The sedimentary dynamics in natural and human-influenced delta channel belts De sedimentatiedynamiek van natuurlijke en door de mens beïnvloede rivieren in delta’s (met een samenvatting in het Nederlands) PROEFSCHRIFT ter verkrijging van de graad van doctor aan de Universiteit Utrecht op gezag van de rector magnificus, prof.dr. G.J. van der Zwaan, ingevolge het besluit van het college voor promoties in het openbaar te verdedigen op donderdag 5 november 2015 des middags te 2.30 uur door Noortje Hobo geboren op 25 november 1980 te Ammerzoden Promotor: Prof.dr. H. Middelkoop Copromotor: Dr. A. Makaske Dit proefschrift werd (mede) mogelijk gemaakt met financiële steun van Delft Cluster, het ministerie van LNV en Alterra The sedimentary dynamics in natural and human-influenced delta channel belts Utrecht Studies in Earth Sciences Local editors Prof.dr. Steven de Jong Dr. Marjan Rossen Prof.dr. Cor Langereis Drs. Jan-Willem de Blok ISSN 2211-4335 Utrecht Studies in Earth Sciences 097 The sedimentary dynamics in natural and human- influenced delta channel belts Noortje Hobo Utrecht 2015 Promotor Prof.dr. H. Middelkoop Copromotor Dr. A. Makaske Examination committee Prof. dr. T.E. Törnqvist, Tulane University Prof. dr. R.T. van Balen, Free University Amsterdam Prof. dr. F. Klijn, Delft University of Technology Dr. R.M. Frings, Aachen University Prof. dr. M.G. Kleinhans, Utrecht University ISBN 978-90-6266-410-8 Cover: High water level of the Nederrijn near Wageningen, the Netherlands. Photo by Noortje Hobo. Copyright © Noortje Hobo, c/o Faculty of Geosciences, Utrecht University, 2015. Niets uit deze uitgave mag worden vermenigvuldigd en/of openbaar gemaakt door middel van druk, fotokopie of op welke andere wijze dan ook zonder voorafgaande schriftelijke toestemming van de uitgevers. All rights reserved. No part of this publication may be reproduced in any form, by print or photo print, microfilm or any other means, without written permission by the publishers. Printed in the Netherlands by CPI - Koninklijke Wöhrmann B.V., Zutphen. Contents Preface 15 1 General introduction 17 1.1 Background 17 1.2 Sedimentary dynamics 18 1.3 The Rhine-Meuse delta 20 1.4 Objectives 22 1.5 Approach and organisation of the thesis 24 2 Sedimentation rates on embanked floodplains determined through quartz optical dating 27 Abstract 27 2.1 Introduction 27 2.2 Samples and equipment 28 2.3 Equivalent dose estimation 29 2.3.1 Equipment and methods 29 2.3.2 Sample preparation 29 2.3.3 Selecting signal integration intervals 30 2.3.4 Ultrafast component 30 2.3.5 Thermal transfer 31 2.3.6 SAR performance 32 2.3.7 Equivalent dose distribution 33 2.4 Dose rate estimation 33 2.5 Results and discussion 34 2.5.1 OSL-dating results and sedimentation rates 34 2.5.2 Internal checks on validity of OSL ages 36 2.5.3 External checks on validity of OSL ages 37 2.6 Conclusion 38 Acknowledgements 38 3 Reconstruction of floodplain sedimentation rates: a combination of methods to optimise estimates 39 Abstract 39 3.1 Introduction 40 3.2 Study sites 41 3.3 Sample collection 43 3.4 Dating methods 43 3.4.1 137 Cs dating 44 3.4.2 Heavy metal analysis 45 3.4.3 Optically Stimulated Luminescence (OSL) dating 46 3.4.4 Flood bed interpretation 47 7 3.5 Results and interpretation 49 3.5.1 137Cs dating 49 3.5.2 Heavy metal analysis 51 3.5.3 OSL dating 51 3.5.4 Flood bed interpretation 53 3.5.5 Sedimentation rates and spatial variability 55 3.5.6 Intercomparison between methods 57 3.6 Discussion 57 3.6.1 Uncertainties associated with each method 57 3.6.2 Best estimates of sedimentation rates 60 3.6.3 Comparison with other studies 60 3.6.4 Optimal ranges of application 61 3.7 Conclusions 63 Acknowledgements 64 4 Reconstruction of eroded and deposited sediment volumes of the embanked river Waal, the Netherlands, for the period 1631 AD – present 65 Abstract 65 4.1 Introduction 66 4.2 Study area 67 4.2.1 Characteristics of the river Waal and the studied floodplains 67 4.2.2 Embanked floodplain formation by downstream migration 68 4.2.3 Geomorphological elements and associated lithogenetic units 69 4.3 Material and methods 71 4.3.1 Concept and data 71 4.3.2 Planform geomorphology 72 4.3.3 Lithogenetic composition 74 4.3.4 Age determination 76 4.3.5 Sedimentation rates 78 4.3.6 Sediment budgets 80 4.3.7 Floodplain elevation 82 4.4 Results 83 4.4.1 Planform geomorphology 83 4.4.2 Lithogenetic units 83 4.4.3 Chronostratigraphy 86 4.4.4 Sedimentation rates 87 4.4.5 Sediment budget 89 4.4.6 Floodplain elevation 90 4.5 Discussion 93 4.5.1 Historic trends 93 4.5.2 Accuracy 