Influences on Discharge Partitioning on a Large River Delta: Case Study of the Mississippi‐Atchafalaya Diversion, 1926–1950

Abstract

 Minor erosion measured in the Mississippi River would have reduced Atchafalaya Discharge, had Atchafalaya Basin remained constant. Lacustrine Deltas in the Atchafalaya Basin did not change partitioning, as they were downstream of a reach with steep water surface slope.

Floodplain Connecting Channels as Critical Paths for Hydrological Connectivity of Deltaic River Networks

“…Shaw et al. (2021) also showed that the dredging of new connecting channels for navigation in the channel network of the lower Atchafalaya River leads to a decreasing water surface slope in the dominant channel, which is consistent with our results (Figure 8). Interestingly, according to Konkol et al.…”

“…The asymmetry of water partitioning at the delta apex decreases with increasing river discharge (Huang et al, 2022), which is consistent with our findings (Figure 4). Shaw et al (2021) also showed that the dredging of new connecting channels for navigation in the channel network of the lower Atchafalaya River leads to a decreasing water surface slope in the dominant channel, which is consistent with our results (Figure 8). Interestingly, according to Konkol et al (2022), deltaic channel networks are also similar to systems such as leaf vascular networks, where the numerous secondary connecting veins link main veins and thus create loops in the network to improve the resilience of the network to perturbations such as vein damage and variations in flow (Katifori et al, 2010).…”

“…As such, the locations of the connecting channels relative to the bifurcation could affect their modulating function and need to be accounted for in making relevant assessments (see Figures S10 and S11 in Supporting Information ). Furthermore, the long‐term evolution of bed elevation and the adjustment of channel width could also be considered, as morphological changes can also feedback on the bed elevation of the branches and water partitioning of the upstream bifurcation (Kleinhans et al., 2013; Shaw et al., 2021). Such an effect is worth further pursuit in future studies, with one‐dimensional models recommended to fully explore a wider parameter space.…”

Artificial bifurcation effect on downstream channel dynamics of a large lowland river, the Atchafalaya

“…At present, shorelines of many deltas in the world are experiencing land loss due to declining sediment supply and accelerating rates of sea‐level rise (Blum & Roberts, 2009; Syvitski & Saito, 2007). Because large river deltas are densely populated and are transportation hubs and industrial and commercial centers, artificial bifurcation have been implemented, or are being considered, as a viable engineering tool to divert flow and sediment for combating coastal land loss, especially on those densely populated deltas such as the Yellow River delta (Carlson et al, 2021; Syvitski & Saito, 2007) and the Mississippi River Delta (Shaw et al, 2021; Wang & Xu, 2020).…”

“…Because large river deltas are densely populated and are transportation hubs and industrial and commercial centers, artificial bifurcation have been implemented, or are being considered, as a viable engineering tool to divert flow and sediment for combating coastal land loss, especially on those densely populated deltas such as the Yellow River delta (Carlson et al, 2021;Syvitski & Saito, 2007) and the Mississippi River Delta (Shaw et al, 2021;.…”