Satellite-based Bathymetric Survey case Study of Dunga Beach in Lake Victoria

Abstract

Bathymetry surveys are essential for understanding the topography and morphology of underwater environments, aiding in key applications such as marine navigation, habitat mapping, environmental monitoring and resource exploration. Accurate Bathymetric maps aids in safe navigation, effective coastal management, protection of marine ecosystem and supports scientific research and explorations. Traditional methods for bathymetric mapping, such as sonar and lidar, remains very important and reliable in terms of accuracy. It provides precise measurements of water depths and seabed features, making it crucial for navigation, charting, and understanding underwater topography. However, this technology can be costly and time-consuming, especially for large and remote inaccessible areas. There has been an increasing amount of attention in the use of satellite-based bathymetric survey that taps the potential of satellite imagery to estimate depths of water in the past few years. This method takes advantage of optical properties of water and depth that allow to provide a cheaper and more efficient means for bathymetric measurement, especially in shallow and optically clear waters. However, Satellite-Based Bathymetric survey faces a challenge relating to accuracy. This project therefore, explores Satellite-Based Bathymetric survey methods of estimating depths, compare its accuracy and reliability. The given project involves testing existing algorithms of remote sensing bathymetric modeling using the case study in order to evaluate the accuracy of the method and to demonstrate the reliability and practicability of large-scale bathymetric mapping. The case study of this project is Dunga beach in Lake Victoria. Sonar bathymetry of the area was done to facilitate establishment of a search and rescue centre by Kenya Maritime Authority (KMA). Sonar Bathymetric data forms the in-situ measurement data used to train samples with the two models Lyzenga and Stumpf algorithms. Lyzenga model bests fit the case study with better accuracy as compared to Stumpf model. The findings indicate that satellite-based methods can provide reliable bathymetric data for large-scale mapping, with accuracy levels comparable to traditional methods, but at a reduced cost and increased efficiency. These results suggest that satellite-based bathymetric surveys are a viable alternative for regions like Lake Victoria, where traditional methods may be challenging to implement due to budget and time constraints.