Quality Accounts

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Quality Accounts
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Outline

• Why Quality Accounts
• Structure of Quality Accounts
• Aquifers
• Rivers
• How to define quality classes?
• Several country examples
• Issues
• Aggregation
• Measurement

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Why quality accounts?

• Quality accounts describe the quality of water
  resources at the beginning and end of the
  accounting period in terms of chemical, physical
  and biological characteristics
• Important because
• Quality limits water availability for certain
  purposes
• It is a first step towards ecosystem accounting
  and its variants
• BUT
• Still experimental (few country experiences
  little or no standardization)
• Link with pressures due to human activities is
  not direct

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Quality of what?

• Quality of water bodies, NOT waterbeds / riparian
  zone
• Water body mass of water distinct from other
  masses of water
• Examples rivers, lakes, aquifers

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Structure of quality accounts
QUALITY CLASSES QUALITY CLASSES QUALITY CLASSES QUALITY CLASSES Physical units
Quality 1 Quality 2 - Quality n Total
Opening stocks
Changes in stocks
Closing stocks
Source SEEAW
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Aquifers Australia
Groundwater quality in Victorian provinces (in
million m3)
Fresh lt500 mg/l Marginal 500-1500 mg/l Brackish 1500-5000 mg/l Saline gt5000 mg/l Total
1995 477.5 339.2 123.3 32.3 972.3
1998 (incomplete) (39.1) (566.6) (141.1) (n.a.) (746.8)

• Based on sustainable yield as a proxy, NOT
  volume of storage

Source Water Account for Australia 1993-94 to
1996-97 - Australian Bureau of Statistics, May
2000.
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Rivers from point to monitoring
Are these statistics relevant?
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Rivers

• Monitoring of points generalisation to
  water systems
• Particular difficulty with water courses how
  to account for their relative size?
• Runoff is measured at the lowest point of a
  basin the quality varies along the stream
• The mere length confuses large rivers and
  small streams
• Statistics of points make sense only when the
  monitoring system is dense rarely the case

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Stretches / Reaches

• Reach or stretch a portion of a stream or river,
  as from one turn to another, supposedly having
  constant characteristics any distance between 2
  monitoring points

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Accounting unit SRU (1)

• River reaches as basic accounting units for
  rivers
• Importance is best measured by length and
  discharge
• Best candidate is SRU (standard river unit)
• reach length ? discharge in m3 s-1
• Large and small rivers can be aggregated when
  measured in SRUs
• Can be classified or weighted with quality
  indexes
• Results comparables from basin to basin
• Robust and easy to compute

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Accounting Unit SRU (2)
Flow
Length
Li
a SRU
X
Qi
Large river
b SRU
X
Lj
Qj
Slow, medium
X
c SRU
Qk
Lk
Fast, small
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Summary

• For compiling quality accounts we need
• SRU value for each river reach for all rivers
• We need to assign a quality for each reach for
  all rivers

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Accounting Unit SRU (2)
Flow
Length
Li
4 SRU Q1
X
Qi
Large river
0.5 SRU Q2
X
Lj
Qj
Slow, medium
X
1.5 SRU Q2
Qk
Lk
Fast, small
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Structure of quality accounts
QUALITY CLASSES QUALITY CLASSES QUALITY CLASSES QUALITY CLASSES Physical units
Quality 1 Quality 2 - Quality n Total
Opening stocks 4 2
Changes in stocks
Closing stocks
Source SEEAW
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Ways of assessing water quality

• According to disturbances/perturbations to
  functions
• Total hydraulic and osmotic power of river basins
• Health of ecosystem approach (resilience)

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Defining quality classes

• Normative values for determinands (parameters)
• Physical temperature, colour
• Chemical pH, NH4
• Biological bacteria, flora, fish
• Etc..
• Allowable deviations from reference conditions
• European Water Framework Directive

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Example Malaysia (1)

• WQI 0.22SI DO 0.19SI BOD 0.16SI COD
  0.15SI AN 0.16SI SS 0.12SI pH
• where SI is the subindex of each parameter.DO -
  Dissolved OxygenBOD - Biological Oxygen
  DemandCOD - Chemical Oxygen DemandAN -
  Ammoniacal NitrogenSS - Suspended SolidpH -
  Acidity/Alkalinity

