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1672-17 History-City of Miami Beach a t-1 Y` t a. -,•d' t T1 q. ..s'aP.PH4 Mt .-: (.'_:.�—:+.L:. [ {'1'.<8 .. ...• . .. ---•:ts:,4 `T'T-}.,t'If F. .. .•..440.0.. --. .. . - ) GEOSCIENCE AND MAN VOLUME XVIII RESEARCH TECHNIQUES LN COASTAL ENVIRONMENTS . ,,. it ,,,. . - � .: ; - , .. r. •: i Il ` k. 4 4.•• \ . .. ' 1 ' % • 411i, 1 •, r : „ r e� fz • ,fr r.s s . . .• . .. • • ` .. ter . . 1 't , * , t ,11111111106400-L 4.1.. 'Ao; . o"CC° R+C 4TT• Lt a .y SCHOOL OF GF'- ` NC's - 7 OUISIANA STATE UNIVERSITY i.� cs. �1K rl GEOSCIENCE AND MAN VOLUME XVIII •r • a «: PUBLISHED BY THE SCHOOL OF GEOSCIENCE LOUISIANA STATE UNIVERSITY RESEARCH TECHNIQUES IN COASTAL ENVIRONMENTS H. J. WALKER Editor for the Volume BATON ROUGE 1977 • • • CARTOGRAPHIC ANALYSIS OF COASTAL CHANGE: NATURAL AND URBAN ROLAND CHARDON Department of Geography and Anthropology Louisiana State University Baton Rouge, Louisiana 70803 ABSTRACT The utility of properly evaluated cartographic materials 1963, 1968). What is sometimes overlooked is that and sources in coastal research is demonstrated by two historical maps and other data, if available and • examples, both in the northern Biscayne Bay area of evaluated properly, can be extremely useful in dating southeastern Florida. In the first case, examination of certain types of coastal changes more precisely than can historical maps indicates that Norris Cut, a tidal inlet other known techniques. Such maps, even if often that exists today south of Miami Beach, was created inaccurate in many ways, can also indicate specific between A.D. 1829 and 1838. In this example,histor- directions in coastal research to be carried out by other ical maps provide more accurate indices for dating means (Chardon, 1975). coastal change than do other known techniques. In addition, cartographic analysis of more modern The second example indicates that cartographic maps can provide a rapid, inexpensive, and relatively comparisons can furnish a rapid and relatively accurate accurate method of estimating the often extensive picture of the geographic extent of dredge and fill changes in coastlines made by human modifications modifications in an urbanized coastal area. United such as dredge and fill operations. Usually, the alterna- States coastal charts drawn in 1887 and 1974 provide tive for constructing a map of dredge and fill areas is a the bases for a map showing most of the areas dredged tedious and frequently incomplete compilation of local and filled in northern Biscayne Bay between those two dredge and fill permits, most of which cover very small years. While the value of the resultant map is di- areas. These permits tend to be scattered in sometimes minished by the limited concept of"coastline" indi- dozens of local administrative offices of autonomous cated on most coastal charts, the map nonetheless pro- municipal and other governmental agencies. vides a method of delineating those major areas of open This paper is concerned with two examples of how water that have been dredged and filled, and of dein- cartographic analysis can be utilized in coastal research. onstrating that roughly 20% of upper Biscayne Bay The first describes how examination of historical maps was filled, and an additional 20% dredged signifi- has permitted the dating of the formation of a tidal cantly, between 1887 and 1974. inlet to within a nine-year period.The second compares two nautical charts, drawn in 1887 and 1974, for the purpose of compiling a map of open-water dredge and INTRODUCTION fill in northern Biscayne Bay:both examples are located in the Miami area of southeastern Florida (Fig. 1). The use of historical maps as evidence of coastal change is not a new technique in coastal analysis(Morgan and THE DATING OF NORRIS CUT Larimore, 1957; deBoer and Carr, 1969; Shepard and Wanless, 1971; King, 1972; Rowntree, 1975; Price, Norris Cut is a tidal inlet,one of four openings through GEOSCIENCE AND MAN,VOLUME XVIII,DECEMBER 30, 1977,PAGES 257-267,5 FIGURES 257 ct • 258 GEOSCIENCE AND MAN, VOLUME XVIII CI—Baker's Haulover Cut — 1 Q .... ,..'''V • (artificial) O# If O 9 / Z:.' • ,. . + 25'52' Study Area / 1, . . El Z • 0- O 3. . Q NAUTICAL MILES . + V + V • + `•', STATUTE MILES I } m W -^ I OKILOMETERS I } E m • 1 ' b I } ,✓. 