Impact of El Abid River Basin Loads on Water Quality of the Bin El Ouidane Lake-Reservoir, Morocco

摘要

This study had two aims. Firstly, it aimed to analyze the transport of suspended matter (S.M.) and nutrients (nitrogen, phosphorus and silica) by flood water in the El Abid river basin and to establish the S.M. and nutrient loads discharged into the Bin El Ouidane lake. It then tried to assess the influence of flood transport on phytoplankton evolution and on physico-chemical parameters at the entrance of the Bin El Ouidane lake during three contrasting hydrological years ; 1995, 1996 and 1997 : 1995 had below average precipitation in 1995, 1996 was a very wet period while 1997 was a semi-humid period. Flood periods affected the level of nutrients at the lake entrance through influencing sediment run-off rates and dilution levels, and consequently S.M. and nutrients. Suspended and dissolved loads in the river influenced phytoplankton development. There was a greater density of algae in 1996 than in 1997. The absence of phytoplankton in 1995 was due to the dryness of this period.