Aggregated Reservoir Variables - HBV emulation

[jwtrubil]

I am setting up a model that generally follows the HBV methods for subsurface flow. However, I'd like multiple subbasins to calibrate to internal gauges. Help me understand the aggregated fast and slow reservoirs a little better. If I have multiple subbasins, do I want to aggregate by subbasin? Not aggregate at all? When I aggregate all HRUs, I get the same fast and slow reservoir flow in all reservoirs, which I don't think is correct.

[rchlumsk]

Hi there

I am not too familiar with the HBV model, but I believe that the SLOW_RESERVOIR and FAST_RESERVOIR are aggregated for each HRU in the model, as per the template on page 141 of the manual. This means that the soil storage layers called SLOW_RESERVOIR and FAST_RESERVOIR are essentially treated as one unit is in the model (across all subbasins/HRUs), rather than each HRU with its own separate storage unit. There is still value added with multiple HRUs in the handling of all other processes, such as infiltration, potetntial evapotranspiration, etc., which can still be modelled differently in each spatial unit.

Whether you aggregate the variables depends somewhat on whether you want to emulate the HBV model closely or just use some of the processes from the HBV model, in which case the aggregation may not be necessary.

Hope that helps, please let me know if there is anything else that is unclear.
Cheers,
Rob