0 IF tb Boca Ratones (1770) o A is N I 7.-11.::-i-:.......'. + 25.48' T MIAMI ,..1.41,4% td : 0 • +. . V - + 0 — C :' Government Cut ` (artificial) yO• '"iy ... Is.. •+ Bear Cut 25.44' A 2) • 2 l v .t.l CO aa Awl 8 + • mo + S 25.40 r c Cope Florida g I I I I I FIGURE 1. Location of study area. • • Chardon/Cartographic Analysis of Coastal Change 259 the island barrier complex that separates northern Bis- been formed;therefore, it was necessary to examine the cayne Bay from the Atlantic Ocean. Two of these generalized maps for more precise dating of the Cut. openings, Government Cut and Baker's Haulover Cut, Figure 2 shows four sketch maps of northern Bis- have been artificially created since the founding of cayne Bay, all traced and enlarged from maps (1823- Miami in 1896; the other two, Norris and Bear Cuts, 1829)covering larger areas. Each, with the exception were formed as a result of natural forces prior to 1896 of the Searcy map (1829), appears to have been con- (Fig. 1). Wanless (1969), on the basis of extensive strutted from detailed reports or on the basis of per- coring, estimated that the island barrier complex sonal observations by the mapmakers. Figure 2a, taken emerged about 3000 years ago and believed the two from a fairly detailed map of Florida published by H.S. natural cuts were opened within the last 1000 years. Tanner(1823), indicates that Boca Ratones, or Indian For a year and a half, I accumulated and examined Creek Inlet, was closed in 1822. Because the Tanner more than 200 historical maps,all drawn before 1896, map specifically shows Indian Creek Inlet as being as well as a number of written descriptions of this area. closed in 1822, it can be assumed that Tanner paid In only one case (Strobel, [1836] 1961) did a noncar- attention to coastal details. His map shows that there tographic document aid significantly in the dating of was no inlet north of Bear Cut, and, therefore, it seems the formation of Norris Cut, although written notes, certain that Norris Cut did not exist in 1823. letters, or reports accompanying some maps provided The next map analyzed is a sketch (Fig. 2b) by substantiation concerning their validity. In this paper, Colonel James Gadsden ([1825] 1958), showing the the cartographic evidence is considered questionable if east coast of Florida from St. Augustine to Key Bis- no other descriptive corroboration exists. cayne. Gadsden, a topographical engineer, had been A preliminary examination of the maps suggested commissioned to make a personal survey for rhe con- that Bear Cut has probably been in existence since the struction of a road from St. Augustine to Cape Florida. sixteenth century. However, an exceptionally accurate Careful examination of the section of Gadsden's sketch survey of the island barrier complex, drawn in 1770 by that covers northern Biscayne Bay shows an indentation William Gerard DeBrahm, shows that Norris Cut did in the mainland barrier north of Key Biscayne, where not exist at that time (Chardon, 1975; DeVorsey, Indian Creek(or Boca Ratones)had existed,but there is 1971). Further, DeBrahm's 1770 survey places another no indication on his map of a cut in that general area. opening about 8 km north of the present Norris Cut; Further, his letter accompanying the sketch identifies this 1770 inlet was known as Boca Ratones and, later, those water and other barriers to be crossed in the event Indian Creek Inlet(Fig. 1), but it did not exist in 1896. a road were to be built, and in this letter he makes no Similar findings were published by Bernard Romans mention of a cut north of Bear Cut(Gadsden, [1825], ([1774]1924)on his map of Florida(Chardon, 1975). 