Hi Everyone,
In some computational aspect for scripting or Expression builder in WEAP, I need Reservoir Surface area related to elevation or volume inside the WEAP. I know WEAP calculated area, because it shows the evaporation as a part of the reservoir mass balance. I was just wondering if is it any option or trick to access reservoir surface area? Although, we can estimate the area base on volume and elevation in the corresponding time step, I'm looking for more accurate way if it is possible.
Thanks,
Hossein

Actually, WEAP does not calculate reservoir surface area when it calculates evaporation. WEAP uses the user-entered volume-elevation curve, to translate the reservoir storage (at the beginning of the timestep) to a corresponding elevation, then subtracts the net evaporation depth to get the new elevation, then uses the VE-Curve to translate the new elevation to a new volume. The new volume minus the old volume is the change in volume due to evaporation.

This is documented in the User Guide and online help: https://www.weap21.org/WebHelp/River_Reservoir_Flows.htm

Jack