Impacts of human modifications  on material transport in deltas

Hariharan, Jayaram; Wright, Kyle; Moodie, Andrew; Tull, Nelson; Passalacqua, Paola

doi:10.5194/esurf-11-405-2023

Cited by 3 publications

(6 citation statements)

References 89 publications

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“…Therefore, it is critical to explore the long-term morphological responses to human intervention in the entire channel network rather than focusing on a single channel reach (Chowdhury et al, 2023;Cox et al, 2021;Wang et al, 2022). The long timescale for recovering the equilibrium (Figures 5 and 7) can lead to significantly cumulative alterations of the water and material supplies to the downstream habitats (Hariharan et al, 2023).…”

Section: Implications For Evolution and Management Of Channel Networkmentioning

confidence: 99%

System‐Wide Effects of Local Bed Disturbance on the Morphological Evolution of a Bifurcating Channel Network

Gao,

Shao,

Wang

et al. 2024

JGR Earth Surface

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Deltaic channel networks are important conduits for water and material supplies to the fluvial and coastal communities. However, increasing human interventions in river deltas have altered the topology and geometry of channel networks as well as their long‐term evolution. While the morphological evolution of a single channel has received extensive studies, the system‐wide morphological responses of channel networks to local disturbances remain largely unclear. Here we investigate the morphological responses of a bifurcating channel network subject to local disturbance of channel deepening due to dredging and sand mining through idealized simulations, and further compare the results with the reference scenarios of a single channel and theoretical analysis of the phase plane. The results show that the infilling of the local deepening is associated with the erosion of the entire branch, which also causes system‐wide effects on the siltation of the other branch. The morphological responses of the bifurcating channel network consist of a relatively short stage for the infilling of the local deepening followed by a relatively long stage for recovering the equilibrium configuration of the river bifurcation. The system‐wide effects of the local disturbance arise from the altered water surface slope and water partitioning downstream of the bifurcation due to the local deepening. Also, the prolonged recovery of the equilibrium configuration is consistent with theoretical analysis, which reveals a slow evolution of the bifurcation when approaching the equilibrium. Our results can help understand the long‐term morphological responses of large‐scale complex channel networks and inform water managements under increasing human interventions.

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Section: Implications For Evolution and Management Of Channel Networkmentioning

confidence: 99%

System‐Wide Effects of Local Bed Disturbance on the Morphological Evolution of a Bifurcating Channel Network

Gao,

Shao,

Wang

et al. 2024

JGR Earth Surface

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“…ANUGA was originally developed for coastal applications such as tsunami modeling and has been validated for such applications (Nielsen et al, 2005;Mungkasi and Roberts, 2013). In recent years, ANUGA has been used for delta and coastal river systems along the U.S. Gulf Coast and other similar applications (Tull et al, 2022;Wright et al, 2022a,b;Hariharan et al, 2023). Additional information on this model and its application to the Trinity River can be found in Tull et al (2022).…”

Section: Numerical Model Developmentmentioning

confidence: 99%

“…dorado uses a weighted random walk algorithm adapted from DeltaRCM (Liang et al, 2015a,b) to simulate passive particle transport through model flow fields on a regular grid. It has been used recently in several modeling studies of coastal river and delta systems (Tull et al, 2022;Wright et al, 2022a;Hariharan et al, 2023); more detail on the routing algorithm can be found in the Methods sections of those studies as well as in the software documentation online.…”

Section: Flux and Residence Time Quantification With Doradomentioning

confidence: 99%

River-floodplain connectivity and residence times controlled by topographic bluffs along a backwater transition

Tull,

Moodie,

Passalacqua

2024

Front. Water

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The morphology of river levees and floodplains is an important control on river-floodplain connectivity within a river system under sub-bankfull conditions, and this morphology changes as a river approaches the coast due to backwater influence. Floodplain width can also vary along a river, and floodplain constrictions in the form of bluffs adjacent to the river can influence inundation extent. However, the relative controls of backwater-influenced floodplain topography and bluff topography on river-floodplain connectivity have not been studied. We measure discharge along the lower Trinity River (Texas, USA) during high flow to determine which floodplain features are associated with major river-floodplain flow exchanges. We develop a numerical model representing the transition to backwater-dominated river hydraulics, and quantify downstream changes in levee channelization, inundation, and fluxes along the river-floodplain boundary. We model passive particle transport through the floodplain, and compute residence times as a function of location where particles enter the floodplain. We find that bluff topography controls flow from the floodplain back to the river, whereas levee topography facilitates flow to the floodplain through floodplain channels. Return flow to the river is limited to locations just upstream of bluffs, even under receding flood conditions, whereas outflow locations are numerous and occur all along the river. Residence times for particles entering the floodplain far upstream of bluffs are as much as two orders of magnitude longer than those for particles entering short distances upstream of bluffs. This study can benefit floodplain ecosystem management and restoration plans by informing on the key locations of lateral exchange and variable residence time distributions in river-floodplain systems.

