Coastal protection with respect to climate change. Practical application on the Belgian coast Trabajo final de Máster Master en transportes, territorio y urbanismo E.T.S. De ing. De caminos, canales y puertos Universitat politecnica de Valencia This master thesis is sumitted to achieve to degree of master of science in Industrial Sciences at KULeuven: industriële wetenschappen Bouwkunde Nicholas Van den Broeck Promotor: Professor Vicent de Esteban Chapapria Academic year 2016-2017 Table of contents List of figures ................................................................................................................................. 4 List of tables .................................................................................................................................. 5 Frequently used parameters ......................................................................................................... 6 Acknowledgements ....................................................................................................................... 7 Abstract ......................................................................................................................................... 8 Resumen ........................................................................................................................................ 9 1 Introduction ........................................................................................................................ 10 2 Coastal landforms................................................................................................................ 13 2.1 Erosional coasts ........................................................................................................... 13 2.1.1 Sea cliffs ............................................................................................................... 13 2.1.2 Headlands and bays ............................................................................................ 14 2.1.3 Sea stacks and arches .......................................................................................... 15 2.2 Depositional coasts ..................................................................................................... 15 2.2.1 Deltas ................................................................................................................... 15 2.2.2 Barrier island/estuarine systems ......................................................................... 18 2.2.3 Strand-plain coasts .............................................................................................. 21 3 Sediment transport ............................................................................................................. 22 3.1 Transport mechanism ................................................................................................. 24 3.1.1 Bedload................................................................................................................ 25 3.1.2 Suspended load ................................................................................................... 27 3.1.3 Wash load ............................................................................................................ 29 3.1.4 Bed ventilation .................................................................................................... 30 3.2 Longshore .................................................................................................................... 32 3.3 Cross-shore .................................................................................................................. 35 4 Different defence mechanisms ........................................................................................... 37 4.1 Hard measures ............................................................................................................ 37 4.1.1 Groynes ............................................................................................................... 37 4.1.2 Seawalls ............................................................................................................... 38 4.1.3 Revetments ......................................................................................................... 42 4.1.4 Gabions ................................................................................................................ 45 4.1.5 Offshore breakwater ........................................................................................... 46 4.1.6 Cliff stabilization .................................................................................................. 49 4.1.7 Entrance training walls ........................................................................................ 54 2 4.2 Soft measures .............................................................................................................. 55 4.2.1 Beach nourishment ............................................................................................. 55 4.2.2 Dune stabilization ................................................................................................ 56 4.2.3 Beach drainage .................................................................................................... 58 4.3 Hard vs soft measures ................................................................................................. 60 5 Climate change .................................................................................................................... 61 5.1 Consequences of climate change ................................................................................ 61 5.1.1 Rise of the ocean’s surface temperature ............................................................ 61 5.1.2 Storm surges ........................................................................................................ 64 5.1.3 Sea level rise ........................................................................................................ 68 5.2 Rise of risk ................................................................................................................... 70 6 Practical application ............................................................................................................ 73 6.1 Introducing the problem ............................................................................................. 73 6.2 Location ....................................................................................................................... 75 6.3 Measures ..................................................................................................................... 76 6.3.1 Beach nourishment ............................................................................................. 77 6.3.2 Seawall ................................................................................................................ 78 6.4 Cost-benefit analysis ................................................................................................... 83 6.4.1 Costs .................................................................................................................... 83 6.4.2 Benefits................................................................................................................ 86 6.4.3 Comparison ......................................................................................................... 87 7 Bibliography ........................................................................................................................ 88 3 List of figures 2. COASTAL LANDFORMS 1 WAVE-CUT NOTCH ........................................................................................................................................ 13 2 WAVE-CUT PLATFORM ................................................................................................................................... 13 3 HEADLAND BAY FORMATION ............................................................................................................................ 14 4 SEA ARCHES AND STACKS ................................................................................................................................ 15 5 DELTA FORMATION ....................................................................................................................................... 16 6 MISSISSIPPI DELTA ........................................................................................................................................ 17 7 TIBER DELTA ................................................................................................................................................ 17 8 NILE DELTA .................................................................................................................................................. 18 9 BARRIER ISLANDS IN THE GULF OF MEXICO ......................................................................................................... 18 10 WADDEN SEA ............................................................................................................................................ 19 11 TIDAL INLET SCHEME.................................................................................................................................... 20 12 STRAND PLAIN, PERU ................................................................................................................................... 21 3. SEDIMENT TRANSPORT