suspended sediment measurements in irish rivers (summary)

Suspended Sediment Measurements in Irish Rivers (summary)

Anna Rymszewicz, John O’Sullivan, Michael Bruen,

Jonathan Turner, Elisabeth Conroy, Mary Kelly-Quinn, Damian Lawler

SILTFLUX Worshop No 3

February 2016

1. Suspended Sediment (SS) Fluxes and Suspended Sediment Concentrations (SSC) in Ireland –overview of published data

2. SS measurements: Siltflux project• Discussion of SS transport characteristics and SS levels

Presentation Overview

• SSC - Suspended Sediment Concentration (mg/l)

• TSS - Total Suspended Solids (mg/l)

• SSF - Suspended Sediment Flux (Load) (tonnes/year)

• SSY- Suspended Sediment Yield (tonnes/ha/year)

Suspended Sediment Measurements

0

200

400

600

0 100 200 300 400TS

S (m

g/l)

Turbidity (NTU)

(Vanmaercke et al., 2011)

European Sediment Yields

GS - Gauging StationsR - Reservoir

SSY in Ireland: 2.1 - 48.4 tonnes km-2 year-1

SSY in Ireland

Catchment Area

(km2)

Sediment yield

(t km-2 year-1)

Reference

Corduff 3.34 6.07 - 22.28 Sherriff et al., 2015

Mount Stewart 7.52 6.7 Thompson et al., 2014

Timoleague 7.9 3.95 - 14.92 Sherriff et al., 2015

Dunleer 9.4 13.5 - 41.8 Melland et al., 2010, Sherriff et al., 2015

Castledockrell 11 2.11 - 23.1 Melland et al., 2010, Sherriff et al., 2015

Ballycanew 11.4 6. 65 - 48.39 Sherriff et al., 2015

Dripsey 15.24 9.8 - 16.1 Kiely et al., 2007

Glenamong 17.91 16 May et al., 2005

Mattock 20.96 44 Thompson et al., 2014

Clarianna 29.8 8.5 Kiely et al,. 2007

The Oona 84.5 29 - 41 Kiely et al., 2007

Owenabue 103 25.6 Harrington & Harrington 2013

Bandon 424 14.2 Harrington & Harrington 2013

Max SSC reported:

SSC in Ireland

• Mean annual SSCs < FFD threshold of 25mg/l, • FFD threshold exceedance occurred 1-11% sampled time

(Sherriff et al., 2015), 8.3%, 17.8% (Thompson et al., 2014)

Land Use Catchment max SSC (mg/l) Reference

Pasture CIT catchments: 837 - 979 mg/l

ACP catchments: 419 - 1020 mg/l

Harrington & Harrington 2013

Sherriff et al., 2015

Arable ACP catchments: 224 - 2141mg/l Sherriff et al., 2015

Forestry Increased SSC after clearfelling

Peak SSC increased from 88mg/l

pre-windrowing to 502mg/l during

windrowing operations

Rodgers et al., 2011

Clarke et al., 2015

• Freshwater pearl mussel

• Fish spawning grounds

• Transport of nutrients, pollutants

Sediments levels – Irish Impacts

Suspended sediment in peatland dominated River Sanginjoki (Finland) (Marttila and Klove, 2015)

Glenamong (18.21 km2), 77% upland peat, 23% forestry• 6.2 tonnes POC km2 year (2010), • 13.6 tonnes POC km2 year

(Oct 2010 to Set 2011) (Ryder et al., 2014)

Photo source: IRD Duhallow Life Project

• High potential for organic particulate matter

Siltflux Catchments

CAMLIN• 31 Typology• Size: 92.1 km2• 86.45% Pasture

SLANEY12 Typology• U/S: 47.3 km2

23% pastureD/S: 207.84 km2

53.5% pasture

GLYDE31 Typology• D/S: 345.27 km221.6% arable land (57% between U/S lakes and D/S monitoring point)

CLODIAGH31 TypologyU/S: 26.85 km2, 15.7% pastureD/S: 116.52 km2, 51% pasture

URRIN12 TypologyU/S 47.8 km2D/S 115.1 km241% arable land

SSF measurements

0

200

400

600

0 100 200 300 400

TSS

(mg/

l)

Turbidity (NTU)

Flow Estimation using HECRAS derivedChannel Survey-1

Completed survey of Gibstown (Slaney) and Kilgortin (Clodiagh) for modelling of rating relationship

