Search Results (3)

This study examines equifinality and compensatory calibration in hydrodynamic modelling of semi-enclosed coastal systems, using the Xiamen–Kinmen coastal waters as a representative tide-dominated case. A progressive diagnostic framework based on the normalized marginal contribution rate (MCR) was developed to quantify the relative effects of open-boundary forcing, spatially heterogeneous bottom friction, and atmospheric forcing within a depth-averaged barotropic model. Multi-metric validation against in situ water-level and depth-averaged current observations shows that the physical consistency of open-boundary forcing is the dominant control on model skill, particularly in reducing systematic elevation bias within the embayment. Bottom-friction parameterization produces more localized and site-dependent improvements, mainly affecting the spatial structure of current speed and direction under geomorphological constraints. Atmospheric forcing contributes only limited marginal gains during the study period, with modest directional corrections under weaker tidal conditions. These results indicate that hydrodynamic optimization for semi-enclosed bays should prioritize boundary consistency before local parameter tuning, thereby reducing compensatory calibration risk and improving physical interpretability. Remaining localized velocity errors in estuaries and high-curvature channels highlight the limitations of the depth-averaged barotropic assumption, under which density-driven baroclinic flows and vertical secondary circulations cannot be explicitly resolved. The proposed framework provides a reproducible approach for diagnosing and optimizing nearshore hydrodynamic models. Full article

Surface thermal environment (STE) is closely related to the comfort and health of residents, affecting regional livability, and its spatial and temporal changes are deeply affected by the urbanization process. Considering there is a lack of effective comparative analysis on STE in different urbanized inhabited islands, the special geographical unit and vital human settlement environment, long-term spatiotemporal characteristics and impact factor quantitative analyses were performed in two inhabited islands via the RS and GIS methods. The results suggest that the surface heat amplitude of the highly urbanized Xiamen Island decreases, with the surface heat intensity continuing to increase from 2000 to 2020, while that of the lowly urbanized Kinmen Island is reversed. Although the land surface temperature (LST) of the two inhabited islands shows similar spatial distribution characteristics with evident cold/hot spots, the geographical distribution characteristics of high LST zones are significantly different, and the thermal landscape of Xiamen Island is more fragmented, discrete, and simple in shape, as revealed by the landscape metrics. We demonstrate that the area proportion between cooling land (water body and greenland) and warming land (bare land and impervious surface) is the most influential factor of LST in the two islands while the marine environment is a unique contributor to STE of inhabited islands compared with inland cities, where the seawater around the island can reduce LST over a range of distances, and the influence of elevation on LST is mostly indirect. These results provide a scientific basis and case support for understanding the STE situation of inhabited islands with different urbanization levels. Full article

Mainland China’s economy has been developing rapidly. Unfortunately, it has led to an increase in municipal and industrial waste, including in Xiamen, in which is has greatly increased. Kinmen is located outside the estuary of the Jiulong River in Fujian, Mainland China, opposite to Xiamen Bay. Whenever there is heavy rainfall, the waste that flows along the Jiulong River is incredible. Kinmen unavoidably has to bear the invasion of floating marine debris due to the effect of ocean currents, tides and monsoons. It does not only pollute the Kinmen sea area, but it also affects the scenery of the beaches in Kinmen. Therefore, this study aimed to explore the data of Kinmen and Xiamen governments regarding the cleaning of floating marine debris, and the differences in distribution areas according to the monsoon, ocean current and tides. In-depth interviews, field investigation, and collection of expert opinions were applied in order to determine the research implication. The results of this study provide information on the marine issues encountered in the governance of the countries surrounding the sea. The study suggests that the transboundary marine governance mechanism should be established in order to effectively solve the problem of floating marine debris in Kinmen–Xiamen Waters. For the welfare of the people, it is expected that the governments of Mainland China and Taiwan will uphold the principle of “pragmatism and reciprocity” by working together to maintain the marine environment in Kinmen–Xiamen waters. Full article