Problem setting
The peninsula is a sandy strip of land with the majority of the area lying below 2.5 m. It is 34 km long and its width varies from about 200 m in the narrowest part to over 3 km at the tip. This spectacular land constitutes a part of the coastal landscape park and is a famous recreational resort for the Polish and foreign tourists. A road and a railway run along the peninsula from the mainland to the town located at the furthest point, Hel, a popular tourist destination. The Hel Peninsula is an example of the area with several mutually related coastal zone management problems in Poland. Erosion has become a serious problem since the construction of a harbour westwards of the Peninsula in 1936 – 1937. The harbour development has aggravated the situation. Since the Peninsula is very narrow it may be turned into an island by winter storms. Sand is supplied in large quantities to beaches to avoid breaching the Hel Peninsula.

Application of the frame of reference approach
The project aims at implementing EUROSION concepts into measurable standards, which can be used and evaluated in practice for any field situation. According to the concept, coastal erosion is a result of a sediment imbalance occurring in a coastal sediment cell. The other key concepts are coastal resilience as a strategic objective, a favourable sediment status as an operational objective and a strategic sediment reservoir as a management goal. Suitable Coastal State Indicators (CSI’s) are developed that can link scientific knowledge, measurements and modelling results to these management concepts.

Strategic objectives
In the case of the Hel Peninsula the preservation of its coastal system has been selected as the strategic objective.

Operational objectives
The selection of strategic objective implies definition of two operational objectives:

• maintaining the beach width,
• preserving breaching.

Coastal sediment cell
The analysis indicates that the natural processes responsible for the erosion along the Hel Peninsula and affecting the management of the coast zone are longshore sediment transport and storm-induced erosion. These two processes have different time and spatial scales. The area affected by the longshore transport covers the whole coastline of the Hel Peninsula (34 km) and the time scale involved counts in decades. The storm-induced erosion is a short event that lasts several hours and affects certain parts of the Hel Peninsula coastline in the order of kilometers.

Hel Peninsula case study in the spatial – temporal plane.

Having defined the objectives and processes, the coastal cell boundaries can be established. According to the coastal sediment cell definition, it contains a complete cycle of sedimentation including sources, transport paths and sinks. The coastal sediment cell must include all coastal processes defined for the Hel Peninsula. Accordingly, the western cell boundary constitutes the breakwater of Wladyslawowo harbour that is impermeable for sand and a short section of the open sea that can take part in the transfer of sediment in the cell. Northern boundary of the coastal cell is an open sea boundary. The eastern boundary is located at the tip of the Hel Peninsula.

Sediment fluxes in the Hel Peninsula coastal cell.

In the presented coastal sediment cell natural processes as well as artificial nourishment are taken into account. The main cause of sand deficit in the cell is a negative balance in the longshore sediment transport in the long-term temporal scale.

Strategic sediment reservoirs
An important process that has to be taken into consideration in the coastal cell is the artificial nourishment. This process requires determination of a strategic sediment reservoir for nourishment activities. In the case of Hel Peninsula sand can be supplied from:

• the entrance channel to the Wladyslawowo harbour,
• offshore areas,
• Puck Bay and Gdansk Bay (under certain conditions).

Quantitative State Concept
Suitable Coastal State Indicators must be defined in the applied approach to link scientific knowledge, measurements and modelling results to management concepts. An analysis of available reports regarding erosion problems indicates that there is a set of parameters, which can be applied in the management of the coastal zone for the Hel Peninsula:

• beach width: 30-40m
• beach height: 1.5-2.0m
• dune width: 40m
• maximum dune height: 4.5m
• dune section area: 180m²
• hinterland height: 2.5m

Update activities and recent research findings

• Conference paper prepared and presented on The 7th International Symposium on Ecohydraulics 2009 – January 2009,
• The new bathymetry and shoreline evolution data were collected and are being analysed,
• Wave measurements campaign - the wave buoy was placed near the tip of Hel Peninsula at 20 meters depth in October 2008. The data from measurements are being analysed.
  

Favourable sediment status and coastal resilience
Collected data indicate complexity of the processes undergoing along the Hel Peninsula. To achieve the strategic objective more information and long-term data are necessary. In particular, long-term data regarding the rate of the sediment flux due to a longshore transport, cross-shore transport, and artificial nourishment. All these activities are necessary to identify a favourable sediment status that can promote coastal resilience and, in consequence, to achieve the strategic objective.