Congruent scales in economics, coastal engineering and morphology

Complex human-environment systems are characterized by a diversity of components and local interactions among them that produce nonlinear feedbacks between different scales. Lack of understanding of micro-foundations of macro-phenomena (such as total economic value of the area or patterns of dune formation) can make coastal zone management and spatial planning policies inefficient and unpredictable. This research project aimed to understand w hat the links between micro and macro scales in economics and coastal morphology are. Two research projects (one with the focus on coastal morphology and another on economics) have generated knowledge and models that contribute to the understanding o f this challenge. We focused on the
Dutch coastal towns with ‘outside-flood defense’ areas, w here the flood defense consisted of foredunes. In this case, the so-called safety line serves as a linking element between the two subprojects. The safety line is the line that is based on the estimated erosion line but can be adjusted (e.g. moved landwards) depending on the value of economic activities at risk. This report first briefly introduces the problem . Then the aim and results from both subprojects are discussed. Namely, the results of the economic land market modeling under various assumptions about individual behavior and implications for coastal policy are discussed. Further, a conceptual
model regarding the impact of soft coastal engineering measures on foredune development over a range of scales is presented, which resulted from morphologic analyses of differently managed foredunes along the Dutch and Danish coastlines. Finally, we provide conclusions and some recommendations that resulted from this research effort.