Exploring Physical and Human Induced Coastal Morphodynamics: A Study with Reference to Nintavur to Addalaichenai Coastal Areas of Ampara District, Sri Lanka

Observing and mapping the long-term coastal morphodynamics because of the human and physical induced factors using conventional methods could not give expected outcomes. State-of-the-art technology and tools are the best methods to do so. Thus, this study is to explore the long-term coastal morphodynamics of coastal strip from Nintavur to Addalaichenai area using the Landsat satellite images of the years 1991, 2001, 2011 and 2019, downloaded from the Earth Explorer website. Google Earth (GE) historical images were also used for the comparison of periodic coastal morphodynamics. Normalized Difference Water Index (NDWI) was processed for land and water separation. Direct observation, perspective of the respective officials and inhabitants, reports concerning the departments and authorities were also considered as the sources for this study. In conclusion, this study has found that the coastal morphological changes have been made because of the both human and physical induced factors of which waves and river flooding withing the study area are the physical factors and construction activities; port and breakwaters are the human activities which have modified the beach in the study area. In comparison, after the construction of the port, remarkable coastal morphodynamics have been recorded in the period from 2011 to 2019 in the study area. Received: 11 February 2021 / Accepted: 22 March 2021 / Published: 10 May 2021

ROUND ABOUT MACHINE LEARNING

In this talk I will review the use of Machine Learning in studies of coastal morphodynamics. I will discuss a number of problems where ML tools have been used and why it makes sense to use ML methods. I will also outline recent advances in ML algorithms and applications, and discuss possible areas for future research.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/X5QnAdD1-T8

Coastal morphodynamics in an Arctic fluvial-tidal transition zone in the deglaciated Dicksonfjord, Svalbard

<p>Pronounced morphologic changes such as coastal retreat and delta progradation occur widely along the Arctic coastal regions in response to increased sediment flux, freshwater runoff, and wave activity caused by climate changes. Compared to open coast and large-scale deltas in the Arctic region, the coastal morphodynamics and associated sediment transport in the Arctic fluvial-tidal transition zone (FTTZ) are less well understood. A series of recurved spits are developed on the upper intertidal zone of microtidal flats in the FTTZ of deglaciated Dicksonfjorden, Svalbard. The morphodynamics and sediment fluxes of the spit complexes were quantified using unmanned aerial vehicle (UAV)-assisted photogrammetry and Real-Time Kinematic GPS. Repeated annual survey indicates that the spits have elongated at 22 m yr<sup>-1</sup> and have migrated landward at 4.3 m yr<sup>-1</sup> over the last four years. The growth and migration rate of the spits increases seaward, where coastal cliffs consisting of an unconsolidated mixture of angular gravels and muds retreats at 0.2 m yr<sup>-1</sup> with net erosion rate of 0.02 m yr<sup>-1</sup> and provides local sediment source for the spits. In contrast, isolated gravel ridges, i.e., cheniers, on the tidal flats in the further landward did not migrate during the survey period. Archives of aerial photographs indicate that the cheniers had remained stationary since the 1930s, when a shoreline was located near the cheniers. The present study demonstrates that wave-induced overwash and longshore drift of coarse-grained sediments originated from the retreating cliffs are vital to the annual spit morphodynamics even in the innermost part of the fjord. Tidal flat progradation accelerated since the Little Ice Age with global warming trends by increased runoff from snow-fed rivers and alluvial fans, controls the centennial spit morphodynamics and distribution of wave-built morphology in the FTTZ of glacier-free Dicksonfjorden by regulating episodic sediment delivery via a seaward-shift in the locus of wave shoaling.</p>