Drought

by

Woonsup Choi

• LAST MODIFIED: 15 January 2020
• DOI: 10.1093/obo/9780199874002-0215

Introduction

Drought is a natural disaster that has plagued human society throughout history. However, the meaning of drought varies by perspective and academic discipline, and the cause of drought is difficult to pinpoint. Despite the variation in its meaning, drought generally refers to the condition of an abnormally low amount of water for a given climate. Here the water can be precipitation, streamflow, soil moisture, groundwater, reservoir storage, and the like, but the lack of precipitation is a precursor for other types of drought. The lack of precipitation is often associated with anomalous atmospheric conditions such as atmospheric-circulation anomalies, higher-than-normal temperatures, and lower-than-normal relative humidity. Sea surface temperature anomalies may lead to sustained atmospheric-circulation anomalies. Drought defined as a lack of precipitation is often called meteorological or climatological drought. Other drought types can be classified within the context of the affected sectors, such as agricultural, hydrological, and socioeconomic drought. Agricultural drought generally refers to a lack of soil moisture, and hydrological drought refers to a lack of surface and subsurface water (e.g., streamflow and groundwater). Socioeconomic drought hampers human activities such as industry or water supply. As meteorological drought persists, other types of drought can follow. Such definitions of drought are regarded as conceptual definitions, but operational definitions are also necessary for quantitative understanding and management of drought events. Operational definitions use quantitative indices to identify the occurrence and characteristics of drought events such as onset, duration, termination, and deficit volume of drought. Much of existing drought research concerns developing, revising, and applying drought indices to investigate spatial and temporal patterns of drought at various geographical scales. Drought research has progressed along several directions, such as causes of drought, characteristics of drought events, impacts, and mitigation. Each of these directions is represented by the works cited in this article.

Books

There are not many scientific volumes devoted to drought, and those that are available tend to cover similar topics, such as concept, science, major past events, and projected changes in the future. Cook 2019 is a comprehensive introduction to drought, covering various aspects of drought in a generally plain language. Tallaksen and van Lanen 2004 is uniquely devoted to drought in streamflow and groundwater.

• Cook, Benjamin I. Drought: An Interdisciplinary Perspective. New York: Columbia University Press, 2019.

  DOI: 10.7312/cook17688

  A comprehensive and concise volume that explains drought in various perspectives, including hydroclimatology, climate change, land management, and groundwater. One of the best introductions for those who pursue scientific understanding of drought.

• Tallaksen, Lena M., and Henny A. J. van Lanen, eds. Hydrological Drought: Processes and Estimation Methods for Streamflow and Groundwater. Amsterdam: Elsevier, 2004.

  A collection of chapters addressing drought in streamflow and groundwater. Chapters about the science or management of drought are adequate for entry-level graduate students, but those about drought estimation methods are highly technical.