1
vote
2answers
35 views

Contour of single feature on QGIS

I'm trying to extract one single contour line at given elevation from a DEM. Taking into account that I want only one contour and not all contours with the given elevation, is there a way to do it in ...
0
votes
0answers
28 views

Merging contour lines generated by gridded data

I have a set of gridded data, which I have used to generate contour lines based on separate values in the data. In the example provided the contour lines shown correlation coefficients. The contours ...
2
votes
1answer
109 views

How to create contour lines from point data?

I'm using QGIS 2.4.0 and I have a shapefile of points with elevation data and X and Y coordinates. I'm using windows 7 OS. The idea is to create a contour line SHP using my point data. My question ...
2
votes
1answer
48 views

Rasterizing Contours - How to remove 0 values

I want to convert vector contours to a DEM. From other posts, I wanted to utilise the Grass r.surf.contours tool. Initially I converted the vector contour layer to a rasterized contours using the ...
1
vote
1answer
24 views

Contour generation using Interpolation - Correcting edge Effects

I utilised the Interpolation feature in QGIS to prepare contours from a DEM I had generated. Sometimes when contours intersect the edge of the DEM area, they run along the edge for some distance. ...
1
vote
1answer
50 views

QGIS Contour plugin: Creating complex isolines leads to isolated areas

I use the contour plugin (v1.1) within QGIS 2.4 to create contour lines. I have streets with different travel costs. I observe problems for streets with low travel costs if they are surrounded by ...
1
vote
1answer
43 views

Problem loading the contour plugin

I have installed the contour plugin on my kubuntu 13 laptop, but when I am opening qgis (2.0.1) I get the following message: Couldn't load plugin contour due an error when calling its classFactory() ...
2
votes
1answer
88 views

QGIS contour plugin exception struck help

I am a fisheries biologist and I am just getting started with QGIS. I took a few GIS classes in college so my GIS knowledge is not extremely high. On to my question. I am trying to make a depth map ...
0
votes
1answer
95 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 ...
1
vote
1answer
111 views

QGIS contours smoothing and cleaning

Trying to utilize the contour extraction QGIS tool but having trouble creating smoothed contours. The smooth, generalize, and dissolve tools have not worked for me. Also the plugin for contours ...
1
vote
2answers
259 views

How to clip a lines vector layer to a polygon layer in QGIS?

I've perused through previous questions and haven't been able to find an appropriate solution to my problem yet, so I wanted to post here. I have a lines layer (a contour map of mean annual ...
0
votes
2answers
106 views

Output map of only 50m-100m contours [closed]

I´ve got the "OS Terrain 50" contours/spot-heights dataset. I would like to output a series of maps with everything above 0m, 50m, 100m etc. from a region. I know almost nothing about GIS, but have a ...
3
votes
2answers
159 views

How to generate Non-smooth/crude Contour Lines in QGIS?

I have an SRTM DEM and I want contour lines generated for specific elevations. This can easily be done using r.contour.level/step etc. but the contours generated are smooth and cover the cells only ...
0
votes
1answer
112 views

How to create a slope map with different colors according to slope percentage or degrees

I have converted a dxf file with contour lines into a polyline shapefile, and I have used the Raster Analysis plugin to create a grayscale slope map from this shapefile. I would now like to have ...
5
votes
2answers
227 views

Creating contours for specific elevations

Input data: 1. an SRTM raster. 2. Point file of peaks. -Attributes contain ID, x, y, z and the elevation at which the peak is completely isolated from a neighboring peak. The output I want is a ...
2
votes
1answer
153 views

Change contour line stroke weight based on elevation?

I have shapefiles of contour lines that I have imported in Qgis. At the moment the contour lines are all the same stroke weight. I'm a beginner to this program, but wanted to know if its possible to ...
0
votes
2answers
487 views

How to capture contour lines from OSM cycle map as vector?

In QGIS, there is a plugin to insert a OSM cycle map layer, that brings as an image from http. But I can't convert this OSM Plugin layer to a raster image. I can't even imagine how to get the contour ...
0
votes
1answer
855 views

How to export QGIS contour attributes in a DXF file?

