Assessment of the Surface Water Quality of Ibrahim River (Lebanon): A Spatio-Temporal Analysis

Monitoring surface water quality offers a clear understanding of its parameters over time and space. The Ibrahim River, one of the main rivers in Lebanon, was monitored over one hydrological year, from March 2021 to April 2022. Samples were collected from seven stations in the watershed, once every two weeks. A total of 504 samples were then analyzed for pH, conductivity, turbidity, total dissolved solids, dissolved oxygen, biochemical oxygen demand, dissolved nitrate, dissolved potassium, dissolved chloride, total alkalinity, fecal coliforms, and total coliforms. Principal Component Analysis (PCA) was able to highlight two principal components (PCs), representing spatial and temporal variations, identifying areas of pollution and the influence of flow on water quality. The adapted Water Quality Index (WQI) confirmed the PCA trend with an overall average for the entire watershed of 83.70 ± 4.97, indicating a “good” water quality.