The Lobo River reservoir, the main source of drinking water supply for the municipality of Daloa, is facing a deterioration in its quality. This study aims to assess the quality of this resource. The physico-chemical and chemical parameters of this water were determined during the two seasons of the year 2020. The methodological approach consisted firstly of characterizing the water in the reservoir in relation to the WHO guide values; secondly, determining the phenomena that govern the mineralization of this water and, thirdly, calculating the organic pollution index (OPI) and the water quality index (WQI) of the reservoir. The results show that the physico-chemical parameters (T, pH and EC) comply with the WHO guide values. However, the water has a high turbidity, with a very strong colour in all seasons. Phosphate (0.93 mg/L), ammonium (1.48 mg/L), total iron (2.99 mg/L) and manganese (0.66 mg/L) concentrations are high. On the other hand, chlorides, nitrates and nitrites remain low in both seasons. On the other hand, chlorides, nitrates and nitrites remain low in both seasons. Normalized Principal Component Analysis (NPCA) revealed that the mineralization of this water is of natural and anthropogenic origin. The water quality (2.25 to 3.25) and organic pollution (429.73 to 693.31) indices show that the water in the reservoir is unfit for consumption, with moderate pollution in the dry season and heavy pollution in the rainy season.

Like the West African countries, the Sassandra river basin limited at Soubré is facing the challenges of climate change. Seen anthropogenic activities have contributed to modifying the climate in a sustainable way, it is important to have as clear an idea as possible of possible climate changes. The main objective of this study is to characterize the variability of climate parameters in order to sustainably manage its impacts on basin development projects. So, the methodology adopted is divided into 2 steps: the characterization of climate variability and the characterization of climate change to 2030 and 2050 horizon. The results of climate variability showed a decrease in rainfall and an increase in temperatures. In terms of climate change, under scenario RCP4.5, minimum and maximum temperatures are projected to increase by 1.4°C to 1.8°C by 2030 and 2050. At the same horizons and under scenario RCP8.5, there is an average increase of 1.4°C to 2.4°C. In terms of annual rainfall, projections show an upward trend of 1% by 2030 and a downward trend of 1% by 2050 under the RCP4.5 scenario. The scenario RCP8.5 predicts an increase in precipitation with rates greater than 35% at both future horizons.