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| Titel |
Geomorphometric assessment of spatial sediment connectivity in small alpine catchments |
| VerfasserIn |
Marco Cavalli, Sebastiano Trevisani, Lorenzo Marchi |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250052932
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| Zusammenfassung |
| Small alpine headwater catchments show high variability of erosion and sediment delivery
processes, which are strongly influenced by the surface morphology and the geo-structural
setting. An important aspect related to sediment dynamics is represented by sediment
connectivity, i.e. the degree of linkage between sediment sources and downstream
areas. The control of morphological conditions on connectivity acts both through
hillslope-channel coupling and decoupling, and through sediment delivery along the
channel network. The spatial characterization of the connectivity patterns in the
catchment is fundamental in the analysis of sediment dynamics because it permits to
estimate the contribution of a given part of the catchment as sediment source, and it
defines sediment transfer paths. The availability of high-resolution digital terrain
models (DTMs), such as those derived from aerial LiDAR, improves our capability to
quantify extensively sediment connectivity. A geomorphometric index, based on the
approach proposed by Borselli et al. (2008), has been developed to assess spatial
sediment connectivity in three small headwaters catchments of the Italian Alps.
This index is aimed at evaluating the potential connection between hillslope and
sinks (channels, lakes, wetlands, basin outlet). The geomorphometric analysis is
coupled with field surveys, which enable the comparison with field evidences and the
collection of experimental data related to sediment sources and transport processes.
The Strimm and Gadria catchments (Autonomous Province of Bolzano, Eastern
Alps) have been chosen as study areas because they are two adjacent basins with
contrasting morphology and affected by different types and intensity of sediment transfer
processes. A third catchment, the Rio Cordon (Dolomites, Eastern Alps), has been
selected in order to evaluate the connectivity of sediment source areas, since a detailed
inventory map of sediment sources, complied by means of field survey and LiDAR data
analysis, was available. The approach followed revealed to be very promising for the
characterization of sediment dynamics in the complex morphological settings of alpine
headwaters.
Reference:
Borselli L., Cassi P., Torri D., 2008. Prolegomena to sediment and flow connectivity
in the landscape: a GIS and field numerical assessment. Catena, 75(3), 268-277 . |
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