Modelling coastal erosion in Bjärred, Lomma municipality - Long-term evolution and protective measures

Abstract

Many coastal areas around the world experience the effects of erosion on the shorelines. This phenomenon leads to great economical, environmental and social losses for the affected communities. The risk of a near future climate change, such as the predicted increase in sea water level might increase the problems to a great extent. This has forced many municipalities to start implement some integrated action plans, in order to protect their shores and properties from the wave action. Historically, Lomma municipality in southern Sweden has faced problems with erosion at different places along the shoreline. One of the most affected areas in the municipality is Bjärred, located some distance north of Lomma village. During winter storms in 2006/2007 erosion caused a waste water pipe to be almost exposed, thus in danger of breaking and polluting Lomma bay. In addition, some walls located right above the cliff were damaged by the wave impact. The consultant company Ramböll Sverige AB was chosen to study the erosion processes taking place, and to suggest protective measures to solve the erosion problem in Bjärred. Protective measures were constructed along some sections of the shore from 2006 and onwards. The aim of this thesis is to evaluate how applied protective measures against coastal erosion in Bjärred have worked so far and to investigate the possibility of introducing additional measures to improve the present conditions. These measures will be investigated on the most affected shoreline stretch in the study area both regarding the present condition as well as for estimated future climate change conditions. A computer model was used to simulate the behaviour of the suggested measures.