Questions tagged [contour]

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

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How to shade between contour lines in ArcMap to create a two toned bathymetry map

I have a shapefile containing the contour lines for a lake. I want to colour the lake by depth above and below a depth threshold of 10 meters (i.e. blue for shallower than 10 meters and grey for ...
Kevin Short's user avatar
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Using DEFRA LiDAR dtm-1m to calculate slopes etc in QGIS

I have a shapefile of woodland polygons and want to calulate slope and slope orientation of the polygons. I am using the LiDAR Composite Digital Terrain Model (DTM) - 1m in QGIS. Available at: https://...
user197410's user avatar
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Contours not exporting correctly from ArcGIS Pro to DGN

I'm running into a problem when using the Export to CAD tool. When I run my contours through the tool it is not exporting all of them to the DGN (seed: template3d_US_Feet). I'm not sure what I could ...
kwwhit5531's user avatar
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What 'options' are available in osgeo.gdal.ContourGenerateEx?

I am working on generating contour polygons with gdal in python. I have a working script, which utilizes the osgeo.gdal.ContourGenerateEx function from the gdal library. However, I am having trouble ...
MarcusR's user avatar
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Breakline for contour

I am trying to generate a break line for generating contour. I have surveyed point data. I am using the river banks/HFl points as breakines. I created a new shape file and drew line along the HFl ...
Usha's user avatar
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Exporting 3D contours to DXF in QGIS

I used to work with QGIS, now I don't remember the stages I have done. So,I wanted to ask you about it. My problem is, when I export 3d contours (that was made from SRTM DEM by doing a [raster>...
ece's user avatar
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QGIS conversion of USGS GeoTIFF to contours leaves strange artifacts at border of tiles?

I downloaded several USGS GeoTIFFs from the USGS Earth Explorer site (https://earthexplorer.usgs.gov/). These were then converted to contours using the qgis toolbox (GDAL -> Raster Extraction ->...
Jeff W's user avatar
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Generating DEM that gives realistic contour

I am quite new QGIS user. I have point data from the field and I generated DEM and contour. However, the contours are a bit unrealistic. I have attached the image. The green contour is the contour ...
Usha's user avatar
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ERROR 1: Input values and/or interval settings would lead to too many levels

I get the following error when generating contours from a LiDAR generated DEM. I have completed this task in the past with no errors and all of a sudden, I now get this error: ERROR 1: Input values ...
Jeremy's user avatar
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ST_Contour doesn't produce polygon

With this version: PostgreSQL 14.0, compiled by Visual C++ build 1914, 64-bit POSTGIS="3.3.2 3.3.2" [EXTENSION] PGSQL="140" GEOS="3.11.1-CAPI-1.17.1" PROJ="7.2.1&...
xyz绿洲's user avatar
5 votes
2 answers
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ST_Polygonize creating single polygon

I have a situation that is very similar to the issue described here. However, the accepted answer does not work for me. I am essentially attempting to create polygons from contour lines generated ...
rumski20's user avatar
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Why does Input Geometry work for one ArcGIS REST Service Map Layer but not another?

In an effort to limit the amount of data I'm retrieving from a couple of ArcGIS REST Services (and thus avoid timeouts) I'm using the Input Geometry field to limit my results to an area much smaller ...
Lost Mapper's user avatar
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How can I limit an ArcGIS REST Servers layer query to the current map extent on screen in QGIS?

I am trying to connect to an ArcGIS REST Service and retrieve vectors for 2ft Contours. It seems like QGIS asks for all features by default which ends up being too large a request and the request ...
Lost Mapper's user avatar
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Calculating MESO-scale slopes from a DEM

I have a coastal DEM which I want to use to calculate the cross-shore slope with ArcGIS Pro. In the image below I've plotted the zer and five meter contours, and what I want is to calculate the ...
anner.paldor's user avatar
1 vote
1 answer
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Query - Select By Attribute

I have contour data of 1 foot contours. How do I write a select by attribute query to only select 10 foot intervals. ie: 750, 760, 770, 780...... Than data range is between 10ft and 900ft, est. So I ...
LIQUE Group's user avatar
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How to add Revit toposolid from GIS KMZ data?

I am new to Revit but I am having trouble importing GIS data (KMZ format) into a toposolid. The KMZ file contains contours, parcel and building footprint information. I have tried several tools and ...
John R's user avatar
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3 votes
2 answers
269 views

Creating topographic "layer cake" map a.k.a. Tanaka contour in QGIS

I'm wondering if there is any way to create a map similar to the image below. Basically, it would be the contours extruded, add a singleband pseudocolor ramp as the color on top, and be able to ...
Jon Altschuld's user avatar
1 vote
0 answers
37 views

How to show labels on all contour lines in QGIS

I want to label the contour lines in my project, but for some reason the elevations from 1820 to 1920 don't show. They are all from the same layer and is it Single labels, not Rule-based labels. Also, ...
tukanium's user avatar
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1 vote
1 answer
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How to extract elevation using contours in Google Earth Engine?

