Monitoring impacts of human activities on Bouskoura stream (periurban of Casablanca, Morocco): 1. Physico-chemistry.

Lhoucine BENHASSANE; Mohammed LOUDIKI; Souad FADLAOUI; Abderrahmane Belhouari; Said OUBRAIM

Volume : IX, Issue : I, January - 2019

Monitoring impacts of human activities on Bouskoura stream (periurban of Casablanca, Morocco): 1. Physico-chemistry.

Lhoucine Benhassane, Mohammed Loudiki, Souad Fadlaoui, Abderrahmane Belhouari, Said Oubraim

Abstract :

The Bouskoura stream (periurban of Casablanca) flows through a highly urbanized and industrialized region where agriculture plays an important role. The installation of important industries on the banks of this stream, the pumping of water for the irrigation of vegetables and cereals crops and the illegal dumping of untreated wastewater have a negative impacts on all levels. This work presents a global report on the physicochemical situation of the waters of this hydrosystem. Thus, only upstream and near source stations, thus free from pollution, are still close to their original situation. It is in these stations that the lowest biodegradability ratios (COD / BOD5) were recorded. Stations receiving untreated liquid discharges from industrial zones and/or urban agglomerations (especially those located downstream) have shown a great variability in their results. The impact of polluting discharges in these stations is reflected dramatically for most of the parameters and thus foreshadowing the difficulties of living conditions of the biocenosis in place. The concentrations of most saprobia parameters and trophic status (nitrogen and phosphorus in particular) in these stations exceed the Moroccan standards for surface water quality and the stream is thus transformed into an open sewer. The Organic Pollution Index (IPO) has been used to assess organic pollution to to assess the organic pollution in the different stations of Bouskoura stream and has highlighted sections of the watercourse with suspicious health conditions that are in poor to very poor quality classes The typological analysis using principal component analysis (PCA), performed on the averages of the 13 physicochemical parameters recorded in 8 stations, has shown that the hydrochemical situations thus identified are ordered according to a gradient of saprobia (upstream– downstream) represented by the first principal component and a trophic and biodegradation gradient represented by the second component