Hydraulic modelling/predictions - Free form evaporation pond planning
Hello all,
We are currently in the planning stages for a Free Form Evaporation (FFE) pond. In our industry FFE ponds are used when we produce excess water, which is discharged into clay swales in an arid dune system environment. Depending on the size and shape of the swale area and the volume of water discharged, we often need to engineer berm walls or similar to contain the water within specific areas.
The image below gives an example of an actual FFE extent overlayed with a 2m DEM. A berm wall was engineered at the southern end of this area to stop water from encroaching on the road.
For planning new areas, ideally I would like to be able to nominate a 'pour point' (or similar) on the DEM and input the water discharge amount (in litres or megalitres) to obtain a final output layer that delineates the predicted surface water extent (in 3D Analyst would be great). I know that this will be affected by evaporation rates, soil types etc. but a 'ball park' prediction would be good enough. I will have a 50cm DEM available for analysis/modelling.
Has anyone got any ideas on the best way to go about this? or the next best thing?
I have been doing a bit of research and it looks like HEC-GeoRAS could be a good way to go. However, if this tool is designed for dendritic systems only, it may be inappropriate for this environment which is a dunal system comprising of long parallel dunes separated by clay swales with numerous natural sinks.
Any ideas/guidance on this would be greatly appreciated!
Thank for the ideas
In order to calculate volumes for specific areas that I wish to simulate flooding, I first had to isolate/clip those areas of the TIN separately.
The trick here was getting the polygon clip shape correct. It was important that the polygon boundary was on the ridgeline or highest point of the basin extent. If I got this slightly wrong, it would throw out the volume calculations substantially.
For the sake of visualisation, I created some constant rasters to represent various flood heights within the basin (see below).
What I would like to do is calculate the area of the simulated flood extent within the basin i.e. the area inside where the constant plain intersects with the TIN. Any ideas?
The 2D area output by the Surface Volume tool doesn't seem quite right.
I am assuming there is a simple fix here but I have been working on this for a while so am struggling to think outside of the box right now. Any help would be appreciated.
