Sensitivity Analysis of the Moneris Model: A First Step Toward the Model Calibration for the Po Catchment

MONERIS model (Modelling Nutrient Emission in River Systems) was developed in order to estimate the nutrient fluxes present into the river basins deriving from point emission sources and various diffuse pathways. The nutrient fluxes are emitted from both point emission sources (i.e., waste water treatment plants, industrial discharge which directly flowing into the rivers) and diffuse emission sources, these ones represented by the sum of different pathways (atm dep, erosion, tile drainage, surface runoff, groundwater and paved urban areas) of the nutrient fluxes. Along the pathway from the source of the emission into the river substances are governed by different processes of transformations, retention and loss. Knowledge of these processes is necessary in order to quantify the nutrient emissions into the rivers. These processes are influences from different chemical and physical parameters analysed in the sensitivity analysis conducted in the present study. In particular, the overall goal of the MONERIS sensitivity analysis is to study the outcome of the model with changing of the parameters which influence the assess of the nutrient fluxes into different pathways, highlighting those more sensitivity from the others. Moreover, the variations of these parameters on the different processes of transformation, retention and loss connected each others, determine a variation on specific pathway and/or global amount of the nutrient fluxes. The intercomparison of the experimental data with the sensitivity analysis of the model is necessary in order to predict future scenarios of the nutrient emissions.