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Sampling frequency and uncertainty: Examples from Norwegian case - - PowerPoint PPT Presentation

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Helcom workshop May 18, 2015 Sampling frequency and uncertainty: Examples from Norwegian case studies Eva Skarbvik & Per Stlnacke Bioforsk Norwegian Institute for Agricultural and Environmental Research Focus on: loads and

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Sampling frequency and uncertainty: Examples from Norwegian case studies

Eva Skarbøvik & Per Stålnacke Bioforsk – Norwegian Institute for Agricultural and Environmental Research

Helcom workshop May 18, 2015

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Focus on: loads and concentrations of sediments – and sediment associated pollutants

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THE OVERALL PROBLEM DISCUSSED: how often do we need to measure to get an accurate and precise result? Or at least a result with acceptable uncertainty?

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Lets first look at concentrations

 The EU Water Framework Directive (WFD) operates with mean (and max) concentrations in rivers and creeks  WFD does not include sediments, but includes sediment associated substances…

Skarbøvik 2012

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Rivers (including creeks) - eutrophication

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Quality element Minimum Recommended Invertebrates Each 3rd yr Annually, 3 times/yr Nutrients Annually, 4 times/year Annually, each 14th day

(+during high water discharges)

(Fish) Each 3rd yr Once a year, annually (Temperature/ ice) Annually, 4 times/yr Continuously (Oxygen) Annually, 4 times/yr

  • (Turbidity)
  • Benthic algae

Each 3rd yr Each 2nd yr (once a year) (Macrophytes) Each 3rd yr Once a year each 2nd yr

Norwegian WFD guidelines for

  • perational (and surveillance) monitoring.

Skarbøvik 2012

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Sediment associated substances:

Example from Numedalslågen, 5500 km2 catchment area, Southern Norway, based on monthly data from 1990-2009:

Substance SPM Arsenic (As) 0.742 Lead (Pb) 0.668 Nickel (Ni) 0.670 Total phosphorus (TP) 0.750 Orthophosphate-P (PO4-P) 0.650

R2

Skarbøvik 2012

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Glomma 100-yr flooding in 1995

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River Glomma during the 1995-flood

Skarbøvik 2012

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Particle associated and dissolved substances can react quite differently

20 40 60 80 100 120 140 500 1000 1500 2000 2500 3000 3500 4000

Q TP

100 200 300 400 500 600 700 800 900 1000 500 1000 1500 2000 2500 3000 3500 4000

Q TN

River Glomma during the 1995-flood

Skarbøvik 2012

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WFD and mean concentrations:  Mean concentrations defines status  If biology shows good status then chemical parameters such as TP and TN must be checked. If the mean concentration of TP or TN is bad, poor or moderate, the water body becomes in MODERATE status. HIGH GOOD MODERATE POOR BAD

ECOLOGICAL STATUS

Skarbøvik 2012

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Investigation in River Numedalslågen

 2001 – 2005: Sediment data were collected twice-a-day  Then we used these data to assess the representativity of less-frequent data.  (both in terms of mean concentrations and loads)

Skarbøvik et al. 2012, Sci Tot Env.

Skarbøvik 2012

Station 1 Station 2

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5 10 15 20 25 30 35 40 45 50 26/01/2001 22/02/2001 27/03/2001 26/04/2001 29/05/2001 24/06/2001 29/07/2001 26/08/2001 23/09/2001 28/10/2001 22/11/2001 17/12/2001 28/01/2002 25/02/2002 18/03/2002 29/04/2002 28/05/2002 30/06/2002 24/07/2002 27/08/2002 01/10/2002 30/10/2002 26/11/2002 SPM mg/l

Daily sampling (NVE) Max 400- 600 mg/l Monthly sampling (from RID) Max 45 mg/l 2001-2002:

600 mg/l 45 mg/l

Skarbøvik et al. 2012, Sci Tot Env.

Skarbøvik 2012

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Another Catchment: Morsa and River Hobølelva

# * # *

  • 6 000

12 000 3 000 Meters

River Hobølelva

River Svinna River Mørkelva River Veidal River Kråkstadelva

Eastern basin Western basin

Lake Sæbyvn Lake Mjær Lake Bindingsvn Lake Langen Lake Sætertjern Lake Våg

Lake Vansjø

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Snittkonsentrasjoner av totalfosfor ved ulik prøvetakingsfrekvens

20 40 60 80 100 120 140 160 180 1987 1988 1990 2006 2007 2008

mikrogram/liter Alle prøver Hver 14 dag Hver måned

Env goal

Average TP Conc at different sampling frequencies

All samples Forthnightly Monthly

Total phosphorus average concentrations in River Hobølelva (south-eastern Norway)

Skarbøvik & Haaland 2010, Vann 45(2)

Skarbøvik 2012

52-55 samples/yr

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Snittkonsentrasjoner av totalfosfor ved ulik prøvetakingsfrekvens

