Agricultural Drought Indices - US Department of Agriculture

Preface
With the world population projected to reach 7.5 billion, the world’s farmers will have to produce
40% more grain in 2020, and the challenge is to revive agricultural growth at the global level. The
Fourth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC) stated that
the world has been more drought-prone during the past 25 years and that climate projections
indicate an increased frequency in the future. This carries significant implications for the
agriculture sector, especially in the developing countries.
One of the critical components of national drought strategies is a comprehensive drought
monitoring system that can provide early warning of the onset and ending of droughts, determine
the severity, and deliver that information to the users in the agriculture sector. In February 2009,
the Commission for Agricultural Meteorology of the World Meteorological Organization (WMO) held
the International Workshop on Drought and Extreme Temperatures in Beijing, China, to review the
increasing frequency and severity of droughts and extreme temperatures around the world. The
workshop adopted several recommendations to cope with the effects of increasing droughts and
extreme temperatures on agriculture, rangelands, and forestry. One of the main recommendations
was for WMO to make appropriate arrangements to identify the methods and marshal resources
for the development of standards for agricultural drought indices in a timely manner.
WMO, together with the National Drought Mitigation Center (NDMC) and the School of Natural
Resources of the University of Nebraska–Lincoln (USA), organized the Inter-Regional Workshop
on Indices and Early Warning Systems for Drought at the University of Nebraska in December
2009. The Lincoln Declaration on Drought Indices recommended that a working group with
representatives from different regions around the world and observers from UN agencies and
research institutions (and water resource management agencies for hydrological droughts) be
established to further discuss and recommend, by the end of 2010, the most comprehensive index
to characterize agricultural drought.
Accordingly, WMO and the United Nations International Strategy for Disaster Reduction (UNISDR),
in collaboration with the Hydrographical Confederation of Segura River Basin and the State
Agency for Meteorology of Spain (AEMET), organized the Expert Group Meeting on Agricultural
Drought Indices in Murcia, Spain, June 2-4, 2010. The meeting reviewed drought indices currently
used around the world for agricultural drought and assessed the capability of these indices to
accurately characterize the severity of droughts and their impacts on agriculture.
Fifteen papers presented at the expert group meeting are brought together in this volume. These
papers present an overview of agricultural drought indices; the strengths, weaknesses, and
limitations of different agricultural drought indices currently in use in selected countries; the
integration of crop, climate, and soil issues in agricultural drought indices; and a summary and
recommendations on agricultural drought indices.
We wish to convey our sincere thanks to Mr. Michel Jarraud, the Secretary-General of WMO; Dr.
Marta Moren Abat, Director General of Water of the Ministry of Environment, Rural and Marine
Sector of Spain; and Dr. Rosario Quesada Gil, President of the Hydrographic Confederation of
Segura, for their encouragement and support in the organization of the expert meeting in Murcia.
We also wish to thank Mr. Mario Urrera Mallebrera, Chief of the Hydrological Planning Office, and
Mr. Adolfo Merida Abril, Chief of the Service of the Hydrographic Confederation of Segura, for their
excellent cooperation in coordinating the arrangements for the meeting.
Mannava V.K. Sivakumar
Raymond P. Motha
Donald A. Wilhite
Deborah A. Wood
Editors
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