I want to extract the elevation values and generate contour lines from SRTM DEM at a 100 m intervals. However, I was able to create the contour lines using a code available here. But I am not able to ...
CESCRA IARI's user avatar
4 votes
2 answers
253 views

Filling gaps in vector contour line

I have downloaded bathymetric data but the submarine contours - at 10m intervals - have gaps. Many gaps - the -10m (submarine) contour has over 700 gaps. So I need a programmatic way of either dealing ...
WestCorkPalaeo's user avatar
1 vote
1 answer
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How to make interpolation and contour for recording distances on images?

I have a question about interpolation and contours. In the images from the animal observation cameras, we would estimate the distance from the camera to the animal. In theory, we had the idea of ...
Tim Pirc's user avatar
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Displaying lake contours as depth rather than elevation

I have a set of contour lines for Lake Erie with negative Z-values. I am happy with how they display in 3d but need them subsurface to show depth rather than elevation. The tallest portion in cyan ...
GeoFreak's user avatar
1 vote
1 answer
174 views

Contours created in Global Mapper have many intersections/crossovers

Working o creating contours from Terrain Grid using Global Mapper with 0.5 m intervals. Generated contours have many crossovers/intersections. Any suggestion on how to prevent the issue?
Wioletta Zebrowska-Bilska's user avatar
2 votes
1 answer
84 views

Specifying ggplot2 aesthetics for factors stored in SpatialLinesDataFrame

I produced a set of 2 contour lines for 6 different individuals. The contours for each individual were originally stored in a single list which contained 6 separate SpatialLinesDataFrames (one per ...
Ryan's user avatar
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2 votes
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98 views

Plotting Mean High Water Mark from DEM LiDAR around mangrove vegetation

I am currently trying to plot a Mean High Water Mark (MHWM) using a 1m DEM created from LiDAR. I have been able to plot a contour value representing MWHM based on tide gauge data. When I create the ...
dwilson's user avatar
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Contour to DEM interpolation

I am using the Topo to Raster tool to convert contours to a DEM, the DEM is ~90% accurate, however in some locations in the DEM the interpolation produces values higher or lower than what the contours ...
Chayan Lahiri's user avatar
1 vote
0 answers
30 views

QGIS grass imports vector line data as points, not vector lines

I am very new to QGIS and Grass. I am trying to create a dxf file with height data using Grass 7 as per this youtube video. (1:35 mark) My contour data and Qgis file is uploaded here. When I go to ...
J.Watt's user avatar
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1 vote
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Problem exporting contour lines between QGIS and Rhino (or AutoCAD)

I am a French student studying architecture in Mexico. Currently, I am trying to retrieve contour lines in QGIS from a raster (.tiff) to export them to Rhino 7. Processes: I import my raster file (it ...
Tristan.B's user avatar
7 votes
3 answers
1k views

Styling contours by colour and by line thickness in QGIS

I commonly deal with new areas where I would like to quickly visualize contours. My aim is to be able to apply a style that contains a color ramp from the lowest to highest values but also to show all ...
Leigh Bettenay's user avatar
2 votes
1 answer
224 views

Getting jagged lines when exporting SVG/PDF and importing into Inkscape/Affinity Designer

I'm having a lot of issues with exporting contour maps in QGIS. Once extracting contours from my SRTM data, I've tried cleaning up my lines in multiple ways before exporting as either .svg or .pdf. I'...
Nick's user avatar
  • 125
2 votes
1 answer
208 views

automatic extraction of contour lines from a scanned paper map

I'm currently trying to detect contour lines from a georeferenced raster image, which looks like this: With the help of FME I could extract the lines very good. But they are divided at every section. ...
mawagi's user avatar
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1 answer
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Why is $length not giving me correct values?

