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| Titel |
Nonlinear analysis of drainage systems to examine surface deformation: an example from Potwar Plateau (Northern Pakistan) |
| VerfasserIn |
F. Shahzad, S. A. Mahmood, R. Gloaguen |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1023-5809
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| Digitales Dokument |
URL |
| Erschienen |
In: Nonlinear Processes in Geophysics ; 17, no. 2 ; Nr. 17, no. 2 (2010-03-22), S.137-147 |
| Datensatznummer |
250013659
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| Publikation (Nr.) |
 copernicus.org/npg-17-137-2010.pdf |
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| Zusammenfassung |
| We devise a procedure in order to characterize the relative vulnerability of
the Earth's surface to tectonic deformation using the geometrical
characteristics of drainage systems. The present study focuses on the
nonlinear analysis of drainage networks extracted from Digital Elevation
Models in order to localize areas strongly influenced by tectonics. We test
this approach on the Potwar Plateau in northern Pakistan. This area is
regularly affected by damaging earthquakes. Conventional studies cannot
pinpoint the zones at risk, as the whole region is characterized by a sparse
and diffuse seismicity. Our approach is based on the fact that rivers tend to
linearize under tectonic forcing. Thus, the low fractal dimensions of the
Swan, Indus and Jehlum Rivers are attributed to neotectonic activity. A
detailed textural analysis is carried out to investigate the linearization,
heterogeneity and connectivity of the drainage patterns. These textural
aspects are quantified using the fractal dimension, as well as lacunarity and
succolarity analysis. These three methods are complimentary in nature,
i.e. objects with similar fractal dimensions can be distinguished further with
lacunarity and/or succolarity analysis. We generate maps of fractal
dimensions, lacunarity and succolarity values using a sliding window of
2.5 arc minutes by 2.5 arc minutes (2.5'×2.5'). These maps are
then interpreted in terms of land surface vulnerability to tectonics. This
approach allowed us to localize several zones where the drainage system is
highly structurally controlled on the Potwar Plateau. The region located
between Muree and Muzaffarabad is found to be prone to destructive events
whereas the area westward from the Indus seems relatively unaffected. We
conclude that a nonlinear analysis of the drainage system is an efficient
additional tool to locate areas likely to be affected by massive destructing
events affecting the Earth's surface and therefore threaten human activities. |
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