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“…Coeval delta and crater production was simulated with the pyDeltaRCM numerical model (Moodie et al, 2021), which is a flexible implementation of the widely used DeltaRCM delta model (Liang et al, 2015a). DeltaRCM model design has been robustly validated (Liang et al, 2015a(Liang et al, , 2015b(Liang et al, , 2016 and used to examine delta morphology and evolution under various external forcings and processes (Lauzon & Murray, 2018;Lauzon et al, 2019;Piliouras et al, 2021;Moodie & Passalacqua, 2021;Hariharan et al, 2021Hariharan et al, , 2022Hariharan et al, , 2023. In this article, we do not describe the complete model implementation, and instead provide a high-level overview that highlights model components relevant to our study design and interpretations; a full model description is given in Liang et al (2015a).…”

Section: Delta Modelmentioning

confidence: 99%

“…We ran simulations for 10,000 timesteps, which amounts to 107×10 6 seconds of intermittent bankfull river flow. Parameters and domain scaling were selected based on prior experience with numerical stability in the model, and minimal deviation from a set of parameters commonly used with DeltaRCM (e.g., Liang et al, 2015a;Lauzon & Murray, 2018;Lauzon et al, 2019;Piliouras et al, 2021;Moodie & Passalacqua, 2021;Hariharan et al, 2021Hariharan et al, , 2022Hariharan et al, , 2023. At the end of the simulation, deposits extend 4-5 km into the basin and span 8-10 km perpendicular to the inlet channel (Figure 3e), therefore maintaining an approximately axissymmetric planform over many cycles of channel movement (Parker et al, 1998;Reitz & Jerolmack, 2012;Moodie et al, 2019).…”

Section: Delta Modelmentioning

confidence: 99%

Fluvial reworking eliminates small craters, but does not meaningfully bias the Mars interbedded-crater record

Moodie,

Goudge

2024

Preprint

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Interpreting structures, morphology, and chemistry of the exposed stratigraphic record on Mars is complicated by ancient surface processes that variably removed parts of the record. Previous research has used the lack of smaller craters (<50 m diameter) interbedded with fluvial deposits to constrain atmospheric pressure when rivers were active on Mars; the notion being that higher atmospheric pressure would have prevented smaller craters from forming. We hypothesize that contemporaneous channel lateral migration and avulsion could have reworked sedimentary deposits and eliminated craters from the stratigraphic record, thereby undermining atmospheric paleo-pressure interpretations. To test this hypothesis, we simulated coeval river-delta development and crater production, and quantified crater preservation in resulting stratigraphy. We document widespread crater degradation (~67% of craters <50 m are at least partially eroded), and observe a marked increase in preservation with increasing crater diameter. That is to say, fluvial reworking preferentially removes smaller craters from the stratigraphic record. However, synthetic crater diameter distributions incorporating fluvial reworking effects do not reproduce observations on Mars, because so many smaller craters are produced and preserved. We find that, although river channels are sometimes in the right place to eliminate crater deposits from the stratigraphic record, production of smaller craters outpaces fluvial reworking under all modeled circumstances, and that a higher pressure ancient atmosphere is necessary to reproduce observations (i.e., consistent with existing interpretations of interbedded crater records). Our findings therefore bolster studies that assert fluvial reworking is not a primary control on smaller interbedded crater counts on Mars.

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Impacts of human modifications on material transport in deltas

Cited by 3 publications

References 89 publications

System‐Wide Effects of Local Bed Disturbance on the Morphological Evolution of a Bifurcating Channel Network

System‐Wide Effects of Local Bed Disturbance on the Morphological Evolution of a Bifurcating Channel Network

River-floodplain connectivity and residence times controlled by topographic bluffs along a backwater transition

Fluvial reworking eliminates small craters, but does not meaningfully bias the Mars interbedded-crater record

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