Multi-Epoch Geospatial Assessment of Seabed Topography and Sediment Dynamics forOil Pipeline Integrity in the New Calabar River, Nigeria
Abstract
Subsea infrastructure in dynamic riverine and estuarine environments is highly vulnerable to instability caused by tidal currents, sediment transport, vessel anchorage, and channel morphology changes. The New Calabar River in the Niger Delta is a tidal-influenced system characterized by high hydrodynamic energy and significant morphological variability, posing considerable risks to the long-term integrity of buried oil pipelines. Insufficient burial depth combined with strong currents can lead to pipeline exposure, lateral displacement, or structural failure, with serious implications for navigation safety and environmental sustainability.
This study evaluates seabed topography and sediment dynamics to assess their impact on pipeline stability. A quantitative approach based on acoustic survey principles was adopted. Bathymetric surveys were conducted in 2018 and 2024 using a GNSS receiver for positioning and a single-beam echo sounder for depth measurements, covering a 3 km by 0.55 km section of the river. Results from 2018 indicate depth values ranging from -3.47 m to -17.204 m, with shallow zones reaching -3.47 m. In 2024, depths ranged from -1.37 m to -19.06 m, with the shallowest area at -1.37 m, indicating notable sediment redistribution and morphological change over time. Digital Terrain Models (DTMs) generated for both survey periods provide spatial evidence of these seabed variations. The findings highlight the susceptibility of oil pipelines to hydrodynamic forces and seabed evolution in tidal river systems. By integrating geospatial monitoring into infrastructure risk assessment, this study supports sustainable energy security (SDG 7), climate resilience (SDG 13), protection of aquatic ecosystems (SDG 14), and responsible resource management (SDG 15). Overall, the research underscores the importance of geodetic and hydrographic techniques in informing evidence-based strategies for the safe and sustainable management of subsea infrastructure in the Niger Delta.
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