Study of the size and distribution of landslides in the Zagros mountains (Iran)

Diplôme Thèse Study of the size and distribution of landslides in the Zagros mountains (Iran) eng 2015-02-17 author Ghazipour Neda 703874 director Bonadonna Costanza 0000-0002-2368-2193 636612 director Simpson Guy 653721 10.13097/archive-ouverte/unige:74729 urn:nbn:ch:unige-747290 Sc. 4806 This study investigates the size distribution of large mass movements in the seismically active Zagros mountain belt (southwest Iran) using a new inventory developed in this project. I have identified and documented 335 large landslides detectable in Google EarthTM images. Geometrical measurements and geological information on landslides were extracted from a digital elevation model with a 30m resolution and 140 geological maps at a 1:100000 scale. Individual landslides have volumes ranging from 104 to 3×1010 m3 and cover areas ranging from 103 to 108 m2. The relationship between landslide volumes (VL) and areas (AL) is well described by a power law of the form VL = ALa where a = 1.49 over five orders of magnitude of AL and seven orders of magnitude of VL. The cumulative volume distribution of the largest slope failures (about 50%) are well describe by an inverse power law of the form NL= 107.3 VL-0.675 for VL = 3.2×107m3. I show that the frequency-size (i.e. volume) distribution is heavy tailed, following a power law for the largest landslides (>107 m3) with a scaling exponent ß = 1.51. Non power law behaviour for smaller landslides is probably an artefact due to the relatively low resolution nature of the data, such that we are essentially missing many small landslides. Comparison of the results with other published datasets shows that the Zagros landslides are truly large and show similar scaling behaviour to that observed in other regions, especially to datasets where landslides are relatively large (deep seated) and occur in relatively resistant materials (e.g. consolidated rocks, as opposed to soil). Dewey 550 Terre et Environnement 131 42 Département des sciences de la Terre 154 false 7e861d03-0829-4c88-89d3-ce1140c35279 Thesis Public Thesis+Final+PDF.compressed.pdf 14692927 application/pdf Restricted 2016-07-29 679fa51fc25a0855a16a0005ba3a50b03da7566497c628bfbb3a34afb44922f8 openAccess Faculté des sciences / Section des sciences de la Terre et de l'Environnement / Département des sciences de la Terre

Title	Published in	Year	Views	Downloads

Size distribution and controls of landslides in the Zagros mountain belt (Iran)	Geological Society of America, Special Paper	2016	493	1
Study of the size and distribution of landslides in the Zagros mountains (Iran)		2015	1,072	531

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Ghazipour, Neda