Geospatial analysis of scour development in offshore wind farms

Scour is one of the most fatal hazards to the foundations of offshore wind turbines. Most of the current research focuses on the formation process and mechanism of scour hole, while there is a lacking of real data monitoring of scour development and real data analysis using data mining techniques and analytical tools for making suitable strategic decisions. In this research, scour phenomenon on a typical offshore wind farm with 72 turbines built on a monopile foundation was inspected consecutively for four times over the course of a year. The geospatial properties of scour, including maximum scour depth, maximum scour extension, scouring and siltation volume were comprehensively analyzed, and the possible autocorrelation between scour data and turbine location was determined using a data-driven decision-making process. The results indicate that the characteristics of the studied scour generally exhibit an upward trend over time, and reflecting strong spatial dependence. Based on local geospatial dependency analysis of maximum scour depth, a High-High gathering area was identified which provides useful clues for making efficient maintenance, protection and planning strategies on specific offshore wind foundations. Formula between average maximum scour depth and inspection time is formulated, which can be used to predict scour development of this offshore wind farm.