GEOG 332 - ANALYTICAL EXERCISE

POPULATION DYNAMICS on FLORIDA'S TREASURE COAST

Instructions and Requirements

Migration has always been a potent force in shaping the fortunes and character of America's regions. Those movements typically form well-delineated patterns of channelized flows. For two centuries the dominant flows were westerly, first across the Appalachian Mountains into what would become Kentucky, Tennessee, and the Midwestern states bordering the Great Lakes. Later paths led to Texas, California, and Oregon. Since the 1970s, migration channels have taken on a narrower and more selective focus. Recent target destinations now are likely to be major urban areas in the so-called Sunbelt states. Major recipients of these population flows are greater Phoenix, Dallas-Fort Worth, Austin, Atlanta, and three metropolitan regions in Florida: Orlando, the Gulf Coast centered on Tampa-St. Petersburg, and the Atlantic coast megalopolis which stretches from Miami northward to West Palm Beach and beyond. Within each of these urban areas one can also find channelized migration, or local mobility streams each creating new places while also reshaping existing communities.

South Florida has one of the nation's most attenuated linear metropolitan regions, stretching 120 miles from Miami to Fort Pierce. Squeezed between the ocean on the east and the uninhabitable Everglades or other swampy lands to the west, this megacity is seldom more than seven to ten miles wide. When the coast is so accessible to most residents obviously the notion of living "close to the beach" does not hold the same meaning as it does in southern California.

This exercise asks you to review and interpret community-level differences along the Treasure Coast of central Florida. The region is defined as the three county corridor which extends northward from Fort Lauderdale to include Palm Beach, Martin, and St. Lucie counties. (See maps.) In 1997 the Treasure Coast was home to 1.3 million residents, scattered among three dozen communities and countless rural subdivisions which lie outside of city boundaries. The two largest cities, West Palm Beach and Port St. Lucie, each were smaller in population than Fullerton at the time.

The purpose of this exercise is to sharpen your understanding of intra-regional variations in urban patterns. Because regional growth is uneven over time and from place to place you will need to interpret and map the variability among places located in this dynamic region. In addition to basic population statistics, the data set for the Treasure Coast includes an array of income, age, housing, and place-of-birth evidence. Because of the large number of places within the region, we have limited the evidence to those places which contained populations of at least 5,000 as of 1990.

Regional Growth and Migration

Much of the population change in this region is a reflection of the northward expansion of the so-called, Gold Coast megalopolis which is centered on two poles, Miami and Fort Lauderdale. The development tide, however, has not been a straightforward northerly trajectory. Described as an urban ladder by one geographer, think of its northward extension as a process in which some "outer rungs" of the ladder are added early, then lower steps are filled in later. Some communities, such as Palm Beach and Lake Worth for example, experienced their major growth spurt before 1970, the initial date listed in your tables of evidence. We may not know exactly when their "rungs on the ladder" appeared but we do know that it was sometime prior to 1970, thus making them mature cities within a newly urbanizing region. In contrast, many other places, including Port St. Lucie, were carved out of fields and marsh lands after the mid-1970s. Some are even newer still, being creations of the 1980s and 1990s.

The most often used indicator of regional population change is the average annual growth rate. This may be expressed either as a real number or as a percentage. For example, the Miami MSA, which is equivalent to Dade County, saw its population increase from 1,626,000 in 1980 to 2,076,000 by 1996. That represents an average annual growth of 28,125 (450,000 divided by 16); it also is equivalent to 1.7 percent per year. Any local or regional growth rate above 3.0 percent annually is considered to be very robust.

Such population changes occur as a consequence of three demographic factors: (1) natural increase, (2) net in-migration from elsewhere in Florida and other states, and (3) international immigration. The state of Florida has consistently ranked as one of the top three or four destinations for people migrating within the U.S. over the past half century. In fact, in-migration accounted for six of every seven new residents (86%) in south Florida during the 1980s. On the other side of the equation, natural increase in Palm Beach County supplied a mere three percent of that area's net increase in the same decade. Over time, the importance of natural increase is expected to gain as a demographic force but for now, migration and the preferences of those newcomers define most of the present urban character along the Treasure Coast.

Elderly Migrants and "Senior Landscapes"

It is well-known that in-migration to south Florida is dominated by retirees. Even so, the proportions are not as striking as many people would think. Approximately one person out of every five in the state is age 65 or older. Note from the data tables that the Treasure Coast counties have even higher proportions of senior citizens. Martin County leads the group with more than 27 percent of its population falling within the senior age cohort. Also observe from the map that the senior concentration varies widely from one community to another.

At the opposite end of the age spectrum are pre-schoolers and school-age children. Their contribution to the regional and local age mix is included in the data set supplied with this exercise. You will see from the figures that in St. Lucie County, these youngsters actually outnumber the senior residents (23.1% to 21.0%) but seniors appear to be gaining proportionately.

The retiree population comes to Florida from two major channels, the prominent metropolitan areas of the Northeast and secondarily, from states in the Midwest. The largest source areas are the greater New York City region, Philadelphia, and Boston. Consequently migrants from those places bring a tradition of relatively high density urban lifestyles which find their expression in numerous 8-10 story high rise apartments or condos rising out of the flat coastal plain of eastern Florida. Other newcomers prefer low density single family tract housing or mobile home communities bundled with such amenities as community swimming pools, recreation centers, and golf courses. Such variations in housing styles in turn create differing patterns of housing cost and housing values. It is not uncommon to find moderately-priced or even lower cost housing close to the sand while more expensive luxury homes are further inland. The overall pattern is more akin to a patchwork quilt lacking in design rather than an easily predictable regularity. Simply put, housing prices in this region will reflect housing types more than location.

