Agricultural Drought Indices - US Department of Agriculture

Support to Regional Institutions
WMO is supporting the strengthening of the capabilities of regional institutions with drought-related
programs and promoting collaboration with other institutions in drought- and desertification-prone
regions, with emphasis on Africa, Asia, Latin America, the Caribbean, and the northern
Mediterranean region. Examples of such institutions in Africa are the AGRHYMET Regional
Centre and the African Centre of Meteorological Applications for Development (ACMAD), both
located in Niamey, Niger, and the WMO Drought Monitoring Centres (DMCs) for eastern and
southern Africa, located in Kenya and Zimbabwe, respectively.
Following the severe droughts in the West African Sahel in the early 1970s, WMO expert missions
in 1972 led to establishment in 1974 of the AGRHYMET Regional Centre in Niamey (Niger) under
the auspices of the Permanent Interstate Committee for Drought Control in the Sahel (CILSS).
The two Drought Monitoring Centres (DMCs) in Nairobi (Kenya) and Harare (Zimbabwe) were
established in 1989/90 by 24 countries in eastern and southern Africa with WMO as executing
agency and with initial funding from the United Nations Development Programme (UNDP). At the
end of the UNDP-funded Project in 1998 and as a result of the increased demand for climate
information and prediction services, the Nairobi and Harare components started operating
independently. DMC–Nairobi caters for countries in IGAD (Intergovernmental Authority on
Development) and other countries in the Horn of Africa region, while DMC–Harare is responsible
for countries in southern Africa. In October 2003, the heads of state and governments of the
Intergovernmental Authority on Development (IGAD) held their 10th Summit in Kampala, Uganda,
where DMC–Nairobi was adopted as a specialized IGAD institution. The name of the institution
was at the same time changed to IGAD Climate Prediction and Applications Centre (ICPAC) in
order to better reflect all its mandates, mission, and objectives within the IGAD system. A protocol
integrating the institution fully into IGAD was signed on 13 April 2007.
WMO and the Economic Commission for Africa (ECA) sponsored the establishment of the African
Centre of Meteorological Applications for Development (ACMAD) in Niamey (Niger) in 1993.
WMO and the UNCCD Secretariat collaborated actively for the establishment of the Drought
Management Centre for Southeastern Europe (DMCSEE) in 2007. The 11 countries in the region
elected Slovenia to host this Centre and an international steering committee is now in place to
guide its establishment and operations.
Conclusions
Agricultural drought depends on the crop evapotranspiration demand and the soil moisture
availability to meet this demand. Agricultural impacts of droughts are the result of short-term
precipitation shortages, temperature anomalies that increase evapotranspiration demand, and soil
water deficits that could adversely affect crop production. Hence an agricultural drought index
should integrate various parameters like rainfall, temperature, evapotranspiration (ET), runoff, and
other water supply indicators into a single number and give a comprehensive picture for decision
making. Agricultural drought indices should be based on soil moisture and evapotranspiration
deficits and should help effectively monitor agricultural drought.
In order to ensure that information to cope with agricultural droughts is generated in a timely and
effective manner and is disseminated widely for use by the farming community for drought
management, it is important to ensure that:
a) Comprehensive data are available to support development of an effective drought monitoring
and early warning system.
b) The most effective and reliable indices and indicators for drought assessment and common
methodologies are developed for application.
c) Effective drought risk assessments are carried out, including the identification of the principal
stakeholders, in order to develop appropriate drought mitigation strategies and policies.
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