Width of dry beach (pilot areas) Dry beach width expressed in metres calculated for three research sections using the XBeach model

The width of dry beach is linked directly to the extent of beach inundation. It shows the distance between the maximum extent of run-up and the dune base (Fig. 1). This index is expressed in metres.

Fig.1 Diagram showing the width of dry beach  Fig.2 Tourist infrastructure on the beach near the Dziwnów Spit (Mierzeja Dziwnowska).

Methodology

The dry beach width index in the SatBałtyk System is defined on the basis of the maximum swash run-up, calculated using the XBeach prognostic model. Then the distance between the maximum extent of swash run-up and the dune base is calculated. The position of the reference point on the dune base is based on field measurements using GPS RTK.

Validation

The accuracy of the width of dry beach is estimated by comparing the width of dry beach calculated using the prognostic model with the width of dry beach  determined from photographs taken by the camera installed at Dziwnówek on the Dziwnów Spit or from photographs/films taken by the cameras recording incoming waves during a short storm event in 15-minute series for the Jamno and Bukowo Spits and the Hel Peninsula. The statistical error, i.e. the mean difference between measured values and those calculated using the model, is ca 5.9 m, which is 16.4% of the width of the test beach at Dziwnówek. More information: validation of the width of dry beach .

Interesting phenomena

This index permits one to assess the threats and risks associated with extreme values of beach inundation. It will significantly improve the safety of persons using the beach and reduce  possible financial losses incurred as a result of damage to tourist infrastructure (buildings), which is often erected on the beach itself (restaurants, inflatable air bags for jumping, slides, beach football pitches etc. (Fig. 3)

Link to the parameter in SatBaltic System:

Width of dry beach  (pilot areas)