Offering a cross-country examination and comparison of drought awareness and experience, this book shows how scientists, water managers, and policy makers approach drought and water scarcity in arid and semi-arid regions of Spain, Mexico, Australia, South Africa and the United States.

Droughts occur in arid and semi-arid areas of the world, but also in humid areas, and can develop over short periods (flash drought) or longer periods (seasons/decades). Even though progress has been made, it remains difficult to adequately characterize, monitor, forecast and manage droughts, due to their multi-faceted nature.Usually, drought does

The semi-arid zones of the world are fragile ecosystems which are being sub stantially modified by the activities of mankind. Increasing human populations have resulted in greater demands on semi-arid zones for providing human susten ance and the possibility that this may enhance desertification is a grave concern. These zones are harsh habitats for humans. The famines that resulted from drought during the late 1960's and the 1970's in the African Sahel illustrated the unreliability of present agricultural systems in this zone. Large fluctuations in ag ricultural production have occurred in semi-arid zones of Australia, North Ameri ca, and the Soviet Union due to periodic droughts, even though considerable ag ricultural technology has been devoted to agricultural development in these zones. The challenge to mankind is to manage these different semi-arid zones so that pro ductivity is increased and stabilized, and environmental deterioration is decreased. Irrigation can be used to increase and stabilize agricultural production in semi-arid zones as discussed in Volume 5 of this series, Arid Zone Irrigation. The present volume, Agriculture in Semi-Arid Environments, focuses on dryland farming in semi-arid zones, and is relevant to the large areas of the world where rainfall is limiting and where water is not available for irrigation. This volume is designed to assist agricultural development in these areas and consists of reviews and analyses of available information by scientists working in Africa, Australia, and at the U ni versity of California.

The hot and temperate deserts and their marginal steppe lands comprise one-third of the land surface of the world and are an increasingly critical area for the economic wellbeing of world populations. The remarkable mechanisms of floral, faunal, and human adaptation to the distinct and difficult environment of these arid zones, as well as the potential of modern technology for facilitating adaptation, are described and explained by Walton in the light of our most recent knowledge of the phenomena and processes involved.Beginning with a clarification of the definitions of arid and semi-arid regions and with the delineation of techniques for measuring the degree of aridity in these areas, the author shows that there is wide variation among the arid zones in landscape and climate and that there are numerous local and microclimates within any single arid region. The life cycles of the plants and animals of the arid zones are described and the water resources, including problems of salinity, mineral contamination, and the construction of reservoirs, are examined. Extensive treatment is given to potential agricultural adaptations and to pastoralism as the most widespread response to dry land. A final chapter summarizes attempts at adaptation to prevailing drought and discusses the kinds of future development that the author deems most likely in arid zones.Throughout the book emphasis is placed on specific, detailed analysis, with adequate tables and formulas for in-depth understanding of particular aspects of aridity. Examples from both Old and New Worlds are used to demonstrate the spheres in which progress is being made and to show the mistakes in past and present land use in arid areas. An essential supplement for courses in physical geography, the book will be useful in many area studies and in studies of economic development.

Water deficiency in many arid and semi-arid regions in Southern Europe is becoming a major constraint for economic welfare and sustainable regional development. These regions are characterised by high spatial and temporal imbalances of water demand and supply, seasonal water uses, inadequate water resources and poor institutional water management. The aim of this book is to formulate appropriate strategies and guidelines for water management necessary for the formulation and implementation of integrated sustainable management of water resources. Lessons are learned from various case studies, which examine competing water use patterns, compare governance structures and how these have evolved in response to scarcity, and structural and non-structural instruments to address water deficiency. Water Management in Arid and Semi-Arid Regions will appeal to policymakers in relevant countries as well as to scholars and researchers of environmental studies and economics.