A theoretical model to estimate the oil burial depth on sandy beaches: A new oil spill management tool

•A model for estimating the oil burial depth on sandy beaches is proposed.•Tests revealed two different beach profile responses to seasonal changes.•Definition of burial depth depends on this seasonal beach behaviour.•Burial and exhumation can coexist on the intertidal area.•A new tool for oil spill management on sandy beaches is proposed.

In oiled sandy beaches, unrecovered fuel can be buried up to several metres. This study proposes a theoretical approach to oil burial estimation along the intertidal area. First, our results revealed the existence of two main patterns in seasonal beach profile behaviour. Type A is characterized by intertidal slopes of time-constant steepness which advance/recede parallel to themselves in response to changing wave conditions. Type B is characterized by slopes of time-varying steepness which intersect at a given point in the intertidal area. This finding has a direct influence on the definition of oil depth. Type A pattern exhibits oil burial along the entire intertidal area following decreasing wave energy, while the type B pattern combines burial in high intertidal and exhumation in mid and/or low intertidal zones, depending on the position of the intersection point. These outcomes should be incorporated as key tools in future oil spill management programs.