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| Titel |
Scaling regimes in landslide patterns: applications in the Umbria region (Italy) |
| VerfasserIn |
Luisa Liucci, Cristian Suteanu, Laura Melelli |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250101242
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| Publikation (Nr.) |
 EGU/EGU2015-350.pdf |
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| Zusammenfassung |
| In areas characterized by high slope instability, landslide events play a predominant role in
shaping the landscape. In order to improve forecasting, numerous techniques are used to
identify areas prone to landslides on the basis of information acquirable from past events.
However, no single model has been able to fully capture the complexity of the distribution of
this phenomenon in space.
This paper studies the spatial distribution of landslides in the Umbria Region (central
Italy). We investigate the scaling properties of patterns produced by two mechanisms, slides
and flows. In the geomorphological context of the study area and due to the outcropping
rocks, both landslide types are mainly triggered by rainfall and represent 80% of mass
movements. The landslide inventory consists of about 24,000 events and it has been
represented as two different types of maps: (i) a point map indicating the top points of
landslides, and (ii) a polygon map showing the extent of each landslide event. The scaling
properties of the landslides are investigated by applying the box-counting algorithm to maps
(i) and (ii), respectively. The analysis reveals that the spatial development of landslides in the
study area possesses a characteristic fractal structure. For map (i) a scaling domain is found
within the range of 1-16 km with an exponent of 1.74 ± 0.03, while for scales
below 1 km the pattern does not preserve its fractal properties. For map (ii) the
result is partly different. Two scaling regimes are identified, separated by a scale
threshold of 1 km. In the range of 1-16 km a scaling exponent of 1.76 ± 0.01 is
observed, which is similar to the one obtained for map (i). However, for this map
scaling is also found within the range of 25 m - 1 km, with an exponent of 1.35 ±
0.02.
The analysis of the frequency distribution of landslide areas reveals that the sizes of boxes
used for the box-counting algorithm in the lower scale range are comparable to those of 98%
of landslides. Therefore, the scaling exponent of 1.35 can be interpreted as reflecting
geometric features characterizing landslides: their areas, shapes, and mutual spatial
relationships. On the other hand, the two scaling exponents obtained in the range of 1-16 km
(1.74 and 1.76) describe the spatial distribution of the landslides, rather than the features of
landslide shapes. |
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