Drainage network evolution and patterns of sedimentation in an experimental wedge

Several recent studies have suggested that maps of flow length normalized for drainage area called chi (χ) could reveal landscapes in a transient state, which are prone to reorganizations of basin geometry, flow line topology and water divide locations. However, the potentially long timescales associated with the evolution of basin geometry make the capability of χ to predict such reorganization challenging to test in natural settings. Here, we investigate the evolution of experimental drainage networks developed on a wedge coupled to a piedmont and growing in oblique convergence. We use this experimental setting to investigate the relationships between χ maps, the imposed tectonic deformation and the drainage network evolution. As deposition can occur within channels or in the piedmont, our experimental streams deviate from purely bedrock channels for which the χ metric has been initially developed. Yet we show that the large‐scale χ pattern of the experimental drainage network is consistent with the imposed deformation field, as ∼2/3 of the observed χ gradients across water divide are oriented in the expected direction with respect to the imposed deformation. This suggests that χ maps can be used to infer the horizontal component of regional deformation in large‐scale natural mountainous fluvial landscapes. In addition, we observe that when a divide affected by a χ gradient migrates, the orientation of the gradient correctly anticipates the sense of landscape reorganization for ∼2/3 of these divides. © 2018 John Wiley & Sons, Ltd.

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“…; Viaplana‐Muzas et al. ). In our experiments, this similarity is supported by several geomorphological parameters.…”

Section: Methodsmentioning

confidence: 97%

“…; Viaplana‐Muzas et al. ). The properties of the upper layer allow simulating fluvial features such as drainage basins, fluvial network, terraces and alluvial fans.…”

Section: Methodsmentioning

confidence: 99%

Landscape ‘stress’ and reorganization from χ‐maps: Insights from experimental drainage networks in oblique collision setting

Guérit

Goren

Dominguez

et al. 2018

Earth Surf Processes Landf

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“…The erosion law in the models can be approximated by the stream power law of the form (e.g. Howard & Kerby, ; Whittaker, Cowie, Attal, Tucker, & Roberts, ):

E = K \cdot \frac{A^{m}}{W} \cdot S^{n},

where the exponents m and n are 0.8 ± 0.2 and 1.5 ± 0.2, respectively (Viaplana‐Muzas et al., ), A is drainage area (as a proxy for catchment discharge), W is channel width and S is downstream channel slope.…”

Section: Methodsmentioning

confidence: 99%

“…We perform new analyses of the models previously presented in Viaplana‐Muzas et al. (), who focused on how shortening, uplift and rainfall rates control the early development of longitudinal channels during the emergence of thrust sheets (early drainage organization). Here, we investigate the factors controlling drainage divide dynamics between early longitudinal channels and expanding transverse channels, by varying systematically model shortening and rainfall rates.…”

Section: Introductionmentioning

confidence: 99%

Modelling of drainage dynamics influence on sediment routing system in a fold‐and‐thrust belt

et al. 2018

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Drainage networks link erosional landscapes and sedimentary basins in a source‐to‐sink system, controlling the spatial and temporal distribution of sediment flux at the outlets. Variations of accumulation rates in a sedimentary basin have been classically interpreted as changes in erosion rates driven by tectonics and/or climate. We studied the interactions between deformation, rainfall rate and the intrinsic dynamics of drainage basins in an experimental fold‐and‐thrust belt subjected to erosion and sedimentation under constant rainfall and shortening rates. The emergence of thrust sheets at the front of a prism may divert antecedent transverse channels (perpendicular to the structural grain) leading to the formation of longitudinal reaches, later uplifted and incorporated in the prism by the ongoing deformation. In the experiments, transverse incisions appear in the external slopes of the emerging thrust sheets. Headward erosion in these transverse channels results in divide migration and capture of the uplifted longitudinal channels located in the inner parts of the prism, leading to drainage network reorganization and modification of the sediment routing system. We show that the rate of drainage reorganization increases with the rainfall rate. It also increases in a nonlinear way with the rate of uplift. We explain this behaviour by an exponent > 1 on the slope variable in the framework of the stream power erosion model. Our results confirm the view that early longitudinal‐dominated networks are progressively replaced by transverse‐dominated rivers during mountain building. We show that drainage network dynamics modulate the distribution of sedimentary fluxes at the outlets of experimental wedges. We propose that under constant shortening and rainfall rates the drainage network reorganization can also modulate the composition and the spatial distribution of clastic fluxes in foreland basins.

