Although we have retained the framework of presentation introduced in the previous edition of this book, we have revised, added, and deleted material for a variety of reasons.

• Current events always mandate an updating of facts and analyses and may suggest discussion of topics hitherto slighted. This eleventh edition would be incomplete without mention of three major natural disasters that occurred after publication of the previous edition: the Southeast Asian tsunami of December 26, 2004; the devastation of New Orleans and nearby areas following the landfall of Hurricane Katrina on August 29, 2005; and the 7.6 moment-magnitude earthquake that struck the Kashmir region of Pakistan and India on October 8, 2005. More prosaically, such things as changes in the production and consumption of natural resources and in spatially variable patterns of population growth and decline require updating in each new edition of our textbook. Every table and figure in the book has been reviewed for accuracy and currency and has been replaced, updated, or otherwise revised where necessary.
• Continuing changes in technology and in social, economic, political, and environmental structures and relationships also require revision of previously published material. Among the topics that merited new or revised treatment in this eleventh edition are fuel economy standards (Chapter 5), illegal immigration across the U.S./Mexico border (Chapter 8), the offshoring and outsourcing of economic activities (Chapter 10), and the disposal of electronic waste (Chapter 12).
• As always, we rely on reviewers of the previous edition to offer suggestions and to call our attention to new emphases or research findings in the different topical areas of geography. Our effort to incorporate their ideas is reflected not only in the brief text modifications or additions in nearly every chapter but also in more significant alterations. See, for example, the treatment of remote sensing and geographic information systems in Chapter 2; the new box "Is Geography Destiny?" in Chapter 7; and a new section reviewing theories and stages of national and regional economic development in Chapter 10.

• Chapter 1 begins with a discussion of the Southeast Asian tsunami, contains a revised "What Is Geography?" section, and has a new section, "Why Geography Matters."
• Chapter 11 has undergone a major reorganization and revision. Much of the material formerly in the chapter has been deleted. New sections include "Origins and Evolution of Cities," "The Functions of Urban Areas," and "Planned Cities." The chapter contains two new boxes: "Central Place Theory" and "The Canadian City."