Derive Floodplain Surface from 3D River Centreline

[PeterWilson]

I've derived a 3D river centreline from my DEM and have increase the elevation for each vertex by 3m, simulating a flood. I've tried generating automated cross sections based on the 3D river centreline, but the placement of the cross sections start crossing each other with different elevation levels. If anyone has a way to generate a surface (TIN\DEM) that I then can use to subtract from the ground surface (DEM) to estimate the floodplain based on the increased elevation along the river centreline.

Any assistance will be apprecaited as I've been struggling with this for the past few days, looking for alternative methodologies to accomplish the following.

Regards

Peter Wilson

[WilliamMortimer]

Hi Peter,

I'll check out the Hydrology tools linked to Spatial Analyst.

There are specific tools that cover watershed areas & water flow modeling.

You might need a mask area for your flood zone as well, so if have a study area its good to have that defined in a shapefile or feature class.

Some tools might need a 3D analyst license to get the best out of them.

ArcGIS Help (10.2, 10.2.1, and 10.2.2)

Hope that helps,

William