reoxygenation effects but upstream deoxygenation in the reservoirs, which are also
more affected by eutrophication. Timber rafting (H) may release tannins. Gravel pits
expose groundwaters to contamination. Docks, disconnected lateral channels and
flooded areas (A2) are areas of pollutant storage which can be analysed to reconstruct former pollution levels and trends [54].
In addition, the comparison of successive maps provides insights into the dynamics of the fluvial system (Table 2). Examples of these dynamics and the methodology
for quantifying these changes are provided in Sect. 4.
This diachronic analysis can be performed through planimetric (surface evolution) or vertical (depth evolution) comparisons (Sect. 4.2). The river network and the
river channel can be completely modified, from the smallest stream orders, whose
modification can lead to changes in the shape and size of the catchment area (Sect.
4.1), to the channelised river where many transformations can be demonstrated by
comparing maps: the disappearance or modification of islands, often to facilitate
navigation (Sect. 4.3), the so-called channel rectification, the channelisation by
engineering works and the resulting channel adjustments, i.e. its natural evolution
following an engineering structure downstream or upstream.
The comparison of maps also provides information on the evolution of land use in
the catchment areas and the possible impact of this evolution on the physical
attributes of the rivers, for instance, the evolution of agriculture towards more
intensive practices, especially in first-order streams, which can lead to conflicts for
water use, the appearance of gravel pits in the alluvial plain which modify its
hydraulics (Sect. 4.2) or the waterproofing of urban soils, which results in the
“urban stream syndrome”, i.e. an increase of rain storm runoff, and riverbed erosion
[32, 55].
Ecological responses to changes in fluvial dynamics can be assessed through
changes in river fish habitat distribution. They can range from immediate (effect of
damming on fish migration) to decadal (effects of minor bed deepening on the
floodplain groundwater dynamics and its ecology).
Visualising and quantifying these changes can also help to understand the
conflicts reported in the archives, such as water resource problems, property conflicts
or increased flood risks.
4 Historical Trajectories of Selected Water Bodies
in the Seine River Basin
The application of the use of historical maps is illustrated here through three
examples: (1) Versailles plateau headwaters (stream orders 1–3), (2) Bassée floodplain (order 6) and (3) the Poses sector (order 7), which marks the limit between the
Lower Seine and the fluvial estuary. All case studies show a pronounced human
impact on the natural river system in the last 200–300 years.
The Evolution of the Seine Basin Water Bodies Through Historical Maps
45
more affected by eutrophication. Timber rafting (H) may release tannins. Gravel pits
expose groundwaters to contamination. Docks, disconnected lateral channels and
flooded areas (A2) are areas of pollutant storage which can be analysed to reconstruct former pollution levels and trends [54].
In addition, the comparison of successive maps provides insights into the dynamics of the fluvial system (Table 2). Examples of these dynamics and the methodology
for quantifying these changes are provided in Sect. 4.
This diachronic analysis can be performed through planimetric (surface evolution) or vertical (depth evolution) comparisons (Sect. 4.2). The river network and the
river channel can be completely modified, from the smallest stream orders, whose
modification can lead to changes in the shape and size of the catchment area (Sect.
4.1), to the channelised river where many transformations can be demonstrated by
comparing maps: the disappearance or modification of islands, often to facilitate
navigation (Sect. 4.3), the so-called channel rectification, the channelisation by
engineering works and the resulting channel adjustments, i.e. its natural evolution
following an engineering structure downstream or upstream.
The comparison of maps also provides information on the evolution of land use in
the catchment areas and the possible impact of this evolution on the physical
attributes of the rivers, for instance, the evolution of agriculture towards more
intensive practices, especially in first-order streams, which can lead to conflicts for
water use, the appearance of gravel pits in the alluvial plain which modify its
hydraulics (Sect. 4.2) or the waterproofing of urban soils, which results in the
“urban stream syndrome”, i.e. an increase of rain storm runoff, and riverbed erosion
[32, 55].
Ecological responses to changes in fluvial dynamics can be assessed through
changes in river fish habitat distribution. They can range from immediate (effect of
damming on fish migration) to decadal (effects of minor bed deepening on the
floodplain groundwater dynamics and its ecology).
Visualising and quantifying these changes can also help to understand the
conflicts reported in the archives, such as water resource problems, property conflicts
or increased flood risks.
4 Historical Trajectories of Selected Water Bodies
in the Seine River Basin
The application of the use of historical maps is illustrated here through three
examples: (1) Versailles plateau headwaters (stream orders 1–3), (2) Bassée floodplain (order 6) and (3) the Poses sector (order 7), which marks the limit between the
Lower Seine and the fluvial estuary. All case studies show a pronounced human
impact on the natural river system in the last 200–300 years.
The Evolution of the Seine Basin Water Bodies Through Historical Maps
45