Landscape evolution models using the stream power incision model show unrealistic behavior when &amp;lt;i&amp;gt;m&amp;lt;/i&amp;gt; ∕ &amp;lt;i&amp;gt;n&amp;lt;/i&amp;gt; equals 0.5

Kwang, Jeffrey; Parker, Gary

doi:10.5194/esurf-5-807-2017

Cited by 15 publications

(20 citation statements)

References 52 publications

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“…6b). This value of m/n is located within the theoretically predicted values of m/n, which ranges from 0.3 to 0.7, from the stream power incision model (Kwang and Parker, 2017;Temme et al, 2017;Whipple and Tucker, 1999).…”

Section: Landscape Evolution Modelsupporting

confidence: 77%

Relative Timing of Uplift along the Zagros Mountain Front Flexure Constrained by Geomorphic Indices and Landscape Modelling, Kurdistan Region of Iraq

Zebari

Grützner

Navabpour

et al. 2018

Preprint

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The Mountain Front Flexure marks a dominant topographic step in the frontal part of the Zagros Fold-Thrust Belt. It is characterized by numerous active anticlines atop of an underlying basement fault. So far, little is known about the relative activity of the anticlines, about their evolution, and about how crustal deformation migrates over time. We assessed the relative 10 landscape maturity of three along-strike anticlines (from SE to NW: Harir, Perat, and Akre) located on the hanging wall of the Mountain Front Flexure in the Kurdistan Region of Iraq to identify the most active structures and to get insights into the evolution of the fault and thrust belt. Landscape maturity was evaluated using geomorphic indices such as hypsometric curves, hypsometric integral, surface roughness, and surface index. Subsequently, numerical landscape evolution models were run to estimate the relative time difference between the onset of growth of the three anticlines, using the present-day topography of 15 the Harir Anticline as a base model. A stream power equation was used to introduce fluvial erosion, and a hillslope diffusion equation was applied to account for colluvial sediment transport. For different time steps of model evolution, we calculated the geomorphic indices generated from the base model. While Akre Anticline shows deeply incised valleys and advanced erosion, Harir and Perat anticlines have relatively smoother surfaces and are supposedly younger than the Akre Anticline. The landscape maturity level decreases from NW to SE. A comparison of the geomorphic indices of the model output to those of 20 the present-day Akre Anticline topography revealed that it would take the Harir Anticline 70±10 kyr and 200±20 kyr to reach the maturity level of the Perat and Akre anticlines, respectively, assuming constant erosion and rock uplift rates along the three anticlines. Since the factors controlling geomorphology (lithology, structural setting and climate) are similar for all three anticlines, and under the assumption of constant growth and erosion rates, we infer that uplift of the Akre Anticline started 200±20 kyr before that of the Harir Anticline, with the Perat Anticline showing an intermediate age. A NW-ward propagation 25of the Harir Anticline itself implies that the uplift has been independent within different segments rather than being continuous from NW to SE. Our method of estimating the relative age difference can be applied to many other anticlines in the Mountain Front Flexure region to construct a model of temporal evolution of this belt. Solid Earth Discuss., https://doi.

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Section: Landscape Evolution Modelsupporting

confidence: 77%

Relative Timing of Uplift along the Zagros Mountain Front Flexure Constrained by Geomorphic Indices and Landscape Modelling, Kurdistan Region of Iraq

Zebari

Grützner

Navabpour

et al. 2018

Preprint

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“…The m/n ratio is frequently assumed to be equal to 0.5, with n assumed to be unity, despite recent compilations of data from multiple landscapes showing that this may not be the case (e.g. Lague, 2014;Harel et al, 2016;Clubb et al, 2016), and numerical modelling studies showing that m/n = 0.5 leads to unrealistic relief structures (Kwang and Parker, 2017).…”

Section: Testing On Numerical Landscapesmentioning

confidence: 99%

How concave are river channels?