I'm new to this. I have a .tiff data file that generates contours in QGis. That's super. I save it as .dxf. The contours don't have any attributes or data. That's bad, because I want to make a 3D ...
1
vote
0answers
30 views

Creating contours from partial data set

Is it possible to create contour lines based on part of the points and not the entire dataset?
0
votes
0answers
92 views

Google Maps basemap not showing up when KML file added as a vector layer in QGIS - only point markers appear

I am trying to make a basic XYZ contour plot in QGIS 1.8.0 (longitude, latitude, depth in an excel file) and can't get past the first step of adding a basemap in QGIS. I've tried using the Open ...
1
vote
0answers
133 views

How to improve creating contours for super-high unnatural mountains?

in a current project I am working on we are not mapping the actual height of a landscape rather mapping the interest which specific stakeholders have in parts of the region. So, what we did was the ...
2
votes
1answer
453 views

How do I run the nvis tool in QGIS GRASS?

I am trying to follow this workflow: [How to generate a DEM from a countour Shapefile?] and it's running fine, and when I hit view output or view results I end up with a flat raster with shading ...
3
votes
1answer
274 views

How to create DEM from contours without ArcGIS Spatial Analyst licence?

I'm trying to create a 3d DEM/DTM from a flat contour shapefile which has height data attached to each contour, but I'm not sure how to do this? I've found this post, on creating a dem from contours ...
0
votes
2answers
169 views

How to derive point height from contour data?

I got vector layer that represents height over sea level. Then, I also have different vector layers. Is there any good way of using QGiS or things related to calculate sea level for those points? ...
0
votes
1answer
42 views

file type needed to add layer containing contour lines

What file format is usable/recognized by qgis to add contour lines to a map? I'm working with Linux Mint 15, and qgis 1.7.5
4
votes
1answer
697 views

How do I add Garmin .img files to QGIS?

I downloaded 10 .img files from garmin.openstreetmap.nl which are supposed to contain the topo tiles for the area I would like to add in qgis. I've been unable to find any instructions on how to use ...
3
votes
2answers
489 views

Is it possible to give 2d contours a Z-height from their attribute table in QGIS? (Or ArcGIS?)

I have a contour data file downloaded from UK Ordnance Survey, which gives 2d contours of an area in gml format (also supplied in .shp format) with the heights of each contour attached to the ...
2
votes
1answer
155 views

ASTER GDEM v2 coastline generation?

I try to generate world coastline 1:30000 from ASTER's DEM with: gdal_contour -a ELEVATION -fl 0 But above produce some of missing coastlines. Whats happening? Is it cliffy shore? How would you ...
0
votes
0answers
352 views

QGIS Contour plugin - contours from points

With QGIS 2.01, the plugin Contour is not available. Anyone have another method to create contours from point / shapefile source, where the points are not a grid?
0
votes
1answer
521 views

How to create filled contour lines in QGIS?

How can I create contour lines that are filled with a graduated symbol usinq QGIS? In ArcGIS for Desktop I can do this. What about in QGIS?
7
votes
1answer
379 views

Creating contours with meaningful values from point data

I recently obtained a CSV containing the locations of all recorded bicycle accidents in Boston over the past few years. As an avid cyclist, I'd like to create a simple contour map that draws attention ...
0
votes
0answers
116 views

QGIS 1.8.0-Lisboa error message when converting DEM to Contours

I am trying to convert a small DEM (1 megabyte) into contours. When I go to - Extraction - Contour- and run it I get the following message: "ERROR 1: CPLRealloc(): Out of memory allocating 416 ...
1
vote
1answer
555 views

Import SketchUp created KML contour lines model to QGIS

There's a neat trick to create contour lines based on the GE 3D terrain using Sketch-Up. The resulting KML however is a model I have looked at ways of importing KML layers to QGIS, like it was ...
3
votes
2answers
1k views

Colouring areas between (vector) contours?

