Solute dispersion in the nearshore: Laboratory and numerical results

The nearshore zone experiences pollutant loading through both the seaward and shoreline boundary. At the seaward limit this occurs through impacts from marine outfalls. However, more importantly close to or at the shoreline, pollutants enter through storm overflow discharges from overloaded sewerage systems during rainfall events. The nearshore zone is an area of high amenity value and there is therefore a strong need to manage efficiently the conflicting demands of waste management, recreation and fisheries. Through a series of hydrodynamic and tracer measurements and their comparisons with numerical modeling results, this study quantifies the physical processes and their integrated effects on a solute tracer in the nearshore zone subject to combined waves and longshore currents. The results improve the estimate of surfzone dispersion coefficients.