SILTFLUX Literature Review - EPA [PDF]

Report No. 176

SILTFLUX Literature Review Authors: D. Lawler, A. Rymszewicz, L. Conroy, J. O’Sullivan, M. Bruen, J. Turner, M. Kelly-Quinn

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clean, productive and well protected environment and for sustainable environmental behaviour.

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EPA RESEARCH PROGRAMME 2014–2020

SILTFLUX Literature Review (2010-W-LS-4) EPA Research Report Prepared for the Environmental Protection Agency by University College Dublin and Coventry University Authors: Damian Lawler, Anna Rymszewicz, Liz Conroy, John O’Sullivan, Michael Bruen, Jonathan Turner and Mary Kelly-Quinn ENVIRONMENTAL PROTECTION AGENCY An Ghníomhaireacht um Chaomhnú Comhshaoil PO Box 3000, Johnstown Castle, Co. Wexford, Ireland Telephone: +353 53 916 0600  Fax: +353 53 916 0699 Email: [email protected]  Website: www.epa.ie

© Environmental Protection Agency 2017

ACKNOWLEDGEMENTS

This report is published as part of the EPA Research Programme 2014–2020. The programme is financed by the Irish Government and administered by the Environmental Protection Agency, which has the statutory function of co-ordinating and promoting environmental research. The project team would like to acknowledge the very valuable input from the project steering committee, Professor Des Walling, Professor John Quinton, Professor Steve Ormerod, Dr Martin McGarrigle, Catherine Bradley, Colin Byrne, Marie Archbold, Wayne Trodd, Donal Daly and Alice Wemaere. In addition, the expert advice of Dr Martin O’Grady in the early stages of the project was invaluable.

DISCLAIMER

Although every effort has been made to ensure the accuracy of the material contained in this publication, complete accuracy cannot be guaranteed. Neither the Environmental Protection Agency nor the authors accept any responsibility whatsoever for loss or damage occasioned, or claimed to have been occasioned, in part or in full, as a consequence of any person acting, or refraining from acting, as a result of a matter contained in this publication. All or part of this publication may be reproduced without further permission, provided the source is acknowledged. The EPA Research Programme addresses the need for research in Ireland to inform policymakers and other stakeholders on a range of questions in relation to environmental protection. These reports are intended as contributions to the necessary debate on the protection of the environment.

EPA RESEARCH PROGRAMME 2014–2020 Published by the Environmental Protection Agency, Ireland ISBN: 978-1-84095-645-0

February 2017

Price: Free

Online version ii

Project Partners

Professor Michael Bruen School of Civil Engineering, UCD Dooge Centre for Water Resources Research and UCD Earth Institute University College Dublin Belfield Dublin 4 Ireland Tel: +353 1 716 3212 Email: [email protected]

Dr Jonathan Turner School of Geography and UCD Earth Institute University College Dublin Belfield Dublin 4 Ireland Tel. +353 1 716 8175 Email: [email protected] Professor Damian Lawler Centre for Agroecology, Water and Resilience James Starley Building Coventry University Coventry CV1 5FB Tel: +44 2477 651674 Email: [email protected]

Dr John O’Sullivan School of Civil Engineering, UCD Dooge Centre for Water Resources Research and UCD Earth Institute University College Dublin Belfield Dublin 4 Ireland Tel: +353 1 716 3213 Email: [email protected]

Ms Anna Rymszewicz School of Civil Engineering, UCD Dooge Centre for Water Resources Research University College Dublin Belfield Dublin 4 Ireland Email: [email protected]

Associate Professor Mary Kelly-Quinn School of Biology and Environmental Science, and UCD Earth Institute University College Dublin Belfield Dublin 4 Ireland Tel.: +353 1 716 2337 Email: [email protected]

Dr Liz Conroy School of Biology and Environmental Science, and UCD Earth Institute University College Dublin Belfield Dublin 4 Ireland Email: [email protected]

