Map source: A. Engebretsen

A tool for communicating confidence in predictions of nutrient abatement effectiveness

David N. Barton(NINA), Alexander Engebretsen(UiO), Koji Tominaga(UiO) , Jannicke Moe (NIVA), Eirik Romstad (UMB)

Nutrient abatement measures & costs

Catchment run-off

Lake water quality

Use suitability

Willingness to pay for lake use suitability

Presentation overview

Norwegian WFD Guidance on evaluation A network approach Results: individual network models Results: integrated network for benefits assessments Discussion Conclusions

Overview

Presentation overview

Norwegian WFD Guidance on evaluation A network approach Results: individual network models Results: integrated network for benefits assessments Discussion Conclusions

Overview

Norwegian WFD Guidance on evaluation

«Less stringent environmental objectives» § 10. (mindre strenge miljømål)

§ 10 Når en vannforekomst er så påvirket av menneskelig virksomhet at det er umulig eller uforholdsmessig kostnadskrevende å nå målene i § 4 – § 6, kan det fastsettes mindre strenge miljømål dersom følgende vilkår er oppfylt: a) de miljømessige og samfunnsøkonomiske behov som denne menneskelige

virksomheten tjener, ikke uten uforholdsmessige kostnader kan oppfylles på andre måter som er miljømessig vesentlig gunstigere,

b) det sikres en høyest mulig tilstand for overflatevann og grunnvann gitt de store påvirkningene som er til stede, og

c) det ikke forekommer ytterligere forringelse av tilstanden i den berørte vannforekomsten

§ 15. (karakterisering, vurdering av miljøpåvirkning og økonomisk analyse) c) en økonomisk analyse være utarbeidet i samsvar med vedlegg III

Permanent derrogation - «if economic costs are greater than benefits [..] be certain that the calculation does not change by the time of the next evaluation..» «there are large margins of error implicit in the evaluations» [of this guidance] Temporary derrogation - « justified by the local impact assessment because measures are controversial…» Continued abatement despite derrogation - «…continue environmental improvement measures, but stop before reaching good ecological status because the’ last’ measures are disproportionately costly».

Guidance on evaluation(I): uncertainty is a key topic in derrogations from the goal of «good ecological status»

«Disproportionate costs» of measures relative to needs is a probability statement

benefit – cost = net benefit

50%

50%

+

-

25%

75%

+

-

5%

95%

+

-

0 0

A B C

1. «Reduce the need to assess benefits of individual measures… by conducting economic assessment of the benefits of packages of measures « 2.»Use the method of ‘backward evaluation’ by removing the least cost-effective measures and re-evaluating…»

Guidance on evaluation(II): What should ‘water authority economists’ do?

Temporal resolution

Spatial resolution

Annual

Farm

Daily

Catchment

Daily

Lake (vertical)

Seasonal (summer)

Lakeshore

Annual

Household location around lake

Nutrient abatement measures & costs

Use suitability (survey data, expert opinion)

Willingness to pay for lake use suitability

(regression model)

Lake water quality MyLake Cyanobacteria

Response/ Driver

Pressure

State

Impact

Impact/ Response

Catchment run-off (SWAT model)

FSSIM model Simple coefficients

-

Com

mun

icat

ion

chal

leng

e?

+

Inte

grat

ed m

odel

unc

erta

inty

+

-

Evaluating disproportionate costs of GES is possible in principle with an integrated model

Presentation overview

Norwegian WFD Guidance on evaluation A network ‘meta-model’ approach Results: individual network models Results: integrated network for benefits assessments Discussion Conclusions

Overview

A network ‘meta-model’ approach

Source: adapted from Fylkesmannen i Østfold. Tilskudd til Regionale Miljøtiltak (2005)

Map source: A. Engebretsen

SWAT-MyLake network ‘meta-model’

Presentation overview

Norwegian WFD Guidance on evaluation A network approach Results: individual network models Results: integrated network for benefits assessments Discussion Conclusions

Overview

ppResults: individual network models

Map source: A. Engebretsen

Ranking effectiveness using a diagnostic approach «working backward»

Relative likelihood of

achieving lowTot-P target

Background trend independent of

measures

SWAT-MyLake ‘meta-model’

Map source: A. Engebretsen

Model uncertainty: low probability of low Tot-P loading

Model uncertainty: low probability of

high loading

Willingness to pay for improvement in ecological status of

lakes in Østfold-Akershus

1113 households Websurvey 2008

Tot-P? Algae P? Secchi depth? correspondance with scenarios?

Expert judgement of water quality illustrations used in valuation study (I)

Expert judgement of water quality illustrations used in valuation study (II)

Water use suitability

0102030405060708090

100

Fishing(trout) Fishing(coarse) Bathing Rowing/paddling Bird watching

Would NOT practiceWould practice

0102030405060708090

100

Fishing(trout) Fishing(coarse) Bathing Rowing/paddling Bird watching

Would NOT practiceWould practice

0102030405060708090

100

Fishing(trout) Fishing(coarse) Bathing Rowing/paddling Bird watching

Would NOT practiceWould practice

0102030405060708090

100

Fishing(trout) Fishing(coarse) Bathing Rowing/paddling Bird watching

Would NOT practiceWould practice

Water use suitability

Willingness to pay increased sewage fees for improved water suitability

Presentation overview

Norwegian WFD Guidance on evaluation A network approach Results: individual network models Results: integrated network for benefits assessments Discussion Conclusions

Overview

Results: integrated network for benefits assessments

Evaluation of benefits of measures on water user suitability (I)

Relative % change of Scenario 4 compared to Scenario 2

Evaluation of benefits of measures on water user suitability (II)

Expected increase in WTP sewage fee /hh yr. for specific ecological states (relative to «red»)

Economic valuation of expected WTP/hh yr. for increased ecological status

Presentation overview

Norwegian WFD Guidance on evaluation A network approach Results: individual network models Results: integrated network for benefits assessments Discussion Conclusions

Overview

Discussion

Do we expect the catchment-lakes system

as a whole to be very responsive to measures

on agricultural land?

60% forest 14% agriculture

Presentation overview

Norwegian WFD Guidance on evaluation A network approach Results: individual network models Results: integrated network for benefits assessments Discussion Conclusions

Overview

Conclusions

• Fuzzy interfaces between disciplinary models (integrating independently conducted studies)

Conclusion Conclusions Extreme measures have a significant effect but are they too costly?..... Disproportionate cost analysis requires …..the evaluation of individual measures… …..with uncertainty quantification using long time series and simulation models that can evaluate abatement Interactions…. ……is VERY time and resource consuming…. …..is a theoretically valid concept, but not a practical tool for watershed management. ….alternative decision rules needed…..