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I am trying to evaluate a number of flood gauges to assess at what levels of river height different flood risks would need to be issued. The gauges are currently set to warn of flood a couple of hundred km downstream but those levels don't affect my AOI. For example a "Major" flood downstream will only result in a "Minor" flood in my area etc.

I am trying to work out a workflow for this work which needs to be delivered in the next 3 days.

We have Arcgis 10.1 (Advanced with 3D Analyst/Spatial Analyst), Global Mapper and QGIS/GRASS. Datasources are Lidar point clouds (4ppm), 1m DEM, 125mm imagery, gauge locations (3D vector) and streams.

What's the best pathway?

So far, ArcGlobe lets me easily fly through the terrain and visualize all but the lidar datasets. Is there someway I can add the buildings as 3D surfaces into this? I am evaluating tools such as LP360, Lidar Analyst and E3D3 to do this (will add results as I work through them)

enter image description here

What I am planning to do is create inundation 3D polygons based on the Gauge height plus 1m, plus 2m etc (up to 10m) and then intersect them with the asset vertical profiles to get an idea of what's affected at different flood levels and how this relates to a Minor-Major local flood.

Global Mapper does the inundation as below but I can't figure out how to specify what height levels I want or extract a 3D polygon of the inundation zone. enter image description here

My intention is to use this post as a thread for people to easily compare the real world functionality of the different options so your comments/suggestions/critiques are welcome.

share|improve this question
It's not clear whether this question is about computing the inundation, displaying it, adding building heights to a DEM, or even performing numerical models to predict downstream flooding. Could you edit it to make it a single answerable question? In the meantime, given the subject nature, How to simulate a flood might provide some ideas to get going with. – whuber Sep 12 '12 at 18:57
Sorry for the delay in responding. It is all the questions that you mentioned. I have put some of these into new questions but am retaining this as the big picture as I need to look at an overall solution and not just the individual steps to that. – GeorgeC Sep 17 '12 at 6:52

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