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“…However, a limitation is that digitalising topography for large model surfaces can be time consuming, and it often requires the model to be stopped. A second technique used to digitise topography is the fringe projection technique Galland et al, 2009;Strak et al, 2011;Viaplana-Muzas et al, 2015). A laser interferometer projects fringes at the surface of the model and a camera records pictures simultaneously from above .…”

Section: Topographymentioning

confidence: 99%

A review of analogue modelling of geodynamic processes: Approaches, scaling, materials and quantification, with an application to subduction experiments

Schellart

Strak

2016

Journal of Geodynamics

126

105

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a b s t r a c tWe present a review of the analogue modelling method, which has been used for 200 years, and continues to be used, to investigate geological phenomena and geodynamic processes. We particularly focus on the following four components: (1) the different fundamental modelling approaches that exist in analogue modelling; (2) the scaling theory and scaling of topography; (3) the different materials and rheologies that are used to simulate the complex behaviour of rocks; and (4) a range of recording techniques that are used for qualitative and quantitative analyses and interpretations of analogue models. Furthermore, we apply these four components to laboratory-based subduction models and describe some of the issues at hand with modelling such systems. Over the last 200 years, a wide variety of analogue materials have been used with different rheologies, including viscous materials (e.g. syrups, silicones, water), brittle materials (e.g. granular materials such as sand, microspheres and sugar), plastic materials (e.g. plasticine), viscoplastic materials (e.g. paraffin, waxes, petrolatum) and visco-elasto-plastic materials (e.g. hydrocarbon compounds and gelatins). These materials have been used in many different set-ups to study processes from the microscale, such as porphyroclast rotation, to the mantle scale, such as subduction and mantle convection. Despite the wide variety of modelling materials and great diversity in model set-ups and processes investigated, all laboratory experiments can be classified into one of three different categories based on three fundamental modelling approaches that have been used in analogue modelling: (1) The external approach, (2) the combined (external + internal) approach, and (3) the internal approach. In the external approach and combined approach, energy is added to the experimental system through the external application of a velocity, temperature gradient or a material influx (or a combination thereof), and so the system is open. In the external approach, all deformation in the system is driven by the externally imposed condition, while in the combined approach, part of the deformation is driven by buoyancy forces internal to the system. In the internal approach, all deformation is driven by buoyancy forces internal to the system and so the system is closed and no energy is added during an experimental run. In the combined approach, the externally imposed force or added energy is generally not quantified nor compared to the internal buoyancy force or potential energy of the system, and so it is not known if these experiments are properly scaled with respect to nature. The scaling theory requires that analogue models are geometrically, kinematically and dynamically similar to the natural prototype. Direct scaling of topography in laboratory models indicates that it is often significantly exaggerated. This can be ascribed to (1) The lack of isostatic compensation, which causes topography to be too high.(2) The lack of erosion, which causes topography to be too high....

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Drainage network evolution and patterns of sedimentation in an experimental wedge

Cited by 33 publications

References 87 publications

Landscape ‘stress’ and reorganization from χ‐maps: Insights from experimental drainage networks in oblique collision setting

Landscape ‘stress’ and reorganization from χ‐maps: Insights from experimental drainage networks in oblique collision setting

Modelling of drainage dynamics influence on sediment routing system in a fold‐and‐thrust belt

A review of analogue modelling of geodynamic processes: Approaches, scaling, materials and quantification, with an application to subduction experiments

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