Abstract

Competition and synergy between tectonic and erosional processes are recognized as the main factors influencingthe shape of many landscapes.While considerable efforts are dedicated to the explanation of particular landscape forms and features, such asthose found in some parts of the Earth surface, another aspect which is rising interest in the scientific communityis the emergence of similar patterns and regularities in a variety of situations and environmental conditions.Recent investigations, for instance, have been dedicated to the analysis of landscape features such as regular valleyspacing in drainage networks evolving on slopes affected by competing tectonic uplift and terrain erosion.Analysis of digital terrain models reproducing either actual features, or simulated surfaces obtained throughapplication of landscape processes to synthetic terrain, have shown how the emergence and persistence ofconsiderable degrees of regularity in the terrain dissection into parallel river basins is a feature common to bothtypes (real and simulated) of landscapes. Such a regularity has been observed in linear mountain fronts, in differenttypes of tectonic and climatic settings [Hovius 1996, Talling et al. 1997, Castelltort & Simpson 2006].Regular river spacing has been also observed in simulated landscapes obtained through application of numericalmodels [Perron et al. 2009], or indoor scaled reproductions of an orogen subject to erosion by rain-wash[Bonnet 2009]. Several classes of explanations have been proposed for the onset and persistence of such spacingregularities. In particular, one critical aspect is the transient phase of reorganization that involves landscapesundergoing changes in geometry.In this work, we investigate the temporal evolution of mean river basin aspect ratio, R, defined as the ratio betweenmountain front width W and basin outlet spacing S, averaged over a number of basins spanning at least a givenfraction (say, 2/3) ofW. The parameter R is analyzed on simulated landscapes obtained by application of numericalmodels of uplift, hillslope diffusion and fluvial erosion to synthetic surfaces, represented as triangulated irregularnetworks (TINs). The model is completely implemented in Matlab, thus leaving ample access to a number ofavailable terrain analysis and visualization tools.We report some observations about the temporal evolution of the R parameter, an aspect not very well covered inrecent investigations. In particular, we investigate its response to different values of uplift rates and erosion power.We also simulate the response of R to the reorganization of the river network following the setup of a gradient inthe precipitation regime.ReferencesBonnet, S. (2009). Shrinking and splitting of drainage basins in orogenic landscapes from the migration ofthe main drainage divide. Nature Geoscience. 2, 766-771Castelltort S. & Simpson G. (2006) - River spacing and drainage networ

Autore Pugliese

• Refice Alberto

Tutti gli autori

• E. Giachetta; D. Capolongo; A. Refice

Titolo volume/Rivista

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Anno di pubblicazione

2011

ISSN

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ISBN

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Numero di citazioni Wos

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Settori ERC

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Codici ASJC

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