A Louisiana Coastal Atlas: Resources, Economies, and Demographics by Scott A. Hemmerling

Loss of coastal land and wetlands in Louisiana has been estimated to be about 1,883 square miles since 1932, with an expected loss of another 1,750 square miles by 2060. This area has always had a shifting coastline as the delta of the Mississippi River has changed course several times, with residents having to adapt over the millennia to changing coastlines and wetlands. Coastal populations in the United States have increased tremendously over the last several decades. The Gulf of Mexico region, however, grew at an even more rapid pace. Like many other coastal regions, extensive flood control systems have developed in Louisiana, although here this infrastructure moved even deeper onto narrow fingers of land where people have settled. The theme of this atlas is that coastal and wetland loss in the region cannot be examined or mitigated by looking at this phenomenon as simply a physical problem alone. Instead, it must recognize the deep impact to the economic and cultural activity that has deep roots in this region. Indeed, "the human population [is] a dynamic part of coastal Louisiana" (2).

This atlas focuses on the parishes in South Louisiana, yet easily moves to other scales when a more narrow or broad focus is required, a great strength of this work, as it is in the entire field of geography. Figure 36, for example, narrows the focus onto the extreme southeastern portion of the coastal region to examine storm surge from Hurricane Katrina (p. 73), while figure 62 is a series of six maps looking at population change for the entire state from 1950 to 2010 (p. 124). The atlas is divided into four chapters, along with an excellent introduction by Craig Colten, and the author's small, but powerful, concluding chapter. While each of the chapters has its own theme, they all focus on the deep, interconnecting human and environmental connections unique to this region.

The maps begin by examining the vulnerability to the social system of the present population, showing settlement stretching onto slivers of vulnerable, slightly higher ground. These populations depend heavily on a variety of unevenly distributed natural resources for their economic livelihood, with a tremendous diversity of economic activities tied to different resources across these parishes. Economic livelihoods here depend on agriculture, fisheries, aquaculture, petroleum, natural gas, water transportation and navigable waterways, and ports. The ability of a community to respond to changes in the physical environment or natural hazards depends a lot on "lack of income, lack of transportation, age, gender, and minority status" (31). Many of these factors interact with one another, and the maps display this interaction. For example, figure 22 (p. 35) shows the high percentage of Native American populations in the extremely vulnerable coastal parishes of Terrebonne, Lafourche, and Plaquemines, and figure 23 (p. 36) illustrates the high dependency ratio for South Louisiana, especially for vulnerable elderly populations.

The historic change of the physical environment, both short- and long- term events, have forced the people of this region to adapt to, prepare for, and recover from often extremely disruptive natural hazards. The natural resources that many people so heavily depend on for their livelihoods is often threatened by natural hazards, as well as man- made ones, such as the release of toxic chemicals and oil spills. Fish and shellfish are particularly affected by various hazards, and while the amount caught might remain stable, the lack of demand, such as after the Deepwater Horizon disaster in 2010, can drive down the economic value of these resources. Economic activity may also scar the land and exacerbate environmental problems. Not only were canals dug through wetlands for pipelines, but also for logging cypress, as the large trees were easier to transport by water, and were often dragged across fragile wetlands to reach the canals. These canals open fragile environments to increased wave action, both natural and man-made by the wake of boats and barges, accelerating land loss.

Communities and regions often respond to environmental changes and hazards in ways that are vastly different from what public policy might prescribe for often short- term solutions. Populations sometimes respond to public policy in ways that are maladaptive in the long term. The National Flood Insurance Program was implemented in 1968 to offer insurance to those in flood- prone areas not covered by private insurance. The goal was to reduce the development, and hence the risk, on floodplains. Instead, the majority of people in this region have subsidized flood insurance so they could build on low- lying, flood- prone areas. Now, any rise in premiums would especially hit those already on the edge of poverty, such as low- income and minority residents. Large-scale levee projects have proven to have historically protected the majority of residents in South Louisiana, but have also encouraged people to develop and populate many areas that are at a significantly higher risk of flooding.

The atlas has so many interesting maps that tell the social, economic, and cultural historical geography of the regions that this review cannot do it justice. The maps are accompanied by very brief descriptions of the factors affecting the topics covered, but this is an atlas, not a monograph, so that is to be expected. While this atlas focuses on South Louisiana, it contains relevant lessons for policy makers and residents of at- risk coastal zones under threat of rising sea levels, and reminds us to include the human element in any assessment of coastal land loss.