This work aims to design a hydraulic model to know the current operation of the drinking water supply network for Korhogo city and to carry out corrective simulations to improve it. To achieve this, we used the EPANET software, to design and simulate the hydraulic model operation using the equal staffing method at each Request Node (DEN). In addition, based on an annual growth rate of 2.08%, the population of the city of Korhogo as well as the total water needs were estimated for different horizons and staffing scenarios. The results indicate that the overall average needs of the city in drinking water for an endowment 45 l/j/ hab. are respectively 678 m3/h for 2020, 750 m3/h for 2025, 830 m3/h for 2030, 1020 m3/h for 2040 and 1252 m3/h for 2050. The simulation of the network with the current injected flow which is 100 l/s, highlight some pressure and speed anomalies. Indeed, the network presents several negative or no conform pressures and unsatisfactory speeds (lower than 0.5 m/s and higher than 2 m/s). The network is apparently undersized and cannot meet the current and future needs of the city. Corrective simulations for optimal network operation until 2030 suggest positive pressures and speeds throughout the city with an endowment of 45 l/j/hab.

Fractured aquifers of gneiss are the main drinking water sources for population living in the north area of Alépé. Neglecting geochemical monitoring of such groundwater is able to deliver water consumers taking unacceptable risks. The quality of water from bedrock in terms of taste can lead people to drink surface water whose chemical quality is lower in comparison with the reference quality. The aim of this study is to estimate the major cations concentration of gneiss groundwater in which mineralization was almost due to silicate hydrolysis. To achieve the aim in view, a study of main mineral of the gneiss aquifer was carried out and a geochemical simulation through inverse modeling by PHREEQCI code was applied on water rock process. The study showed that the main silicate minerals of gneiss that contained major cations were albite, K feldspar, plagioclases and amphibole. The dissolution mean rates of minerals able to increase groundwater mineralization by hydrolysis were 1.3 x 10-5 mol L-1 for K-feldspar, 3.8 x 10-4 mol L-1 and 1.0 x 10-4 mol L-1 for oligoclase and amphibole (ferro-tshermakite), respectively. Through these results, it shown that oligoclase would be the mineral more favourable for hydrolysis among feldspars studied in the gneiss. In gneiss groundwater, sodium was mainly supplied by oligoclase, potassium was supplied by K-feldspar and ferro-tshermakite, magnesium was supplied by ferro-tshermakite only and calcium was supplied by oligoclase and ferro-tshermakite.