Integrated framework for assessing coastal water auto-purification potential

In tourism-oriented coastal regions, maintaining water quality is critical amidst growing anthropogenic pressures. Balancing the natural auto-purification capacity of coastal waters with human interventions requires innovative approaches to mitigate and manage pollution. This study presents a multidisciplinary and integrated framework for assessing auto-purification potential, demonstrated through a case study in the Brač Channel and Kaštela Bay in the Eastern Adriatic Sea. Using the results of atmospheric-oceanographic modelling with WRF-ROMS, Lagrangian particle tracking was applied to simulate non-conservative pollutant transport under varying hydrodynamic conditions. Stochastic ensemble analysis and spatially integrated statistics were utilized to develop a novel, scale-adaptive methodology for quantifying auto-purification potential. Results revealed significant differences in pollutant dispersion during characteristic Bora and Sirocco events, offering actionable insights for monitoring strategies and managing additional pressure inputs. While focused on this case study, the framework provides a scalable approach for evaluating and sustaining water quality in other critical recreational coastal zones.