I'm attempting to make a topographical map of Death Valley National Park, CA. I'm using EPSG:26911 and having an issue with filtering by length. In order to get rid of all of the tiny geometries that ...
Nick's user avatar
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42 views

Creating non-smoothed / Stepped DEM from contours (ArcMap or ArcGIS Pro)

I am attempting to create an artificial DEM that is stepped / not smoothed (imagine the profile below). I have created contours for levels A & B Topo to Raster produces a smoothed profile (see ...
GeoSeal's user avatar
1 vote
0 answers
51 views

QGIS XYZ to 3D coloured contoured surface [closed]

I am using QGIS. I have XYZ data in a CSV file. I want to show it as a 3D surface that is contoured (every 10’) and is coloured between contours. The z data is below sea level so negative. I can ...
Dan 's user avatar
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4 votes
1 answer
134 views

Creating contours within an upper limited boundary

I'm trying to create a series of contours for a dam site at 1m intervals below the full supply level. I created the supply area by extracting a specific contour line and cutting it off at the nominal ...
PeterMac's user avatar
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1 vote
0 answers
105 views

Closing Gaps in QGIS contour lines

I'm creating a contour map from a DEM, but the lines have gaps on the edge, what should I do to get rid of them? I've attached a screenshot below showing the type of area I need to fix
Richie Tozier's user avatar
1 vote
1 answer
109 views

Improving use of QGIS GDAL Contour Polygon function

I'm trying to extract vector contour polygons from a DEM, but it always takes a long time. While the Line function can finish the DEM in an hour at most, with the same parameters, the Polygon function ...
Richie Tozier's user avatar
8 votes
1 answer
631 views

Avoiding too curly contours in QGIS

I had point data in DXF and generated contours using QGIS. The contours had smaller islands and the contours in itself are too curly. I smoothed the contours too and I could avoid that unwanted island ...
Usha's user avatar
  • 137
0 votes
1 answer
36 views

Rotating contour labels on Canvec layer [closed]

I have created a QGIS map using CANVEC layers including elevation features. The resulting contour lines look good, but the elevation labels are not aligned with the contour lines (see screenshot below)...
Roland's user avatar
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2 votes
1 answer
245 views

Create clipping masks using contour lines in QGIS

I'm new to QGIS and GIS in general. I'm trying to find a way to create height layers automatically and then use them to clip other layers. In detail: Below is my area of interest. I have a raster ...
user215646's user avatar
0 votes
1 answer
243 views

GPX based contours in QGIS

I am an amateur orienteering mapper working on a complicated piece of ground. I can survey the ground with a very accurate GNSS RTK NTRIP connected receiver which records a GPX track. The GPX contains ...
Davy WDN's user avatar
0 votes
0 answers
135 views

Use the contour plugin in QGIS without error message: python matplotlib not available

I have recently downloaded the up to date stable version of QGIS (3.22.11) on my MacBook Pro. I downloaded the Contour plugin however when I try to use it I receive the message: python matplotlib not ...
olivine3's user avatar
1 vote
0 answers
179 views

Export the contour lines to vectors will only get "polygons" but not true vector "curves" in Google Earth Engine

I am new to Google Earth Engine. Now I can successfully generate contour lines for geometry. However, when exporting these contour lines to vector curves, it just outputs vector polygons. //Make the ...
Edward Zhou's user avatar
3 votes
1 answer
366 views

Contours into polygons with QGIS

I'm using QGIS 3.26 to create a precipitation map for Los Angeles. I started with Final 85th Percentile, 24-hr Rainfall contours from here: https://dpw.lacounty.gov/wrd/hydrologygis/ I brought the ...
interwebjill's user avatar
0 votes
0 answers
216 views

How to extract contour lines from bathymetry profiles (mainly cross sections)

I need to extract contour lines from surveyed bathymetry profiles. The profiles are .csv files with multiple points and X, Y and Z coordinates. There are cross sections and a single longitudinal ...
tukanium's user avatar
  • 192
1 vote
1 answer
268 views

Cannot show ocean bathymetry contour lines in Google Earth Engine

I am new to Google Earth Engine (GEE). Recently I hope to show the ocean bathymetry contour lines by using the ETOPO1 dataset. Here is my code: // Import ETOPO1 bathymetry dataset and choose a band. /...
Edward Zhou's user avatar
1 vote
0 answers
104 views

Extending line features to another line features with same attribute value using ArcGIS Pro

I am using ArcGIS Pro. I have received a set of contour lines from a third-party person. After analyzing the polyline data, I have seen a bunch of contour lines having a gap between other contour ...
Akmal Nizar's user avatar
2 votes
2 answers
383 views

Changing contours from 5 ft to 10 ft in attribute table using QGIS

I downloaded a file of contour lines that has a line every 5 ft of elevation change. This data is extremely dense and makes the map hard to read. Because I don't have the DEM or source data I can't ...
Chris's user avatar
  • 21
0 votes
1 answer
32 views

Select values of noise contours along one road

I have a map of noise contours across a city and am using ArcGIS Pro. I want to select one road (not straight) and export the noise values along that road to a table but I'm having trouble selecting ...
rwog's user avatar
  • 1
1 vote
1 answer
105 views

Offset lines to find self intersection lines

I've been trying, with no success, to create of negative offset from line shapefiles (contour lines, actually). My objective is, with the x offset I define, to use the topology rules to identify the ...
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