Project 2 - Analyses of Beach Nourishment

The objective in project 2 is to gain insight in the behavior of local beach nourishments in different localities. Beach nourishment has been used on several occasions on Danish coast and has previously been analyzed in the projects under Nourtec and COADAPT. Analyzes of 4 beach nourishments on 4 different stretches are established and incorporated into the BwN project in order to gain further insight in the nourishment behaviors and effects. Despite variations in morphology the aim has been to analyze within the same analyze frameworks using common parameters, making findings comparable between localities. This makes for a comparison on the results, which can be utilized in a final report in which recommendations on nourishment design can be given.

The localities chosen for analyze is presented in figure 1 and is in short described in the following.

Figure 1 – Showcasing the different areas of interest for each area.

Hald

Hald beach is located in the northern part of Zealand. This stretch underwent an extensive beach nourishment trial in the period 1984-86, where sand was pumped in with ship and redistributed by bulldozers. The objective at the time was to gain insight on beach nourishment behavior, the degree of protection gained and the costs compared to that of the at that time traditional hard constructions. As there is an impressive and in-depth report, with highly detailed descriptions, high spatial and temporal degree of data collected, from which knowledge and know-how can be utilized, the results and findings of this full-scale beach nourishment will be re-analyzed.

Krogen

On the central part of the Jutlandic west coast, the location of Krogen was beach nourished in 2012 with 660.300m³ of sand. Here the nourishment has been placed unevenly on the beach over a 2,4 km stretch with an average nourishment volume of 252 m³/m. This nourishment has already been analyzed under the "COADAPT" project, but it is included here for reanalyses in order to gain further insight, knowledge and know-how on the stretch and the methods used and overall for comparison with the remaining stretches analyzed.

Løkken and Nørlev

Two sand nourishments have been performed at Løkken and Nørlev, both found in the northern part of the west coast. These nourishments are special because they have been placed with dumpers and revetments have been installed in the dune front. In both cases the nourishments have been placed in the dune front on stretches from 340m to 600m. The beaches are measured by the Danish Coastal Authority on several occasions with local transect measurements. These, together with other available climatic data are analyzed to quantify the effect of the sand nourishments and to analyze how the nourishment develops over time.

This project started in 2016 and will be concluded in 2019 and the goal is to present a complete report on the findings and conclusions on the behavior of the beach nourishments, also containing updated suggestions for future beach nourishments.