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

learn more… | top users | synonyms

2
votes
2answers
59 views

Slope Analysis in QGIS

Im New to QGIS, I have the Contour Information in the form of Line Features, How can I do a Slope Analysis. Is it Possbile at all? For Reference I am attaching the Image. the lines in the Polygon ...
0
votes
0answers
35 views

Drawing contour with python QGIS?

I have one point layer and one contour layer and I was trying to draw a line around one contour, making a circle but not a uniform one, it has to have an irregular shape. I cannot find a tool that ...
1
vote
0answers
9 views

Any way to remove 2 point polylines in bulk?

QGIS: I have successfully created contours from a DEM and subsequently cleaned them up using generalizer tools in the following order: 1. Vertex reduction 2. McMinimans distance algorithm. The ...
3
votes
1answer
708 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 ...
1
vote
3answers
50 views

QGIS Heatmap by value (NOT by point-densty)

I need a heat map generated by points value irrespective of how close or far apart the points may be in QGIS 2.6.1 So far I'm using the raster/heatmap/heatmap function. I need the same colour to run ...
1
vote
1answer
34 views

Grid thematic map in Mapinfo

I have a tab file with the contour lines for an area, and also a tab file with the land polygon. Now, I'm following a tutorial written by a colleague a couple years ago, where a thematic map is ...
4
votes
0answers
65 views

Convert raster to smooth contour polygons in QGIS

I have had limited success creating smooth contour polygons from a raster layers. I have created contour lines and boundary polylines and then used QGIS Union. Then I use QGIS Polygonize. Then ...
4
votes
2answers
2k views

Adding Garmin *.img files to QGIS?

I downloaded 10 .img files from garmin.openstreetmap.nl which are supposed to contain the topo tiles for the area I would like to add in qgis. I've been unable to find any instructions on how to use ...
-4
votes
1answer
45 views

Help with definition query [closed]

I have a layer of 5ft contour lines, and it includes a field called "Elevation" that has the elevation of that particular line in feet, (ex: 1555, 1560, 1565 etc.). I want to only show lines for every ...
1
vote
1answer
229 views

Generate 3D elevation points grid from 3D contour lines!

I have a shape file with 3D contour lines. I want that based on this information to generate for all this area a 3D grid of points with certain distance from each-other like every 50cm. I use ...
0
votes
1answer
240 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? ...
-1
votes
0answers
28 views

Using ArcGIS Spatial Analyst for elevation?

I have many csv files of ~1000 points with elevation and x,y data. These points were manually recorded off of scanned images of the surveyor's drawings at an archaeological site. I have made each of ...
4
votes
0answers
58 views

QGIS Contours plugin [closed]

I managed to load osm-data with osm2po, pgrouting, postgis and postgresql into qgis. Then I did a drivingdistance analysis based on cost to finally get the qgis contours plugin up and running. But ...
0
votes
0answers
18 views

Contouring and rendering bathymetric & other attributes in QGIS

I wish to visualise (2d & 3D) and contour point sampled bathymetric and other associated attribute data (biovolume and bottom hardness) in QGIS. The source data files are CSV files consist of ...
3
votes
1answer
959 views

Problem with generating contour lines and filled contours

I am trying to create contour lines and filled contours from a shape file of height points using the contour plug in (have tried other tools but with no success). The data is sourced from the UK ...
1
vote
0answers
9 views

Converting Labels to Annotations moves position of labels

Why are my contour line labels moving after I convert them to annotations? I am using Maplex to place them. But if they still move after I converte them to annotations, the whole maplex placing ...
3
votes
1answer
63 views

How to fix label contour lines layer displays on top of all layers in QGIS

How can I fix the situation, when the label contour lines displays (on top of all layers) on top of this layer? QGIS 2.15.0-Master
0
votes
0answers
13 views

Converting polygons to contours based on value in polygon table

I have the following and data and have been asked for a map that shows the same data set but displayed as contours. Each polygon has a value in it's table called "count". The "count" field is used to ...
2
votes
1answer
4k views

Exporting QGIS contour attributes in DXF file?

I have a .tiff data file that generates contours in QGIS. I save it as .dxf. The contours don't have any attributes or data. That's bad, because I want to make a 3D landscape in Revit using the ...
4
votes
1answer
260 views

Exporting Contours from QGIS into AutoCAD [duplicate]

I'm trying to export contour lines from QGIS into standard AutoCAD but I'm not having much luck. It does not seem to matter what type of file I select as the output during the contour creating (eg. ...
2
votes
1answer
33 views

How to calculate mean elevation in a DEM between a specific interval?

