10-08-19 HBV model implementation

A new simple conceptual model similar to the original HBV model has been implemented. The Switch HBV Soil model (Model structure group) make it possible to run the new model as complementary to the ordinary Richards equation type of soil that is used in the CoupModel. The new switch may also exclude the use of the Richards equation model Note that the model can use any time resolution but it works on the resolution that is specified by the input file time resolution. Normally daily values can be used and only 1 iteration per day is required to get rapid calculations of the runoff using this module.

The module is defined from 1 soil storage and 2 ground water storage.

Note that the HBV model can be used with snow and various evapotranspiration models but with some restrictions if the Richards equation and the soil heat equations are excluded from the CoupModel. For example in such a case no separate soil evaporation will be calculated. The heat storage will not have any interactions on the evaporation calculations and not either on the snow melt.

The follow variables are added:

State Variables:

Base GW Storage

Peak GW Storage

Soil Storage

Flow Variables

Base Flow

HBV Evap

HBV GW Redist

HBV Input GW

HBV Input SOIL

HBV RunOff

HBV_Input

Peak Flow

Parameters:

BetaCoef

Critical Uptake Frac

Discharge Alfa

Discharge K1

Discharge K2

Field Capacity

Initial Base Storage

Initial Peak Storage

Initial Soil Storage

PMaxPerc