Spatial Patterns of Ne Sediment Supply and Transfer in the River Esk, North
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Durham E-Theses Spatial patterns of ne sediment supply and transfer in the River Esk, North York Moors. Robinson, Katherine S. How to cite: Robinson, Katherine S. (2006) Spatial patterns of ne sediment supply and transfer in the River Esk, North York Moors., Durham theses, Durham University. Available at Durham E-Theses Online: http://etheses.dur.ac.uk/2784/ Use policy The full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that: • a full bibliographic reference is made to the original source • a link is made to the metadata record in Durham E-Theses • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders. Please consult the full Durham E-Theses policy for further details. Academic Support Oce, Durham University, University Oce, Old Elvet, Durham DH1 3HP e-mail: [email protected] Tel: +44 0191 334 6107 http://etheses.dur.ac.uk 2 Spatial patterns of fine sediment supply and transfer in the River Esk, North York Moors. The copyright of this thesis rests with the author or the university to which it was submitted. No quotation from it, or information derived from it may be published without the prior written consent of the author or university, and any information derived from it should be acknowledged. MSc (by Research) Katherine. S. Robinson Department of Geography Durham University September 2006 11 JUN 2007 Declaration This thesis is the result of my own work. Data from other authors which are referred to in the thesis are acknowledged at the appropriate point in the text. Statement of Copyright The copyright of this thesis rests with the author. No quotation from it should be published without their prior written consent and information derived from it should be acknowledge. ii Abstract . A detailed field study of spatial and temporal patterns of fine sediment transfer was undertaken in the River Esk catchment, North York Moors in response to ecological problems associated with in-channel fine sedimentation. Fine sediment flux and specific sediment yields were estimated from bulk suspended sediment samples collected from a network of 17 spatially distributed Time Integrated Samplers (TIMS). These samplers were deployed over a six month monitoring period from December 2005 - June 2006. Channel characteristics (bank height; bank material; vegetation cover I type; and erosion extent I type); catchment properties (e.g. drains, tributaries and areas of saturated runoff); and land use were mapped using a stream reconnaissance survey covering 61 km of the River Esk and dominant tributaries. These mapped attributes were combined in ArcGIS with other spatial data (e.g. geology; land elevation and slope) to create a GIS database. Dominant sediment source areas were identified by comparing sediment characteristics (e.g. colour; magnetic susceptibility; and metal concentrations) of the suspended material retained in the TIMS samplers with those of channel bank and catchment source samples. Two main areas of high fine sediment flux were identified on the Esk between: Danby to Duck Bridge; and Egton Bridge to Grosmont. Fine sediment in the Danby to Duck Bridge reach was sourced predominantly from local channel banks as a result of geotechnical failures. However from Egton Bridge to Grosmont, catchment sediment sources, from the steep, forested, boulder clay sub-catchments of the dominant tributaries (Glaisdale Beck and Butter Beck), were most significant. To alleviate high level of sedimentation in these locations, the main areas requiring management are the channel banks of the Esk near Danby; intensively farm areas of Danby Beck and Great Fryup Beck; and the steep, wooded regions in Glaisdale Beck and Butter Beck sub-catchments. Suitable target initiatives should include: riparian fencing; bank reinforcements; livestock rotation; and the creation of buffer zones. iii Acknowledgements First and foremost, I would like to thank my supervisors Dr Louise Bracken and Dr Jeff Warburton for their invaluble help with this research project. Louise for her guidance, support and encouragement in this project, espeically during the writing upstages, and Jeff for his constant enthusiam, assistance and reccomendations during the planning, fieldwork and final stages of the project. Secondly, thanks must go to the lab techicians, particularly Dereck Coates, Mervyn Brown, Alison Clark, Frank Davies, Amanda Hayton, Ed Million, Neil Tunstall and Martin West, for their never-ending help and assistance during the laboratary and fieldwork parts of this project. Thanks to Carolyn Mills, partner in the field, for making splashing about in the river during snow storms in January more bearable! Thanks to the Environment Agency for their finicial support, guidance and providing data needs. Additional thanks to the Department of Geography, Durham University, for their finicial support. Finally I would like to thank my family for their support during the past year. IV Contents Abstract ........................................................................................... .i Declaration ................................................................................................................... iii Acknowledgements ...................................................................................................... iv Contents ........................................................................................... v List of figures .................................................................................... vii List ofTables .................................................................................... xii Chapter One: INTRODUCTION ............................................................................... ! 1.1 Research rationale .............................................................................................. 1 1.2 Research aims and objectives ............................................................................. 4 1.3 Thesis structure .................................................................................................. 6 Chapter Two: BACKGROUND TO FINE SEDIMENT FLUX IN FLUVIAL SYSTEMS ............................................................................................................ 8 2.1 Overview ............................................................................................................ 8 2.2 Fine sediment definitions ................................................................................... 8 2.3 Fine sediment transfer in the fluvial system .................................................... 10 2.4 Catchment controls governing fine sediment flux ........................................... 13 2.5 Importance of documenting fine sediment flux in the British Uplands ........... 17 2.6 Linking land use practices to spatial patterns of fine sediment flux ................ 18 2.7 Linking fine sediment flux with aquatic habitats ............................................. 21 2.7.1 Salmonids ......................................................................................... 21 2. 7.2 Freshwater pearl mussels ................................................................. 23 2.8 Implications for catchment mananagement ..................................................... 24 2.9 Monitoring spatial variability in fine sediment flux ........................................ 26 2.9.1 Fine sediment flux ............................................................................ 26 2.9.2 Stream reconnaissance surveys ........................................................ 28 2.1 0 Identifying dominant sediment source areas .................................................... 29 2.11 Chapter summary .............................................................................................. 35 Chapter Five: SPATIAL AND TEMPORAL PATTERNS OF FINE SEDIMENT TRA.NSFER .......................................................................................................... 65 5.1 Overview .......................................................................................................... 65 5.2 Spatial patterns of sediment flux ...................................................................... 65 5.2.1 Sediment flux ................................................................................... 65 5.2.2 Weighted sediment flux ................................................................... 68 5.2.3 Site specific sediment yields ............................................................ 72 5.3 Storm 'gulp' samples ....................................................................................... 74 5.4 Temporal trends ............................................................................................... 77 5.4.1 Seasonal trend in weighted sediment flux ........................................ 78 5.4.2 Weighted sediment flux and peak stage ........................................... 80 5.4.3 Weighted sediment flux and rainfall ................................................ 84 5.4.4 Temporal trends summary ................................................................ 86 v Chapter Six: SIGNIFICANCE OF CHANNEL AND CATCHMENT CHARACTERISTICS ......................................................................................... 87 6.1 Overview .........................................................................................................