#watercourses

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

Flood hazard prevention plans and watercourse management require a lot of data; the most important is the flood event that will serve as a reference. In practice, this reference flood is often assumed to be the greatest ever known historical flood or the 100-year flood if the latter would be greater than the recorded historical one. The purpose of this paper is to provide some data that help in the elaboration of such plans. Indeed, analysis of severe storms and extreme discharge records in the Saf Saf wadi watershed and statistical data processing (frequency analysis) revealed that the December 28th, 1984 to January 1st, 1985 heavy storm is an exceptional event with respect to the intensity (324mm in 5 days), the magnitude of the generated flood (peak discharge: 754m3/s, flood volume: 75hm3 at the Zardézas dam) and the extent of property damages and human losses (11 dead). Historical data and frequency analysis results show that this deadly well documented event could be a good reference to elaborate flood control and watercourse management plans to reduce vulnerability to flooding in the Saf-Saf wadi basin.