The economic circumstances of residents along the Treasure Coast are also highly varied. Some bring considerable wealth and solid incomes from hearty pensions and investments. A far greater number have more modest means. Indeed, even the term "retiree" is not completely accurate, as one recent survey found that one-fifth of the region's population over age 65 was employed either full- or part-time. Regardless of income, the newcomers to the area stimulate the local economy, particularly in terms of the demand for medical services, financial services, recreation, and leisure pursuits. Even retailing enjoys a healthy boost, no doubt, as many senior citizens have ample time to shop and resources to spend, especially when the purchases are made for their grandchildren and children.

Data Set & Terminology

Before you begin to work with the evidence on this region, you need to be aware of some basic terminology and some data limitations. Most evidence is extracted from the 1990 U.S. Census of Population and Housing. However, the state of Florida has provided estimates of the April 1997 population for the counties and municipalities in each county. Those are formally incorporated places with clear boundaries and legal powers granted by the state; we commonly use the terms towns and cities as interchangeable with municipality. About one-fourth of the places in the data set are closely settled communities which may exist as post office addresses, have no formal boundaries, and no legal standing in the sense of a local government. Those are termed census designated places (or CDPs). For example, Hobe Sound in Martin County is one such CDP. [These CDPs also may be found here in California - Foothill Ranch and Coto de Caza.]

A few social and economic indicators are included in the evidence packet. Percent age 65+ and percent under age 18 enable us to identify places which are dominated by senior citizens or have a stronger "young family" character. Percent born in Florida or its mirror image (100 minus that value) provides a clue about those places that have been largely shaped by native Floridians or an in-migration of people from other states. Upper quartile housing value refers to the market value of the most expensive one-fourth of the housing stock in a given community. As you can see, some of the Treasure Coast towns and cities have housing costs which are comparable to those in southern California; others are dramatically lower in price --- even in recently developed places. Finally, the median household income is the dollar amount which divides households into two groups, half whose income is above that amount and half whose incomes fall below that median bench-mark. We have also indexed household income to the statewide level for Florida to provide a frame of reference for interpretation. The income index of 0.69 shown for Fort Pierce, for example, means that the median household income in that city is just 69% of the value for the state of Florida in general. Put another way, its income level is 31% below the state's average.

Instructions & Detailed Questions

Using only the materials provided, please answer the following questions and submit them as "The Communities of Florida's Treasure Coast." That typewritten packet does not need to repeat the detailed questions, a simple numbering of your responses will be adequate. Some may be answered in just a few words; others may require a paragraph or two. One "point pattern" map is also to be submitted with this exercise. Do not submit the original data set or these instructions.

1. What was the rate of population growth for the entire region

a. during the 1970s?

b. during the 1980s?

c. since 1990?

2.  Why are there no population figures provided for several places for 1997?  Think of yourself as the 'census enumerator,' and comment on why CDP locations are problematic for data collection and for determining trends.

3. Maps are a powerful tool for visualizing spatial patterns and monitoring the impacts of processes upon the landscape over time. Review the map which displays the "Percent of Population Age 65+" to answer the following questions. (a) Which places have the strongest concentrations of older persons? (b) Are these randomly distributed across the region or is there some clustering; where is(are) the cluster(s)? Where might you find a possible future cluster? (c) Speculate on what factor(s) might have led to a concentration of senior residents in particular cities -- aside from the fact that they might prefer to live close to each other.

4. Which places have been the leading destinations in this region for the retirement age migrants to Florida? (No more than the top four, please) What evidence did you use to choose those cities? What else can you say about the character of those retirement havens based on the available evidence?

5. Using the base maps and data provided, prepare a new map which shows the decade of peak growth for each place. Display those patterns via four symbols: pre-1970, 1970-79, 1980-89, and since 1990. Each community will have only one symbol based on when its peak growth occurred. Now that you have the map you may be able to see some clustering of growth and the shifting of the "growth waves" across the Treasure Coast region over time. Discuss these patterns in one paragraph.

6. A casual drive through any urban area reveals considerable variability in housing, based on the time period of construction, quality, and value. So too does a "tour" of the statistical evidence for an urban region. Offer possible explanations for the sharp differences in housing values from place to place in the region and provide some examples.  Note:  Location relative to the ocean plays only a small role in this Florida region because virtually every place is within three or four miles of the water.  What other factors may have caused the differences listed in the housing values? (One paragraph)

7. You have sat in your last southern California traffic jam. Please address the following scenario: Imagine that you and your significant other plan to move to this part of Florida and raise a family. You want to be a physical therapist working with gerontology; your partner wants to teach in a local high school. Neither of you likes a lengthy commute. Realistically, what would be your top four choices of towns or cities in which to live? Explain why you chose those. (Use approximately three paragraphs)

Submission Requirements

At the top of the first page of your exercise include your name the title, "The Communities of Florida's Treasure Coast". No special covers or binders please! Responses to the questions plus the accompanying map are due not later than the date listed in your syllabus. Late papers are subject to grade penalties.

last updated 09/16/24