12/30/2023 0 Comments Earth science meander definitionIn starking contrast to these different chief-landforming processes, however, TM and FM display several remarkable analogies: they are characterized by similar values of sinuosity, as well as ratios between channel width and other relevant features such as mean flow depth, meander amplitude, wavelength and radius of curvature (Fig. On the contrary, the highest water stages in purely tidal landscapes correspond to low flow conditions (i.e., high slack-water periods), and the maximum along-channel discharges rapidly decline as channels extend landward, leading to a peculiar progressive reduction of channel widths (i.e., channel funneling) 9, 11, 12 (Fig. In addition, maximum flow discharges in fluvial settings are attained when water level is at the top of river banks (i.e., bankfull stage) and generally remain constant along the river course until a major confluence is found. While the basic flow in FM is invariably directed downstream, a periodic flow reversal in response to varying tidal phases controls TM dynamics 3, 10. Questions concerning analogies and differences among tidal and fluvial meanders (TM and FM hereafter) have long been debated 8, 9, 10, mainly because of the different chief-landforming processes they are formed by. 1) and is central in controlling the eco-morphodynamic evolution and sedimentary architecture of the landscapes they cut through 3, 4, 5, 6, 7. Their extensive presence typically characterizes both tidal and fluvial landscapes (Fig. Highly sinuous meandering channels are among the most fascinating morphological patterns existing in nature 1, 2. Allowing one to effectively infer processes from landforms, a fundamental inverse problem in geomorphology, our results have relevant implications for the conservation and restoration of tidal environments, as well as from planetary exploration perspectives. Based on existing theoretical, numerical, and field studies, we suggest that our empirical observations can be explained by the more regular processes carving tidal meanders, as well as by the higher lithological homogeneity of the substrates they typically cut through. Moreover, we show that tidal meanders are less morphologically complex and display more spatially homogeneous characteristics compared to fluvial meanders. We find that fluvial and tidal meanders can be distinguished on the exclusive basis of their remotely-sensed planforms. Here we use satellite imagery, measurements of meandering patterns, and different statistical analyses applied to about 10,000 tidal and fluvial meanders worldwide to objectively disclose fingerprints of the different physical processes they are shaped by. In spite of an apparently striking dissimilarity of the governing processes, planform dimensions of tidal and fluvial meanders consistently scale to local channel width, and previous studies were unable to identify quantitative planimetric differences between these landforms. Meandering channels extensively dissect fluvial and tidal landscapes, critically controlling their morphodynamic evolution and sedimentary architecture.
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