Hello everyone. I would like to solve a question I have, but first I need to explain a little about the project I am working on. I have a small area that I flew over with a drone to obtain images and I would like to use these images and my previous project of the same area made in SewerGEMS to generate the 3D simulation as proposed by Openflows FLOOD. I was following some videos like this and the following manual. However, following the manual, I was a little doubtful at step 13, where a layer of buildings is used. I would like to know if this is one of the files resulting from Context Capture or if not, what is the best way to get this layer.
Manual/Video
Mine
Hello Luis,
If you have generated a file with the terrain data (XYZ, raster, etc.) using ContextCapture than most likely this terrain data includes the buildings elevations. Thus, in order to create the terrain model Grid Data file you simply have to create a computational grid and interpolate the terrain elevations onto that grid.
The buildings shapefile layer in the user manual is used for generating additional layers needed in OpenFlows FLOOD e.g. Manning's, Curve Number, etc.
I am not sure if it's possible to derive the building outlines directly from ContextCapture, you can ask that in the Reality Modelling forum, but that are several open source data that you can use that normally have up-to-date information.
I hope this helps, please let me know if you require any additional information.
Kind regards;Luis
Answer Verified By: Luis Souza
Hi Luis! Thanks for the help. As I understand it then, my file generated in Context Capture already includes the elevations of the buildings, right? In the case of the Layer used in the manual, will I need to create a layer just for this, as in the manual, to do the 3D simulations of the flooding points in my area? Or is this more used in case of a more in-depth study? My idea is to generate a risk map to identify the affected areas, basically.
Hi Luis,
Yes, your file created in ContextCapture, based on the image you've posted, have looks to have the buildings elevations.
You will only need the buildings outlines shapefile if you want to assign different Manning's n, different Curve Numbers, etc for each set of cells representing buildings. If you choose to use a constant Manning's n or constant CurveNumber then you don't need that layer.
Of course, the more detail you provide to your model (e.g. accurate representation of friction using different Manning's n and Curve Numbers for different types of land surface use) the more accurate you'll be in mapping those flood risk areas.
Kind regards,Luis