Contour maps depict spatially-varying values, such as elevation, by means of curves of equal value.

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Extract elevation data from contour lines

I am working with QGIS. I used raster-extract-contour to get contour lines from a raster image. Now I want to break up my single vector file into multiple layers based on elevation. How do I do this?
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1answer
36 views

Pattern fill for raster contours in QGIS

How do I fill the area within raster contours with a pattern fill, instead of colors in QGIS? Is this even possible?
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34 views

Getting from PDF contour map of Z in area to values of Z specific points in area?

I have a PDF of a contour map of value Z for an area. For the same area, I have a set of points that I would like to match with Z values interpolated from this contour map. For an individual point, ...
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1answer
97 views

Making DEM from contours without elevation data?

I got a shapefile with contours, but no elevation data is present. We can assume as known info, that the contours mark elevations at known steps (say, 20 m). Is it still possible to restore the ...
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1answer
443 views

How to get smooth contours from points or IDW raster in QGIS

Hello I'm an artist trying different ways of drawing contours in QGIS using points with income values. I've been able to import a shp file with the data, create a layer with centroids of the census ...
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2answers
391 views

Losing elevation values converting to CAD in ArcGIS for Desktop?

This is complex and my first question. I'm using 10.3 and need to export a lot of contour files to CAD. When I do this individually, they convert fine and retain the elevation values. Having hundreds, ...
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1answer
46 views

Duplicated vertices in contour features of GRASS?

I use GRASS to produce contours from DEM (r.contours for SRTM rasters). They looks fine, but most of the line features occures to be duplicated; i.e. verticies duplicated. Here are pictures of output ...
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2answers
182 views

Problem with contour lines thickness in bigger zoom levels

I'm a beginner user of GDAL tools. I'd like to rasterize contour lines into Tiff file (for example such region: N47E006), everything works for quite small zoom levels e.g. 10... but the problem is ...
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128 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() ...
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2k 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 ...
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1answer
1k 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 ...
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333 views

contour lines from point shape attribute

I have a point shape file and one of the attribute refers to the altitude. Is is possible to obtain a contour lines shape file in GRASS?
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1k views

Problem creating TIN from multiple contour shapefiles with ArcGIS 9.3 Spatial Analyst

I have about 20 shapefiles that contain contours lines, and I'm trying to convert them to one TIN using Spatial Analyst in ArcGIS 9.3. I included all of the SHP's as input to generate a TIN, but it ...
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1k views

Calculate the distance between two contours

I have two contour polylines (single shapefile) and I would like to calculate the mean, min and max distances between the two lines. Is there a function in ArcMap 10 (ArcInfo license, incl. Spatial ...
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1answer
26 views

Generating Contours from csv Concentrations

I have a shp file showing locations of various wells on a site. I have linked (joined) a csv file of analytical results to this file. I am now looking for a method to generate contours based upon ...
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9 views

Any way to remove 2 point polylines in bulk?

QGIS: I have successfully created contours from a DEM and subsequently cleaned them up using generalizer tools in the following order: 1. Vertex reduction 2. McMinimans distance algorithm. The ...
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1answer
60 views

Grid thematic map in Mapinfo

I have a tab file with the contour lines for an area, and also a tab file with the land polygon. Now, I'm following a tutorial written by a colleague a couple years ago, where a thematic map is ...
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15 views

Converting Labels to Annotations moves position of labels

Why are my contour line labels moving after I convert them to annotations? I am using Maplex to place them. But if they still move after I converte them to annotations, the whole maplex placing ...
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53 views

Optimize Postgis contour lines DB

I'd like to try to optimize a world-wide 10m contour lines (isohypses) Postgis database(from SRTM). The complete DB takes 504GB on disk, contour lines are already in epsg:3857, and simplified with ...
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3answers
69 views

QGIS Heatmap by value (NOT by point-densty)

I need a heat map generated by points value irrespective of how close or far apart the points may be in QGIS 2.6.1 So far I'm using the raster/heatmap/heatmap function. I need the same colour to run ...
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25 views

Faulty altitude point between contours

I have point(picket?) between 2 contour lines with even number altitudes. Now i got these new 5 meters steps contour in between. As you see, this point between red lines was OK, but now that this 175 ...
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24 views

Contouring with cliff faces in ArcGIS for Desktop?

I am trying to create some contour lines that are around cliff faces. What is the best way to create contour lines that are effected by cliff faces and is there a way to automatically draw the cliff ...
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1answer
154 views

Displaying contour lines calculated from SRTM in Google Earth?

I'm relatively inexperienced in GIS, but would like to display contour lines calculated from SRTM data in Google Earth. It doesn't matter whether they are actual linestrings or just an image overlay....
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how can I make contour lines out of points with different heigths?

