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

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4
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44 views

Simplified flood “model” / estimation from elevation data

The goal is to present an estimation of potential flooded area. But still keeping it simple. I know this will not be accurate. The question is: will it be good enough for at gestimate / rough ...
4
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88 views

Flow direction generated for river is incorrect

I am trying to generate a hydrologic model and I can not really proceed on the next processes. I have this problem on generating flow direction. I have already executed fill sinks and the next is flow ...
4
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41 views

Has anyone used ArcGIS for 'automatically' detecting lineaments from a high-resolution (1m) DEM?

I have a set of DEM's produced from LIDAR data. I am wondering if anyone is familiar with or knew of any published research papers which looked at (semi-)automatically detecting lineaments /or ...
3
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15 views

3D distance and topography

I have a set of points and want to find out the nearest distance to a water body (poly lines) taking into account the terrain and get a surface distance calculation. I understand that the way is to ...
3
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0answers
36 views

How to calculate an Illumination raster for fire ignition danger analysis?

I am doing a fire ignition danger analysis using this equation that I found in Millington (2012) http://www.jmecology.com/wp-content/uploads/2014/03/33-42-MILLINGTON.pdf IR = 4H + 3V + 2I – E Where: ...
3
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58 views

Creating one DEM from multiple ASC files

I am struggling with this several days and now its time to ask how to do it in QGIS. I have very detailed 27 ASC grid files with overall size of 9 GB created from 1m contours of large area (600 m2). ...
3
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78 views

Calculate surface elevation from DEM of pit and known volume with which it is being filled

I am using ArcGIS 10.1. I have a DEM of a pit. I have a known volume of material that I want to put in the pit. I want to know what the elevation of the flat surface of this material will be ...
3
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109 views

Shapefile and DEM: check rivers behaviour

I'm working with shapefiles representing rivers (rivers.shp), and DEM for the terrain elevation (terrain.tif). Basically, I want to check that my rivers (stored as polylines in my shapefile) behave ...
3
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44 views

Adjacent DEM files have narrow triangular gaps when joined

Newbie here. I've downloaded several DEM files from GeoCommunity which correspond to adjacent regions. When I join them together to form a larger relief map there are triangular 'gaps' on all four ...
2
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11 views

Intersection of a vector linestring and underlying DEM

Following is an screen-shot where ASTER DEM raster layer has been overlaid by a road linestring vector layer. I want to extract those DEM pixels which are lying exactly beneath the linestrings. I want ...
2
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90 views

When computing flow direction, the D8 algorithm is used - are there major differences if others are used?

I am a student working with Hydrological models. Within these models we can route water across a DEM (within a delineated watershed or just within an un-delineated DEM) using many different flow ...
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52 views

Define uphill side of roads and buildings

I have a big raster of a mountain region and I need to extract the uphill side of roads and buildings, from these elements to the pick of mountains. For a road I know the uphill side changes in ...
2
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93 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 ...
2
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0answers
85 views

Choosing the right parameters to interpolate a DEM from contours

This is my first question on the forums, so be gentle :) I have a 5 meter interval contour lines feature class which I would like to interpolate to a DEM. I am well aware of at least 2 tools ("tin ...
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0answers
24 views

How many function templates can be applied to single image service in ArcGIS for Server?

I am trying to minimize space used on our server by producing a single image service for each county in Maryland. However, I need to display 6 different derivatives for each county: DEM in feet, ...
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91 views

Displaying DEM raster in QGIS

Using Raster>Analysis>DEM to display hillshade produces the message "gdaldem.exe had stopped working" so I asked the community. I'm new to QGIS, and I now realise after a little experimentation that I ...
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333 views

How to limit a specific area in order to have a topographic 3D map using MatLab?

I am using MatLab, I want to build a topographic 3D map, I am following this guide, I have been doing the steps listed on the section Draping Geoid Heights over Topography, and I do not have any ...
2
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68 views

Arcpy: Counting number of segments where altitude rises or decreases based on DEM?

