Table 3: Nitrogen load model calibration.

ParameterDefault valuesSUFI-2 estimated values
MinMaxNew minNew maxFitted value valuea (sensitivity analysis)

RCN0.0015.007.09821.32714.2120.000***
NPERCO0.011.000.4761.4100.9430.000***
BIOMIX0.001.00−0.2120.5970.1920.000***
UPDIS0.0050.0014.00024.70019.3000.001***
AI10.070.090.0840.1120.0980.268
RSDCO0.021.000.0480.1060.0770.379
CDN0.003.000.8802.6451.7620.822

Statistical summary of the calibration procedure
ConstituentPeriod -factor -factor NSEPbiasRSR

N organicMar-1999/Aug-19990.431.010.880.6021.160.63
Nitrates and nitritesMar-1999/Aug-19990.680.790.850.5342.490.69

Monitoring point: USGS 0357479650; RCN: concentration of nitrogen in rainfall; NPERCO: nitrogen percolation coefficient; BIOMIX: biological mixing efficiency; N_UPDIS: nitrogen uptake distribution parameter. ***99% confidence intervals. aprobability of the test statistic of the coefficients obtained by regressing the Latin hypercube parameters, generated during the calibration procedure and against the objective function values [23].