20 40 60 80 100 120 140 160 180 1987 1988 1990 2006 2007 2008

mikrogram/liter Alle prøver Hver 14 dag Hver måned

Env goal

Average TP Conc at different sampling frequencies

All samples Forthnightly Monthly Skarbøvik & Haaland 2010, Vann 45(2)

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Snittkonsentrasjoner av totalfosfor ved ulik prøvetakingsfrekvens

20 40 60 80 100 120 140 160 180 1987 1988 1990 2006 2007 2008

mikrogram/liter Alle prøver Hver 14 dag Hver måned

Env goal

Average TP Conc at different sampling frequencies

All samples Forthnightly Monthly Skarbøvik & Haaland 2010, Vann 45(2)

Skarbøvik 2012

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Snittkonsentrasjoner av totalfosfor ved ulik prøvetakingsfrekvens

20 40 60 80 100 120 140 160 180 1987 1988 1990 2006 2007 2008

mikrogram/liter Alle prøver Hver 14 dag Hver måned

Env goal

Average TP Conc at different sampling frequencies

All samples Forthnightly Monthly Skarbøvik & Haaland 2010, Vann 45(2)

Skarbøvik 2012

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Snittkonsentrasjoner av totalfosfor ved ulik prøvetakingsfrekvens

20 40 60 80 100 120 140 160 180 1987 1988 1990 2006 2007 2008

mikrogram/liter Alle prøver Hver 14 dag Hver måned

Env goal

Average TP Conc at different sampling frequencies

All samples Forthnightly Monthly Skarbøvik & Haaland 2010, Vann 45(2)

Skarbøvik 2012

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Snittkonsentrasjoner av totalfosfor ved ulik prøvetakingsfrekvens

20 40 60 80 100 120 140 160 180 1987 1988 1990 2006 2007 2008

mikrogram/liter Alle prøver Hver 14 dag Hver måned

Env goal

Average TP Conc at different sampling frequencies

All samples Forthnightly Monthly Skarbøvik & Haaland 2010, Vann 45(2)

Skarbøvik 2012

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TP i Hobølelva 2010

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51 53 55 TP (mg/l)

0.1 0.2 0.3 0.4 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 TP (

Env goal

Question to managers

When would you like me to take your 4 samples?

Skarbøvik 2012

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Monitoring 46 rivers for 20 years

 From north to south  To assess loads to the sea  Part of the Oslo-Paris (OSPAR) Convention to assess pollutant loads to the North Atlantic

Skarbøvik 2012

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Frequent monitoring Number of parameters Tot-P, Tot-N, NH4, NO3, PO4 SPM, TOC, SiO2, Cond, pH Cd, Cr, Cu, Ni, Pb, Zn, As, Hg Lindane, PCB Continuous Water Discharge => 4 – 12(15) samples/year

Skarbøvik 2012

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The purpose of the monitoring:

Annual loads to the sea Cu River Alta Trends?

Metals, nutrients, pesticides

Skarbøvik 2012

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Do we trust the data? Do we trust the trends? And does it matter?

Skarbøvik 2012

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Investigation in River Numedalslågen

 2001 – 2005: Sediment data were collected twice-a-day  Then we used these data to assess the representativity of less-frequent data.  (both in terms of mean concentrations and loads)

Skarbøvik et al. 2012, Sci Tot Env.

Skarbøvik 2012

Station 1 Station 2

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Loads calculated by different methods and sampling frequencies

Skarbøvik et al. 2012, Sci Tot Env.

Skarbøvik 2012

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Skarbøvik et al. 2012, Sci Tot Env.

Skarbøvik 2012

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Winter episode (Øygarden, 2000)

January 30

Runoff: 25 mm Soil loss: 2 kg ha-1

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Runoff: 77 mm Soil loss: 3 050 kg ha-1

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Short-term variability in nitrate-N concentrations on a small agricultural catchment (Høyjord /S Norway) October 6-9, 1995

(Vagstad, Deelstra and Eggestad)

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Does it matter if we get it wrong?

 Death of sugar kelp in the sea…  Have sediments

  • r nutrients

increased over time?

Skarbøvik 2012

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Determine environ- mental state Grab sampling Composite sampling (incl. passive samplers) Assess effect

  • f measures

Source apportionment Process understanding Assess trends Estimate loads Objectives Sampling strategy Continuous sampling (incl. sensors) Station network Few stations Stable network Duration Many stations Changing network Long term Short term Parameters Stable Few Many Variable

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 The understanding of transport mechanisms

  • f sediment associated substances in rivers

seems to be under-communicated  Uncertainties in mean concentrations (and max concentrations) are not taken into management consideration  Huge monitoring programs sample too infrequent and therefore have high uncertainties

To sum up…

Skarbøvik 2012

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Future?

 Today, many monitoring programmes in Europe are being reviewed due to the WFD, MSFD.  Important to ensure that future monitoring and data interpretation are done according to current knowledge.  Important to bridge the gap between disciplines; and between science and management.

Skarbøvik 2012

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Thanks for listening!

Skarbøvik 2012