line

Read through the previous post how to find close and parallel lines but still looking for a simpler solution. Found several ArcGIS forums post on the topic but no answers there either. It seems ...
0
votes
1answer
62 views

netcdf daily data to monthly raster layers

I have a netcdf (.nc) file of 95GB which consisted of daily data for a 50 years period. I tried to process this with ArcGIS (Multidimension tools – MakeNetCDFRasterLayer command) and it was not ...
1
vote
2answers
89 views

GIS Survey Line Plans

Has anyone ever heard of any tools in either Arcmap, QGIS, Mapwindow GIS etc, that could create a line plan (Survey Lines) across a polygon (Survey Area)? A form of input such as distance between ...
1
vote
0answers
104 views

QGIS 2.2.0 GRASS not worked

I use QGIS 2.2.0 on Windows 8 64 bit. I try to install use Standalone installer and OSGeo4W and still get the error And then i start GRASS C:\Program Files (x86)\GRASS 6.4.2>grass64 ╬╪╚┴╩└: ...
2
votes
1answer
54 views

Method for automatic aggregation of polys with sparse data

I am part of a project on presenting health related data on maps. In order to maximize the analytical usefulness of the data, we wish to divide them into as small areas as possible. However, to ...
1
vote
2answers
79 views

How to split a (road) buffer using the centerline?

I have a road centreline dataset which I have buffered using the road width. I used the standard QGIS buffer tool. I realise for my analysis I actually need to split the road buffer in half and ...
1
vote
3answers
34 views

Adding combined footage to points from the beginning of a line

I'm trying to add the footage of each point from the beginning of the line to the end. There are around 4k vertexes between the two ends that I need to put the footage from the beginning of the line ...
0
votes
0answers
47 views

Digitizing with OpenLayers Plugin seems incorrect

I am attempting to digitize some buildings based on floor plans using QGIS. To do this, I have taken the blueprints, georeferenced them against openlayers bing aerial plugin. I then digitized the ...
3
votes
0answers
47 views

Is there a “Disperse Markers” tool for QGIS?

I am using ArcGIS, but either I would like to use QGIS and maybe want to switch completely later. A have a point overlapping problem, as a result of geocoding of addresses. I have not found any ...
0
votes
2answers
76 views

Identifying clusters of points within a given distance

So I have a database of lats/longs representing incidents occurring on or near roadways. My goal is to identify the street block areas with the highest number of incidents in the database. I don't ...
1
vote
2answers
63 views

Create Shapefile of all overlapping features from single Shapefile

I need to create a Shapefile out of another Spahefile that consists all overlaps of features within the initial Shapefile. I'm sure there is a simple solution using ArcMap or QGIS, but at the moment ...
1
vote
2answers
83 views

User defined Coordinate Reference System (CRS) in QGIS is not located where expected?

I have received a shapefile with a user defined projection (i.e., +proj=krovak +lat_0=-32.923433 +lon_0=116.47485 +alpha=111.423433 +k=1.00004 +x_0=44328.529781 +y_0=1345943.211845 +ellps=GRS80 ...
1
vote
1answer
81 views

How can I open a .pmf file with QGIS?

I have spatial data that has been put together with ArcGIS and exported to me as a .pmf file. I'm spearheading a complete move from ArcGIS to QGIS and trying to make our old data still useful and able ...
0
votes
0answers
37 views

How to overlay polygons that are in the same layer

I need to INTERSECT many polygons that are in the same layer. Actually each polygons from my layer represent an area of influence from one specific bird species. Since I used to use ArcMap, I found ...
0
votes
1answer
51 views

Copy .prj file into QGIS projection folder

I want a custom projection used in ArcGIS be available in QGIS. I have the .prj file copied out of a ArcGIS folder (containing different projections). Now, I want this file to be added into QGIS. Is ...
0
votes
1answer
56 views

How to georeference a map - which is in projected coordinate system - using geographic lat long? [duplicate]

We have some hard copy maps which were projected in Gauss Kruger coordinate system (in the legend it has been mentioned). But, the coordinates were given in Geographic lat long (Beijing 1954). In ...
0
votes
2answers
73 views

Geo- referencing Projected coordinated raster with GCS - ArcGIS

I have raster displaying Lat/ Long grid, but map information shows that, it s been mapped in Gauss Krugger projetion/ Beijing 1954. So, technically we need to geo reference the map in Gauss Krugger/ ...
0
votes
0answers
42 views

Determining whether point location is left or right of line?

I have one line layer and one point layer. Points are located both sides of line. I want to know whether points are located on the right side or the left of the line. Is it possible to determine ...
1
vote
1answer
89 views

Finding left and right side of line in arcgis

i have road layer as line and polygon layer as building,i want to know left and right side of road in relation with buildings is it possible in Qgis or Arcgis?
0
votes
0answers
34 views

Determine Transect line to cover area

I'm near certain this is a solved problem, but I haven't been able to find a solution from searches so here's my situation (probably I'm searching the wrong thing)... I need to compute the ...
1
vote
2answers
37 views

Set border symbology by bordering feature?

I'm using a US state shapefile, and I want to have different border types based on properties specific to the border, not to any state. For example, I might want the Florida-Georgia border to be ...
0
votes
0answers
27 views

Cross platform gis api wrapper architecture

I have a python class library for arcpy which is just a couple of class definitions with my common code attached as methods and properties so that I can do code centralization for stuff that I have ...
0
votes
1answer
52 views

Mac QGIS files to Windows Arc GIS compatibility

If I download QGIS on to Mac will the shapefiles and layers I create be compatible with ESRI ArcGIS 10.1 on windows?
1
vote
0answers
79 views

How to get Drainage Divide and Streams from DTM

Does anyone know how you can get a map like this attached, having the digital terrain model? I'm sorry, but I do not know what is the exact technical term in English for them. I hope you understand ...
0
votes
1answer
60 views

In QGIS are there similare construction tools to ArcGIS?

For a project we are using ArcGIS to reshape autogenerated features. For that we often use the construction tools polygon, rectangel, circle, etc in ArcGIS. The right angle is also an often used tool. ...
2
votes
2answers
155 views

Convert from Julian Date to Calender Date in Field Calculator

Does anyone know of a way to convert from a Julian date to a regular calender date in either QGIS or ArcGIS field calculator? Thanks...
1
vote
1answer
41 views

How to export a IDW raster while keeping the search radius data

I want to export my IDW rasters that I made in ArcGIS to QGIS, however when I export my raster, the values are there but are no longer displayed. They are stored within each cell and are not ...