LISFLOOD calibration is performed on 14 parameters using an evolutionary optimisation algorithm (EA) with the modified Kling-Gupta Efficiency (KGE') as objective function (Kling et al., 2012). The selected parameters relate to overland and groundwater processes as well as channel routing and snow melt and are listed in following table. Feasible parameter ranges were defined for each parameter used in calibration to obtain more physically realistic calibrated parameters. Additional parameters were used to calibrate reservoirs and lakes.
SnowMeltCoef | Snow melt rate in degree day model equation [mm/(C day)] | M | 2.5 | 6.5 | 4 |
b_Xinanjiang | Exponent in Xinanjiang equation for infiltration capacity of the soil [-] | INFact | 0.01 | 5 | 0.5 |
PowerPrefFlow | Exponent in the empirical function describing the preferential flow (i.e. flow that bypasses the soil matrix and drains directly to the groundwater) [-] | Dpref,gw | 0.01 | 8 | 4 |
UpperZoneTimeConstant | Time constant for upper groundwater zone [days] | Qugw | 0.01 | 40 | 10 |
GwPercValue | Maximum percolation rate from upper to lower groundwater zone [mm/day] | Dugw,lgw | 0.01 | 2 | 0.8 |
LowerZoneTimeConstant | Time constant for lower groundwater zone [days] | Qlgw | 40 | 10000 | 100 |
LZThreshold | Threshold to stop outflow from lower groundwater zone to the channel [mm] | Qlgw | 0 | 30 | 10 |
GwLoss | Maximum loss rate out of lower groundwater zone expressed as a fraction of lower zone outflow [−] | Qlgw | 0 | 0.5 | 0 |
QSplitMult | Multiplier to adjust discharge triggering floodplains flow [-] | Qch | 0 | 20 | 2 |
CalChanMan1 | Multiplier for channel Manning's coefficient n for riverbed [−] | Qch | 0.5 | 2 | 1 |
CalChanMan2 | Multiplier for channel Manning's coefficient n for floodplains [−] | Qch | 0.5 | 5 | 1 |
adjust_Normal_Flood | Multiplier to adjust reservoir normal filling (balance between lower and upper limit of reservoir filling). [-] | Qres | 0.01 | 0.99 | 0.8 |
ReservoirRnormqMult | Multiplier to adjust normal reservoir outflow [−] | Qres | 0.25 | 2 | 1 |
LakeMultiplier | Multiplier to adjust lake outflow [−] | Qlake | 0.5 | 2 | 1 |
Table 1 - A list of LISFLOOD calibration parameters for EFAS v4.0.