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

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3
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0answers
75 views

Is it possible to add intermediate contour values automatically in QGIS?

Let me explain the scenario. We have 100's of elevation contour shp files. In each file, only the 10th contour line has values (200, 450, 700, etc..). We have to attribute values for all the ...
1
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1answer
87 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 ...
1
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1answer
106 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 ...
2
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0answers
51 views

Fixing undesirable lines between tiles from SRTM contour line extraction?

I'm trying to make a South American topography map based on SRTM data on QGIS. The problem is a visual one. If the topography contours are extracted from individual SRTM tiles, it results a little ...
2
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0answers
43 views

How do I calculate kernel density using cases and controls in QGIS?

I have a dataset with approx 1250 geolocated points - approx 150 are cases of a disease and the rest are controls. My area of interest is around 20km by 20km with wide variation in population density. ...
1
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1answer
82 views

General guidelines for topographic contour to DEM conversion?

It seems that many different DEM resolutions (10m, 30m, 100m) could be created from a contour map (with, for instance 50m elevation changes marked), but of course some of the resulting DEMs will be ...
2
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0answers
57 views

Acquiring Digital Elevation Models for Argentina from commercial providers

I'm interested in obtaining Digital Elevation Models for areas in the 20,000 acre range, as I use them to create contour maps for agriculture. The USGS Earth Explorer has a wonderful free DEM ...
-2
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2answers
41 views

Drawing Contours using ArcGIS for Desktop? [closed]

Could you explain step by step of creating contours in ArcGIS 10.1 for Desktop? Starting from data input (also I need explanation on the type of data format ) to finally drawing the contours.
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0answers
30 views

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 ...
1
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1answer
62 views

QGIS - how to see the minimum and maximum elevations in contour layer

I am using QGIS 2.12 on a Macbook Pro running OS X Yosemite 10.10.5. I have a contour layer representing elevations. How can I find what the maximum and minimum elevation values in the layer?
4
votes
1answer
255 views

Workflow for generation of contours with LiDAR data and OCAD

I am updating our maps for an orienteering club in Illinois. I was very excited to find out that we have access to .las lidar data in 2000x2000ft files. I checked out OCAD11 and it can handle .las ...
0
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0answers
47 views

Calculate z value for contour line from x,y in dxf file

I am working on a project about route chart and cross section generation for hiking with Hong Kong Lands Department's Digital Topographic Map B5000 (sample). Height information are required for this ...
2
votes
2answers
165 views

Selecting suitable web GIS for project? [duplicate]

I need to develop a web-based map using existing shape files. Using the web-map, we must be able to select a region and produce contours for that selected region. Can any one suggest the best open ...
5
votes
1answer
6k views

Labeling contour lines in ArcMap [duplicate]

Can anybody give me advice on how to label contours as shown in Figure 2 below? I would like to be able to put the label "on" the line, which is easy enough. But I'd also like for the contour line to ...
0
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0answers
47 views

Terrain elevation in QGIS

How can I get started with creating a map with elevation just like this one: Basically I need a map that looks like the one above. Can someone tell me where can I get the data, and how do I process ...
5
votes
1answer
286 views

Contour lines with imported shape file using Blender GIS - wrong Z values

I've been making experiments with Blender GIS and QGIS. I'm having problems when importing Shapefiles with contour lines, with a field for elevation (ELEVATION FROM FIELD selected when importing). ...
0
votes
0answers
73 views

Creating a DTM from Contours, via the command line or Python

I am looking to create a gridded DTM/DEM (Digital Terrain/Elevation Model) or TIN (Triangulated Irregular Network) from a set of contours. There are a number of similar questions on both this site ...
15
votes
2answers
2k views

Generating contours from DEM using GDAL?

We have just received a large set of DEMs at work and I would like to generate contours from them. The DEMs have a resolution of 1m and a size of 1kmx1km. Output from gdalinfo: Driver: ...
1
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0answers
46 views

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 ...
2
votes
2answers
117 views

Adding elevation data from contour lines to point layer using QGIS?

