Coast Lines: How Mapmakers Frame the World and Chart Environmental Change (review)

Mark Monmonier is a cartographer, distinguished professor, and writer extraordinaire who has produced fifteen books on various themes tied to mapping. This volume, on mapping shorelines, is yet another excellent contribution, and one that fits well within the theme of technology and culture.

The aim of the book is to present to a general audience an overview of how mapmakers have represented various intersections of land and the sea. Monmonier identifies four distinct coastlines: a high-water line, represented on most maps and atlases; a low-water line, developed in the nineteenth century as a navigation aid for larger vessels; shorelines projected on the basis of storm activity and coastal erosion; and shorelines projected as a result of sea-level-rise forecast models. In the preface, Monmonier admits that the content can get quite technical. However, the technical details are, for the most part, relegated to the references and endnotes, and the overall read of the book is smooth and straightforward.

The eleven chapters support the scope well. The first chapter is a primer on concepts in mapping, especially as applied to shoreline, and includes discussions of scale, generalization, resolution, types of navigation charts, and map accuracy. Chapter 2 is a primer on tides, tidal datums, coastal surveying, and coastal mapping. Monmonier includes a nice summary of U.S. Coast and Geodetic Survey mapping and also Flood Insurance Rate Maps. Chapter 3 goes over the history of coastal mapping, from the portolan charts to early experimentation with grid systems to mythical islands. Chapter 4 covers nineteenth-century technologies, notably the theodolite and triangulation, especially as used by U.S. coastal surveyors.

Chapter 5 introduces aerial photography and how it advanced coastal mapping. It covers stereoscopy and advances in topographic mapping and ends with an overview of lidar mapping (topographic and bathymetric). Chapter 6 examines map projections and global reference datums (geoids, spheroids, ellipsoids) and their improvements and digitization over time. Chapter 7 continues a historical overview, here beginning with the later-nineteenth-century movement to map the world at a decent (1:1,000,000) scale. While this took many decades, most of the early maps were of coastal areas. This work culminated in the modern electronic databases, including the World Vector Shoreline.

Chapter 8 addresses coastal baselines and boundaries and territorial seas. It is a good summary of how jurisdictional waters are determined (and how disputes are settled). Chapter 9 focuses on the third set of coastlines by examining FEMA’s 100- and 500-year flood-elevation and SLOSH models that project storm surge elevations, and the myriad of shortcomings associated with them. Chapter 10 looks at the fourth set of coastlines, those associated with future sea-level projections. Historic depictions of sea-level rise are followed by modern, often alarmist, projections of future levels. Many of these exhibit inaccuracies because of variations in slope and new equilibria in beach profiles (e.g., the so-called Bruun Rule). Chapter 11 summarizes by noting the evolving technology of mapping, from engraved portolan charts to coastal thematic maps produced by Adobe Illustrator.

This book provides an excellent overview of coastal mapping. Many of the topics such as coastal boundaries and baselines are complex, but Monmonier keeps the discussion simple and directs the reader to the appropriate sources for further information. I found Coast Lines to be comprehensive and mostly error-free. One exception is Figure 9.3 (p. 122), which purports to show Charlotte Harbor, Florida, when in fact it covers the same area as Figures 9.5, 9.6, and 9.7 (pp. 127–29), namely Lee County’s lower Caloosahatchee River.

The value of this book is as an introduction to coastal mapping. Specialists in the field may find it too broad-brush, and, as an academic, I cannot see using it as a textbook other than perhaps as additional reading. But the projected audience is a general one, and that may be the...