Analytical estimates of hydraulic parameters for an urbanized estuary – Flushing Bay

Abstract

Summary Prediction of water quality improvements in urban estuaries is an urgent priority for decision making about alternative mitigation measures, especially in the context of changing pollutant loadings and freshwater discharges. Flushing Bay, an embayment of the New York–New Jersey Harbor Estuary, is a “short” estuary (a special class of coastal plain estuary with specific geometric characteristics), in which source loading is changing and little is known about resultant mixing processes and characteristics. First-order values of longitudinal dispersion coefficient, tidal excursion and tidal prism for this estuary have been estimated from non-synoptic salinity data using an adaptation of a one-dimensional theoretical salinity intrusion model. Results indicate that ranges of longitudinal dispersion coefficient are highly dependent on estimates of groundwater discharge, and the spatial distribution of salinity and dispersion coefficient values is most sensitive to conditions at low water slack (LWS). These findings represent a starting point for further investigation of either groundwater discharge to the bay using numerical modeling or field studies of longitudinal dispersion coefficient and mixing using sophisticated tracer methods.