Journal of Geography, Environment and Earth Science International

Shorelines are highly dynamic boundaries where land meets water, continuously reshaped by natural forces such as waves, tides, currents, and sea-level rise, as well as human activities including sand mining, dredging, and coastal development. The study assessed the shoreline dynamics of a section of the Forcados River, Nigeria, using the digital shoreline analysis system. This study investigates the shoreline dynamics of a section of the Forcados River in the Niger Delta, Nigeria, over a 20-year period (2004–2024). This study assessed the Spatio-temporal variations in the shoreline of a specific segment of the Forcados River, specifically around the Patani Bridge in the Niger Delta region of Nigeria. It focuses on three key time periods: 2004, 2014, and 2024. Employing advanced geospatial techniques and the Digital Shoreline Analysis System (DSAS), the research seeks to quantify and visualize shoreline changes across these epochs. Multi-temporal satellite imagery, Landsat and Sentinel-2, were acquired and processed to delineate shoreline positions for 2004, 2014, and 2024. Pre-processing steps included radiometric and geometric correction to ensure accuracy and consistency across epochs. To enhance shoreline detection, the Sobel edge detection filter was applied in IDRISI TerrSet, after which the shorelines were digitized, exported in GeoJSON format, and integrated into DSAS for quantitative analysis. The results revealed significant spatial and temporal variability in shoreline behaviour, characterised by alternating zones of erosion and accretion. On the north side of the bridge, erosion was dominant, accounting for approximately 31.53% (409,772.22 m²) of total shoreline change, while accretion covered only 10.43% (135,591.04 m²). Conversely, the south side exhibited strong accretion, with 46.75% (607,489.07 m²) of total change, compared to erosion of 11.29% (146,708.48 m²). In the northern section, 35.8% (EPR) and 37.66% (LRR) of transects recorded accretion. Similarly, the southern section showed accretion at 28.36% (EPR) and 28.79% (LRR). Transect-based analyses using End Point Rate (EPR) and Linear Regression Rate (LRR) confirmed these trends, with erosion hotspots concentrated along the north bank and major accretional zones dominating the south bank. The study underscores the relevance of geospatial technologies in shoreline monitoring and provides evidence-based insights to support adaptive management, conservation strategies, and sustainable coastal planning in the Niger Delta. This study has provided an evidence-based understanding of the shoreline dynamics of the section of the Forcados River, offering insights that can guide future interventions aimed at preserving riverbank stability, protecting infrastructure, and ensuring sustainable use of the river environment.