iii

Contents

Acknowledgementsii Disclaimerii Project Partners

iii

List of Figures

vii

List of Tables

x

Executive Summary

xiii

1 Introduction

1

2

4

3

4

Fine Sediment Sources, Delivery and Budgets  2.1

Sediment Sources and Delivery

4

2.2

River Bank Erosion as a Suspended Sediment Source

9

2.3

Deposition and Mobilisation

14

2.4

Construction Activities

14

2.5 External Discharges, Urban Drainage, Wastewater Treatment Plants and Farmyard Drains

15

Physical and Chemical Impacts of Fine River Sediments in Fluvial Systems

17

3.1

Importance and Processes

17

3.2

In-stream Processes

17

3.3

Sediment-associated Pollutants

21

3.4

Impacts on River Morphology

23

3.5

Impacts on Riverine Structures

24

3.6

Downstream Effects of Siltation in Rivers, Lakes, Reservoirs and Harbours

24

Ecological Impacts of Fine River Sediments in Fluvial Systems

27

4.1 Introduction

27

4.2

5

Periphyton and Macrophytes

27

4.3 Macroinvertebrates

31

4.4 Fish

33

Measuring and Monitoring Suspended Sediment Concentrations and Loads

35

5.1 Introduction

35

5.2

36

Manual Sampling

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6

7

8

9

10

5.3

Acoustic Doppler Current Profiler Method

38

5.4

Automatic Sampling for Suspended Sediment Concentration Time Series

38

5.5

Turbidimetric Instrumentation

40

5.6

Optical Backscatter Sensor Instrumentation

43

5.7

Laser In Situ Scattering and Transmissometry

44

5.8

Remote Sensing of Suspended Sediment Concentration

45

5.9

Estimation of Suspended Sediment Loads

45

Suspended Sediment Concentrations, Fluxes and Yields

49

6.1 Introduction

49

6.2 Ireland

49

6.3

51

Britain and Northern Europe

Storm-Event and Seasonal Suspended Sediment Dynamics

56

7.1

56

Storm-Event Suspended Sediment Dynamics

7.2 Hysteresis

56

7.3

Seasonal Changes in Suspended Sediment Fluxes

58

7.4

Longer Term Changes

60

Effects of Land Use and Climate Change on Sediment Fluxes

61

8.1 Introduction

61

8.2

Climate Change with Particular Reference to Ireland

61

8.3

Land Use

62

Management Implications

66

9.1

Reducing Sediment Load

66

9.2

Monitoring the Effectiveness of Measures

68

9.3

The Use of Modelling for the Design and Evaluation of Measures

68

Standards and Targets

69

References71 Abbreviations93

vi

List of Figures

Figure 1.1.

Suspended sediment in the River Alne, Warwickshire

2

Figure 1.2.

Suspended sediment of a very different colour (and probably source) in the River Alne, Warwickshire, at the same bridge site as shown in Figure 1.1, but looking upstream

2

Figure 2.1.

Example of an advanced classification system for potential hillslope and river channel suspended sediment sources

4

Figure 2.2.

Sediment connectivity in the fluvial system

5

Figure 2.3.

Natural and anthropogenic catchment and river processes that affect sediment dynamics

6

Figure 2.4.

Eroding arable fields – an example of a sediment source in Shropshire, UK

6

Figure 2.5.

The conceptual basis of the fingerprinting technique used to establish suspended sediment sources in the PSYCHIC study

7

Figure 2.6.

The conceptual framework that underpins the numerical INCA-Sed of Jarritt and Lawrence (2006)

8

Figure 2.7.

Sediment budget examples from catchments in central England

9

Figure 2.8.

River bank erosion on the River Allow, Ireland, is a sediment source

Figure 2.9.

Eroding river banks around a sedimentation zone on the River South Tyne, Northumberland11

11

Figure 2.10. World river bank erosion rates with respect to drainage basin area

12

Figure 2.11. River bank erosion as a sediment source in a reach-scale budget

12

Figure 2.12. River bank erosion events detected automatically with the PEEP system on the River Severn

13

Figure 3.1.

Turbid waters at high flow in the River Alne, near Little Alne, Warwickshire, UK

Figure 3.2.

Turbid conditions in the urban Bournbrook stream, River Tame catchment, Birmingham17

Figure 3.3.

Sediment infiltration mechanisms

18

Figure 3.4.

The hyporheic zone

19

Figure 3.5.

The relationship between stream power and sediment size in UK stream types: upland (Type I), small chalk (Type 2) and sandstone/limestone (Type 3)

19

Figure 3.6.

Downstream change in the hydraulic properties of the River Dart, southwest England

20

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SILTFLUX Literature Review

Figure 3.7.

Decline in oxygen supply rate with the accumulation of fine sediment within artificial redds

21

Figure 3.8.

Sediment pollution event in the nearshore zone derived from erosion of a coastal catchment during an intense Mediterranean rainstorm, east-central Spain, 24 August 1997

23

The continuum of channel planform variants of alluvial river morphology along an energy gradient is closely related to predominant sediment load and channel stability

24

Figure 3.9.

Figure 4.1.

Negative impacts of anthropogenically enhanced sediment on lotic aquatic systems27

Figure 4.2.

Schematic showing the mechanisms by which macroinvertebrates are affected (directly and indirectly) by suspended, deposited and saltating sediment particles

32

Figure 5.1.

Schematic of SSC cross-sectional variations

36

Figure 5.2.

