Deserts are parts of the Earth that receive little or no rain; 25 cm or less per year. The physical processes that act upon these parched lands are vastly different from those that shape the more humid parts of the terrestrial landmasses. In the desert, wind is a major agent of erosion and transportation. As the results of recent space missions have indicated, this is also true in the case of the planet Mars. Thus, our understanding of desert processes sheds light on fundamental planetary processes that may apply on any planetary body that is enveloped by a windy atmosphere. An understanding of the physical layout of arid lands, and the nature of processes that initiate changes therein is also fundamental to thoughtful utilization of these lands for the benefit of mankind. It is with this in mind that we prepared this book for publication. We believe that the collection of articles in this book will be useful to scientists who are interested in desert landforms and processes, and to planners of economic develop ment of arid lands. The book also serves as a guide for students as to the state of our knowledge in this field as well as to the topics that require additional research."

Remote sensing is the study of a region from a distance, particularly from an airplane or a spacecraft. It is a tool that can be used in conjunction with other methods of research and investigation. This tool is especially applicable to the study of the deserts and arid lands of the Earth because of their immense size and their inaccessibility to detailed study by conventional means. In this book examples are given of the utility of aerial photographs and space images in the study of semi-arid, arid, and hyper-arid terrains. Emphasis is placed on the physical features and terrain types using examples from around the world. The authors I have called upon to prepare each chapter are renowned specialists whose contributions have received international recognition. To the general reader, this book is a review of our knowledge of the relatively dry parts of the Earth, their classification and varied features, their evolution in space and time, and their development potentials. To the specialist, it is a detailed account of the deserts and arid lands, not only in North America, but also their relatively unknown counterparts in North Africa, Australia, China, India, and Arabia.

Deserts are parts of the Earth that receive little or no rain; 25 cm or less per year. The physical processes that act upon these parched lands are vastly different from those that shape the more humid parts of the terrestrial landmasses. In the desert, wind is a major agent of erosion and transportation. As the results of recent space missions have indicated, this is also true in the case of the planet Mars. Thus, our understanding of desert processes sheds light on fundamental planetary processes that may apply on any planetary body that is enveloped by a windy atmosphere. An understanding of the physical layout of arid lands, and the nature of processes that initiate changes therein is also fundamental to thoughtful utilization of these lands for the benefit of mankind. It is with this in mind that we prepared this book for publication. We believe that the collection of articles in this book will be useful to scientists who are interested in desert landforms and processes, and to planners of economic develop ment of arid lands. The book also serves as a guide for students as to the state of our knowledge in this field as well as to the topics that require additional research.

Remote sensing is the study of a region from a distance, particularly from an airplane or a spacecraft. It is a tool that can be used in conjunction with other methods of research and investigation. This tool is especially applicable to the study of the deserts and arid lands of the Earth because of their immense size and their inaccessibility to detailed study by conventional means. In this book examples are given of the utility of aerial photographs and space images in the study of semi-arid, arid, and hyper-arid terrains. Emphasis is placed on the physical features and terrain types using examples from around the world. The authors I have called upon to prepare each chapter are renowned specialists whose contributions have received international recognition. To the general reader, this book is a review of our knowledge of the relatively dry parts of the Earth, their classification and varied features, their evolution in space and time, and their development potentials. To the specialist, it is a detailed account of the deserts and arid lands, not only in North America, but also their relatively unknown counterparts in North Africa, Australia, China, India, and Arabia.