SUMMARY Given hydrology's significance to the entire South Florida environmental restoration ... more SUMMARY Given hydrology's significance to the entire South Florida environmental restoration and water management functions of the South Florida Water Management District (District or SFWMD), it is presented as a separate chapter in the 2006 South Florida Environmental Report - Volume I. This chapter updates hydrologic data and analysis from the 2005 South Florida Environmental Report with coverage on hydrology
World Environmental and Water Resource Congress 2006, 2006
South Florida was hit by one hurricane, two major hurricanes, and a remnant of a fourth hurricane... more South Florida was hit by one hurricane, two major hurricanes, and a remnant of a fourth hurricane in less than a seven-week period in 2004. Hurricanes Charley, Frances, and Jeanne along with remnants of Hurricane Ivan had hydrologic impact on South Florida. A similar series of events had not been observed in records dating back to 1871. The property losses from these hurricanes were extremely high. High rainfall, high surface water flows and a rise in lake water levels were experienced. Most of the rainfall occurred on the Upper and Lower Kissimmee Basins, the headwaters of Lake Okeechobee, which is the central component of the South Florida water management system. In these basins, the 100-year return period of monthly rainfall was observed for September 2004. The resulting surface water flow raised the water level in Lake Okeechobee, a 433,000 acre lake, by 5.38 ft between August and October 2004 resulting in a storage increase of 2.37 million ac-ft. It impacted surface water management in South Florida. This paper presents an analysis for the individual and combined hydrologic impacts of the 2004 hurricanes on South Florida.
World Environmental and Water Resources Congress 2007, 2007
The ecological and physical characteristics of South Florida have been shaped by years of hydrolo... more The ecological and physical characteristics of South Florida have been shaped by years of hydrologic variation. South Florida hydrology is driven by continuous balance of rainfall and evapotranspiration reflected in surface water runoff, surface and subsurface storage, flows ...
The ecological and physical characteristics of South Florida have been shaped by years of hydrolo... more The ecological and physical characteristics of South Florida have been shaped by years of hydrologic variation. South Florida hydrology is driven by continuous balance of rainfall and evapotranspiration reflected in surface water runoff, surface and subsurface ...
ABSTRACT Subsurface vapor migration of volatile chemicals may impact ambient and indoor air quali... more ABSTRACT Subsurface vapor migration of volatile chemicals may impact ambient and indoor air quality, increasing the importance to investigate the fate and transport of these chemicals. This project involved both modeling and experimental work to study the vapor phase transport behavior of single, binary, and tertiary component systems present in the gas phase. The experimental phase resulted in the development of a diffusion cell for measuring vapor phase transport. Three organic compounds (toluene, cumene, and isooctane) common to petroleum-based products were selected. The objective of this research project was to evaluate how the rate of a component diffusing alone in a stagnant gas mixture compares to the rate of the same component when diffusing in the presence of multiple diffusing species. The equipment was first validated by measuring the unobstructed gas phase diffusion fluxes for each organic compound. The diffusion coefficients were then calculated from the experimentally measured diffusive fluxes using Fick's Law at 20 and 25°C and compared to the respective literature values. The experimental/literature (E/L) ratio was calculated for toluene, cumene, and isooctane. The range of the average E/L ratio for the single component data sets is 0.93 to 1.05. The validation data provided the baseline for extending the research to multicomponent data. The multi-component systems research was characterized as either binary systems or a three-component system. The binary systems were either isooctane/tolu-ene or isooctane/cumene. The three-component system consisted of a mixture of all three compounds. For both temperatures and all compounds the flux rate decreased for any single component due to the dilution effect by incorporation into a mixture. Applying Fick's Law to calculate the effective diffusion coefficient for each compound that corresponded to the resulting concentration gradient by the mixture, an enhancement in the diffusive flux of each individual species was observed. This enhancement can be explained by a compositional coupling of each component to all others which results in a total vapor phase mass flux comprised of both diffusive and pseudo-advective mass transport. This pseudo-advective component is attributed to simultaneous diffusion of other species in the presence of the one of interest. Since