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

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43
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3answers
8k views

How to smooth the polygons in a contour map

Here is a contour map for which all the polygons of levels are available. Let ask how to smooth the polygons keeping all vertices preserved in their exact locations? Indeed the contour is made on ...
2
votes
2answers
327 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
35 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?
2
votes
0answers
45 views

Adding z values to contours without attribute data

I have a set of contour lines with 5 meter interval which doesn't have any height set in the attribute data. Now I'd like to assign (preferably automatic) z values to these contours since I want to ...
3
votes
2answers
5k views

Creating shaded relief in ArcGIS Desktop?

How can I create shaded relief from contour lines (.shp format)? I see Hillshade in ArcToolbox, but it asks for a raster file. I have ArcGIS 10.0.
3
votes
0answers
36 views

Open source alternative to the “Contours with Barriers” Tool in ArcGIS

I am trying to create a contour file for the globe for a project and am using open source GIS software packages. I was trained for several years on ArcGIS and there is a tool to create contours with ...
3
votes
2answers
925 views

How calculate areas between certain contour lines in qgis? [closed]

How do I calculate the area between certain contour lines (e.g. 0-800, 800-1400, 1400-2100...) from a given shape file. What I need is the area of the the certain elevational levels. shape file is ...
2
votes
1answer
92 views

Annotation masks disappearing

I have created annotation from the labels of a set of contour lines in ArcGIS and used Feature Outline Mask to create a mask layer in order to mask the lines using Advanced Drawing Options and make ...
1
vote
1answer
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, ...
0
votes
1answer
41 views

Contours from NED in QGIS — “oversampled” NED? [duplicate]

I have downloaded an IMG file of NED data from the USGS National Map elevation products site and I want to create a contour map using QGIS. The problem is, the NED raster is "oversampled". There are ...
4
votes
3answers
426 views

Creating bathymetric contours using shoreline point data and transect point data

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 ...
5
votes
3answers
1k views

How to position contour labels in Maplex above the line?

I would like to utilize the "contour placement" options of "Uphill alignment" and "Laddering" while positioning the label above the contour not over it. This does not seem to be an option under the ...
0
votes
1answer
40 views

Polygon Representation from Contours

I have contours lines along with their elevations in ArcGIS. I want to create a polygon representation from those contour lines. How can i create polygons from those contours which may help me to ...
2
votes
1answer
438 views

Filling contour levels with grain (texture) using Leaflet

I created a program to draw temperature contour map of France: This is the code: library(ggplot2) library(gstat) library(sp) library(maptools) require(rgeos) library(rgdal) library(foreign) library(...
3
votes
1answer
107 views

How to exclude water during contour generation?

I recently acquired a LiDAR data set that included a 1 meter DEM. I generated 1, 2 and 5m contour layers but I am seeing a lot of contours within water bodies. I suspect this is either caused by wave ...
3
votes
0answers
89 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
vote
1answer
95 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
vote
1answer
139 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....
2
votes
0answers
55 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
votes
0answers
53 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
vote
1answer
114 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
votes
0answers
76 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
votes
2answers
42 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.
1
vote
0answers
34 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
vote
1answer
91 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
260 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
votes
0answers
53 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
167 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
votes
0answers
54 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
368 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). I'...
0
votes
0answers
87 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: AAIGrid/Arc/...
1
vote
0answers
48 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
142 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
vote
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
145 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
417 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
vote
0answers
70 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
vote
0answers
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 ...
1
vote
0answers
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 ...
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
213 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
56 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
994 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
vote
0answers
115 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
406 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
193 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 ...
1
vote
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
vote
0answers
95 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 ...