Questions tagged [contour]

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

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1answer
621 views

Grid-type shapefile from raster GeoTIFF

I need to produce a shapefile from a raster. I need to be able to specify either an interval, or manually define the intervals. The input file is a GeoTIFF. I would like to use GDAL and/or Python. ...
2
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1answer
51 views

Labelling polygons intersecting another polygon file

I have a series of polygons representing land packages and another shapefile representing contour polygons of flood elevations in steps i.e 2-5m 5-10m >10m. I am wanting to label a polygon with the ...
2
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1answer
163 views

Display coastline

I have a raster converted from shapefile (tool point to raster). Can anybody prompt, how to display coastline? I can use contours, but are not focused at condition "elevation = 0". Is there any ...
2
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1answer
2k views

Relationship between contour interval and spatial resolution of a generated DEM

If I have contour lines with interval say 10, 5, or 2 (etc.), and I generated a DEM from them, what is the relationship between between the contour interval and the resolution of the DEM? Irrespective ...
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3answers
1k views

Creating bathymetric contours using shoreline point data and transect point data in ArcGIS Desktop?

I have been given a set of depth points for a waterbody that were taken along the shoreline and along linear transects. What is the best way to use these points to interpolate/extrapolate bathymetric ...
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1answer
313 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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2answers
230 views

DEM with bathymetric contour lines in GRASS

I am trying to create a DEM from a bathymetric contour lines. Contours are in vector format and the elevation value is negative. To create the surface I have converted the contours in raster (v.to ...
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1answer
63 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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1answer
6k views

Creating 3D terrain/model from contour lines, preferably using Open Source GIS?

I am looking to create 3D terrain from a contour map that I have (originally inside a PDF). The contour lines are able to be viewed as paths in Adobe Illustrator. There are two types of lines: 7m and ...
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2answers
379 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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1answer
264 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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0answers
2k views

Converting contour lines to DEM in ArcGIS for Desktop? [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
85 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 not ...
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2answers
3k views

Postgis 2.1: ERROR: Shell is not a line - SQL state: XX000

My current setup is PostgreSQL 9.3.6 & PostGIS 2.1.5 I have a table with contour lines (multilinestrings) that I wish to group by the attribute 'elevation', and make polygons out of them. The ...
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1answer
628 views

Exporting linework layer with 'altitude' attribute in QGIS to DXF with lines raised in z according to altitude attribute?

I have contours which I have brought into QGIS from a GEOjson - the lines have an attribute of 'altitude'. I want to export these contour lines as a DXF with the lines raised in the zplane according ...
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0answers
250 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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2answers
3k views

Create DEM with 1 foot contours from lidar data with 1.4 meter resolution [duplicate]

I have Lidar data which contains multiple .las files for an entire quad. I have figured out which .las is the area I am looking for. I was told the data is in 1.4 meter resolution and would work to ...
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1answer
1k views

How to draw contour line between certain elevation range?

I have a raster and I want to draw contour lines just between certain elevation range. For example I want to draw contour lines between elevation 700 (m) and 1000 (m) with the interval of 10. So there ...
1
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1answer
2k views

Convert .xyz to contours?

Can anyone help me convert .xyz file to a contours? I have recieved some .xyz files from the local council and am hoping to turn them into a terrain for 3d modelling. I have tried the ASCII to feature ...
2
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2answers
314 views

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 ...
2
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0answers
533 views

Generate contour lines for big DEMs and import into PostGis

I've downloaded the SRTM DEM files for most of Europe, from both 3arc_v4.1 and 1arc_v3 versions. The first comes in 5x5 degrees tiles, the latter in 1x1. I can stitch them together with gdalbuildvrt ...
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2answers
1k 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, ...
2
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1answer
234 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 ...
2
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0answers
255 views

Connect two contour lines with calculated line length

Is it possible to make a plugin for QGIS like PEGGER for arcview 3.2? Problem is, how to make path over contour lines with a gradient in percent? Formula is: K= e*100/G*M ; K=10*100/0.08*10000=1.25m ...
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0answers
117 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
504 views

Displaying steep slopes with use of Contours in ArcGIS Desktop?

