Evaluation of the SWAT Model With Respect to Different Variables Within the Tomebamba River Sub-Basin Belonging to the Paute River Basin, Ecuador

Luis Miguel Santillan Quiroga¹, Cinthya Cristina Bravo Morocho², Juan Carlos Caicedo Ballesteros³, and Carlos Rolando Rosero Erazo² 

1. University of Turin, Italy 

2. Escuela Superior Politecnica del Chimborazo, Ecuador

3. Universidad Nacional de Chimborazo, Ecuador

Abstract: The objective of this study is to evaluate the efficiency of the SWAT model with respect to simulations of nitrates, organic phosphorus, dissolved oxygen, sediments and evapotranspiration, taking as reference data observed in continuous monitoring stations. The results showed that the correlation between the simulated and observed data is practically null if a linear relationship were established between them (Pearson correlation coefficient). On the other hand, the simulations overestimated the values of evapotranspiration, dissolved oxygen and sediments; and underestimated the values of nitrates and organic phosphorus, according to the PBIAS%. The RSR statistical criterion indicates that the performance of the modeling is unsatisfactory for nitrates, evapotranspiration and dissolved oxygen; and it is very good for organic phosphorus and the sediments of the Llaviuco station, which was verified with the application of the NSE statistical criterion. It is very important to pay attention to the initial calibration of the model.