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

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45 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 ...
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107 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
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375 views

How calculate areas between certain contour lines in qgis?

Sorry for asking a question which I found in similar ways already here, but I am trying this for days and just got no result: How do I calculate the area between certain contour lines (e.g. 0-800, ...
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31 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 ...
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503 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 ...
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27 views

Contouring surface with barriers?

I'm using ArcGIS Desktop 9.3, and I want to contour a surface with barriers. Every time the result is a polyline contour shape file which covers only a part of the surface not the whole surface. ...
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35 views

gdal_contour transparent contour as png

I started using the GDAL Library in a c++ project. It is a great library, but I am a bit stuck right now with different aspects of it. What is the best way to use gdal_contour in my c++ programm? ...
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59 views

Surfer problem - overlapping grd bln

I have the following problems with Surfer: 1, I have a grid file and a bln but i'm not sure that they overlap each other exactly. I set the coordinate system with grd and bln! (WGS84) but there is no ...
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48 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 ...
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346 views

How to contour irregular point data for overlay on Google maps?

I am having some serious trouble finding a solution to fit my current needs. I am attempting to create contour maps from irregularly spaced point-data on the fly to overlay on a Google map. I have ...
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86 views

Whats the best way to create bathymetric contour lines?

I have a raster dataset with both Topographic and Bathymetric stored in it. What is the best way to create exact contours of the lake-bed? This becomes tricky when I want to make the contour for depth ...
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233 views

Best method to convert CSV file of lat/lon and depth data to bathymetry polygon?

I'm trying to create bathymetry polygons based on lat/long and depth data. I have tried several methods and the resulting polygons are clunky. Make XY Event Layer-->Copy Features--> Project--> ...
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74 views

Applying depth to Shapefile

Apologies if this question has been answered before. I'm digitizing a historic coastline and would like to add a single depth figure to it in order to merge it with a current contour model. Is there ...
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659 views

Dynamic Contour generation and project on google maps

Is it possible to generate contour map layer at runtime and overlap or project on google maps. I am using google map api v3 and want to generate contour map layer using data from sql server and ...
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16 views

Contour generation using Interpolation - Correcting edge Effects

I utilised the Interpolation feature in QGIS to prepare contours from a DEM I had generated. Sometimes when contours intersect the edge of the DEM area, they run along the edge for some distance. ...
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30 views

How to define disturbed/clipped contours elevation for Volume Polygon?

I want to calculate surface volume for different layer on TIN surface. I am working on an area in Norway which is 1 km * 1 km. The aim is to calculate surface volume of different imaginary elevation. ...
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80 views

Labelling Kriging result (contour)

I've finished Kriging, creating a contour-map, representing groundwater-height in my area. By a reason I don't know, it isn't possible to label my results. Neither can i export my data to vectors ...
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168 views

Contour tool in ArcGIS 10.1 giving syntax errors

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 ...
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54 views

Trouble intersecting a polyline and contours (Hack index / stream length gradient index)

Working on creating polylines for measurement using SL index (hack index). So far I have the main trunk of a stream, and contours at 10m. What I am trying to do is a) get the elevation at each ...
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27 views

Creating contours from partial data set

Is it possible to create contour lines based on part of the points and not the entire dataset?
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130 views

How to improve creating contours for super-high unnatural mountains?

in a current project I am working on we are not mapping the actual height of a landscape rather mapping the interest which specific stakeholders have in parts of the region. So, what we did was the ...
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74 views

Contours generated from merged TIFs huge - much bigger than individually

I'm generating contours from four 5x5 degree SRTM DEMs in southeastern Australia. I'm using gdalwarp to reproject the DEM, then gdal_contour to generate contours. First, I generated contours for each ...
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92 views

Unsplit lines based on length and attributes

I have a contour dilemma. Using Microstation, 1-ft contours have been made on a til-by-tile basis in our project. These DGNs were imported into a GDB, so the polylines have already been merged ...
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327 views

Arrow flow lines from a contour map

using QGIS (or even GRASS) is it possible to label a contour lines shape with arrows that indicate the flow direction? Briefly: I have a point shape with elevation values. I make an interpolation map ...
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444 views

How to clip the contour map with the polygon using R software?

Hi I am wondering how can I create the contour lines from the discrete x, y and z dataset and then add the shapefile to cut the contour lines by polygon. I want to clip the contour map by the shape ...
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71 views

DEM/DSM from contour lines and slopes

I want to create a DEM with as much detail as possible. The problem is, that the area contains several (manmade) slopes. I got contour lines and lines that mark the location of the slopes, but no ...
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25 views

ContourList error

i use ArcGIS Desktop 10.1 in Windows 7 and develop with visual studio 2010, .net v3.5. This is a quite strange problem. I have a Console Application that calls this simple function: public void ...
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56 views

Creation of drainage ditch in ArcGIS - Line with a certain slope

I have a digital terrain model and a list of problematic points, in which water accumulates. It's not important how I obtained these points (by observing or some algorythm). I would like to use these ...
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83 views

Google Maps basemap not showing up when KML file added as a vector layer in QGIS - only point markers appear

I am trying to make a basic XYZ contour plot in QGIS 1.8.0 (longitude, latitude, depth in an excel file) and can't get past the first step of adding a basemap in QGIS. I've tried using the Open ...
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49 views

How can i get the contour (boundry line) of a feature collection

I have all parcels of given locality as a FeatureCollection. Each parcel is a Feature with a MultiPolygon outlinine the boundry of that parcel. I would like to get a Multipolygon that has the shape ...
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28 views

Find area that it's in one GeoJSON file but not the other

I have two GeoJSON files, A and B. The features in A contain everything in B, and more (they're contour lines, and A is a lower elevation). How can I get the difference between the two files? As ...
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296 views

QGIS Contour plugin - contours from points

With QGIS 2.01, the plugin Contour is not available. Anyone have another method to create contours from point / shapefile source, where the points are not a grid?
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272 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. ...
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112 views

QGIS 1.8.0-Lisboa error message when converting DEM to Contours

I am trying to convert a small DEM (1 megabyte) into contours. When I go to - Extraction - Contour- and run it I get the following message: "ERROR 1: CPLRealloc(): Out of memory allocating 416 ...