1958). It seems clear, then, that Norris Cut did not Thus, from the inspection of a few historical maps, it exist in 1825. became clear that Boca Ratones had closed some time John Lee Williams ([1837], 1962) published a re- between 1770 and 1896 and that Norris Cut had been port on the Territory of Florida, with accompanying formed during the same 126-year period. Other maps map, from which Figure 2c is derived. Although his for the period 1770 to 1896 indicated that probable report was published in 1837, Williams personally dates of the Norris Cut opening could be reduced,with visited the northern Biscayne Bay area only in 1828 reasonable certainty, to within nine years,and possibly (Hammond, 1961)and based part of his report on what only one year. The procedure followed is illustrated by he saw in that year. His book was not published until a discussion of eight sketch maps, none of which, by public interest in south Florida was aroused by the themselves, can be considered very accurate. Second Seminole War, 1835 to 1842. Williams' map For the period 1770 to 1823, I have found no maps of the Biscayne Bay region is not accurate, but outlines of the area that were derived from other than De- the bay well enough for our purposes. He definitely Brahm's or Romans' maps, or from earlier Spanish indicates that the peninsula north of Bear Cut was not maps. However, after the transfer of Florida to the interrupted—further evidence that Norris Cut did not United States in 1821, interest in the new territory led exist in 1828. to the compiling of numerous generalized maps of the A fourth map(Fig. 2d)was drawn in 1829 by 1. G. region from the 1820s to the 1840s. In the 1850s, the Searcy, of the Public Land Office in Tallahassee. This United States Coast Survey carefully charted portions of map was "constructed principally from authentic Biscayne Bay, and afterward, maps of the area were documents" (Searcy, 1829), apparently including , much more accurate. In the meantime, Norris Cut had Tanner(1823)for Biscayne Bay. Although he identifies 4 i 260 GEOSCIENCE AND MAN, VOLUME XVIII i a Ki b 1 _ .4 t 26° 0 -31 00 ' 70 Arch CrBaker's Haulover — Raronnes, 17- e 4 • ' Indian Creek Inlet r9 m now (1822) shut Miami Cope Florida Settlement �. Bear Cut Rifer • 0 .hKey Biscayne 43' -- C? , - - A Cape Florida Cape Florida °Soldier Key Key Biscayne Tanner Map-1823 Gadsden Map-1825 d 0 • • 1N / c d -i� , Arch c i 26° _� 26° �ir• 'river. L.% Thio Ratones Bear Cut Baker's Houlover si Key Biscayne ---..\ ®� aeap Cope Florida 0 Indian Creek Inlet Bear Cut QSoldier Keys t Key Biscayne 1, Cope Florida 1 Williams Map-1828 Searcy Map 1829 FIGURE 2. Sketch maps of northern Biscayne Bay, 1823-1829, derived from Williams map;d. Sears m (see text and references): a, Tanner map; b, Gadsden map;c, y ap. • • Chardon/Cartographic Analysis of Coastal Change 261 Indian Creek Inlet in its proper location, his map does questionable, even though Colonel Abert was a topo- not show that inlet, nor any other north of Bear Cut, open in 1829. ably above question. Because the two maps were compiledgraphic engineer whose cartographic integrity is prob- ably Searcy map, admittedly from other, primarily drawn to represent the actual areas of military probably secondary, sources, inay not be reliable con- operations on the mainland in the Everglades area, they cerning Norris Cut and thus represents a caveat against may have represented the relatively unimportant bar- uncritical use of historical maps for solution of the kind rier complex as it had been portrayed on earlier maps, of problem posed in this paper. Fortunately, support- without updating. On the other hand, it also may be ing evidence for the fact that there was no inlet north of that both the Jesup and the Abert maps do correctly Bear Cut is provided by the reports of a medical doctor, indicate the absence of Norris Cut during the time they B. B. Strobel, who visited the northern Biscayne Bay were prepared. region in September, 1829. Strobel, like Williams, did not publish his travel record until some years after The problem is not easy co resolve. If the former een his visit (Haininond, 1961). However, he specified formed any uation rti neebetw bed, then tween andorris Cs 1838. Butcould he if the ✓ with no uncertainty that the barrier peninsula north of latter, then it may be that the Jesup and Abert maps Bear Cut was "mainland" (Hammond, 1961), and it were prepared in early or mid 1838, prior to the draw- seems reasonably certain that Norris Cut did not exist ing of the Johnston map(Fig. 3b)in the same year. In prior to late 1829. this case, Norris Cut would have been created only in Figure 3 portrays Biscayne Bay as depicted