Digital Elevation Model (DEM), which could be a Digital Terrain Model (DTM) or a Digital Surface Model (DSM).

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-2
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0answers
10 views

How to show map direction of a DEM in Q gis [on hold]

How to show map direction of a DEM in QGIS and how to show direction of the MAP?
0
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0answers
10 views

Getting latitude and longitude in decimal degrees from DEM-raster in UTM

I have a digital elevation model (details: ~4300 cols x 3600 rows, cell size 10 m x 10 m, tiff format, projection: WGS1984 UTM, false_easting: 500000, false_northing:0). I would like to have 2 ...
-1
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0answers
27 views

Calculating total area overlapping raster DEM color interval whose boundaries are confined by another vector? [duplicate]

Example: I tried running raster calculator on intersections then zonal statistics checking "count" and "sum" but I get a huge table of 8000+ rows and two columns, however each cell usually have a ...
2
votes
1answer
70 views

Calculating total area overlapping specific raster DEM color interval whose boundaries are confined by another vector?

I know this sounds quite difficult, but maybe it isn't for you or at least it shouldn't if I explain it correctly. (I'm using QGIS 2.14) I'd like to know to calculate total area overlapping a ...
6
votes
1answer
174 views

In hydrologic terrain analysis is there a difference between “pits”, “depressions”, and “sinks”?

In hydrologic terrain analysis is there a difference between "pits" and "depressions"? For instance, Planchon and Darboux (2002) state The usual numerical methods for removing the depressions of ...
5
votes
2answers
84 views

DEM out of a shaded relief LiDAR?

I have a DEM built from LiDAR data and the file extension is .tif. When I open this file in ArcMap it seems to be a shaded relief DEM (see the screenshot below). It happens I want to visualize the ...
1
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1answer
31 views

How to reverse colour-ramped DEM to its original elevation value?

A have a GeoTIFF, LIDAR images which display DEM in its color-ramp version (color relief) from blue (minimum value) to red (maximum value) and green (in between). I dont have the original elevation ...
1
vote
1answer
241 views

Merging USGS DEMs in ArcMap?

I've downloaded some USGS DEMs from the National Map, which appear to be .adf files. I can open them in ArcMap 10.2, but I need to merge them into a single mosaic. To do this, I've created a raster ...
2
votes
2answers
57 views

Topography data to elevation raster

In a previous question (convert-xyz-points-to-topography-and-calculate-mean-slope), I asked how to interpolate point elevation data to a raster in order to measure slope. Thus I use the Raster > ...
0
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1answer
43 views

How do I convert a DEM GeoTIFF to Contour Shapefile

I have a digital elevation model as a GeoTIFF and I'm looking to generate a Shapefile of contours with 5m bands on the command line. Is this possible? Ideally using GDAL and Python.
1
vote
1answer
24 views

CRS and Spatial join problem

I try to match two layers. First one is point-type with cities in Europe. Second one is grid layer (polygon) with elevation value. What I want to achieve is to to join the "Z" value from grid layer to ...
4
votes
1answer
61 views

30m/10m/1m resolution DEM for microtopography research

I am conducting research in a region of Illinois that does not have a LiDAR dataset. I am looking to develop a fine scale habitat species distribution model; however, the coarse data available ...
2
votes
2answers
106 views

Where is the nviz tool in qgis 2.14 with GRASS 7.0.3?

I hope Im not blind but I looked in the grass tools (modules) and qgis plugins but couldnt find it. When i try to run nviz from GRASS the whole programme chrashes just before concluding. Its a ...
3
votes
2answers
75 views

How to calculate the relative share of an area of a circle that has a slope >15% in Germany

I need to calculate the share of buildable land for the 15 major german cities within a 50 kilometer radius of the city center. Part 1 of the definition buildable is that the area must have a slope ...
15
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10answers
32k views

Converting XYZ files (with regularly spaced xy) to ESRI GRID format?

Normally consultants (LiDAR survey) provide me with data to my specifications; already in ESRI GRID or ASCII GRID format. This way LiDAR data can be easily used with ArcGIS. This time I only have xyz ...
7
votes
3answers
528 views

Is there a difference between the Planchon & Darboux and Wang and Liu depression filling algorithms? Other than speed?

