THE ROLE OF ANTHROPOGENIC ACTIVITIES ON WATER QUALITY AND RIVER RESTORATION. A CASE OF MONIK RIVER, ARUSHA-TANZANIA

This study assessed seasonal and spatial variations in physicochemical water-quality parameters in the Monik River and evaluated the influence of anthropogenic activities on river health. Water samples were collected from upstream, midstream, and downstream locations during dry and rainy seasons and analyzed for temperature, dissolved oxygen (DO), electrical conductivity (EC), nitrate (NO3⁻), phosphate (PO4³⁻), pH, total dissolved solids (TDS), turbidity, biochemical oxygen demand (BOD), and chemical oxygen demand (COD). Results indicated significant seasonal variation in most parameters (p < 0.05), with higher turbidity, nutrient concentrations, BOD, and COD observed during the rainy season, primarily due to surface runoff from agricultural and livestock activities. However, most measured parameters remained within WHO and TBS permissible limits, suggesting generally acceptable water quality with moderate pollution levels. Cluster and heatmap analyses further revealed distinct seasonal groupings, identifying potential pollution hotspots associated with nutrient loading and organic matter inputs. The findings highlight the influence of land-use activities on river water quality and emphasize the need for riparian buffer restoration, improved agricultural practices, livestock control, and continuous monitoring to protect and sustain the ecological integrity of the Monik River.