Finkl, Charles W.

In Florida beach renourishment is the preferred management technique used to maintain the integrity of local beaches, which generate over 7.9 billion a year in revenues from tourism. Beaches are dynamic and often exhibit accelerated rates of erosion and shoreline retreat. Sites that erode more than twice the regional background rate are classified as "erosional hot spots" (EHS). Emergency remediation of EHS is necessary to avoid loss of beach sand from renourished beaches. Because suitable offshore borrow materials are limited in Broward County, coastal managers are seeking alternative sources of compatible beach fill materials. The manufacturing of glass sand from processed recycled glass is a new, innovative technology. This report evaluates the potential application of glass sand for EHS remediation along renourished shores. Benefits of processed glass sand are: (1) preferred grain size by crushing of recycled glass, (2) an environmentally inert material, and (3) physical properties similar to the composition and color of native sand. The recycling industry in Florida generates almost 100,000 m^3 of glass a year, 30% of which is unsuitable for recycling. Alternative uses for waste glass cullet are being sought to reduce the high cost of disposal in landfills.

Protection of groundwater resources in southeastern Florida is essential because of increasing demands on water quality and supply. Because water is furnished to public and private water systems from production wells that tap the non-artesian surficial aquifer, contamination of groundwater from leaking petroleum storage tanks must be curtailed. In the study, a series of land use maps is developed based on aerial photographs (1970, 1984, and 1991) for a 40 square mile area in southeastern Palm Beach County, Florida. The locations of petroleum storage tank systems and contaminated sites are mapped. The point biserial correlation coefficient is used to examine the strength of the relationships between historical land use, storage tank system capacity, and the presence of petroleum. contamination. The results indicate no correlation between the intensity of urbanization (historical land use) and petroleum contamination and positive correlation between petroleum storage system capacity and petroleum contamination.

The interaction of tidal currents and bathymetry in the nearshore environment is investigated as an essential component in the study of cross-shore turbidity plumes. Clay and silt-sized grains which comprise a minor portion of natural beaches and artificial fills are modulated through the water column by nearshore currents. Tidal jets and undertow currents are forcing factors in the expansion of circulation currents that carry fine-grained suspended sediments offshore in large mega-plumes. Enhanced contextual coverages from satellite imagery delineating plume morphology show a strong relationship between bathymetry and tidal current. The forces exerted by tidal action and frictions resisting this movement are examined by incorporating techniques of image processing, modeling, and statistical analysis in a GIS database environment. This analysis examines an experimental anisotropic cost distance algorithm that is utilized in the modeling of turbidity plumes to better understand the dispersion of suspended sediments in coastal Broward County.

Shorelines are prefigured by inherited geologic features and spatially-defined process-form relationships that require in depth study. This thesis is based on the interpretation, delineation, and analysis of coastal geomorphological features, as mapped from large-scale (e.g. 1:3600), digital, georeferenced, stereo-paired, color, aerial photography. The morphologic features identified include coral-algae reef tracts, rock reefs, sedimentary features such as bars, troughs, and sandflats, and different types of engineering works. Interrelationships between these morphologic features are analyzed using a remote sensing-GIS/MIS (Geographic and Marine Information Systems) framework, and applying interpretive approaches in the analysis of beach and nearshore morphodynamics. Sediment and wave data is used to calculate the dimensionless fall velocity (O), which combined with local geomorphology, defines beach types. Special purpose geomorphological and morphodynamic maps generated here, together with assessment of beach types and analysis of downdrift erosion provides new insights and deep understanding of large scale coastal behavior, which is of great use to management planning strategies.