in four 1838. Pending corroborating evidence one way or maps that cover larger territory. Unfortunately, I have another, the Jesup and Abert maps present uncertain not yet found any maps of the region for the period evidence for the dating of the formation of Norris Cut. 1829 to 1838, and the maps used in Figure 3 were In any case, in 1839, another "Map of the Seat of drawn in connection with military operations during War in Florida" was drawn for General Taylor by two the Second Seminole War. topographic engineers(Mackey and Blake, 1839). On In the late 1830s, at least two maps "of the Seat of this map,Norris Cut is definitely shown in its correct War in Florida" were drawn: one for General Thomas an unknown location (Fig. 3 c). This map was based on personal Jesup in 1837-1838(not shown here) by observation, as was Sprague's sketch map of southern draftsman and the other for General Zachary Taylor, by Florida (Sprague, [1846J 1964 ; Fig. 3d), which also Colonel J. J. Abert (1838) (Fig. 3a). Neither map clearly shows Norris Cut. Further, the Cut's existence shows Norris Cut in 1837 or 1838 and, at first glance, was strongly implied by sailing directions issued dur- j this would seem to indicate that the Cut had not yet ing that time (Blunt, 1842). After 1849, all United been formed by 1838. But here a note of caution must States Coast Survey maps show Norris Cut in the posi- be inserted, for another sketch map(Johnston, 1838) tion where it is now shown on nautical charts and other clearly shows an unnamed opening in the barrier north maps. of Bear Cut, at the approximate location of Norris Cut In summary, rhe historical cartographic evidence (Fig. ;b). indicates that, prior to 1829, Norris Cut did not exist Johnston's map, although filed in isolation and un- (Fig. 2). Johnston's and other maps show that, from accompanied by any known notes, was almost certainly 1838, an opening did exist where Norris Cut is now based on personal observations. He was part of a Indic- located(Fig. 3b-d). For the years 1829 to 1838, those ary sweep down Florida's east coast during the winter of maps or other documents relating to Norris Cut are 1837-1838, arriving at Key Biscayne in February, subject to some question concerning their reliability 1838(Buker, 1975, p. 59-64). Later commissioned as with regard to the island barrier complex. Therefore, it a first lieutenant in the topographical engineers, he seems reasonable to conclude that Norris Cut was would have had no reason to indicate a cut on his map, created some time between 1829 and 1838;it may have if in fact there had been none. We do nor know, been formed in 1838 specifically. however, just when in 1838 Johnston drew his map. Although peripheral to the main theme of this The sources for the Abert map (and the Jesup map paper, it may be added that natural conditions were not shown here) are so far equally unknown. Thus, sufficient to have created Norris Cut between 1829 and these two maps cannot now be demonstrated to have 1838. While no major storm is known to have struck been compiled either on the basis of personal observa- the Biscayne Bay area itself in 1838, two powerful tion or from primary sources, where the island barrier hurricanes are recorded as having crossed the region, 1 complex is concerned. Therefore, their reliability is one in 1835 and the other in 1837 (Ludlum, 1963). I illi- • ;6; GEOSCIENCE AND MAN, VOLUME XVIII i i a b 3 N ...! . -260 r '3o -26° 0 1 m d ,o•>s 4; .% '9 co SG'tc Key Biscayne CO -(Norris Cut) Q�` Cope Floridaio Dey Biscayne �, Soldier Key Nk- •Soldier Key Abert Map- 1838 Johnston Map-1838 ,, d -25 r26° -/T.7 -$. lr .,"),90�r/e R o0 Via_----' 1111 it' \, �i,9 4� (Norris Cut) V �c C err/P Boca Ratones �'9 m O�J� • C Bear Cut M%an��R �� 67 Key Biscayne Bear Cuts Cut) It Cape Florida • ©Bear QKey Biscayne °o Soldier Key vSoldier Key 1 3 f Mackay and Blake Map-1839 Sprague Map-1846 I FIGURE 3. Sketch maps of northern Biscayne Bay, 1838-1846, derived from (see text and references); a, Abert map; b, Johnston map; c, Mackay and Blake map;d. Sprague map. • 1 • Chardon/Cartographic Analysis of Coastal Change 263 (Chardon, 1976a) have favored the south Florida hur- A third method of obtaining