et al. 2018

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Abstract. For over a century, geomorphologists have attempted to unravel information about landscape evolution, and processes that drive it, using river profiles. Many studies have combined new topographic datasets with theoretical models of channel incision to infer erosion rates, identify rock types with different resistance to erosion, and detect potential regions of tectonic activity. The most common metric used to analyse river profile geometry is channel steepness, or k s . However, the calculation of channel steepness requires the normalisation of channel gradient by drainage area. This normalisation requires a power law exponent that is referred to as the channel concavity index. Despite the concavity index being crucial in determining channel steepness, it is challenging to constrain. In this contribution, we compare both slope-area methods for calculating the concavity index and methods based on integrating drainage area along the length of the channel, using so-called "chi" (χ) analysis. We present a new χ-based method which directly compares χ values of tributary nodes to those on the main stem; this method allows us to constrain the concavity index in transient landscapes without assuming a linear relationship between χ and elevation. Patterns of the concavity index have been linked to the ratio of the area and slope exponents of the stream power incision model (m/n); we therefore construct simple numerical models obeying detachment-limited stream power and test the different methods against simulations with imposed m and n. We find that χ-based methods are better than slope-area methods at reproducing imposed m/n ratios when our numerical landscapes are subject to either transient uplift or spatially varying uplift and fluvial erodibility. We also test our methods on several real landscapes, including sites with both lithological and structural heterogeneity, to provide examples of the methods' performance and limitations. These methods are made available in a new software package so that other workers can explore how the concavity index varies across diverse landscapes, with the aim to improve our understanding of the physics behind bedrock channel incision.

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“…5 km thick Upper Triassic-Quaternary stratigraphic succession ( Fig. 2; Jassim and Goff, 2006;Law et al, 2014). Most anticlines are made up of Cretaceous carbonate rocks, while Upper Triassic-Lower Cretaceous strata are only exposed in the core of some anticlines.…”

Section: Geological Settingmentioning

confidence: 99%

“…Thicknesses are given as in well Bijeel-1 ( Fig. 2), which is located 5 km to the south of Perat Anticline (modified after Law et al, 2014). The column is scaled to the stratigraphic thicknesses.…”

Section: Geological Settingmentioning

confidence: 99%

Relative timing of uplift along the Zagros Mountain Front Flexure (Kurdistan Region of Iraq): Constrained by geomorphic indices and landscape evolution modeling

et al. 2019

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Abstract. The Mountain Front Flexure marks a dominant topographic step in the frontal part of the Zagros Fold–Thrust Belt. It is characterized by numerous active anticlines atop of a basement fault. So far, little is known about the relative activity of the anticlines, about their evolution, or about how crustal deformation migrates over time. We assessed the relative landscape maturity of three along-strike anticlines (from SE to NW: Harir, Perat, and Akre) located on the hanging wall of the Mountain Front Flexure in the Kurdistan Region of Iraq to identify the most active structures and to gain insights into the evolution of the fold–thrust belt. Landscape maturity was evaluated using geomorphic indices such as hypsometric curves, hypsometric integral, surface roughness, and surface index. Subsequently, numerical landscape evolution models were run to estimate the relative time difference between the onset of growth of the anticlines, using the present-day topography of the Harir Anticline as a base model. A stream power equation was used to introduce fluvial erosion, and a hillslope diffusion equation was applied to account for colluvial sediment transport. For different time steps of model evolution, we calculated the geomorphic indices generated from the base model. While Akre Anticline shows deeply incised valleys and advanced erosion, Harir and Perat anticlines have relatively smoother surfaces and are supposedly younger than the Akre Anticline. The landscape maturity level decreases from NW to SE. A comparison of the geomorphic indices of the model output to those of the present-day topography of Perat and Akre anticlines revealed that it would take the Harir Anticline about 80–100 and 160–200 kyr to reach the maturity level of the Perat and Akre anticlines, respectively, assuming erosion under constant conditions and constant rock uplift rates along the three anticlines. Since the factors controlling geomorphology (lithology, structural setting, and climate) are similar for all three anticlines, and under the assumption of constant growth and erosion conditions, we infer that uplift of the Akre Anticline started 160–200 kyr before that of the Harir Anticline, with the Perat Anticline showing an intermediate age. A NW-ward propagation of the Harir Anticline itself implies that the uplift has been independent within different segments. Our method of estimating the relative age difference can be applied to many other anticlines in the Mountain Front Flexure region to construct a model of temporal evolution of this belt.

show abstract

Landscape evolution models using the stream power incision model show unrealistic behavior when <i>m</i> ∕ <i>n</i> equals 0.5

Cited by 15 publications

References 52 publications

Relative Timing of Uplift along the Zagros Mountain Front Flexure Constrained by Geomorphic Indices and Landscape Modelling, Kurdistan Region of Iraq

Relative Timing of Uplift along the Zagros Mountain Front Flexure Constrained by Geomorphic Indices and Landscape Modelling, Kurdistan Region of Iraq

How concave are river channels?

Relative timing of uplift along the Zagros Mountain Front Flexure (Kurdistan Region of Iraq): Constrained by geomorphic indices and landscape evolution modeling

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