Bathymetric Survey for Determination of Bottom Morphology at Niwa Dockyard Jetty, Warri, Delta State

Abstract

Maintaining adequate depth at jetties involves periodic determination of the bottom morphology to ensure that the water capacity and depth around the jetty is sufficient for safe navigation of vessels. This study which was carried out at NIWA Dockyard Jetty, Warri, Delta State, Nigeria, was aimed at producing a chart showing the variation of bottom depth of the river bed. Acoustic method of depth determination was utilized. Positioning of the Echo Sounder was done using a Hemisphere V200s GNSS receiver for determining the geospatial position of the distributed depth values; a South SDE-28 Single-beam Echo Sounder was utilized in determining the depth. Hypack Navigation Software was used for previewing, analyzing and displaying depth data in relation to sounding lines. Further processing was carried out with ArcGIS 10.8 software, for creating map layers and evaluating relationships between mapped features and regions of the Surveyed area, Surfer 10,was used for creating the topographic profiles of the bottom of the river as well as dimensions. On completion of data analysis, contour map, Digital Elevation Model, and 3D surface map of the bottom morphology at the Jetty were produced. The result of the bathymetric survey showed that the lowest sounded depth was 0.30m and the highest was 15.80m. A total of 772 sounded depths were obtained. The result of analysis further showed that only limited areas within the Jetty had sufficient depth to provide enough clearance for vessels