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3

Try splitting your raster into smaller parts. It seems to be really big. I just found this post: http://forums.esri.com/Thread.asp?c=93&f=995&t=225045, someone had a similar problem as you: Quote from link above: Any count exceeding 2^31-1 will therefore "roll over" into the most negative numbers; for instance, (2^31-1) + 1 will appear as ...


1

It can be done in QGIS. It's called digitising when you're drawing over a scanned map (image, or raster in GIS terminology). Check this handy, simple yet accurate tutorial Digitizing Map Data and come back if you run into more questions.


2

Ok, so I found a solution to my problem. I basically don't change the method described in the question. However, I add a step before step 1: Clipped the buffered river polygon layer (with a "cliff area" polygon layer, which I derived from the DEM's slope I created with the slope tool) so that cliffs have no influence on step 2 Clipped the buffered river ...


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At first, as you did not tell, you want to create a raster form the points. A similar question about this can be found here: How can I create an DEM from Point-Data Second, I think there are tools in grass, callable from qgis, to make a depressionless dem, like the r.fill.dir tool. Other GIS-people tend to use saga gis functions, as described here: ...


0

Posting refers to the square cell dimensions of a given raster dataset e.g. post = 10 m means a cell size of 10 m x 10 m. What often gets mixed up though is the assumption that a DEM of a posting of 10 m has a resolution of 10 m when in fact you could represent data of a given resolution at any posting that you like. A smaller post value will never ...


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I suggest you to explore the Generalisation toolbox. Usually different combinations of its tools are used for tasks like this. http://desktop.arcgis.com/en/arcmap/10.3/tools/cartography-toolbox/an-overview-of-the-generalization-toolset.htm


3

PDAL can do this for you, and the easiest way to use PDAL is to install Docker Toolbox and then follow the PDAL Docker Tutorial to verify you have the basics working. Once you're confident things are good, run the following command on the data: docker run -v //c/Users/Howard:/data \ pdal/master \ pdal translate //data/point_cloud_classified.las ...


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You need to import it as a CSV file. Since you're new to GIS, I suggest you follow this tutorial: Importing Spreadsheets.


0

For Germany you can order the DGM10 from the Federal Agency for Cartogrpahy. The Official Elevation Datasets are available in 10 m to 1000 m spatial resolution with a height accuracy of 0.5-2 m.


4

This will be possible with the Project tool with ArcGIS 10.4 (already available as pre-release). An additional parameter 'Vertical' allows you to specify an input and output vertical coordinate system, in addition to the horizontal coordinate system: This new parameter is mentioned in this What's new in 10.4 document (without much detail).


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Suggested workflow: Draw perpendiculars to road segments at regular step Interpolate them to 3D lines using DEM Convert vertices to points Find lowest point If it is “close enough” to centreline, road runs in depression This shows the test I’ve applied to check if already existing streams are matching newly developed DEM: You can also check results ...


4

The offset that you have between your bathymetry and your elevation model relates to the difference between the Mean Seal Level (MSL) and the Lowest Astronomical Tide (LAT). From the well written text found here we can read that: The MSL surface is in a state of gravitational equilibrium. It can be regarded as extending under the continents and is a ...


3

A great tool that is often used for vertical datum transformations is called V-datum, developed by NOAA. This is the tool that I have seen cited most often for similar tasks with a range of different datums including tidal. The V-datum docs has some information, as well as this gis.stackexchange answer on EGM96. I'm not familiar with lowest astronomical ...


0

The solution proposed by Spacedman is easy to do with GRASS GIS and Python scripting or or OpenJump's "planar graph" command. 1) Generate random points (or specific points) from the DEM and sample elevation at each of these points. (v.random, v.drape) 2) Compute a TIN with the Delaunay algorithm (v.delaunay, 3D) 3) Compute the Planar Graph (with ...


2

you can subsample aster to 4 m and combine both DEMs using simple IF ELSE statements. Note that no new information will be created in the subsampling.


0

Here is some code that will take a line, and generate a perpendicular line to that line. You could take a river center line, divide it by vertex, run this tool, proportion the perpendicular lines, populate the sections with z values, and MAYBE glean some river banks from the results assuming that the surface model was collected when the river was at low ...


2

In response to Jakob's suggestion to use Cut Fill, you could do a comparison of the original DEM and a depression-less DEM (a DEM resulting from using the Fill tool) and that should give you a volume for any given area showing as a sink on the original DEM.


2

It's hard to remember when under a crunch, but computer systems sometimes fail in partial or non-apparent forms. When you're being driven crazy by a an unexplainable failure, it's often best to lock the screen, take a quick walk about the floor or building, and work out a fallback procedure. Ask yourself: Could the data be bad? What other tool can I use ...


3

The comment by user Nir led me to the "Nibble" tool (Spatial Analyst Tools - Generalization). I had to do some preparations before I could use it and also some postprocessing. This is the model which works for me: This is the resulting DEM without the obstacle: And this are the watersheds and flow accumulations:



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