## 5 Conclusions  
Considering the criteria for evaluating the flow setting, we note that the SWAT model is capable of simulating transfers in the Lobo watershed at Nibehibe. The evaluation criteria R2, NSE, and PBIAS had values of 0.63, 0.62, and \(-8.1\), respectively. P-factor P and R-factor gave 0.48 and 0.52. On the basis of these values obtained, it appears that the SWAT model is indicated for the simulation of flows and nutrient transfers in tropical agricultural watersheds, in particular that of the Lobo. The estimation of the average quantities of N and P applied to the crops gave 47.24 kg ha\({}^{-1}\) of N and 21.25 kg ha\({}^{-1}\) of P. The flows of inorganic N and soluble P vary from 0 to 0.049 kg ha\({}^{-1}\) for inorganic N and from 0 to 0.31 kg ha\({}^{-1}\) for soluble phosphorus. The northern and southern parts of the basin are more vulnerable to a large input of inorganic N when the central part remains vulnerable to the soluble phosphorus transfer. Simulations relating to the organic N transfer revealed values ranging from 0.2 to 5 kg ha\({}^{-1}\), the southern part showing the highest fluxes. As for the flow of organic phosphorus, they vary from 0.3 to 1.3 kg ha\({}^{-1}\). Unlike organic N, the greatest amounts are observed in the north. By comparing the flows of mineral (inorganic) nutrients with those of organic nutrients, one can say that the eutrophication observed in the Lobo water reservoir (sub-basin 29) would mainly have an exogenous origin (domestic, etc.) and organic. Predictions of nitrates concentrations and soluble phosphorus in the stream made using the SWAT model revealed concentrations of nitrates between 14 and 30 mg L\({}^{-1}\) and soluble phosphorus between 0.1 and 1.8 mg L\({}^{-1}\). Field measurement points with high concentrations usually fall in areas of the stream with high concentrations simulated by SWAT. Apart from the limitations of this study related to the quality and quantity of the input data, it allowed us to gain a spatial understanding of the evolution and distribution of nutrients in the watershed. It also made it possible to identify the major inflow areas that would further contribute to eutrophication in the Lobo reservoir. To limit the impact of eutrophication on watercourses, it is necessary to regulate the use of fertilizers and phytosanitary products. In areas of high nutrient supply, it would be essential to implement vegetative filter strips around water bodies in order to capture the nutrients flow coming from upstream. These results constitute a solid basis which can serve as a basis in the fight against the phenomenon of eutrophication of water bodies in the watersheds of Cote d'Ivoire.  
Conceptualization, T.J.-J.K. and R.S.; methodology, T.J.-J.K.; software, R.S., T.A.A., Y.D. and J.J.; validation, T.J.-J.K., R.S. and Y.D.; writing--original draft preparation, T.J.-J.K.; writing--review and editing, T.J.-J.K., R.S. and J.J.; supervision, J.J.; project administration, J.J.; funding acquisition, T.J.-J.K. All authors have read and agreed to the published version of the manuscript.  
This research was funded in part by J. William Fulbright Foreign Scholarship program, grant number PS00285574.  
Not applicable.  
Informed Consent Statement: Informed consent was obtained from all subjects involved in the study.  
All the data used in this paper can be traced back to the cited references.  
I thank the J. William Fulbright Foreign Scholarship program which granted me a scholarship to carry out part of this study. I acknowledge the support given by The Spatial Science Laboratory at Texas A&M University (TAMU) in College Station (Texas) that provided me with an office, a computer, and assistance for this study during my Fulbright mobility.  
The authors declare no conflict of interest.