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Abstract:
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Coastal zones are transitional environments between terrestrial and marine realms; within them, estuaries and coastal lagoons stand out as dynamic ecosystems whose hydrodynamics are governed by various hydrological forcing factors. This study analyzes using monitoring data and statistical techniques how these forces influence water level fluctuations in coastal lagoons. Coastal lagoons are of great environmental, economic, and social importance; however, knowledge gaps remain regarding how different hydrometeorological forces influence their dynamics across various time scales, which serves as the primary motivation for this research. The study aims to examine these dynamics by performing parametric and non-parametric correlation analyses between hydrological forcing factors specifically precipitation and ocean levels and the water level of the Lagoa da Conceição lagoon in Florianópolis, Santa Catarina. The dataset includes precipitation, ocean level, and lagoon level data provided by EPAGRI (Itacorubi), the CASAN wastewater treatment plant (Lagoa da Conceição), and LAHIMAR (UFSC). Non-parametric correlation tests (Spearman, Gamma, and Kendall’s Tau) were conducted for each case, with a p-value < 0.05 considered significant. Subsequently, variable distribution was assessed using the Shapiro-Wilk (SW-W) and Kolmogorov-Smirnov (D) tests. Precipitation data required transformation to logarithmic and Box-Cox transformations to enable Pearson correlation analysis. Overall results indicate generally weak to moderate non-parametric correlations; some negative correlations were observed, suggesting a response lag between precipitation and lagoon levels a pattern also reflected in the Pearson correlation results. Sea level, in turn, showed weak correlation in non-parametric tests and moderate correlation in the Pearson test. From a hydrological perspective, it can be concluded that precipitation plays a significant role in the lagoon's hydraulic load; however, it did not elicit an immediate response in the lagoon level, contributing only partially to the water level as a factor conditioned by other drivers, such as ocean levels. |