I have different points in a polygon. The points have the attribute "depth" and either have 0m, 2m or 4m depth. My task is now to create some sort of contour lines with the points with the same depth ...
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GPS point elevation vs Contours layer elevation

I have some survey grade GPS points whose elevation is approx 55 feet lower than my contours layer elevations. I am using 1 ft contours and comparing point elevations with contours in the same ...
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72 views

How to extract area information from a raster based on a DEM or contour lines

I have a raster representing the distribution of a specific land cover type - the raster values are 1 for where the land cover type is present and 0 where it isn't. I also have a DEM with 5m ...
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32 views

Contours from delaunay triangles

I have generated a delaunay polygon file that represents terrain data. Is there a way I can produce contours from the polygon file? I know I can convert the polygon to an Esri TIN, and then produce ...
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31 views

Clip Categorized Polygon with another Polygon

Ok, so first off, I've gone through the forum, and looked at every post that sounds similar. They have all been solved, but none of the solutions have worked for me. Basically, I have created a ...
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124 views

How to create contours from an IDW raster

I'm new to QGIS and am trying to create vector contours from this IDW raster. I followed Ujaval Gandhi's "Interpolating Point Data" tutorial step by step but am not getting the same results for step ...
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1answer
264 views

Generate 3D elevation points grid from 3D contour lines!

I have a shape file with 3D contour lines. I want that based on this information to generate for all this area a 3D grid of points with certain distance from each-other like every 50cm. I use ...
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100 views

Import ARCGIS web dataset contours into Sketchup

My local council has online ARCGIS data sources including 1m elevation contours. I am trying to import these into a sandbox terrain model in sketchup to do some landscape planning. Conceptually I ...
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94 views

How to convert poly-line contour feature class into heat map displaying heights [closed]

I'm looking for a way to be able to convert contour data (as lines) into a heat map that would display the data warmest at the highest points and coolest at the lowest. I have access to QGIS, ArcMap ...
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1answer
130 views

How to view .dwg group layers in ArcMap? [closed]

I'm trying to view 3 .dwg group layers in ArcMap 10.1. Whenever I add them to the map, I get an error message that says they are missing a spatial reference. That's fine. I'm just trying to view ...
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116 views

gdal_contour is missing lines below a certain elevation

I have a very strange problem with gdal_contour. I have a very large GeoTif of Europe and would like to generate contour-lines for that region. Everything worked fine when I had lines every 25m but ...
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543 views

Convert contour lines to DEM in ArcGIS [closed]

I've been trying without success to convert contour lines to DEM (Converting to spot heights is also a possible solution but I have not found a way for that either) using ArcGIS 10.2 (Advanced license)...
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1answer
55 views

raster topo map with gaps to DEM

I'm trying to create a DEM from this raster map: I managed to clean all the shapes and text. I tried to write a program which finds the curve pieces and connects them. But, I realized that it is ...
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91 views

Isolate contour line with a minimum number of points (to eliminate small polygons) with ArcGIS

I extracted a single contour line (altitude 3660 m) with ArcGIS. How can I eliminate small polygons ? I know how to do it with a GRASS command (generate contour lines) which simply asks for a minimum ...
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64 views

QGIS creating contour lines ERROR 1 CPLRealloc() out of memory allocationg 416 bytes

When i try to create contour lines from raster (tiff file) in QGIS 2.6.0 Brighton i get the following message: I thought it could be irregular size of raster that causes error so i clipped it in ...
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2answers
247 views

How to make a contour map from a list of points and values? [duplicate]

I need to create a nice map with contours that represent various thematic data on a scale of a country, for instance, average temperatures in Germany. I have a list of coordinates with the values, ...
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1answer
76 views

Comparing 2 contour data set files

I have 2 feature class files of contour lines for an area of interest - from 2 different sources. We would like to select just one to use and I'm looking for any methods to effectively compare the ...
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64 views

How to make input data matrix in flowmapper

I have problem with using flowmapper. I'm confused, how do I enter a text record? Can you give me an example of an appropriate text file? I've been doing interpolation and made a contour of the ground ...
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1answer
169 views

How to display steep slopes with the use of Contours?

I am using Arc Map 10.1. I have downloaded contour data as a shapefile. Is there any way to use the contours to display steep slopes so 15%-25% or 25% and greater.
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1answer
111 views

Chained rendering to create contour gives correct WMS but incorrect WFS using openlayers

I'm trying to create a contour as vector layer using this example: http://boundlessgeo.com/2013/01/chaining-rendering-transformations-in-geoserver/. My setup is GeoServer v2.5.3 and gwt-openlayers. ...
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1answer
125 views

Creating an irregular points grid — one with regular along-slope distances [closed]

I am currently using QGIS to try and prepare a series of equally spaced -- along the terrain slopes -- sampling points within various NVC (National Vegetation Classification) sites in the UK. I am ...
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82 views

Regenerate contour lost parts

I have some countour datasets where some parts were cut by labels, like this: Can these parts be regenerated? What I've tried is to create a straigth line between the dangling ends, but there are ...
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22 views

How to create contour lines from 4 hgt files? [duplicate]

Is it possible to draw contour line for 4 different .hgt raster in one operation ? If I load them to cover a large region, do I need to extract-> contour for each of them or is there a tool opposite ...
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16 views

Where can I find the format specification for LSLIFF data?

I have an LSLIFF file which should contain some map contour data, and I want to write a renderer for it, but to do that I need to understand the file format. A preliminary search has not turned up ...
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146 views

Contour command in Spatial Ecology's GME

Has anyone been successful using the contour command from GME (Geospatial Modelling Environment)? I'm trying to create contours out of a DEM. I know you can do it in ArcGIS with 3D or Spatial Analyst ...
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1answer
70 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. ...
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96 views

How to define disturbed/clipped contours elevation for Volume Polygon?

I want to calculate surface volume for different layer on TIN surface. I am working on an area in Norway which is 1 km * 1 km. The aim is to calculate surface volume of different imaginary elevation. ...