The Effects of Riparian Deforestation on Stream Water Quality in Taraba State, North East Nigeria

Riparian vegetation zones serve as critical buffers that regulate sediment delivery, nutrient loading, and thermal conditions in stream systems, and their removal through agricultural expansion and firewood extraction exposes watercourses to accelerated degradation. This study investigates the effects of riparian deforestation on stream water quality in two river catchments in Taraba State, North East Nigeria. Paired catchment methodology was employed, with one deforested and one comparatively intact riparian corridor selected for each of two river systems. Water quality parameters including turbidity, total suspended solids, nitrate, phosphate, dissolved oxygen, and temperature were measured at upstream and downstream stations in both catchment types across wet and dry season sampling campaigns. Riparian vegetation cover was assessed using Sentinel-2 imagery and field transect surveys. Results demonstrate significantly elevated turbidity and suspended sediment loads in the deforested catchment compared to the intact riparian corridor during rainfall events, with peak post-storm turbidity values exceeding WHO guidelines by a factor of twelve. Dissolved oxygen levels are consistently lower in deforested stream reaches, with implications for aquatic biodiversity. The thermal buffering capacity of intact riparian canopy is evidenced by temperature differentials of 2.8 degrees Celsius between intact and deforested reaches during dry-season low-flow conditions. Recommendations address enforcement of riparian buffer zone regulations, community-based reforestation incentives, and integration of riparian management into Taraba State's watershed management plans. Keywords: riparian deforestation, stream water quality, turbidity, Taraba State, watershed management.