Cross-over analysis of the climate-change delta situation of the cities Gdansk (Baltic-sea) and Rotterdam (Nord-sea)

Gdansk and the city Haarlem in the Netherlands share a long-term relationship that started with the establishment of Dutch Mennonites in the Vistula delta in the 16th Century. A small city was founded called Holland and these immigrants reclaimed the surrounding delta area. This area of 1,000 km 2 , with hundreds of small ‘polders’ separated and defended by 17,000 dikes, has become an important agricultural area for the whole of Poland, similar to the Rhine delta in the Netherlands. Despite these civil defense works in the past, both coastlines nevertheless experienced floods: the Dutch southwest coast in 1953, Dutch Rhine riverbank in 1993 and 1995, and Vistula delta recently in 2001. Climate change figures show that both the Polish Gdansk and Dutch Rhine deltas will suffer flooding with sea level rises, with accumulating severe rainfall accompanied by high river levels. Although both the Baltic Sea and the North Sea are next to each other and coupled to the Atlantic Ocean, there are differences in how soon or severely climate change trends, such as seawater level rises and water thrust, become critical. From cross-over analysis it can be concluded that Poland and the Netherlands have a virtually identical approach when it comes to climate change impacts on their current situation. With regard to long-term climate change, the Netherlands is exploring the future in a planned manner with the development of new scenarios for the protection of cities. The enclosure of the Baltic Sea, on the other hand, probably offers more options for exchanging knowledge with neighbor states. In that respect, the Netherlands is more isolated in their situation with the North Sea and its Delta Plan. The situation of Gdansk and Rotterdam is quite similar; these cities can take steps forward by learning from each other’s actions.