Bathymetric Mapping And Channel Depth Evaluation of Part of Marina/Badagary Channel, Lagos State Nigeria

Abstract

Accurate bathymetric mapping is essential for ensuring safe navigation, planning maritime infrastructure, and managing coastal environments. The Marina/Badagry Channel in Lagos State, Nigeria, plays a crucial role in water transportation, yet limited and outdated depth data have hindered effective channel maintenance and navigation safety. This study employed a combination of single-beam echo sounding and GNSS positioning systems to evaluate the depth characteristics of a section of the channel. Data acquisition was conducted during low tide conditions to capture reliable measurements, and depth values were spatially analyzed using GIS-based interpolation techniques. The results revealed four depth classes: Shallow, Moderate, Deep, and Very Deep, with each class supporting varying levels of marine activities. The shallow areas, covering 34.49% of the total channel area, are prone to sediment deposition and may require dredging for navigability, particularly for larger vessels. Moderate depth zones support medium-sized vessels and balance sediment dynamics, covering 24.18% of the area. The deeper zones, which make up 41.31% of the channel area, enhance its capacity to handle larger vessels, reducing the need for extensive dredging. These findings provide critical input for dredging decisions and marine infrastructure planning. The study underscores the importance of regular hydrographic surveys for sustainable inland waterway management in Nigeria.