I have a DEM with different elevations between 100 m & 3828 m. I just want to calculate mean elevation higher than 1500 m? Can I do that?
3
votes
1answer
49 views

Scripts to automate conversion from DEM to contour shape files

I am using the DEM files in the Cornell CUGIR repository to build contour layers in QGIS. The problem I have is that while it is easy to do, it requires many manual steps in QGIS that are both ...
2
votes
3answers
75 views

DEM polygonize (raster to vector) doesn't work for contour lines less than 1 meter apart? (QGIS)

I tried to make polygon from DEM (geotiff) in QGIS. My requirement is that elevation value was every 0.5m of polygon. If I use the function polygonize (raster to vector) , polygon is created but ...
2
votes
1answer
29 views

contour lines/ basement contour extraction

My purpose: getting out area between elevation contours (like b/w 600m and 700m). The contours could either be elevation ones or the basement contours. I got elevation contours using spatial analyst ...
2
votes
1answer
59 views

Polygons between contour lines in QGIS?

I am trying to create polygons between contour polylines within a defined area (for which i have both polygon and polyline shps) but I seem to be thwarted at every turn. Using QGIS 2.14, I am sure it ...
1
vote
0answers
35 views

Optimize Postgis contour lines DB

I'd like to try to optimize a world-wide 10m contour lines (isohypses) Postgis database(from SRTM). The complete DB takes 504GB on disk, contour lines are already in epsg:3857, and simplified with ...
1
vote
0answers
24 views

Faulty altitude point between contours

I have point(picket?) between 2 contour lines with even number altitudes. Now i got these new 5 meters steps contour in between. As you see, this point between red lines was OK, but now that this 175 ...
3
votes
3answers
2k 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 ...
1
vote
2answers
357 views

Contouring range only using ArcGIS Spatial Analyst?

I have a grid (in .img format) with pixel values ranging from -10,000 to 10,000, which i would like to contour. but i would like to contour only -3000 to 0 range. is this possible to set this up ...
6
votes
3answers
5k views

How to create contour lines from point data using QGIS?

I'm using QGIS 2.4.0 and I have a shapefile of points with elevation data and X and Y coordinates. I'm using windows 7 OS. The idea is to create a contour line SHP using my point data. My question ...
23
votes
5answers
2k views
2
votes
1answer
295 views

ArcGIS, How do I get smoother contours?

I am trying to get nice smooth contours using ArcGIS. I have already smoothed out the DEM using focal statistics, simplified and smoothed the contours. The current result looks like this, which is way ...
2
votes
2answers
76 views

Generate multiple contour lines at specific elevations

Can anyone suggest a method by which I can produce several user-defined contour lines (from a DEM) within a single shapefile using QGIS/GRASS (2.12.x) and its plugins. Each approach I have tried has ...
2
votes
1answer
63 views

Download of very detailed DEM files for Portugal?

Operating system: Windows 10, 64 bit. QGIS Version: 2.13.3 which I installed via the QGIS.org website. I need contour lines for a small area in Portugal. I saw a guide posted here: ...
0
votes
1answer
33 views

How to assign elevation values to contours derived from a raster elevation file

I extracted contours from a raster elevation file (SRTM). The contour layer does not contain elevation values. How can I use qgis to assign elevation values to the contour layer? Is there a better ...
0
votes
1answer
243 views

Exporting linework layer with 'altitude' attribute in QGIS to DXF with lines raised in z according to altitude attribute?

I have contours which I have brought into QGIS from a GEOjson - the lines have an attribute of 'altitude'. I want to export these contour lines as a DXF with the lines raised in the zplane according ...
-3
votes
1answer
58 views

Calculating number of roads between two polylines in ArcMap?

I have a file that contains contour lines and want to know how the number of roads that are located between each set of contour lines. How can I go about achieving this? I provided an example ...
2
votes
1answer
508 views

Checking if z values of contour lines are correct using ArcGIS Desktop?

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.
1
vote
0answers
18 views

Contouring with cliff faces in ArcGIS for Desktop?

I am trying to create some contour lines that are around cliff faces. What is the best way to create contour lines that are effected by cliff faces and is there a way to automatically draw the cliff ...
19
votes
4answers
16k views

Creating DEM from contours in QGIS?

Is it possible to make a DEM from contours in QGIS? I have a shp file (contours) and their heights, can I use QGIS for produce a DEM without using GRASS? I found this creating a dem from contours ...
0
votes
1answer
39 views

Contour extraction from raster does not finish in Qgis. How to find out if a raster is damaged

Execution of "extraction" - "contours" in Qgis is impossible. The process never finishes, I stopped it after 35 min. The contour extraction works for all other raster files. I have tried with ...
43
votes
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
319 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
31 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
39 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
35 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
900 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
79 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
33 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, ...