areal data, on at least ricane of 1835, whose center apparently passed some shoreline changes, is to examine and combine squarely over northern Biscayne Bay,as the most prob- local dredge and fill permits and completions. These able major agent that formed Norris Cut. It should be are found in the offices of the various governmental stressed that this is only a tentative explanation, be- agencies under whose jurisdictions the operations took cause no eye-witness accounts of a new-born Norris Cut place. This method provides data only on authorized have yet been found, and tidal inlets can be created dredge and fill activities. It is also dependent on the under a variety of conditions. availability and accuracy of dredge and fill records, which in turn reflect the varying policies and effective- ness of the governmental agencies involved. Indeed, DREDGE AND FILL IN NORTHERN BISCAYNE BAY some records can and do get lost. In other situations, some dredge and fill activities took place prior to The second example of cartographic comparison as a governmental control. Further, there is no reliable useful technique in describing and analyzing coastal check on these sources other than a complete field change is based on two maps,encompassing an 87-year check. Once again, field sampling techniques are not period during which extensive human activities have very useful in this case, partly because data sources are significantly modified the shoreline of northern Bis- not standardized. Even if everything went well, map- cayne Bay. The prime agents of these shoreline modifi- ping of every dredge and fill permit is extremely time- cations have been the dredge and fill operations under- consuming, particularly since, in the case of the Bis- taken since before Miami was founded in 1896. These cayne Bay area, the agencies involved are many and • have aggregated over the years, as urbanization in- dispersed. creased, to affect a substantial — some say total — A fourth technique is the one proposed here, portion of the northern Bay. The cartographic namely, comparative analyses of detailed maps or technique described below also points to other altera- charts of the shoreline. In most cases, fairly accurate tions that have occurred, especially along the Atlantic pre-urban maps are available for coastal urban areas, coast beach of the island barrier complex. and can therefore be utilized to represent shorelines Various techniques can be utilized to indicate those existing before dredge and fill operations and other areas where shoreline modifications have occurred. One modifications took place. And, of course, recent de- is to compare sequential aerial photographs and other tailed maps are almost always available, and they are remote sensing data. Under controlled conditions and increasing in accuracy. with proper interpretation, these data clearly and pre- In the case of northern Biscayne Bay,two charts have cisely indicate shoreline changes; they can also identify been used for cartographic analysis of shoreline filled and, if the water is not too deep, dredged areas. changes. The first was compiled by the United States Unfortunately, such techniques are relatively new and, Coast and Geodetic Survey (1887), showing all of the in many cases, the availability of remote sensing data presently urbanized coastal area of northern Biscayne postdates much dredge and fill for most of the world's Bay. Originally published at a scale of 1: 80,000, this coastal cities. In the case of northern Biscayne Bay, chart covers the Florida east coast, from Hillsboro Inlet aerial photographs are useful indicators of dredge and to Fowey Rocks, with northern Biscayne Bay compris- fill for some parts of the bay since the early 1920s, but ing slightly less than half of this coast. Although are of relatively little value for earlier years, except latitudinal and longitudinal grid coordinates are not perhaps as substantiating evidence. quite correctly located on this chart, corrections have A second way to estimate shoreline modification is to been provided by the Coast and Geodetic Survey in sample the entire area and then sink cores to determine later years, and these require only minor adjustments. where