Is it possible to colour areas between (vector) contours without making it a DEM first? Joshdoe seems to have done so in Create filled contour map with GRASS but does not say how.
1
vote
1answer
229 views

Extraction of contour lines starting from 0 elevation

I need your help regarding extraction of contour lines in QGIS. I am new to QGIS (in GIS actually). I followed the tutorials on extracting contour lines from DEM (which I downloaded from cgiar.srtm) ...
1
vote
0answers
365 views

Arrow flow lines from a contour map

using QGIS (or even GRASS) is it possible to label a contour lines shape with arrows that indicate the flow direction? Briefly: I have a point shape with elevation values. I make an interpolation map ...
4
votes
2answers
3k views

How to generate a DEM from a contour Shapefile?

I want to create a DEM from depth contours (shapefile) in QGIS. I've been trying to work out how to do this based on this previous question, notably from this link from that page, however I'm stuck, ...
3
votes
1answer
447 views

How calculate areas between certain contour lines in qgis?

Sorry for asking a question which I found in similar ways already here, but I am trying this for days and just got no result: How do I calculate the area between certain contour lines (e.g. 0-800, ...
2
votes
2answers
2k views

How to install the Python module shapely for QGIS use?

I'm using QGIS 1.8.0 on a Mac with OSX 10.6.8 (Snow Leopard). I've installed QGIS including GDAL, GSL, UNIXImageIO, Freetype, and Matplotlib all from www.kyngchaos.com. When installing the plugin ...
11
votes
3answers
545 views

Contours: Interrupt contour lines beneath a elevation number

Is there a way to interrupt a contour line beneath a elevation number? Thanks!
5
votes
2answers
158 views

Using field calculator to delete specific contours

I have 3 contour shapefiles with 25m, 50m and 100m equidistance. Now I want to delete in the 25m-shp-file every **50m and **00m contour and in the 50m-shp-file every **00 contour. How can I show them ...
3
votes
1answer
559 views

Problem with generating contour lines and filled contours

I am trying to create contour lines and filled contours from a shape file of height points using the contour plug in (have tried other tools but with no success). The data is sourced from the UK ...
6
votes
3answers
2k views

How to extract slope from topographic raster map?

I am working on a project for a machine learning class wherein I extract features from a topographic raster map and then classify the traversability of the terrain. One of the features I need to ...
2
votes
1answer
541 views

Contour Lines Raster Extraction

I've been playing with Mapbox's blog post about converting heat maps to contour lines, and I'm stuck at the extraction part of this process. I used the CSV plugin to create a vector layer of points, ...
4
votes
2answers
1k views

TIN Creation from 3D Contour File

I'm currently trying to import a 3D contour file into a Quantum GIS project. My question is, how can I export the DXF file from Microstation with height information? I already have imported it to the ...
9
votes
3answers
854 views

What are common methods for converting raster digital elevation data to vector contours?

In researching this I have found many references to the opposite, creating elevation data from contours, but nothing regarding contour creation. Preferably, I am looking for open source solutions like ...
1
vote
2answers
463 views

How to batch process (100s) of interpolations in QGIS or other open source software programs?

Is there an efficient way to run 100s of interpolations in QGIS or other open source software programs? I have groundwater contamination data collected from monitoring wells at about 800 different ...
12
votes
4answers
2k views

How to place elevation numbers on contours with uphill orientation and position?

I want to orient my elevation labels uphill. Is that possible? I'm currently using the labeling tool from QGIS (not that one in layer settings). I want the labels curved and uphill oriented (and I ...
2
votes
2answers
266 views

Losing large portions of elevation contours from QGIS to PDF

Please forgive me as I'm new to GIS and all this might be a silly question, the wrong place for this question, or a hack way of going about what I'm getting at. So any suggestions on better practice ...
1
vote
2answers
769 views

Interpolation of contours (from one “main-contour-shapefile”)

I calculated, that the best and smalest possible äquidistance (equidistant) for my map is 30m. After I generlized my DHM, I extracted contours of a intervall of 30m and smoothed them. Now I have my ...