River discharge into the River discharge into the Mediterranean Sea and Mediterranean Sea and

estimation of the associated estimation of the associated nutrient loadnutrient load

Task 5.4.2Task 5.4.2

O.G.S.: Alessandro Crise, Cosimo Solidoro, Sebastiano O.G.S.: Alessandro Crise, Cosimo Solidoro, Sebastiano TrevisaniTrevisani

ENEA: Salvatore Marullo, M.Vittoria StrugliaENEA: Salvatore Marullo, M.Vittoria Struglia

CIRCE MEETING Bologna, 2 May 2007

SummarySummary

Statement of the problemStatement of the problem

Aims of the taskAims of the task

Description of planned activitiesDescription of planned activities

A view of the Mediterranean seaA view of the Mediterranean sea

Sea - Wifs image from EEA Topic Report 7 2001Sea - Wifs image from EEA Topic Report 7 2001

Two sides of the same coin:Two sides of the same coin: Eutrophication and Eutrophication and OligotrophicationOligotrophication

EutrophicationEutrophication refers to an increase in the refers to an increase in the rate of supply of organic matter to an rate of supply of organic matter to an ecosystem, which most commonly is related ecosystem, which most commonly is related to nutrient enrichment enhancing the primary to nutrient enrichment enhancing the primary production in the system (Nixon, 1995). production in the system (Nixon, 1995).

OligotrophicationOligotrophication is the reversal of the is the reversal of the eutrophication process and can occur as the eutrophication process and can occur as the result of changes in precipitation and runoff result of changes in precipitation and runoff regime or of operation of advanced waste regime or of operation of advanced waste treatment facilities on inflowing riverstreatment facilities on inflowing rivers

Impacts of eu/oligo-Impacts of eu/oligo-trophicationtrophication

changes in the structure and functioning of the marine ecosystems;

reductions in biodiversity; reductions in the natural resources of demersal

fish and shellfish; reduced income from maricultures of fish and

shellfish; reduced recreational value and income from

tourism; increased risk of poisoning of animals including

humans by algal toxins.

The nutrients’ loadThe nutrients’ load

We focus our analysis on We focus our analysis on nutrientsnutrients carried by carried by rivers as causes of rivers as causes of eutrophication/oligotrophication.eutrophication/oligotrophication.

Total nutrient loads can be estimated by the Total nutrient loads can be estimated by the time integration of instantaneous fluxes time integration of instantaneous fluxes

C x QC x Q(nutrient concentration x river discharge) (nutrient concentration x river discharge)

The temporal variability of river discharge is The temporal variability of river discharge is a dominant factor in this processa dominant factor in this process

Our aimsOur aims

1.1. Evaluate the impacts of interannual Evaluate the impacts of interannual and decadal variability of river and decadal variability of river discharge on the marine discharge on the marine environment and ecosystemenvironment and ecosystem under under current climate conditionscurrent climate conditions

2.2. Attempt a description of the impact Attempt a description of the impact that climate changes may have that climate changes may have onto the nutrient loads. onto the nutrient loads.

Our planOur plan An empirical model will be developed based An empirical model will be developed based

on:on: - land use information- land use information - nutrient retention and loss within - nutrient retention and loss within

river system river system - river discharge data- river discharge data

A limited number of river basins, possibly A limited number of river basins, possibly representative of the response of the representative of the response of the European and African coasts, will be selected European and African coasts, will be selected as case studies. as case studies.

Results from this model will be compared with Results from this model will be compared with available observed (satellite or in-situ) available observed (satellite or in-situ) quantities linked to riverine nutrient load.quantities linked to riverine nutrient load.

Total nutrient load can be evaluated by means of different methodologies characterized by different

degrees of complexity. For example for the Rhone T. Moutin et Alii made the evaluation considering water flux and nutrients concentration. Then, in the case of

Nile, S. Nixon evaluated nutrients load taking in to consideration the population, sewage systems and

fertilizer use.T. Moutin et Alii, 1998, “The input of nutrients by the Rhone river into the Mediterranean Sea: recent observation and Comparison with earlier data”, Hydrobiologia, pp. 237-246.

S.W. Nixon, 2003, “Replacing the Nile: Are Anthropogenic Nutrients Providing the Fertility Once Brought to the Mediterranean by a Great River”, Ambio, Vol.32, No. 1.

Land use and nutrient loadLand use and nutrient load

Reasonably, in order to perform a scenario based analysis (climate change, demographic variations, different land use, etc.) there could be the need of numerical models

(SWAT, MONERIS, POLFLOW, POL, as an example) able to simulate the temporal variation in nutrients load related to the set of physical and chemical processes involved.

The choice of the model to be used is related to the hydrological characteristics of the basin, to the data

available and to the target of our analysis. Likely these models should be linked or integrated in to a geographical

information systemS.L. Neitsch, J.G. Arnold, J.R. Kiniry and J.R Williams, 2005, “Soil and Water Assessment Tool Theoretical Documentation”, Texas.

M. Tournoud, S. Payraudeau, F. Cernesson and C. Salles, 2005, “Origins and quantification of nitrogen inputs into a coastal lagoon: application to the Thau lagoon (France)”, Ecological Modelling, 193, pp. 19-33.

M.J. M. de Wit, 2000, “Nutrient fluxes at the river basin scale. I: the PolFlow model”, Hydrological processes, 15, pp. 743-759.

L. Palmeri, G. Bendoricchio and Y. Artioli, 2005, “Modeling nutrient emissions from river systems and loads to the coastal zone: Po river case study, Italy”, Ecological Modeling, 184, pp. 37-53.

River discharge dataRiver discharge data Current climateCurrent climate: historical time series from several on-line : historical time series from several on-line

database (GRDC, MMA, Med-Hycos, sage, UNESCO) are available database (GRDC, MMA, Med-Hycos, sage, UNESCO) are available and will be analyzed respect to climatology and interannual and and will be analyzed respect to climatology and interannual and decadal variability:decadal variability:

RiverRiver Years availableYears availableRhoneRhone 1920-19971920-1997

PoPo 1918-19961918-1996

EbroEbro 1954-20011954-2001

MoulouyaMoulouya 1957-19881957-1988

Climate changeClimate change: informations from other RL’s are : informations from other RL’s are expectedexpected

Contribution of major rivers to total runoffContribution of major rivers to total runoff

Interannual variability in the Adriatic Sea and in the Gulf of Lion.From Struglia et al. Journal of climate, 2004

In a first instance three Mediterranean rivers will be considered: Rhone, Po and Nile (these cover around

1/3 of the total riverine input into the

Mediterranean Sea)

In order to understand these rivers and their relations with the sea two aspects should be considered:

hydrologic and hydrochemical behaviour of the rivers

hydrochemical characteristics and spatio-temporal variation of marine coastal waters in the proximity of estuaries

Validation of the modelValidation of the model

In situIn situ measures measures

Ocean color satellite dataOcean color satellite data

Chlorophyll climatology by SEA-WIFSOpen ocean optical remote sensing of the Mediterranean Sea by R. Santoleri, G. Volpe, S. Marullo, B. Buongiorno Nardelli to appear on the book "Remote sensing of the European Seas"

Seasonal and year to year variability can be studied using time series of ocean color satellite data.

SeaWiFS data permit to investigate the variability of the Chlorophyll field (or other ocean color derived parameters) in the Adriatic Sea for the period from 1998 to today.

April 22 2004

Courtesy of ADRICOSM NERES project and ENEA