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?
2
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1answer
181 views

Models -> [Example Models] -> Contour lines from points: on MAC

I'm running QGIS2.6 on a Mac and can't seem to locate the "Contour Lines from Points" Example Model. SAGA is installed.
2
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1answer
620 views

How to make label show up on contour vector in QGIS? [closed]

I'm new to QGIS (version 2.6.0). I think my question should be easy to solve but I still get stuck at making labels show up on contour lines. These lines were generated from extracting raster (asc ...
1
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1answer
167 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. ...
1
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1answer
229 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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2answers
224 views

Where to find the “contours from points” model in QGIS 2.6?

I can't find the example model "contours from points" in QGIS 2.6. Is there another tool for creating contours from points, besides the QGIS Contour plugin?
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1answer
363 views

Contours with negative values using the model example in QGIS?

I have a data set of water level ranging from -6 m below sea level to +30 meters. But when I use the model example for creating contours from points, the minimum contour value is zero (0). What can be ...
4
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1answer
1k views

Digitizing contour lines from paper maps using QGIS?

Is it possible to give digitized altitude lines (from paper map) heights using QGIS?
3
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2answers
3k views

How to calculate the area between two contour line?

I created contours by using SRTM30 data. Now I need to find area between two contours like in between 0 m to 50 m depth and 50 m to 100 m.
1
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0answers
118 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 ...
12
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4answers
8k views

Choosing only one contour line to label in QGIS?

Is it possible to select only one contour line for labelling? I have numerous labels for each line and I'll prefer to label only the main ones, such as 1000 m and 1500 m
1
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0answers
52 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 ...
2
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1answer
2k views

How to reproduce contour-style labeling with rasterVis::contourplot?

I am currently working with a digital elevation model (DEM) of Mt. Kilimanjaro, Tanzania. The referring raster grid can be downloaded from DIVA-GIS (Country: Tanzania; Subject: Elevation). After ...
4
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1answer
186 views

Problem of irregular contour from a DEM

I've created contour lines every 5 meters from a grid DEM with 5x5 meter of resolution. But strangely I've obtained that the contour lines are segmented and rich of lines that goes up and down, ...
2
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2answers
662 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 ...
3
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0answers
948 views

Formula for maximum coverage of a geostationary satellite based on earth station elevation

I am trying to create a JavaScript function to represent the maximum coverage of a geo satellite for different antenna elevations (0 degrees, 5 and 10 degrees) with 3 leaflet polylines. The result is ...
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1answer
3k views

Creating isohyetal map in ArcGIS

How can I create an isohyetal map in ArcGIS 10. I have the precipitation values from a number of weather stations in my area of interest. What tools should I use to create these contour lines?
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0answers
22 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 ...
2
votes
1answer
913 views

shapefile to gmt format

I have an ESRI shapefile of the contours of my study area, and I want to convert it into a format that is acceptable by GMT, so I can make an elevation map of my study area. Is that even possible? ...
1
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0answers
410 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 ...
10
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3answers
21k views

How to create contour lines from point data using QGIS?

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 ...
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0answers
230 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 ...
1
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1answer
4k views

How to extract elevation information from contour lines?

I'm working with OS windows 7 and using ArcGIS 10.2 and I have a point shape, which I must extract elevation for every point in it but the only useful data is a contour line shape. Not sure if it's ...
6
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2answers
914 views

PostGIS - Interpolate point between contours

Using PostGIS, what is the best method to interpolate the z value for points (the orange dot in the image below) located between each contour layer (blue lines and red lines in the image below)? So ...
3
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1answer
2k views

Recommendations for creating contour map from depth points

I am trying to put together a safe routes map for a local lake. I have an old paper map that has a grid of various depths as points. I would like to draw contour lines through these points and create ...