I want to calculate the number of vacant lots within 300m from a given building. My source file contains point layers of buildings and vacant lots. Here's a short description of my workflow. I've ...
1
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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 ...
0
votes
0answers
121 views

Difference in contour lines derived from IDW and TIN in ArcGIS for Desktop?

I would like to know the difference between contour lines derived from IDW and contour lines derived from TIN. I have collected GPS points, and I know the elevations are not accurate but it is within ...
4
votes
2answers
394 views

95 percent volume contour

I generated, from point data, a kernel density map using GRASS, and I would like to identify the 95% volume contour in it. Is it possible in GRASS? Thank you
1
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0answers
66 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 ...
1
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0answers
27 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 ...
1
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0answers
30 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 ...
0
votes
1answer
5k views

Converting shapefile labels to graphics ArcMap?

I have a shapefile that represents contours. Because I have clipped the contours to the map boundary they are broken in several places. Now that I have labeled the contours there are labels that are ...
3
votes
1answer
169 views

QGIS Contour Plugin Says No Shapely; can import shapely in QGIS console

I'm keen to create some contours (isochrones for a pedestrian 'ped-shed' catchment) from a point dataset in QGIS, using the contour plugin from the Plugins repository. I installed the plugin, but ...
0
votes
2answers
47 views

Equidistance on line contour from DEM

I am using a SRTM 30 meters for slope and elevation. When i'm using this 30x30 rasters to generate contours i set a 30m equidistance for contour, and the results are ok. Now i'm wondering if it's ...
0
votes
2answers
851 views

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

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 ...
1
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0answers
105 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 ...
1
vote
1answer
309 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 ...
2
votes
3answers
170 views

Too many contours labels are showing up in ArcMap, not just ones for selected subset?

I created a shapefile for contours lines on the basis of a raster. Since I am interested in just 5 contours (out of, say, 50), I selected for display just the contours I am interested in. I achieved ...
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2answers
1k views

How to create a raster (topo to raster) with non-rectangular shape?

I'm using Arcmap 10, I need to create a raster from contour lines. These contour lines were clipped out with a certain shape with the purpose to modify them only within that shape and then create the ...
1
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0answers
84 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 ...
4
votes
1answer
2k views

TIN Creation from 3D Contour File

I'm currently trying to import a 3D contour file into a QGIS project. How can I export the DXF file from Microstation with height information? I already have imported it to the QGIS project but ...
2
votes
1answer
762 views

Continents geometry data / extracting contours of continents from country geometry

I have an ESRI Shapefile data from Natural Earth (Admin-0 Countries). I converted it to geoJSON format. There is no world or continents geometry there, only the county one. And I'd like to extract eg. ...
1
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0answers
87 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 ...
1
vote
2answers
296 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, ...
9
votes
2answers
1k views

What is the smallest contour interval possible when derived from a DTM?

I am converting a 2m DTM to contours, and would like to have the smallest interval possible. Is there a theoretical limit, or even a rule of thumb for defining contour intervals based on the ...
0
votes
1answer
173 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. ...
0
votes
0answers
88 views

Using Raster Calculator with Elevation Data from Contour Map

I am following this tutorial to attempt to determine flooding in the Gulf region based on estimated rises in sea level. I have taken topographic maps from the USGS and used to contouring tool to turn ...
1
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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 ...
5
votes
2answers
654 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
2answers
596 views

How to create contour from NetCDF?

I have downloaded Bathymetry data from GEBCO. Its in NetCDF format. I want to create contour from it. I tried so many tools to convert the file into raster but couldn't do so. How can I create raster ...
2
votes
1answer
26 views

Labelling polygons intersecting another polygon file

I have a series of polygons representing land packages and another shape file representing contour polygons of flood elevations in steps i.e 2-5m 5-10m >10m. I am wanting to label a polygon with the ...
0
votes
0answers
383 views

Contour tool in ArcGIS 10.1 giving syntax errors [duplicate]

I am trying to run the contour tool on a raster in 10.1 and get the following error messages? Does anyone know if this is a bug and is there a work around? ERROR 010328: Syntax error at or near ...
2
votes
1answer
58 views

Display coastline

I have a raster converted from shape file(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 simple ...
2
votes
1answer
334 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 ...
1
vote
1answer
120 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 ...