Climate responsive spatial research by design - A case study analysis on the coastal area of Flanders

In search of alternative adaptation strategies for the Belgian coast: Low-lying coastal zones are highly vulnerable to climate change and coastal protection attracts special attention within adaptation planning. The Intergovernmental Panel on Climate Change (IPCC) defined an international framework describing three strategies within coastal adaptation practices; protect, retreat and accommodate (IPCC CZMS 1990; Klein and Tol 1997). In Flanders the Coastal Division of the Flemish government recently developed the Master Plan for Flanders Coastal Safety to assure the necessary protection
until 2050 (Afdeling Kust 2011). This master plan lists different measures, e.g. elevated dikes and beach nourishment, all within the protect strategy...

Climate related challenges at the Belgian coast: Sea level rise dominates the international literature and debate on climate adaptation in coastal areas (Nicholls, Wong et al. 2007). Belgium is no exception as current adaptation policies are restricted to maintaining coastal safety. As the coastal zone is an interface between land and sea, it is indeed vulnerable to coastal erosion and flooding during storm at sea. At the Belgian coast, sea level rise will raise water levels near the current coastline. This will cause higher waves and increases the impact of a storm at sea. At the Belgian coast sea level rise by only one meter would cause waves up to four meters (Reyns, Verwaest et al. 2011). In addition, climate induced coastal erosion would cause loss of beaches by 17 to 50 percent by the year 2100 (Van der Biest, Verwaest et al. 2009)...

Compartmentalization as framework for technical and spatial adaptation measures As an answer to the climate related challenges, the CcASPAR project researched a new concept: compartmentalization. Within the compartmentalization concept, the current system and its safety levels are revisited at a local scale. As all climate impacts are water related (either flooding or drought) new embankments are added to split up the coastal zone into different compartments, each with its own water management. Such division creates a possibility to rescale the adaptation debate. Whether or not coastal erosion, fluvial and pluvial flooding, drought and salinization (might) occur and whether or not this will cause problems, can be analyzed for each compartment individually. Furthermore, the system within each compartment -its land use, its socio-economic characteristics and its landscape- can be revisited separately. If one wishes to maintain the existing system, technical strategies (e.g. dyke reinforcement, new pumps and increased water supply) are in order. If not, the climate impacts could be integrated into the compartment through conditions. Such conditions are not particular destinations (e.g. floodplains) but guidelines for local land use. In this way, space and spatial measures (e.g. elevated buildings, salt resistant crops and building restrictions) become part of the climate adaptation planning.

Feasibility at the Flemish coast: The implementation of the proposed concept demands the development of a new infrastructural layer: a pattern of dykes. However, in the past millennium several
embankments (e.g. historical dykes, roads, motorways, railways, sound and sight barriers) were built within the coastal region. Flood models, like the one developed within the Master Plan for Flanders Coastal Safety, mark that these structures already reduce the consequences of flooding. Yet, the embankments are not continuous or designed to function as dykes. The research by design within CcASPAR proposes to reuse the current framework as basis of the compartmentalization...

Benefits of the compartmentalization concept: The compartmentalization concept has several benefits and puts current developments in perspective. Firstly, the new pattern of embankments offers opportunities to balance the system and its safety levels at a local scale. As such, one can avoid implementing extreme protection measures wherever they are unnecessary or undesirable. Especially when sea level keeps rising and dyke reinforcement gets more and more expensive, this may be an important benefit. Moreover, investments can be spread over time. The proposed framework of dykes does not have to be developed immediately and the embankments might be purely theoretical. Only when the safety level is locally modified, they must be constructed...