Looping Network Meetings

#40 March 24, 2023

Monday, 15:00 CET

Alejandro Tejedor

Characteristics scales of Delta Channel Networks

Abstract:
River deltas are landscapes at the land–water interface of great significance as they sustain dense human populations, diverse ecosystems, and offer disproportionately abundant food and energy resources. Delta morphologies exhibit a large variety of stunning and complex patterns in response to different forcings (e.g., river, tides, and waves) and the physical properties of their sediment (e.g., particle size, cohesiveness). Examining river deltas through their channel networks, capitalizing on different concepts borrowed from Network Theory, offers the potential of establishing quantitative relationships between network patterns and the underlying dominant forcings controlling delta form and its evolution. In this talk, we present some preliminary results related to the fundamental issue that arises when Delta Channel Networks (DCNs) are extracted from remote sensing data: What is the appropriate scale/resolution at which DCNs should be extracted and characterized? Specifically, we first define the effective resolution as the scale at which the resolved DCN is the one that effectively governs the transport of riverine water and sediment fluxes from the delta apex to its shoreline. To achieve this, we utilize a graph-theoretic approach to compute steady-state fluxes efficiently. This allows us to systematically investigate the DCN by incorporating channels sequentially based on their contribution to the DCN flux distribution. Consequently, we determine the channels that lead to the DCN that effectively controls the flux distribution at the delta scale. Finally, we explore the emergence of two more characteristic scales related to the loops appearing on DCNs at different scales.

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