A Software Application to Obtain the Depth of Closure from Beach Profile Data

Abstract

The depth of closure of the beach profile, from now on termed as DoC, is a key parameter to perform effective evaluations of beach nourishments or coastal defence works. It is defined for a given time interval, as the closest depth to the shore at which there is no significant change in seabed elevation and no significant net sediment transport between the nearshore and offshore. To obtain this point it is necessary to compare profile surveys at a given period of time, and evaluate them to find the point in the profile where the depth variation is equal to, or less than, a pre-selected criteria. In order to manage all this information, a software application has been developed. On providing the input of the beach profiles, this tool offers the possibility of selecting the dates of the desired period of study, graph the profiles and then obtain, for each XY coordinate, all the required parameters, such as offshore distance, maximum, average and minimum depth, standard deviation and area difference between profiles. By evaluating each point along the profile, the DoC can be obtained at that point that meets the criteria. Moreover, this tool allows to graph not only the initial and final profile of the period, but all the beach profiles recorded, creating its maximum and minimum envelope. In addition, if the user introduces the parameters related to the equilibrium beach profile, this tool also corrects the area difference, taking into account the morphological changes (erosion– accretion) that may have occurred during the period studied. In conclusion, this tool has a friendly interface for obtaining the DoC with accuracy by interactive selection of the period of study. It also stores all the information and exports it to different formats.