and, if possible, when changes occurred. This There exists no other data base of comparable accuracy technique, while quantitative, involves so many dif- for the entire northern Biscayne Bay area for that faculties that it can be discarded. There are serious period,and the 1887 chart is therefore taken as the best problems in obtaining valid and meaningful samples available portrayal of the shoreline prior to the found- where total geographic coverage of an area is desired,so ing of Miami in 1896 and before dredge and fill opera- that sampling is of dubious value at best. Further, the tions began on a significant scale in 1895 (Chardon, costs of point or traverse coring and analysis are high 19766). and require much tiine, even it it werepossible to cov- The second map used for demonstrating those areas er the northern Bay adequately on a sampling basis. dredged and filled in the Bay is a recent nautical chart, -- .- . • 264 GEOSCIENCE AND MAN, VOLUME XVIII published by the United States National Ocean Survey was constructed, with land area changes marked as in 1974, at a scale of 1:40,000. This chart either"added" or"submerged."This map is shown as (U.S.N.O.S., 1974) was selected in preference to the Figure 5;the black areas indicate fill or accretion above latest United States Geological Survey topographic mean high water, and the diagonal-pattern zones indi- sheets of the same area principally because the nautical tate either dredge or erosion to below mean sea level. In chart, updated annually, is more recent, and incorpo- other words, the black areas were"land" in 1974, but rates coastal changes shown on the United States not in 1887, and the diagonal areas were "land" in Geological Survey maps, as well as other sources. 1887, but not in 1974. The shorelines of the 1887 and the 1974 charts were Thus, Figure 5 shows how land-water areas have traced, and the 1974 shoreline reduced to a scale of 1: changed between 1887 and 1974. Most of the changes 80,000. The 1887 shoreline is shown in Figure 4,with within the bay resulted from dredge and fill opera- tions, although map differences in"land areas"do not, by themselves, identify dredge and fill areas. However, °° m they do greatly facilitate the gross determination of • those changes that result from dredge and fill, as con- trasted to natural sedimentation or erosion. With the land changes mapped, this determination can be ac- _as°sz o d _ complished in two ways. First, sampling can now be Nautical Niko undertaken and field research carried out to establish o 2 ,'� whether a particular area of land change is the result of t sfatvp Wes dredge or fill, or of other factors. The results can then o."1! 2 be projected to the entire area on the basis of standard Kilometersstatistical techniques. A second method, of greater geographic reliability, i : although not absolutely accurate, is to examine and —25'481 �� — compare, by inspection, the water depths indicated on o the two original charts. Any unusual differences in depth can thereby be noted and mapped. This was done 41:, for northern Biscayne Bay, and it was found that large segments of the bay were considerably(as much as 2-3 in)deeper in 1974 than they had been in 1887: these :4. 0 Nwrfs Cut areas are shown by a stippled pattern in Figure 5. +'," 1 Because it is unlikely, in this case, that such large —zs°" v — increases in depth over broad areas of bottom would Sew Cu? CI occur as a result of natural factors, it may be assumed, a pending evidence to the contrary, that they are the result of dredging. Accordingly, the author has indi- cared them as bottom dredging (Fig. 5). It may be further assumed, barring other likely explanations, that adjacent"new land areas"have been created by fill. _zS°or _ With the aid of the charts, only one week was Cope Florida required to construct the map shown as Figure 5. On the basis of field experience, I estimate it would have taken several months to compile a similar map derived 1 i 1 from local dredge and fill permits and maps, without assurance of total coverage. With such a large temporal FIGURE 4. Northern Biscayne Bay shoreline, 1887. investment required, it is not surprising that there are no maps of dredge and fill available for all of northern geographical coordinates corrected; the 1974 shoreline Biscayne Bay, and Figure 5 is the first such map, is the one shown in Figure 1. The 1974 map was then tentative though it may be, to be published for this laid over the 1887 shoreline map, and a third map, region. showing the differences between the two shorelines, It should be recognized that Figure 5 represents a . , t I ' Chardon/Cartographic Analysis of Coastal Change 265 Dot . 