Storm surge, resulting in an 

 increase in high tides and rough 

 seas, is caused by a complex inter- 

 action of storm wind, minimum pres- 

 sure, and the slope of the bottom 

 topography of waters adjacent to the 

 land (Gentry 1974). The effects are 

 of course more pronounced when the 

 storm moves onshore, as opposed to 

 moving along the coastline. Since 

 1873, 8 hurricanes have caused 

 record storm tides in south Florida, 

 2 of them within the study area 

 (Simpson et al. 1969). There ap- 

 pears to be no discernible pattern 

 in the occurence of these great 

 storms - all areas of the coast have 

 been equally affected. Record storm 

 surge tides range between 2.9 and 

 5.5 meters (9.5 and 18 feet) above 

 undisturbed or still water levels 

 (Simpson et al. 1969). In addition, 

 coastal areas are also subject to 

 strong wave action which causes 

 waters to reach even further inland 

 than indicated by tide heights alone 

 (Gentry 1974). 



The amount of rainfall associ- 

 ated with tropical storms varies 

 greatly depending on several fac- 

 tors, the more obvious ones being 

 the intensity of rainfall, the for- 

 ward movement, and the size of the 

 storm (Gentry 1974). Because of the 

 violent nature of the storm, the 

 error in the rainfall measurements 

 may be as high as 50%. Usually 

 12.5 to 25 centimeters (5 to 10 

 inches) of rain are recorded during 

 the passage of a tropical storm 

 (Gentry 1974). 



3.8 AIR POLLUTION 



Three general types of atmo- 

 spheric contaminants (related to 

 both natural and man-made sources) 

 affect the south Florida environment 

 (Echternacht 1975). These are: (1) 

 sources for small particulate matter 

 that can form condensation nuclei, 

 (2) sources for particulate matter 



suspended in the air that can be 

 scavenged by falling raindrops, and 

 (3) sources of solutes which are 

 dissolved in condensation particles 

 (cloud droplets). The sources for 

 all three and their geographic dis- 

 tributions are dependent on the 

 basin weather patterns. For the 

 Everglades/Bay/Keys basin this means 

 the wet-dry season variation. Pas- 

 sage of large scale synoptic systems 

 during the dry season (November- 

 April) may contain pollutants from 

 sources far removed from the state 

 (Echternacht 1975), in addition to 

 localized sources (Holle 1971). Wet 

 season convective systems exhibit 

 diurnal activity related to land-sea 

 breeze interactions. These systems 

 convey atmospheric contaminants 

 primarily from local sources, i.e., 

 automobile emissions, stack gases, 

 fertilizer and pesticide dusts, and 

 ash from burned marsh grasses and 

 sugar cane residue (Holle 1971, 

 Echternacht 1975). 



Two mechanisms are involved in 

 the movement of ail — borne contami- 

 nants from the atmosphere to the 

 land and water surfaces. The mate- 

 rial, inorganic and organic, is 

 transported either by (1) wet or 

 (2) dry fallout (Irwin and Kirkland 

 1980). Material associated with dry 

 fallout is in a continuous flux of 

 suspension and deposition, e.g., 

 wind generated dust, car emissions. 

 Those materials deposited during wet 

 fallout or rainfall, either in a 

 dissolved or particulate form, are 

 affected by two processes referred 

 to as rainout and washout (Echter- 

 nacht 1975). Semonim and Adams 

 (1971) describe rainout as the re- 

 moval of aerosols in the rainmaking 

 process and washout as the process 

 of falling rain scavenging air-borne 

 particulates. For instance, in 



south Florida Echternacht (1975) 

 concluded that with nutrient fallout 

 total phosphate (TP0 4 ) in the par- 

 ticulate form is subject to the 



42 