Flow Estimation using HECRAS derivedChannel Survey-2

Flow Estimation using HECRAS derivedrating relationship - 1

1000 992

986.*

980

977.*

974

972.*

970 955 941.*

927.* 919.2*

917.6* 916.*

914.4* 912.8*

911.2* 909.6*

908.* 906.4*

904.8* 903.2*

901.6* 900

Clodiaghds Plan: Plan 01 10/11/2015

Legend

Ground

Bank Sta

Ground


1000 992

986.*

980

977.*

974

972.*

970 955 941.*

927.* 919.2*

917.6* 916.*

914.4* 912.8*

911.2* 909.6*

908.* 906.4*

904.8* 903.2*

901.6* 900


Legend

WS PF 9

Ground

Bank Sta

Ground

1000 992

986.*

980

977.*

974

972.*

970 955 941.*

927.* 919.2*

917.6* 916.*

914.4* 912.8*

911.2* 909.6*

908.* 906.4*

904.8* 903.2*

901.6* 900


Legend

WS PF 7

Ground

Bank Sta

Ground


1000 992

986.*

980

977.*

974

972.*

970 955 941.*

927.* 919.2*

917.6* 916.*

914.4* 912.8*

911.2* 909.6*

908.* 906.4*

904.8* 903.2*

901.6* 900


Legend

WS PF 3

Ground

Bank Sta

Ground



1000 992

986.*

980

977.*

974

972.*

970 955 941.*

927.* 919.2*

917.6* 916.*

914.4* 912.8*

911.2* 909.6*

908.* 906.4*

904.8* 903.2*

901.6* 900


Legend

WS PF 1

WS PF 2

WS PF 3

WS PF 4

WS PF 5

WS PF 6

WS PF 7

WS PF 8

Ground

Bank Sta

Ground

HECRAS derived rating relationship - 6

0 2 4 6 8 10

8.2

8.4

8.6

8.8

9.0

9.2

9.4

9.6

Clodiaghds Plan: Plan 01 12/11/2015 u/s boundary

Q Total (m3/s)

W.S

. E

lev

(m

)

Legend

W.S. Elev

Clodiagh d/s

Siltflux SSY estimates and SSC –preliminary results

CamlinSSC up to 200-300Max SSC ~857 mg/l

GlydeLow SSC: 40-50mg/l,Up to ~150 mg/l

SlaneySSC ~200/300mg/l

Clodiagh~ Max SSC 585 mg/l

UrrinSSC up to 300-400mg/lMax SSC ~900 mg/l

Sediment Transport - Slaney

• Majority of sediment transported in short period of time• Between 16th Dec – 24th Feb. (in 19.5%of time) 83.4% of sediment load

May 2013 – May 2014

Sediment Transport - Slaney

• Sediment peak usually preceding event peak• Steeper sediment rise on the rising limb

Sediment Transport - Camlin

Camlin Oct 2014 - Oct 2015

• Nov-Jan – 53% of Total SSF• Different sediment levels for the same magnitude events

Month Oct Nov Dec Jan Feb March Apr May Jun July Aug Sept Oct

% SSF 7.1 26 13 14.2 8.3 8.4 5.5 7.5 0.6 1 7.7 0.8 0.1

Sediment Transport - Glyde

• Relatively low SSY in comparison to European levels

• Inter-annual variability of SSY

• Mean annual SSC not exceeding 25mg/l, however high SSC recorded during the storms for all land uses (published Irish data)

• Majority of sediment transported in a short period of year

• Different sediment levels between same magnitude events (complex relationship between sediment exhaustion and supply)

• Sediment peak usually preceding discharge peak (positive sediment hysteresis) suggesting source limited sediment transport

Sediment transport characteristics -summary

• Clarke, J., et al. (2015) The effect of forest windrowing on physico-chemical water quality in Ireland. Science of the Total Environment, 514, 155-169.

• Harrington, S. T. & Harrington, J. R. (2013) An assessment of the suspended sediment rating curve approach for load estimation on the Rivers Bandon and Owenabue, Ireland. Geomorphology, 185, 27-38.

• Kiely, G., et al. (2007) Eutrophication from agricultural sources (Phosphorus and Nitrogen). Sub-project Soil and Phosphorus: Catchment Studies. EPA, Ireland (Ref. 2000–LS–2.1.1a–M1).

• May, L., et al. (2005) Modelling soil erosion and transport in the Burrishoole catchment, Newport, Co. Mayo, Ireland. Freshwater Forum, 23, 139-154.

• Marttila, H. and Kløve, B. (2015) Spatial and temporal variation in particle size and particulate organic matter content in suspended particulate matter from peatland-dominated catchments in Finland. Hydrological Processes, 29, 1069-1079.

• Melland, A.R., et al. (2012) Stream water quality in intensive cereal cropping catchments with regulated nutrient management. Environmental Science & Policy, 24, 58-70.

• Rodgers, M., et al. (2011) Suspended solid yield from forest harvesting on upland blanket peat. Hydrological Process, 25, 207-216.

• Ryder, E., et al. (2014) Identifying the role of environmental drivers in organic carbon export from a forested peat catchment. Science of the Total Environment, 490, 28-36.

• Sherriff, S. et al. (2015) Identifying the controls of soil loss in agricultural catchments using ex situ turbidity-based suspended sediment monitoring. Hydrology and Earth System Sciences , 12, 2707-2740.

• Thompson, J., et al. (2014) Assessing suspended sediment dynamics in relation to ecological thresholds and sampling strategies in two Irish headwater catchments. Science of the Total Environment, 468-469, 345-357.

• Vanmaercke, M., et al. (2011) Sediment yield in Europe: Spatial patterns and scale dependency. Geomorphology, 130, 142-161.

References