Influence Mechanism of Geomorphological Evolution in a Tidal Lagoon with Rising Sea Level

A tidal lagoon system has multiple environmental, societal, and economic implications. To investigate the mechanism of influence of the geomorphological evolution of a tidal lagoon, the effect of critical erosion shear stress, critical deposition shear stress, sediment settling velocity, and initial bed elevation were assessed by applying the MIKE hydro- and morpho-dynamic model to a typical tidal lagoon, Qilihai Lagoon. According to the simulation results, without sediment supply, an increase of critical erosion, deposition shear stress, or sediment settling velocity gives rise to tidal networks with a stable terrain. Such an equilibrium state can be defined as when the change of net erosion has little variation, which can be achieved due to counter actions between the erosion and deposition effect. Moreover, the influence of the initial bed elevation depends on the lowest tidal level. When the initial bed elevation is below the lowest tidal level, the tidal networks tend to be fully developed. A Spearman correlation analysis indicated that the geomorphological evolution is more sensitive to critical erosion or deposition shear stress than sediment settling velocity and initial bed elevation. Exponential sea level rise contributes to more intensive erosion than the linear or the parabolic sea level rise in the long-term evolution of a tidal lagoon.

A Novel Enhanced Russell Graph Efficiency Measure in Network DEA

Hitherto, the presented models for measuring the efficiency score of multi-stage decision-making units (DMUs) either are nonlinear or require to specify the weights for combining their divisional efficiencies. The nonlinearity leads to high computational complexity for these models, especially when used for problems with enormous dimensions, and also assigning various weights to the divisional efficiencies causes to obtain different efficiency scores for the multi-stage network system. To tackle these problems, this study contributes to network DEA by introducing a novel enhanced Russell graph (ERG) efficiency measure for evaluating the general two-stage series network structures. Then, the proposed model is extended into the general multi-stage series network structures. This study also describes the managerial and economic implications of measuring the efficiency score of the multi-stage DMUs and provides two numerical and empirical examples for illustrating the use of our proposed model.

A Systematic Review of the Impact of COVID-19 on Global Sporting Events in 2020: The Tokyo 2020 Summer Olympics

The Corona virus disease 2019 (COVID-19), like no other pandemic has taken the world by storm, affecting all and any spheres of life. This effect has also impacted global sporting events such as the 2020 Summer Olympics that were scheduled for the 24th of July 2020 to the 9th of July 2020 in Tokyo, Japan. Historically, the Summer Olympics have been cancelled 3 times due to war but the postponement that occurred in 2020 is unprecedented. The socio-economic implications are still yet to be fully explored and realised. The purpose of this research is to therefore examine the impact of COVID-19 on the Tokyo 2020 Summer Olympics. The study will adopt a systematic literature review of material on the COVID-19 pandemic in relation to sporting events and statistical inferences will be conducted based on publicly accessible secondary data sources. Considering that the pandemic is still an ongoing phenomenon the findings and analysis cannot be conclusive, a snapshot based on current data and scientific predictions will be provided on what COVID-19 meant to global sporting events. A broad analysis of the pandemic’s impact on sport will be provided despite the focus being on the Tokyo 2020 Summer Olympics. Last, this study serves as a template for further research on COVID-19’s impact on sporting events in general, preferably studies conducted post the pandemic for reflection purposes based on more conclusive data.