Schematic cross-sectional variation in flow velocity, SSC and sediment flux

36

Figure 5.3.

Vertical distribution of concentration of various particle sizes in a stream section

37

Figure 5.4.

Time-integrating suspended sediment sampler for collecting large amounts of suspended sediment for composition analysis

39

Figure 5.5.

Infiltration basket for capturing fine sediment in gravel river beds

39

Figure 5.6.

Declining water clarity in Lake Tahoe, measured using the Secchi disk

40

Figure 5.7.

Turbidity versus SSC: calibration for the urbanised area at James Bridge, River Tame, Birmingham, UK

42

Figure 5.8.

Turbidity versus SSC: calibration for the large Skaftá river, south Iceland

43

Figure 5.9.

Dependence of light absorbance on sediment particle size

44

Figure 5.10. Effect of particle size on OBS response

44

Figure 5.11. Examples of SSC–Q relationships for two British rivers

46

Figure 5.12. Relationships between suspended sediment and area-weighted Q for several named British rivers

46

Figure 6.1.

Catchments that have been studied in recent sediment-related Irish studies

50

Figure 6.2.

Observed sediment yield (bedload and suspended load) data as a function of catchment area for UK rivers

52

Figure 6.3.

Downstream changes in optical water quality in six rivers in Wisconsin (USA) and New Zealand

55

Figure 7.1.

SSC response dynamics: SSC leading the flow and the classic positive hysteresis and first-flush model of sediment dynamics

57

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Figure 7.2.

Classic suspended sediment dynamics in response to storm-event discharge changes on the River Dart, south-west England

58

Figure 7.3.

The typical suspended sediment dynamic response in the urbanised River Tame catchment (Birmingham, UK) is negative, anticlockwise hysteresis, in which peak SSCs occur just after the flow maximum

59

Clockwise hysteresis and anticlockwise hysteresis (the most common loops in the Q–turbidity relationship) for the River Tame, Birmingham

59

Figure 7.4.

ix

List of Tables

Table 1.1.

Initially proposed thresholds of SSCs for different effects on fish

1

Table 1.2.

Characteristics of fine sediments from selected UK rivers

3

Table 2.1.

Typical catchment sediment sources, and the likely variation in a downstream direction

5

Table 2.2.

Sediment sources for several south-west England catchments (delivery to watercourses in kg/ha per year), with information on source types for each catchment10

Table 2.3.

Summary of studies that have documented an increase in SSs downstream of river crossing construction sites

15

Table 2.4.

Major point sources of sediment

15

Table 3.1.

Selected examples of sediment-associated contaminants, their sources and their effects on fluvial systems

22

Table 3.2.

Bedform classification system

25

Table 3.3.

Alluvial depositional environments in which fine sediments may accumulate

25

Table 4.1.

The ecological impact and sources of suspended and deposited sediment in rivers

28

Table 4.2.

The effects of varying the concentrations of and the duration of exposure to suspended sediment on periphyton and macrophytes

29

Table 4.3.

The effects of varying the concentrations of and the duration of exposure to suspended sediment on macroinvertebrates

30

Table 4.4.

The effects of varying the concentrations of and the duration of exposure to sediment on fish

31

Table 6.1.

Summary of Irish sediment yields reported in the scientific literature

50

Table 6.2.

The Walling catchment typology: links to suspended sediment yield

53

Table 6.3.

The WFD catchment typology: links to suspended sediment yield

53

Table 6.4.

The new “Natural England” typology: links to catchment suspended sediment yield

54

Table 8.1.

Some effects of land cover changes on catchment characteristics

63

Table 8.2.

Total net rainfall, runoff and soil loss resulting from 30 storms between 28 May 1980 and 27 February 1981 in Nacogdoches, Texas

64

Table 9.1.

Reducing mobilisation of sediment from agricultural activities

67

Table 9.2.

Reducing delivery of mobilised sediment to watercourse

67

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Table 9.3.

Some estimated sediment reduction efficiencies

67

Table 9.4.

Reducing sediment export from urban areas to watercourses

68

Table 9.5.

Estimates of reduction efficiencies of best management practices for urban sediment

68

Table 10.1.

Proposed target and critical suspended sediment yields for various catchment types in England and Wales

69

Table 10.2.

Examples of standards/regulations for various countries

70

xi

Executive Summary

Sediment is a natural and dynamic component of river catchment systems, in which it is transported as bedload and/or suspended load, depending on the relationship between flow conditions, sediment supply and the structure, density, size and shape of materials. Although sediment does not feature explicitly within the Water Framework Directive (WFD), the ecological focus of the legislation with regard to surface waters means that the role of sediment as an essential component of the sustainable management of aquatic systems is recognised. Suspended sediment particles are typically