BATHYMETRIC SURVEY TO DETERMINE THE BOTTOM MORPHOLOGY

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 in and out of the Jetty, as well as to allow for well-informed, proactive measures to be taken to increase the bottom depth when the need arises. This project, 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 within the Jetty. 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 distribution across the sea bed. Hypack Navigation Software was used for previewing, analyzing and displaying depth data in relation to sounding lines. Further processing was carried out with the aid of ArcGIS 10.8 software, for creating map layers and evaluating relationships between mapped features and regions of the Surveyed area, Surfer 10, for creating topographic profiles of the bottom of the river as well as dimensions, and Microsoft Excel, for sorting, organizing and managing the large quantity of depth data acquired on site. On completion of data analysis, contour map, Digital Elevation Model (DEM), and 3D surface map of the bottom morphology at the Jetty were produced.