I have a DEM of Sudety mountains and linear .shp with several hiking paths. I'm trying solve one problem: How to make a script based on input DEM and input line shapes that would count number of ...
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453 views

How to calculate Solar Radiation falling on vertical surfaces using DEMs and ArcGIS?

I am using ArcGIS10 Area Solar Radiation tool to calculate irradiation on horizontal surfaces (building roofs) but need to do the same for vertical surfaces (building facades). Any ideas on how to do ...
2
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468 views

GDAL tiling DTED (dt2) dataset as gdal2tiles for 3D Maps

i am searching some webgl technologies to create 3d map with digital elevation data. for web tech. i have found ReadyMap SDK to create 3d map from TMS... in ReadyMap for elevation data it uses sth ...
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17 views

Buffering/extrusion of a dem surface

I have a surface representing a DEM and i would like to add it some thickness. If i simply duplicate the surface and translate it down by my thickness, i get non uniform thickness, ie thinner where ...
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17 views

How to convert shapefiles into ascii grid .asc in QGIS?

I downloaded multiple zips that cover a small island from the Rhode Island Geographic Information System webpage, specifically the geographic files that make up Block Island. Here's the source: ...
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15 views

Contour command in Spatial Ecology's GME

Has anyone been successful using the contour command from GME (Geospatial Modelling Environment)? I'm trying to create contours out of a DEM. I know you can do it in ArcGIS with 3D or Spatial Analyst ...
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72 views

Correlation between point feature (disease) and elevation

I have a problem! How can I calculate the correlation between point feature and Dem raster? Hypothesis: disease prevalence in high altitude is more than low altitude. I must do this in ArcGIS 10 and ...
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28 views

Question about projected coordinate systems 30m DEM for Contiguous US

What is the best Projected Coordinate System (PCS) for the contiguous US (whole, not parts) if I want to maintain distance and area accuracy as much as possible across a nationwide DEM dataset? I'm ...
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44 views

DTM Extraction/Smoothing in ArcGIS

I have an .las file, intended to be a DTM (bare earth) that I generated from a photogrammetry software package that has come out just a bit too lumpy. I now have the license for that software tied up ...
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38 views

Using GeoBrain WCS4DEM in QGIS?

I added the GeoBrain WCS server to the server list: http://geobrain.laits.gmu.edu/cgi-bin/gbwcs-dem?version=1.0.0& I connect to the server and get a list of layers. I select the first one listed ...
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37 views

How do I split a DEM at a certain elevation?

I have a DEM that includes bathymetry and terrain elevation and I would like to split it at the coastline. Ideally, I would end up with one tif that's land and one tif that's bathymetry. I have ...
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99 views

What steps does SAGA GIS take when calculating Topographic Wetness, specifically when handling depression filled (by ArcMap) DEM

I am a grad student involved with hydrological modeling. In the model I work on, we are calculating the Topographic Index (TI; without transmissivity - or set to 1) using Quinn's MFD algorithm. We do ...
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206 views

Merge overlapping DEMs with irregular boundaries

I have a 10m DEM covering part of a state, a 20m DEM covering the whole state, and a 90m DEM covering the whole country. How can I merge them together, getting the best quality available in each area? ...
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48 views

Multiple metadata within a single mosaic dataset

I am creating a mosaic dataset consisting of thousands of different DEMs. These will make up a single State, however I need the Counties to be able to hold their own metadata. Each raster contains ...
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134 views

What is most suitable DEM to delineate watershed (from spot height, ASTER and SRTM)?

I have three DEMs of our country which are spot height DEM, SRTM DEM and ASTER DEM. SRTM has 90m resolution and ASTER has 30m resolution. My supervisor told me to delineate watershed using these ...
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138 views

Error Message Orthorectifying ASTER Imagery in ArcMap 10 with DEM

I am trying to orthorectify ASTER imagery (VNIR, 15m resolution) in ArcMap using an ASTER DEM that I have downloaded from the GDEM website. The area is in the Andes, there are very high elevation ...
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122 views

DEM data - Central Europe - noise in heights

I have downloaded DEM data from this page: http://www.viewfinderpanoramas.org/dem3.html. I have written simple program in C++ that takes "bricks" and build resulting height map. Hovewer, I have ...
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313 views

“topo to raster” tool

is there any analogue of "topo to raster" tool (ArcGIS) in QGIS? I need to creates surfaces from shp for some cases from points and for some from lines and this instrument is very convenient.
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58 views

Is there any accuracy difference between standard DTM editing tools like DT Master and automatic removal of artefacts using ERDAS?

