摘要：In fl uvial systems, fl ooding as well as the
associated erosion, transport and deposition
of sediments are controlled by
climate impacts and moderated by land
use. Even though land use and climate are
not independent, they change at diff erent
spatial and temporal scales, exerting
a complex driver pattern on fl uvial systems.
With respect to the PAGES Focus 4
(PHAROS), which addresses the long-term
interactions between past climate, human
activities, and other ecological processes,
it is of great importance to understand the
spatial and temporal dynamics of erosion
and sedimentation in more detail. In hydrological
and geomorphological terms,
the data are proxies for long-term changes
in fl ood regime; the long-term erosion of
soil, sediment and organic matter; and the
changing sediment fl ux to coastal systems.
From an ecological point of view, the importance
lies in terms of understanding
nutrient delivery downstream (to the
coastal zone) and in modifying channel
and riparian habitats. River systems are
characterized by intricate behavior with
variable sediment sources, temporal gaps
in downstream sediment propagation and
changing trapping effi ciency of sediment
sinks.
