Geoscience Reference
In-Depth Information
Figure 18.5
Between the Pont des Marais and Pont Rouge the Aire retains many natural qualities, despite receiving
runoff and sediment load from the disturbed reaches upstream. Photo by author, October 2010.
Throughout Switzerland and Europe generally, the
past three decades have seen an explosion of
restoration projects, many of which have involved
restoring meander bends to straightened river
channels, and removing bank protection to allow
the rivers to erode, deposit, and shift their course,
within a delimited corridor (Brookes, 1987; Binder
et al.
, 1993; Brookes and Shields, 1996). These
projects have become ubiquitous on small streams,
especially in rural areas where conflicts with
infrastructure are minimal, and are also observed
increasingly on larger rivers (such as the Danube
in Baden Wittenburg) and in urban settings
with more complex constraints. By re-establishing
meander bends, the overall gradient of the river is
reduced, and flow patterns become more complex.
This, in combination with the removal of hardened
bank structures creates opportunities for erosion,
deposition and creation of complex fluvial forms
that in turn provide habitats for a variety of species
and life-stages (Habersack and Pi egay, 2008).
Thus, both flood control and the river ecosystem
were in need of improved management. The
Canton of Geneva revised its water law in 1997
to require improved water quality, enhanced
ecological values and better public access to
the Aire, and established a fund to support
revitalization of the river. After completing
studies of hydrology, landscape, ecology and river
management to provide a basis for a restoration
strategy (DIAE, 2003) the Canton selected the
proposal
of
the
group
Superpositions
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