Developing a seabed resurvey strategy: A GIS approach to modelling seabed changes and resurvey risk

There has been a steady transition towards the representation, analysis and modelling of dynamic spatio-temporal relationships in geographical information systems (GISs). These developments open up opportunities for investigating and modelling the dynamic relationships that occur in the coastal and marine environments and how these relate to human activities. Such a spatio-temporal approach is applied in this research to address an issue faced by the bodies responsible for maintaining navigation safety in territorial waters and this paper introduces the developed resurvey decision support system. The developed system models morphological change in response to hydrodynamic conditions and determines the seabed locations that require resurvey based on the modelled change and navigation characteristics. System validation tests indicate that the morphological modelling tool is under-predicting the magnitude and lateral extent of the change which then influences the locations that require resurvey. Additional sensitivity tests of the morphological modelling parameters highlight the influence of the parameters on the outputs and derived predictions. The achieved modelling results and resurvey decision indicate the applicability of utilising a GIS to model seabed change as an input into decision support systems for planning and management purposes. The results also suggest the applicability of the modelling and decision support methodology to similar problems in the coastal and marine environments.