this research project incorporated a mixture of toluene and cumene present in a background carrier solvent of isooctane, by calculating the ratios Dexp(3-component)/ Dexp(2-component) and Dexp(2-compo-nent)/Dexp(single component), an estimate is obtained of the enhancement effect due to the advective component of simultaneously diffusing chemicals. The diffusivity ratios for the three-component system compared to the dual component system ranged from 0.8 to 3.7. The diffusivity ratios for individual compounds were for 1.5-3.7 cumene, 0.8-1.2 for toluene, and 1.0-1.2 for isooctane. The diffusivity ratios for the dual component system to the single component systems ranged from 0.8 to 4.0. The range of diffusivity ratios for individual compounds were for 2.0-4.0 for cumene, 0.8-1.6 for toluene, and 1.1-1.4 for isooctane. A ratio greater than 1.0 indicated an enhancement effect on the molecular diffusion rate due to the presence of one or more additional diffusing chemical species present. The majority of fate and transport models are based on single component behavior modeled by Fick's Law using the pure gas phase diffusion coefficient. The enhancement of the individual diffusive flux in a multicomponent mixture observed in this study and accounted for by pseudo-advec-tive mass transport results in an under-prediction of the actual multicomponent diffusive fluxes. It is recommended that a more rigorous diffusion equation such as the Stefan-Maxwell equation be considered for incorporation into vapor phase transport models when modeling multicomponent/ contaminant systems.
World Water & Environmental Resources Congress 2003, 2003
The South Florida Water Management District is responsible for managing water resources in a 46,4... more The South Florida Water Management District is responsible for managing water resources in a 46,439 square-kilometer (17,930 square-mile) region. The area extends from Orlando to Key West and from the Gulf Coast to the Atlantic Ocean and contains the country's second ...
Journal of the Air & Waste Management Association, 1999
Résumé/Abstract A major route for transport of volatile organic compounds within porous media is ... more Résumé/Abstract A major route for transport of volatile organic compounds within porous media is vapor phase diffusion. The diffusion rate through a porous medium is less than that through free-air due to the decreased cross-sectional area available for gas movement ...
SUMMARY Given hydrology's significance to the entire South Florida environmental restoration ... more SUMMARY Given hydrology's significance to the entire South Florida environmental restoration and water management functions of the South Florida Water Management District (District or SFWMD), it is presented as a separate chapter in the 2006 South Florida Environmental Report - Volume I. This chapter updates hydrologic data and analysis from the 2005 South Florida Environmental Report with coverage on hydrology
World Environmental and Water Resource Congress 2006, 2006
South Florida was hit by one hurricane, two major hurricanes, and a remnant of a fourth hurricane... more South Florida was hit by one hurricane, two major hurricanes, and a remnant of a fourth hurricane in less than a seven-week period in 2004. Hurricanes Charley, Frances, and Jeanne along with remnants of Hurricane Ivan had hydrologic impact on South Florida. A similar series of events had not been observed in records dating back to 1871. The property losses from these hurricanes were extremely high. High rainfall, high surface water flows and a rise in lake water levels were experienced. Most of the rainfall occurred on the Upper and Lower Kissimmee Basins, the headwaters of Lake Okeechobee, which is the central component of the South Florida water management system. In these basins, the 100-year return period of monthly rainfall was observed for September 2004. The resulting surface water flow raised the water level in Lake Okeechobee, a 433,000 acre lake, by 5.38 ft between August and October 2004 resulting in a storage increase of 2.37 million ac-ft. It impacted surface water management in South Florida. This paper presents an analysis for the individual and combined hydrologic impacts of the 2004 hurricanes on South Florida.
World Environmental and Water Resources Congress 2007, 2007
The ecological and physical characteristics of South Florida have been shaped by years of hydrolo... more The ecological and physical characteristics of South Florida have been shaped by years of hydrologic variation. South Florida hydrology is driven by continuous balance of rainfall and evapotranspiration reflected in surface water runoff, surface and subsurface storage, flows ...
The ecological and physical characteristics of South Florida have been shaped by years of hydrolo... more The ecological and physical characteristics of South Florida have been shaped by years of hydrologic variation. South Florida hydrology is driven by continuous balance of rainfall and evapotranspiration reflected in surface water runoff, surface and subsurface ...