I would like to know whether there is any accuracy difference while editing DTM points using standard photogrammetry software like Inpho DT Master and automatics removal of artefacts in ERDAS imagine. ...
0
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11 views

Draw the bounday through DEM

I want to calculate/draw the boundary extent in Glacier valley with the help of DEM. Can you please guide me which is the best tools in ArcGIS and steps to calculate.
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35 views

Striping Artifact in Aster DEM Mosaic

I'm working with SRTM and ASTER data for a university project. My goal is to delineate watersheds and evaluation of these with ArcGis 10 and ArcHydro. But a striping error occurs with the flow ...
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27 views

QGIS DEM Output cell size does not match DEM input cell size

As my first post I offer a humble apology if this is such a basic question as to make any of you cringe. I feel like I have exhausted my search skills and read through the QGIS documentation ...
0
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0answers
12 views

Manipulating Interpolation Outputs

I would like to clip the edges of my interpolation output to cover only a specific Local Study Area and also combine the output with a DEM to create a spatially defined 3D model in ArcGIS 10.1. Two ...
0
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82 views

DXF (points and lines) in QGIS - Doesnt import z coordinates

Trying to get to grips with QGIS, coming from a Mapinfo and Civil3D background. I have a DXF file with points (X,Y,Z) and lines. I want to open this in QGIS and use the interpolate plugin to create ...
0
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50 views

How to create .dem file in QGIS?

I have an elevation data in .asc file, but need to convert it to .dem file to later use in COMSOL. However, in Raster--> Analyzes-->DEM I got just error message: ERROR 1: DEM Default Setup: Importing ...
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46 views

Advice on how to present a cross section

So, I'll try to best explain what I want to do. I have a DEM of a volcano (only showing half the DEM in pictures below) and I have identified a lava flow that I would like to make a cross ...
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47 views

QGIS 2.2. raster color ramp

I have just upgraded from QGIS 1.8 to QGIS 2.2 and I am missing very much 1-band raster color ramp plugin that I had easily colorized my DEMs by using pre made color brewer such as DEM screen or DEM ...
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48 views

passing tif image as input to openlayers code (wps implementation)

how to pass dem(tif) or raster layer as input to the openlayers ... //OpenLayers.ProxyHost = 'proxy.cgi?url='; OpenLayers.ProxyHost = "/cgi-bin/proxy.cgi?url="; //OpenLayers.ProxyHost = ''; var map, ...
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29 views

Finding normal vector to DEM

I have a DEM grid (Surfer, or whatever format) and an x,y position on that grid. I also have a series of depths from the surface. I need to calculate, for each depth, the x,y,z of the projected ...
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22 views

How to make DTM Qgis-grass

Good evening, I need help. Should I create a dtm of an area in the province of Vicenza. It 's the first time I try, I tried the tutorials on the Internet but I could not understand how to do it. Could ...
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28 views

Things to consider while and after merging DEM-Tiles?

In some tutorials it is said that after merging you should stretch the “histogram to full dataset” (also mentioned in the QGIS Training Manual). Is there anything else you would suggest doing after ...
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64 views

Why does merge/mosaic four DEMs into one give ERROR 01042?

I'm unable to merge 4 dems into one using ArcGIS Home 10.2. Raster Calculator, adding them, gives me the error: RuntimeError: ERROR 010422: Error in processing the environment mask. I created a ...
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18 views

Calculating std dev for ruggedness using QGIS?

I have a DEM raster image and a vector layer with 200+ grids. Using QGIS, I got the terrain ruggedness index for the DEM layer. Now, I want the std dev (i.e. variation in ruggedness) for each of the ...