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

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2answers
589 views

Interpolation of contours (from one “main-contour-shapefile”)

I calculated, that the best and smalest possible äquidistance (equidistant) for my map is 30m. After I generlized my DHM, I extracted contours of a intervall of 30m and smoothed them. Now I have my ...
32
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1answer
3k 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 ...
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1answer
936 views

How to generate smooth contours from cropped raster?

I’m trying to create contours from a raster layer in QGIS. On my first attempt, I cropped my raster layer in Photoshop and reimported it, but it lost coordinate data I think. I made the contours ...
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4answers
689 views

How to automatically plot intermediate contours with QGIS, GRASS GIS or SAGA GIS?

I'm mapping a steep mountain range. My main contour interval is 50 m and my intermediate contour interval is 10 m. In steep areas, the interval of 10 m is too small, so I need to leave ...
7
votes
2answers
744 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 ...
7
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2answers
2k views

How to Create Contours for Zonation

I'm still new in the world of GIS. I'm currently doing some zonation with "test points." Each has its own coordinates and "P" value. I want to make contours of these data, to divide the whole area ...
9
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5answers
1k views

Measuring straightness of a curve segment (represented as a polyline)

I'm working on an automatic elevation contour labeling algorithm and one of the factors that I want to take into account when deciding the positions of labels is how "straight" a particular segment of ...
4
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1answer
511 views

Obtaining a contour as a single polygon in ArcGIS?

I have a DEM that I want to retrieve a single contour polygon from at a given elevation. I can use the Contour tool to obtain a series of polylines at a given elevation by setting the contour interval ...
5
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1answer
1k views

Create filled contour map with GRASS

Background I'm trying to make contour/isoline/isochrone maps to show what areas are within walking distance to schools for my pet project to help with the Safe Routes to School program. I followed ...
4
votes
3answers
948 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 ...
3
votes
2answers
3k views

How to create shaded relief in ArcGIS?

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.
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2answers
1k views

Java Contour Algorithm

Does anyone know if there is an open source project in Java that will take a set of (x, y, z) points and create a contour map for Google Maps/Earth? There does not seem to be a good contouring ...
2
votes
2answers
359 views

Easiest way to check if z values of contour lines are correct

What is the easiest way to check if z values of contour lines are correct in ArcGIS? I need just to look at the values, to see if equidistance between them is correct and unchanged.
4
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4answers
3k views

Symbology of contour lines in ArcMap

I have contour lines with height values from 0 to 1030 (sorted by height 110, 115, 120, 125). Values with in-between number (like 5, 15, 115, 135...) should be grouped and colored with same color, and ...