Can anyone tell me, based on actual analytical experience, if there is a difference between these two depression filling algorithms, other than the speed at which they process and fill depressions ...
1
vote
1answer
36 views

Add DEM layer to Leaflet

I want to add a digital elevation model (DEM) layer to my leaflet map and access the height data through javascript, i.e. I cannot use .png files or qgis2webplugin but rather .tif or some compressed ...
2
votes
1answer
29 views

Applying base heights to raster is giving me different results

I have applied the DEM's base heights to both the raster image, the raster DEM, and a vector file. The DEM and vector file match up but the satellite image does not match up at all. Any suggestions ...
-1
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0answers
31 views

How to project SRTM DEM data?

I am trying to project a SRTM DEM file (raster format GRID) that covers my study region to a better projection and I hope with this I will figure out the cell size in meters. The DEM is currently in ...
4
votes
2answers
64 views

Faster way to calculate slope between two points on DEM using ArcGIS for Desktop?

I'm a forester, and I do lots of work with LiDAR derived DEM's. I'm looking for a quick-and-easy tool to calculate the slope between two points. The application for this would be drawing a proposed ...
1
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0answers
12 views

“Select a tool” error Saga: Accumulated cost (isotropic)

I'm trying to run Saga's accumulated cost operation in QGIS on a DEM and set of raster destination points, but keep receiving an "Error: select a tool" in the log after a failed run. There are no ...
0
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0answers
14 views

QGIS asc to GeoTIFF error: “File short, can't read line 3687”

I tried to convert an asc file to GeoTIFF and I had the following error: ERROR 3: File short, can't read line 3687. ERROR 1: (..:)/mdt.asc, band 1: IReadBlock failed at X offset 0, Y offset 3687 ...
1
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0answers
23 views

Applying values to highest terminal segments in channel network using PostgreSQL?

I extracted a channel network from a dem but due to some technical difficulties the layer had some discontinuities. So after filling them, i suddenly realised that the Strahler orders it gave me were ...
1
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0answers
21 views

QGIS: How to create a crosstab using SAGA toolbox cross calssification and tabulation?

I am trying to use Cross classification and tabulation SAGA toolbox. I have a raster DEM file (14 classes) and raster file precipitation (13 classes). I want to do cross-tab - but I don't know how ...
2
votes
1answer
736 views

How to fill holes/missing values in XYZ data / a DEM with QGIS?

I have equidistant XYZ point (text) data that I used to create a point grid. However, it's not perfect - there are some holes. I then created a DSM raster from it, which obviously has the holes too. ...
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0answers
12 views

How can I make a DEM of a Dam Watershed? [duplicate]

How can I make a DEM of a Dam Watershed If if I have only the Latitude and longitude of Dam Site? Also guide me how to locate Meteorological and Hydro-logical Gauging stations within the catchment ...
2
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0answers
40 views

Draw raster on top of a Leaflet map

I want to implement a raster layer on top of a Leaflet map that includes the following functionalities: Digital Elevation Model (DEM) terrain height included in each raster cell GPS-Track (I use ...
1
vote
1answer
49 views

Raster calculator fails with large raster in QGIS

I'm working in QGIS 2.14.1 with a DEM ranging from 200 feet to 1600 feet elevation called "dem_3m_Zft1b" (geotiff, 16822 X 33349 cells, No-data =-9999) If I enter "dem_3m_Zft1b" > 0 in the ...
2
votes
1answer
27 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
44 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 ...
4
votes
2answers
270 views

Which method is better for display terrain in OpenLayers?

I want to display terrain in OpenLayers. So, I tried to use dem(.img) and convert it to dem(.jpg) on QGIS. But, the effect is very bad. My expected effect is (This picture is captured from google ...
1
vote
1answer
33 views

Hillshade effect not working when no data is on screen

I'm working on a DEM and I selected hillshade effect to be active. The problem is that I can't get it to appear when a no-data area is shown on my screen. If I move the area just enough for the ...
4
votes
1answer
32 views

Grid size of a Digital Elevation Model developed from topographic surveyed elevation contour line?

