3. Results and discussion3.1. Temporal trends in water quality index (Y) and year of (X)For each dependent variable (Y, WQI), the coefficient-of-determination of the corresponding linear regression modelon year of measurement (X) (R2%), the unstandardized (B) regression coefficient and the statistical significance (P)are shown.3.1.1. Drains discharging to Lake ManzalaCCME WQI values of Bahr ElBaqar Drain indicated that water quality for aquatic uses could be related as poorto marginal (Fig. 4). The temporal trend significance increases (P < 0.05; Table 3). Unstandardized (B) regression