2.4 Industries and Navigation
Heavy industrialization began in Paris and its suburbs on the eve of the nineteenth
century. Until the end of the “Thirty Glorious Years” (1946–1975), industries were
mostly located in Paris megacity, along the Lower Seine industrial corridors and along
one of its main tributaries, the Oise River (see Fig. 1). Industrial wastewaters were
barely treated on site and were discharged directly to the closest rivers, with the official
assumption that they would be diluted and that rivers had enough self-cleaning
potential. Deindustrialization and industrial wastewater treatment promoted by the
Seine-Normandy Basin Agency (AESN) led to an improvement in the quality of the
Seine River’s water. Until the late 1980s, the level of toxic substances in the river, the
fluxes released by both the city and its industries, and their effects on receiving waters
were largely ignored by French scientists and authorities [26, 42, 47].
A further factor affecting the river has been the demand for deeper, larger, and
more extended navigated reaches in the basin, specifically after the 1837 law for the
improvement of navigation on the Seine River, allowing increased sand and gravel
extraction in the floodplain, transported by waterway and used for Paris urban
growth [48].
3 PIREN-Seine Research on the River Basin Trajectories
An investigation of the trajectories of this highly modified hydrosystem in the longue
durée is the main focus of this book. The study of river systems over several
centuries using historical data or sediment core analysis reveals a dynamic that
contemporary observation – over a few years or decades – is not able to capture. It
allows for the construction of trajectories that link societal evolution and changes in
the overall state of the river. These trajectories represent simplified expressions of
our understanding at a given stage of (1) the spatial description of the system state
and its functioning, (2) its temporal evolution in the longue durée, (3) the relationships between river/water actors, and (4) the evolving position of river basins
within the Earth system, particularly within the new Anthropocene concept
[42, 49]. Trajectories bridge the gap between natural scientists and social scientists
and make some results more readily available to our partners and to the public
[50]. When possible, the usage of numerical models leads to quantitative results that
help to define trajectories. A few examples are provided here. Their time window
exceeds the 50 years of environmental monitoring in France and extends to two
centuries and even more, owing to particularly abundant archives and historical data
for the Seine River basin.
Within the PIREN-Seine, the ways of studying the trajectories of the Seine basin
have evolved over time. The first representations were spatial: a catchment area in
which a human dimension was introduced to reconstruct water and material flows
within the whole catchment (e.g. metals) or to model the biogeochemical cycles of
10
N. Flipo et al.
Heavy industrialization began in Paris and its suburbs on the eve of the nineteenth
century. Until the end of the “Thirty Glorious Years” (1946–1975), industries were
mostly located in Paris megacity, along the Lower Seine industrial corridors and along
one of its main tributaries, the Oise River (see Fig. 1). Industrial wastewaters were
barely treated on site and were discharged directly to the closest rivers, with the official
assumption that they would be diluted and that rivers had enough self-cleaning
potential. Deindustrialization and industrial wastewater treatment promoted by the
Seine-Normandy Basin Agency (AESN) led to an improvement in the quality of the
Seine River’s water. Until the late 1980s, the level of toxic substances in the river, the
fluxes released by both the city and its industries, and their effects on receiving waters
were largely ignored by French scientists and authorities [26, 42, 47].
A further factor affecting the river has been the demand for deeper, larger, and
more extended navigated reaches in the basin, specifically after the 1837 law for the
improvement of navigation on the Seine River, allowing increased sand and gravel
extraction in the floodplain, transported by waterway and used for Paris urban
growth [48].
3 PIREN-Seine Research on the River Basin Trajectories
An investigation of the trajectories of this highly modified hydrosystem in the longue
durée is the main focus of this book. The study of river systems over several
centuries using historical data or sediment core analysis reveals a dynamic that
contemporary observation – over a few years or decades – is not able to capture. It
allows for the construction of trajectories that link societal evolution and changes in
the overall state of the river. These trajectories represent simplified expressions of
our understanding at a given stage of (1) the spatial description of the system state
and its functioning, (2) its temporal evolution in the longue durée, (3) the relationships between river/water actors, and (4) the evolving position of river basins
within the Earth system, particularly within the new Anthropocene concept
[42, 49]. Trajectories bridge the gap between natural scientists and social scientists
and make some results more readily available to our partners and to the public
[50]. When possible, the usage of numerical models leads to quantitative results that
help to define trajectories. A few examples are provided here. Their time window
exceeds the 50 years of environmental monitoring in France and extends to two
centuries and even more, owing to particularly abundant archives and historical data
for the Seine River basin.
Within the PIREN-Seine, the ways of studying the trajectories of the Seine basin
have evolved over time. The first representations were spatial: a catchment area in
which a human dimension was introduced to reconstruct water and material flows
within the whole catchment (e.g. metals) or to model the biogeochemical cycles of
10
N. Flipo et al.