I have generated a Digital Elevation Model from elevation contour line. I got these elevation contour line at 20 cm interval from DGPS survey. What would be the grid size of generated DEM in "m". ...
2
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0answers
26 views

Watershed delineation with meandering river

I'm using ArcGIS (Hydrology toolbox) for watershed delineation for a number of pour points, and I'm running into problems with very meandering rivers on extremely flat alluvial land (Amazon basin). ...
19
votes
3answers
4k views

How to produce high-resolution DEMs from new Sentinel-1 data?

This is a general question relating to the new Sentinel-1 data. I'm interested in the potential for using this data to create high resolution DEMs in GIS (I use QGIS), to investigate archaeological ...
1
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0answers
35 views

SAGA GIS Channel network crash

So, i had this very weird bug while treating my dem data lately. I used SAGA to create flows channel networks on a dem i acquired a little while ago. Preprocessed it using sink route detection and ...
2
votes
1answer
26 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 ...
1
vote
1answer
40 views

How to do diagram block with open source software?

I would like to do a block diagram (topographic and geological representation). Is it possible to do this with QGIS (or other open source software), in Windows 7?
2
votes
1answer
30 views

How to calculate the right area in polygons with help of DEM?

I have used infra red photos to identify territories in Norway where I have drawn polygons for different vegetation. I wonder if there is a way to use the polygons with elevation data to get the exact ...
1
vote
1answer
24 views

5x5 raster filter in ArcGIS?

Normally, I am using the 3x3 lowpass filter if I need to filter a DEM. However in one case, for better results in curvature calculations, I would like to do a 5x5 filtering. How is this possible in ...
3
votes
1answer
35 views

Do outputs (shp, dwg) inherit vertical datum from input (las) files?

I'm working in ArcMap. I pulled LiDAR data off earth explorer and created a DEM with the LiDAR data. I then created contours as a SHP file and exported to DWG (CAD). I was asked if the CAD file's ...
3
votes
1answer
36 views

Reading 1/3 arcsecond DEM data using C++?

I am writing my own application to use and present elevation data. So far, I've been easily using the three arc second SRTM data presented in ArcInfo ASCII format. But now I'm looking to use the ...
1
vote
1answer
2k views

Creating Cost Surface Raster for Least Cost Path Analysis?

I have a DEM raster and would like to carry out a cost path analysis. Among other factors such as slope, proximity rivers etc. I would also like to take elevation into consideration. According to ...
0
votes
0answers
32 views

Is it valid to resample a raster from 1m to 3 feet?

I know that in general it is not a good idea to up-sample. I am curious if it would still be be a "bad idea" with a minor change like this from 1m resolution to 3 feet? Going to 3 feet would not ...
0
votes
1answer
42 views

Get Elevation of XY points [duplicate]

I am working with ArcMap 10.3. I have imported DEM files. When I imported the files they had the extension of .DDF. I would now like to be able to take a list of XY coordinates and, for lack of a ...
6
votes
3answers
229 views

Extracting Values to Points without ArcGIS Spatial Analyst?

I have a raster DEM & multiple points. I want to determine the DEM elevation at each point. Other than manually examining the DEM at each point, (very time consuming with lots of points) is ...
0
votes
1answer
27 views

How can I blend DEM rasters with GDAL?

I have several DEM rasters in different projections and at different resolutions. The rasters are not rectangular, but they have appropriate NoData values. They overlap enough that I should be able ...
2
votes
1answer
367 views

Polyline ZM: automatic vertex height errors correction

Paolo I've got many rivers (polylines ZM) with a lot of height errors in Polylines 'vertices. Vertices' Z errors are not all equal in height (i.e. they are not all at zero height). I must create a TIN ...
1
vote
1answer
36 views

How to speed up raster2pgsql?

I'm trying to upload a 37 GB raster dataset to PostGIS. The raster is out-of-db (-R option), so the actual pixel values are not stored in PostGIS. I'm using this command: raster2pgsql -s 25833 -C -I ...
1
vote
2answers
68 views

programmatic DEM downloads similar to landsat-util

I recently discovered landsat-util, and was wondering if there was an equivalent command-line application for global elevation data, (for data around 1 arcsecond resolution, preferably geotiff) or if ...