Over the past 10 years, the programme has developed a network of multiple
chemical sensors that provide a continuous record of many analytes. They are mainly
located in the Lower Seine, where they are used to focus on the impact caused by
Paris (Box 1). Another continuous recording station has now been placed in the
Orgeval experimental stream catchment (II on Fig. 1 in [5]), where it registers finescale variability in a drained agricultural basin. This monitoring generates an
enormous amount of information on chemical and biogeochemical processes. The
data then need to be assimilated in order to provide specific information on the real
exposure of aquatic species to water quality variability.
At the opposite end of the temporal scale, the programme analyses trends over
several decades (e.g. the impact of sewage treatment, the impact of phosphorus
control on eutrophication and the expected hydrological changes due to climate
change). Finally, the longue durée approach (50 years and more) is a specific feature
of the PIREN-Seine, which aims to understand the interactions between river
basins, their territories and their society. This is achieved by means of (1) historical
research (e.g. [6]), (2) retrospective modelling based on data on past pressures
established by scientists and on pressure–state models and (3) analysis of sedimentary archives [7].
Box 1
Simulated high-frequency measurements of river water chemistry and their use
in the design of water quality surveys, using ammonia as an example.
The ProSe model generates high-frequency concentrations in the Parisian
sector of the Seine River up to the estuary. This sector receives the discharges
of more than 10 million inhabitants, including discharges from the Seine Aval
wastewater treatment plant (SAV), Europe’s largest. The upper distribution
(90%) of NH 4 concentrations (left scale in Fig. 2) is simulated for the
2007–2011 period over 200 km, according to a longitudinal profile of the
Seine from Paris to the Poses station, the Seine basin outlet [8, 9].
Different survey frequencies are simulated here, from 15 min to 3 months.
The impact of the main sewage treatment plant, Seine Aval (SAV), is best
simulated when the survey frequency is less than 3 days. The summer storm
events within Paris centre generate combined sewer overflows (CSOs) that
generate minor ammonia peaks, with limited impact at the interannual scale.
The regulatory degradation of river water quality at the SAV facility is
quantified and qualified by the colour scale derived from the European
Water Framework Directive (WFD). Water quality is decreased by two colour
codes at the SAV facility over 10 km and by one scale over 130 km, up to the
Poses station.
386
C. Carré et al.
chemical sensors that provide a continuous record of many analytes. They are mainly
located in the Lower Seine, where they are used to focus on the impact caused by
Paris (Box 1). Another continuous recording station has now been placed in the
Orgeval experimental stream catchment (II on Fig. 1 in [5]), where it registers finescale variability in a drained agricultural basin. This monitoring generates an
enormous amount of information on chemical and biogeochemical processes. The
data then need to be assimilated in order to provide specific information on the real
exposure of aquatic species to water quality variability.
At the opposite end of the temporal scale, the programme analyses trends over
several decades (e.g. the impact of sewage treatment, the impact of phosphorus
control on eutrophication and the expected hydrological changes due to climate
change). Finally, the longue durée approach (50 years and more) is a specific feature
of the PIREN-Seine, which aims to understand the interactions between river
basins, their territories and their society. This is achieved by means of (1) historical
research (e.g. [6]), (2) retrospective modelling based on data on past pressures
established by scientists and on pressure–state models and (3) analysis of sedimentary archives [7].
Box 1
Simulated high-frequency measurements of river water chemistry and their use
in the design of water quality surveys, using ammonia as an example.
The ProSe model generates high-frequency concentrations in the Parisian
sector of the Seine River up to the estuary. This sector receives the discharges
of more than 10 million inhabitants, including discharges from the Seine Aval
wastewater treatment plant (SAV), Europe’s largest. The upper distribution
(90%) of NH 4 concentrations (left scale in Fig. 2) is simulated for the
2007–2011 period over 200 km, according to a longitudinal profile of the
Seine from Paris to the Poses station, the Seine basin outlet [8, 9].
Different survey frequencies are simulated here, from 15 min to 3 months.
The impact of the main sewage treatment plant, Seine Aval (SAV), is best
simulated when the survey frequency is less than 3 days. The summer storm
events within Paris centre generate combined sewer overflows (CSOs) that
generate minor ammonia peaks, with limited impact at the interannual scale.
The regulatory degradation of river water quality at the SAV facility is
quantified and qualified by the colour scale derived from the European
Water Framework Directive (WFD). Water quality is decreased by two colour
codes at the SAV facility over 10 km and by one scale over 130 km, up to the
Poses station.
386
C. Carré et al.