94 4.5.3 Comparison to other studies 95 4.6 Conclusions 96 Acknowledgements 97 8 5 Decadal to century-scale sediment dynamics in channel belts of the natural Rhine delta 99 Abstract 99 5.1 Introduction 99 5.2 Concept 101 5.2.1 Stages in channel life cycle 101 5.2.2 Sediment budget 103 5.3 Approach and study area 103 5.3.1 Approach 103 5.3.2 Holocene Rhine-Meuse delta 104 5.3.3 The Hennisdijk fluvial system 106 5.4 Methods and data 106 5.4.1 Sediment budget reconstruction based on maps and cross-sections 106 5.4.2 Bank Stability and Toe Erosion Model 111 5.4.3 Determination of input variables 120 5.4.4 Calculation of sediment reworking 124 5.5 Results 125 5.5.1 Reconstructed sediment budgets 125 5.5.2 Channel migration rates 127 5.5.3 Duration of stages 128 5.5.4 Sediment reworking 128 5.5.5 Sediment budget 129 5.6 Discussion 133 5.6.1 Channel-belt life-cycle stages 133 5.6.2 Sedimentary dynamics 134 5.7 Conclusion 136 6 Changing sedimentary dynamics under increasing human influence (synthesis and conclusion) 139 6.1 Introduction 139 6.2 Estimating sedimentary dynamics 140 6.3 Sedimentary dynamics of channel sediments 142 6.3.1 Holocene delta 142 6.3.2 Natural channel belts 143 6.3.3 Embanked channel belts 147 6.3.4 Normalized channel belts 148 6.4 Sedimentary dynamics of overbank sediments 150 6.4.1 Holocene delta 150 6.4.2 Natural channel belts 151 6.4.3 Embanked channel belts 153 6.4.4 Normalized channel belts 155 6.5 Comparison between channel and overbank sedimentary dynamics 157 6.6 Application 164 6.7 Conclusions 165 9 Summary 167 Samenvatting 173 References 179 Appendix A 191 About the author 195 List of publications 195 10 Figures 1.1 Geological–geomorphological map of the Rhine-Meuse delta, the 21 Netherlands. 1.2 West-east cross-section through the Rhine-Meuse delta. 22 1.3 Fragment of a south–north cross-section through the Rhine-Meuse delta, 23 showing Holocene floodbasin deposits of clay and peat, on top of the Pleistocene subsurface, intersected by channel belts of different age. 1.4 The main differences between a natural channel (A), and embanked channel 25 (B), and a normalized channel (C) in the Rhine delta. 2.1 Location of the study site and cross section of overbank deposits with quartz 28 OSL ages. 2.2 LM-OSL measurements on an aliquot of sample NCL-1107144 after a 10s 31 preheat at 180 oC and after additional IR exposure. 2.3 Offset in equivalent dose caused by thermal transfer. 32 2.4 Probability density functions (PDFs) of the OSL single aliquot age 35 distributions for all samples. 2.5 Age vs. depth plots indicating OSL ages and 137 Cs ages for the distal, levee, 36 and proximal cores. 3.1 Schematic cross section of a river channel with embanked floodplains in the 40 Netherlands during high discharge. 3.2 Locations of the studied floodplain sites in the Netherlands, and topographic 42 maps of the Rijswaard, Vreugderijkerwaard and Cortenoever study areas, showing locations of cores and the studied transects. 3.3 Heavy metal concentration in the Rhine sediment. 46 3.4 Flood bed interpretation, following a two-step count-from-the-top method: 48 (1) correlation of the largest flood beds to the largest flood events, indicated by the solid arrows, and (2) correlation of the smaller flood beds to the smaller flood events, indicated by the dashed arrows. 3.5 137 Cs activity profiles of floodplain cores and reference cores from the 50 Rijswaard, Cortenoever, and Vreugderijkerwaard study sites. 3.6 Heavy metal profiles of floodplain cores from the Rijswaard, Cortenoever, 52 and Vreugderijkerwaard study sites. Interpreted ages of characteristic changes in the profiles are also given. 3.7 Flood bed interpretation results: the flood bed succession in the 1-m-long soil 54 core, the duration and flooding depth of all flood events, and the lines that connect the flood beds to potential depositional flood events. 3.8 Age-depth plots for all investigated cores, showing: the 137 Cs activity peaks of 56 1963 and 1986 AD, corrected for vertical migration, the ages of characteristic changes in the heavy metal profiles, the OSL-dating results, and the age of the flood events correlated to flood beds. Linear-fitted trend lines, forced through origin, indicate the average sedimentation rates. 11 3.9 Spatial and temporal ranges of application of each method, and the reasons 62 for each boundary. 4.1 Studied floodplains: Gouverneursche polder (GOU), Hiensche uiterwaarden 68 (HIE), Wolferensche waard (WOL), Drutensche waarden (DRU), Afferdensche en Deestsche waarden (AFF) and Winssensche waarden (WIN).