'N- o vpi) . FILLED ABOVE MEAN HIGH WATER \ L Bakei4 III DREDGED OR ERODED i0 MEAN SEA LEVEL ' Haulo er — Lm4C 1, Cut CD BOTTOM DREDGING INTRACCYISTAL WATERWAY ,.., T / A + ' `r 1 NAUTICAL MILES Litte q,� �0 / 4/1" 1 - STATUTE MILES 1—...I '.li .-1.._-1._1 1 2 1,? • - KILOMETERS :Bird Key t + + • NI i • MIAMI -- • e."111111411q1 --"•- Government + — / Cut Is '.: Norris Cut + Bea,Cu + 2 I' o� , -1- i + ± Nt r ii6/7 t I t I t FIGURE 5. Northern Biscayne Bay:dredge and fill of open bay(preliminary). I r. 266 GEOSCIENCE AND MAN, VOLUME XVIII preliminary generalized map of land-water changes and Figure 5 also includes those areas, notably along the should be used with caution. First, it needs to be field Atlantic coast, that have largely accreted by sedimenta- checked. Second, it indicates only chose areas of open tion(e.g., the beach just north of Government Cut)or ii bay that have been dredged and that have been filled eroded(e.g., Virginia Key,south of Government Cut). i and raised above mean high water since 1887. Third, Along the Atlantic side of the island barrier complex, the dredged bay bottomlands are indicated in general 44%of the shore length has undergone some accretion fashion only; the map does not show many other bay or erosion since 1887. Some of this change has followed 1 depth changes of lesser degree, which may have re- construction of breakwaters into the ocean from Gov- suited from some of the dredging operations or other eminent Cut that partially block the normal net human activities. Fourth, because both the 1887 and north-south sand transport along the ocean shore. Of 1974 charts identify"land"on the basis of some vegeta- interest is the apparent indication that the beach at tion lines as shoreline (i.e., bayward boundaries of Miami Beach has actually "advanced" since 1887, in mangrove swamps are shown as limits of mean high contrast to the commonly accepted impression that the water), Figure 5 presents a somewhat misleading con- hotel beaches are eroding. Of course, this interpreta- cept of"land;" it also does not show the extensive areas tion may be the result of the scale and degree of accu- of mangrove and other intertidal zones, hidden by tree racy of Figure 5; also it does not take into account cover, that have been cleared and filled. These areas lie short-term changes in beach configurations. primarily on the bay side of the island barrier complex, from Baker's Haulover Cut to the southern tip of Key CONCLUSIONS Biscayne: unless they were under open water in 1887, they are not shown here. The two examples presented above represent carto- In spite of these drawbacks, Figure 5 is useful in graphic analytical techniques that are useful in describ- providing a rapid and relatively inexpensive areal pres- ing and analyzing coastal change. They indicate that entation of the dredge and fill aspects, along with natural and cultural factors have modified northern seaside changes resulting from sedimentation and ero- Biscayne Bay considerably and show what some of those sion(also, partly the result of human activities) in the modifications have been. In the first instance, histori- northern Biscayne Bay area. In a brief paper, it is not cal maps identified with fair precision the dating of a possible to identify all of the changes that have taken locally significant coastal change, namely, the creation place, even in the originally open waters of the bay. of a tidal inlet. In the second example, historical charts However, a crude estimate of the areal extent of change provide the bases for relatively rapid and inexpensive can quickly be obtained by overlaying a grid mesh over means of areal depiction of surface land-water changes, Figure 5 (I used a 5 X 5 mm plastic grid). It is and