The Water quality management of the Thau lagoon: modeling an pre-formulation of the bacterial pollution processes system

Transcription

1 The Water quality management of the Thau lagoon: modeling an pre-formulation of the bacterial pollution processes system Présentation : J. A. Pérez Agúndez, Annie Fiandrino (collective work of teams from Sète/Montpellier and Brest)

2 Main topics of the presentation 1. How the socioeconomic dimensions of this issue are integrated in the model? 2. Which are the economic processes of the system and by what economic methods can be analyzed and formulated? 3. Which are the bio- physical processes of the system (ecological dimension)? 4. How to couple the different elements?

3 Brest, le 14/10/08 Main issue (quick reminder) lfremer S.A.F. Formulation - General context : population rate increased by +40% over the past 30 years to reach approximately 130,000 residents. - Increase of anthropogenic uses, ecological pressures and conflicts - Management has been based mainly on spatial segmentation, by sector, by conflict. The results have not been satisfactory New ways of governance : the example of water quality management - A new concerted land planning process has been launched on the Thau lagoon - Objective : Implementation of a Territorial Management Plan including a Water Management Plan framed by : French Water Law (1992, 2003) Schéma Directeur d Aménagement et de Gestion des Eaux (SDAGE Rhône Méditerranée) (1996 Current)) The WFD (2000).

4 Two main roles of Spicosa (in terms of modeling) -Structure, format and integrate the knowledge about the issue treated (support by a systemic approach) -To accompany the deliberative and decision making processes (supported by multimedia tools) Objectives of the site study (the bacterial management issue) -Formulate an integrative model nature-society and processes-actors concerned by the problems of water bacterial contamination -To simulate prospectively sustainable scenarios Socioeconomic modeling into the Thau system : illustrated by - The local economy system dimension : (greened) regional accounting methods - The economic dimension of the water treatment : a public economic analysis - The micro-economy decisions of the shellfish farming sector

5 The general system Brest, le 14/10/08 lfremer S.A.F. Formulation

6 Brest, le 14/10/08 Managing the water contamination in the Thau lagoon : a DPSIR approach Drivers Upstream Uses Indicators : expected state of the system Pressures Bacterial emissions Economic development Traditional activities Ecosystem preservation Recreative uses & amenities lfremer S.A.F. Formulation State Impacts (water contamination) Water quality in the Lagoon -Short run: closures -Long run: classification Downstream Uses Water treatment Ecosystem services Responses Multi-objectives local policies under public budget constraint Governance system Settlement: space allocation Access regulation Economic incentives (taxes) Public investments Rules: sanitory norms

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8 The anthropogenic uses in the Thau lagoon concerned by water quality

9 Brest, le 14/10/08 Economic analysis based on I-O matrix lfremer S.A.F. Formulation The impact of policy options on production level in other sectors (and so on the economy), i.e. indirect impacts of environmental policies The impact of policy options on total employment in the region or in a particular sector The impact of policy options on prices of goods and services

10 Brest, le 14/10/08 The ecological system Analysis of bacterial emissions on watershed is carried out in the framework of the regional project (OMEGA-THAU ) River-basin pollution sources identification on watershed cutting out in 11 sub-river-basins. 13 types of pollution sources have been identified lfremer S.A.F. Formulation Waste water collective network Picking up entry (pumping of waste water)

11 Brest, le 14/10/08 The ecological system lfremer S.A.F. Formulation Bacterial sources linked to anthropogenic uses: - resident effluents (linked to WWTP or not) - tourism effluents (seasonal pop. linked to WWTP, camping ) - farming (wine culture, cattle farming, shellfish ) - harbour and boating activities on lagoon - dysfunction of WW collective network during rainfall - runoff in urban area during rainfall Waste water treatment plant Bact Flux Source (E.coli/d) = Nb inh. Bact inh Abat Nb inh = Number of inhabitants linked to the collective network (function of the season) Bact inh (E.coli/d) = Bacteria charge produced by 1 Inh.Eq. (5, E.coli/d) Abat (log unity) = depuration by WWTP For each source Bact Flux River Mouth = Bact Flux Source.10 -d/(v.t90) d (m) = distance from source to river mouth v (m/s) = speed transfer in river (function of rainfall) T90 (s -1 ) = bacteria mortality in river

12 Brest, le 14/10/08 The ecological system lfremer S.A.F. Formulation Results of spatialized hydrodynamical 3D model will be used to assess a transfer function of bacteria contaminants from river mouth to microbiological monitoring network (REMI) stations ( ) into the lagoon. Annual frequency of sanitary thresholds exceeding (number of closure of the shellfish farming zones).

13 The economic dimension of the water treatment : a public economic analysis Different ways to analyze the processes - (I) CBA (restricted) - (II) CEA and (integration of space allocation and opportunity costs) - (III) multi-criteria (integration of non market uses)

14 The economic impacts of the water quality: The micro-economy decisions of the shellfish farming sector

15 The governance box (linked with most elements of the model)

16 Brest, le 14/10/08 Final remarks The integration can be made not only by disciplines but by methods into a same discipline lfremer S.A.F. Formulation The socioeconomic processes are quantitative but qualitative as well (need indicators) Necessity to make some simplifications : importance of the system and not a box This is a preformulating exercise, but new adjustments need to be done in the next mathematical formulating step

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18 An Input-output matrix (I-O) is a representation of national or regional economic accounting that records the way economic branches trade with one another and produce for consumption and investments. Farming Tourism Shellfish farming Pollutant abatement activities Households consumption Total output Farming 0,2 0,6 Industry 0,1 0,1 Pollutant emissions Work (Added value) Xf bacterial concent. / output farming Xt bacterial concent / output tourism 0,7 0,3 Production of goods and services resulting from the implementation of the environmental measures for pollutant elimination in each sector ( ) Household Consumption Agric Household Consumption ind X RPT (residual pollution tolerated) X agric X ind X treated (residual pollution tolerated) Total input 1 1