ABSTRACT
This introduction presents an overview of the key concepts discussed in the subsequent chapters of this book. The book presents at a symposium entitled which took place in Denver on the morning of February 21, 1977 as one of the first sessions of the 1977 annual meeting of the American Association for the Advancement of Science. It demonstrates that drought is a recurrent and inevitable feature of the climate of the North American mid-continent. The book utilizes the Palmer Drought Severity Index as a tool for mapping the temporal and aerial occurrence of drought across the continental United States. It shows that the greatest seasonal or climatic fluctuation associated with negative deviations of corn yields is drought. The book suggests that good seasonal weather and bad seasonal weather years to not occur at random in time or space and that, historically, in North America they have occurred over series of years roughly in alternate decades.