ABSTRACT Subsurface vapor migration of volatile chemicals may impact ambient and indoor air quali... more ABSTRACT Subsurface vapor migration of volatile chemicals may impact ambient and indoor air quality, increasing the importance to investigate the fate and transport of these chemicals. This project involved both modeling and experimental work to study the vapor phase transport behavior of single, binary, and tertiary component systems present in the gas phase. The experimental phase resulted in the development of a diffusion cell for measuring vapor phase transport. Three organic compounds (toluene, cumene, and isooctane) common to petroleum-based products were selected. The objective of this research project was to evaluate how the rate of a component diffusing alone in a stagnant gas mixture compares to the rate of the same component when diffusing in the presence of multiple diffusing species. The equipment was first validated by measuring the unobstructed gas phase diffusion fluxes for each organic compound. The diffusion coefficients were then calculated from the experimentally measured diffusive fluxes using Fick's Law at 20 and 25°C and compared to the respective literature values. The experimental/literature (E/L) ratio was calculated for toluene, cumene, and isooctane. The range of the average E/L ratio for the single component data sets is 0.93 to 1.05. The validation data provided the baseline for extending the research to multicomponent data. The multi-component systems research was characterized as either binary systems or a three-component system. The binary systems were either isooctane/tolu-ene or isooctane/cumene. The three-component system consisted of a mixture of all three compounds. For both temperatures and all compounds the flux rate decreased for any single component due to the dilution effect by incorporation into a mixture. Applying Fick's Law to calculate the effective diffusion coefficient for each compound that corresponded to the resulting concentration gradient by the mixture, an enhancement in the diffusive flux of each individual species was observed. This enhancement can be explained by a compositional coupling of each component to all others which results in a total vapor phase mass flux comprised of both diffusive and pseudo-advective mass transport. This pseudo-advective component is attributed to simultaneous diffusion of other species in the presence of the one of interest. Since this research project incorporated a mixture of toluene and cumene present in a background carrier solvent of isooctane, by calculating the ratios Dexp(3-component)/ Dexp(2-component) and Dexp(2-compo-nent)/Dexp(single component), an estimate is obtained of the enhancement effect due to the advective component of simultaneously diffusing chemicals. The diffusivity ratios for the three-component system compared to the dual component system ranged from 0.8 to 3.7. The diffusivity ratios for individual compounds were for 1.5-3.7 cumene, 0.8-1.2 for toluene, and 1.0-1.2 for isooctane. The diffusivity ratios for the dual component system to the single component systems ranged from 0.8 to 4.0. The range of diffusivity ratios for individual compounds were for 2.0-4.0 for cumene, 0.8-1.6 for toluene, and 1.1-1.4 for isooctane. A ratio greater than 1.0 indicated an enhancement effect on the molecular diffusion rate due to the presence of one or more additional diffusing chemical species present. The majority of fate and transport models are based on single component behavior modeled by Fick's Law using the pure gas phase diffusion coefficient. The enhancement of the individual diffusive flux in a multicomponent mixture observed in this study and accounted for by pseudo-advec-tive mass transport results in an under-prediction of the actual multicomponent diffusive fluxes. It is recommended that a more rigorous diffusion equation such as the Stefan-Maxwell equation be considered for incorporation into vapor phase transport models when modeling multicomponent/ contaminant systems.
World Water & Environmental Resources Congress 2003, 2003
The South Florida Water Management District is responsible for managing water resources in a 46,4... more The South Florida Water Management District is responsible for managing water resources in a 46,439 square-kilometer (17,930 square-mile) region. The area extends from Orlando to Key West and from the Gulf Coast to the Atlantic Ocean and contains the country's second ...
Journal of the Air & Waste Management Association, 1999
Résumé/Abstract A major route for transport of volatile organic compounds within porous media is ... more Résumé/Abstract A major route for transport of volatile organic compounds within porous media is vapor phase diffusion. The diffusion rate through a porous medium is less than that through free-air due to the decreased cross-sectional area available for gas movement ...
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