Application of non-parametric statistical methods for analyzing sea surface temperature and salinity trends in the Southern Coast of Viet Nam

Tóm tắt

This study analyzes the long-term and seasonal trends of sea surface temperature and salinity from 2003 to 2023 at six monitoring stations located along the coast and on islands in Southern Viet Nam using non-parametric statistical methods, including the Mann-Kendall trend test and Sen’s slope estimator. These methods are well-suited for non-normally distributed and highly variable time series data. The results show a general warming trend in sea surface temperature, more pronounced during the rainy season, with statistically significant increases observed at Phu Quoc and Tho Chu, indicating regional ocean warming in the Southwestern coast, while Vung Tau exhibits a slight cooling trend. Sea surface salinity trends are more spatially heterogeneous, with Truong Sa being the only station showing a consistent and statistically significant decline in salinity across both seasons, whereas other stations display weak or statistically insignificant variations. These findings reflect differences in oceanographic dynamics, including the effects of rainfall, evaporation, ocean currents, and regional climate variability across the Southern coastal region and the East Sea. The study provides a valuable scientific basis for environmental monitoring, marine spatial planning, sustainable fisheries development, and climate change adaptation, and recommends enhancing data coverage through expanded observations, remote sensing integration, and regional ocean climate modeling to improve future trend assessments.