to some extent, bottom changes, between two estimated that about 20% of the 1887 area of open specified years. While drawbacks are inherent in the water in the bay north of Bear Cut has been filled and use of historical maps, they nonetheless often provide roughly another 20%dredged.Thus,about 40%of the the best available means of evaluating coastal change northern bay has been altered by significant dredge or over time and can point the way to further research fill since 1887. where more precise methods can perhaps be applied. References ki 't ABERT,J., 1838,Map of the seat of war in Florida:Copy in collection CHARDON, R. E., 1972,Northern Biscayne Bay in 1776:Tequesta, of Hist. Assoc. Southern Florida, Miami. v. 35, p. 37-75. BLUNT, E. M., 1842, The American Coast Pilot: 14th ed., New 1976a, The formation of Norris Cut: unpubl. MS. York, E. M. Blunt, 316 p. 19766, A geographical history of the northern Biscayne Bay fBUKER, G. E., 1975, Swamp sailors, Riverine warfare in The area: in Biscayne Bay, Past, Present, Future, Anitra Thorhaug Etrrglades, 1833-1842: Gainesville, Univ. Presses of Florida, (ed.), Univ. Miami,Sea Grant Spec. Rept. n. 5, p. 235-246. 152 p. i i • 1 • • Chardon/Cartographic Analysis of Coastal Change 267 DEBOER,G.and CARR,A.P., 1969,Early maps as historical evidence R. W. Fairbridge(ed.), New York, Reinhold Book Corp., p. for coastal change: Geograph.Jour., v. 135, pt. 1, p. 17-39. 1152-1155. DE VORSEY,L.(ed.), 1971,DeBrahm's report of thegeneral survey in the ROMANS,BERNARD,(1774), 1924,Map of East Florida:Republished southern district of North America:Univ.South Carolina Press,325 by P.Lee Phillips to accompany his notes on the life and works of P. Bernard Romans:Florida State Hist.Soc.,Pubin.n.2,13 sheets. GADSDEN,J.,(1825), 1958,Sketch of the Atlantic coast of Florida from ROWNTREE,R.A., 1975,Morphological aging in a California estuary, the St. Mary's River to the Cape. . . : in The Territorial Papers of Myth and institutions in coastal resource policy:in Coastal Resources, the United States, C. E. Carter (comp., y ed.), v. 23, H.J. Walker(ed.), Geoscience and Man, v. 12, p. 31-41. Washington, D.C., Natl. Arch., p. 301-309. SEARCY,I.G., 1829,Map of Florida.:Tallahassee and Baltimore,I. • HAMMOND,E. A.(ed.), 1961,Dr.Strobel reports on southeast Florida, G. Searcy and F. Lucas, Washington, D.C.,Natl. Arch. Ref. 1836: Tequesta, v. 21, p. 65-75. Coll., Florida, 1829. JESUP, T., 1837, 1838, Map of the seat of war in Florida during the SHEPARD,F. P.and WANLESS,H. R., 1971, Our changing coastlines: winter of 1837-1838: Washington, D.C.,Natl.Arch.& Rec. New York, McGraw-Hill, 579 p. Serv., Record Group 77. SPRAGUE,J.T.(1848), 1964,The origin,progress,and conclusion of the JOHNSTON,J. E., 1838, Sketch map of the eastern coast of Florida: Florida War:Floridiana Facs.,Reprint Ser.,Univ. Florida, 557 Washington,D.C., Natl. Arch.& Rec.Serv., Record Group p. 77, Map L-45. STROBEL, B. B.,Sketches of the peninsula of Florida: in Dr. Strobel KING,C. A. M., 1972, Beaches and coasts:2d ed.,New York,St. Reports on Southeast Florida, 1836, E. A. Hammond (ed.), Martin's Press, 570 p. Tequesta, v. 21, p. 65-75. LUDLUM, D. M., 1963, Early American hurricanes, 1492-1870: TANNER, H. S., 1823, Map of Florida: Washington, D.C., Libr. Boston, Amer. Meteorol. Soc., 198 p. Cong., Geogr.& Map Div. MACKAY,J.and BLAKE,J.E., 1839,Map of the seat of war in Florida: U.S. COAST and GEODETIC SURVEY, 1887, Hillsboro Inlet to Fowey Washington,D.C.,Natl.Arch. & Rec. Serv., Record Group Rocks: U.S. Coast Chart 165. 77. U.S. NATIONAL OCEAN SURVEY, 1974, Intracoastal Waterway-West • MORGAN,J. P.and LARIMORE,P.B., 1957, Changes in the Louisiana Palm Beach to Miami: Nautical Chart 11467. shoreline: Gulf Coast Assoc. Geol. Soc., Trans., v. 7, p. 303- WANLESS, H. R., 1969, Sediments of Biscayne Bay, Distribution and 310. depositional history: Univ. Miami, Inst. Mar. Sci. Tech. Rept. PRICE, W. A., 1963, Patterns of flow and channeling in tidal inlets: 69-2, 260 p. Jour. Sed. Petrol., v. 33, n. 2, p. 279-290. WILLIAMS,J. L. (1837), 1962, The Territory of Florida: Floridiana 1968, Tidal inlet:in The Encyclopedia of Geomorphology, Facs.& Reprint Ser., Univ. Florida, 304 p. • .._. . , t .. ..