The San Pedro River is subject to the effect of land use change in its watershed. Originating in the primary forest of the PNT, it flows through a large agricultural area of agro-industrial hevea blocks, palm trees and village plantations, before emptying into the Atlantic Ocean in the urban area of San Pedro. In order to assess the impact of anthropization of its watershed, the San Pedro River was investigated from May 2016 to April 2017. The physico-chemical and ionic variables of the water were collected monthly in three study stations respectively through a multiparameter type Lovibond Senso Direct 150 and miniphotometers brand Hanna. Different statistical approaches (Kruskall-Wallis, Mann-Withney and Principal Component Analysis) were applied to a dataset of 1836 values in order to interpret the spatio-temporal variation of the water quality of this coastal river. Significant spatial variation (p