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Example Malaysia (2)
Usage  10 20 30 40 50 60 70 80 90 100 WQI
General Very Polluted Very Polluted Very Polluted Very Polluted Very Polluted Very Polluted Slightly Polluted Slightly Polluted Clean Clean Clean
Water Class V V V V IV III III III II I I
Public Water Supply Not Acceptable Not Acceptable Not Acceptable Not Acceptable Doubtful Necessary Treatment Becoming more Expensive Necessary Treatment Becoming more Expensive Necessary Treatment Becoming more Expensive Minor Purific Required Purification not Necessary Purification not Necessary
Recreation Not Acceptable Not Acceptable Obvious Pollution Appearing Only for Boating Doubtful for Water Contact Becoming Polluted Still Acceptable Need Bacteria Count Becoming Polluted Still Acceptable Need Bacteria Count Acceptable for all Sports Acceptable for all Sports Acceptable for all Sports Acceptable for all Sports
Fish, Shellfish and Wildlife Not Acceptable Not Acceptable Not Acceptable Coarse Fish Only Handy Fish Only Doubtful for Sensitive Fish Marginal for Trout Acceptable for all Fish Acceptable for all Fish Acceptable for all Fish Acceptable for all Fish
Navigation Not Acceptable Not Acceptable Not Acceptable Obvious Pollution Appearing Acceptable Acceptable Acceptable Acceptable Acceptable Acceptable Acceptable
Treated water Transportation Not Acceptable Acceptable Acceptable Acceptable Acceptable Acceptable Acceptable Acceptable Acceptable Acceptable Acceptable
  10 20 30 40 50 60 70 80 90 100 WQI
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Example France (1)

• SEQ-eau
• Use-oriented
• Recognizes drinking water, leisure, irrigation,
  livestock watering, aquaculture aquatic life
• Based on 15 suitability indicators
• Computed from 135 determinants
• Matrices
• determinants X indicators (computed from)
• uses X indicators (significant for)
• determinants X classes (threshold values)

Source Presentation User-Producer Conference by
R. Lalement
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Example France (2)
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Example France (3)
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Example France (4)

• Results in
• a class of suitability for each use
• an index (and class) for overall quality
• For each indicator, the worst determinant wins
• For each use, the worst indicator wins
• For each determinant, apply the percentile 90
  rule to multiple samples (not the average)
• this is called Rule of the worst
• ... an in depth assessment for uses,
• but little ecology independent of  ecotype 

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France Monitoring Costs (5)

• The estimated cost of the surveillance monitoring
  programme is
• 77 M for rivers and
• 8M for lakes
• for a management plan, or
• 50 k for rivers
• 40 k for lakes
• per site for a management plan, or
• 150 /km2 (rivers and lakes), or
• 150 /km (rivers).

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Example Canada
S scope, number of failed determinands/total F
frequency, number of failed tests/total E
excursion, target value/observed value
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Results French Quality Accounts
ExampleFrance 1992-1994 Results organic matter
indicator in SRU1000
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ISSUES

• Choice of determinands
• Classification of uses
• Assessment Rule of worst
• Temporal issues
• Aggregation over space (indicators)
• Link with economic sphere

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Choice of determinands
Determinand group Number of determinands Number of determinands Number of determinands Number of determinands Number of determinands
Determinand group Total of which Specific to Canada of which Specific to France of which Specific to South Africa of which Common determinands
Environmental 10 1 1 1 6
Gases dissolved 5 2 1 1
Metals (and metalloids) 24 3 2 1 9
Nutrients 5 1 1 1
Pesticides 68 22 23 6 4
Radioactivity 26 26
Salinity 14 1 3 4
Toxics (n-metal, n-pesticides) 104 36 38 3 2

• Country and context dependent
• Based on functions or uses

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Classification of uses

• No standardized classification of uses or
  functions
• Different uses for different type of water
  bodies? (case of France)
• Different uses per water body? (USA)
• How to deal with multiple use?
• Choose the most stringent use? (AUS)

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Assessment Rule of the worst

• One out, all out
• Reason assure equal weight to all parameters
• Applicable at level of determinands, indicators
  or uses
• Problem
• Extreme values seasonal variations
• Improvement of monitoring leads to increased
  probability of finding bad status

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Rule of the worst Application
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Aggregation space (1)

• Which rivers to include?
• Scale determines outcome
• River basin
• Weighted average indicator
• Hotspots
• Pattern index

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Aggregation space (2)

• River Quality Global Index (RQGI)
• Aggregates over river basin
• Weighted average of SRU according to quality
  class
• Scale 0-10
• n is number of classes

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Aggregation space (3)

• Pattern index
• Measures the variability in space in quality of
  the River Basin
• Able to distinguish hotspots

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Temporal issues

• How to reflect seasonal variations in the quality
  accounts?
• What to do with inter-annual variations (wet
  years..)
• Actual SRU or averages?
• How to deal with sudden events
• Frequency of monitoring
• SEEAW advocates compilation of Quarterly Accounts

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Link with economic sphere (1)

• Water quality accounts
• Ideal is to measure efficiency of water quality
  management programmes at basin level
• BUT changes in water quality can have different
  causes
• Water quality t1 f(Water quality t0,
  ?(uncontrolled events), ?(abstractions),
  ?(emissions), ?(expenditure))
• f() unknown
• Therefore.

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Link with economic sphere (2)
QC1 QC2 - QCn Total
Opening stock
Changes due to economic causes
Discharge of waste water
Abstraction
Returns
Changes due to natural causes

accidents
Closing stock
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Questions

• Data availability?
• Frequency?
• Distribution of monitoring stations?
• Are flows and quality measured simultaneously?
• Which determinands are measured?
• Economic data per river basin?
• Are different uses distinguished?
• Experience in compilation?