Assessment of the Physico-Chemical Pollution of a Water Body in a Perspective of Integrated Water Resource Management: Case Study of Nokoué Lake

Abstract

Nokoué Lake is the most important surface of brackish waters of Benin and one of the biggest West African lagoons, in point of view of its surface (about 150 km 2), its productivity and exploitation. The aim of this study is to monitor the temporal and spatial variation of physico-chemical parameters of Nokoué lake water for its sustainable management. A total of twenty (20) points of sampling have been followed during a period of one year. The results of the monitoring reveal low dissolved oxygen and high concentration in phosphorus and chlorophyll a, sign of eutrophication. In addition, nutrient concentrations (nitrites, phosphates, nitrates) responsible for the phenomenon compared to water quality assessment grid of the Organisation for Economic Cooperation and Development, (OECD) used to classify the waters in the range of hyper-eutrophic waters characterized by the proliferation of aquatic plants. So some measures have been proposed to reme-diate to this pollution in order to an integrated management.