Properties and dynamics of suspended load and near‐bed fine cohesive sediments in highly impacted estuaries Case studies from the Weser, Ems and Elbe estuaries (Germany) Dissertation zur Erlangung des Doktorgrades der Mathematischen-Naturwissenschaftlichen Fakultät der Christian-Albrechts Universität zu Kiel vorgelegt von Svenja Papenmeier Kiel, 2012 Erste Gutachterin: Prof. Dr. Kerstin Schrottke Zweiter Gutachter: Prof. Dr. Karl Stattegger Tag der mündlichen Prüfung: 24.10.2012 Zum Druck genehmigt: 24.10.2012 gez. (Prof. Dr. Wolfgang J. Duschl), Dekan Contents Contents ABSTRACT ...................................................................................................................... 1 ZUSAMMENFASSUNG ..................................................................................................... 3 CHAPTER 1: GENERAL INTRODUCTION ........................................................................... 5 CHAPTER 2: MOTIVATION .............................................................................................. 8 CHAPTER 3: GEOLOGICAL SETTINGS ............................................................................... 9 CHAPTER 4: METHODOLOGY ........................................................................................ 11 4.1: FIELD METHODS ......................................................................................................................... 11 4.1.1: LASER IN‐SITU SCATTERING AND TRANSMISSOMETRY .............................................................. 11 4.1.2: ACOUSTIC DOPPLER CURRENT PROFILER ................................................................................... 13 4.1.3: SEDIMENT ECHO SOUNDER ....................................................................................................... 15 4.1.4: SIDE SCAN SONAR ...................................................................................................................... 16 4.1.5: OPTICAL BACK SCATTER SENSOR ............................................................................................... 18 4.2: SUSPENDED AND SOLID SEDIMENT SAMPLING ........................................................................... 18 4.2.1: RUMOHR‐TYPE GRAVITY CORER ................................................................................................ 18 4.2.2: HORIZONTAL WATER SAMPLER ................................................................................................. 20 4.3: LABORATORY METHODS ............................................................................................................ 21 4.3.1: SSC AND POM DETERMINATION ................................................................................................ 21 4.3.2: GRAIN SIZE ANALYSIS ................................................................................................................. 21 4.3.2.1: SETTLING TUBE .................................................................................................................. 22 4.3.2.2: SEDIGRAPH ........................................................................................................................ 23 4.3.2.3: LASER DIFFRACTION PARTICLE SIZER ................................................................................. 24 4.3.3: RHEOLOGICAL INVESTIGATIONS ................................................................................................ 26 CHAPTER 5: CHANGING CHARACTERISTICS OF ESTUARINE SUSPENDED PARTICLES IN THE GERMAN WESER AND ELBE ESTUARIES ........................................................................ 30 ABSTRACT ......................................................................................................................................... 30 5.1: INTRODUCTION .......................................................................................................................... 31 I Contents 5.2: REGIONAL SETTINGS ................................................................................................................... 34 5.3: MATERIAL AND METHODS .......................................................................................................... 38 5.4: RESULTS ..................................................................................................................................... 40 5.4.1: HYDROLOGICAL CONDITION ....................................................................................................... 40 5.4.2: IN‐SITU PARTICLE SIZE DISTRIBUTIONS ....................................................................................... 41 5.4.3: PRIMARY PARTICLE SIZE DISTRIBUTIONS .................................................................................... 44 5.5: DISCUSSION................................................................................................................................ 48 5.6: CONCLUSION .............................................................................................................................. 51 ACKNOWLEDGEMENTS...................................................................................................................... 52 CHAPTER 6: SEDIMENTOLOGICAL AND RHEOLOGICAL PROPERTIES OF THE WATER– SOLID BED INTERFACE IN THE WESER AND EMS ESTUARIES, NORTH SEA, GERMANY: IMPLICATIONS FOR FLUID MUD CLASSIFICATION .......................................................... 53 ABSTRACT ......................................................................................................................................... 53 6.1: INTRODUCTION .......................................................................................................................... 54 6.2: REGIONAL SETTINGS ................................................................................................................... 58 6.3: METHODS AND DATA BASE......................................................................................................... 62 6.4: RESULTS ..................................................................................................................................... 65 6.5: DISCUSSION................................................................................................................................ 70 6.6: CONCLUSION .............................................................................................................................. 73 ACKNOWLEDGEMENTS...................................................................................................................... 74 CHAPTER 7: THE USE OF ACOUSTIC INTERFACES FOR THE QUANTIFICATION OF THE FLUID MUD BOUNDARY IN THE WESER AND ELBE ESTUARIES (GERMANY) ................... 76 ABSTRACT ......................................................................................................................................... 76 7.1: INTRODUCTION .......................................................................................................................... 77 7.2: REGIONAL SETTINGS ................................................................................................................... 78 7.3: METHODS ................................................................................................................................... 79 7.4: RESULTS ..................................................................................................................................... 80 7.4.1: TEMPORAL AND SPATIAL OCCURRENCE OF ACOUSTICAL INTERFACES ...................................... 80 7.4.2: INTERFACE CHARACTERISTICS .................................................................................................... 85 7.5: INTERPRETATION AND DISCUSSION ............................................................................................ 88 Contents 7.6: CONCLUSION .............................................................................................................................. 90 ACKNOWLEDGEMENTS ..................................................................................................................... 91 CHAPTER 8: CONSEQUENCES OF WATER INJECTION DREDGING ON ESTUARINE SUSPENDED SEDIMENT DYNAMICS AND RIVER BED STRUCTURES: A CASE STUDY IN THE SUBAQUEOUS DUNE REACHES OF THE GERMAN WESER ESTUARY ............................... 92 ABSTRACT ......................................................................................................................................... 92 8.1: INTRODUCTION .......................................................................................................................... 93 8.2: MOTIVATION AND OBJECTIVES ................................................................................................... 94 8.3: STUDY AREA ............................................................................................................................... 95 8.4: MATERIAL AND METHODS .......................................................................................................... 96 8.5: RESULTS ..................................................................................................................................... 98 8.5.1: RIVER BED ................................................................................................................................... 98 8.5.2: WATER COLUMN ...................................................................................................................... 101 8.6: INTERPRETATION AND DISCUSSION .........................................................................................