"Prepared for presentation at the Open Meeting of the Global Environmental Change Research Community, Rio de Janeiro, 6-8 October, 2001."
INTEGRATING CLIMATE FORECAST INFORMATION IN AGRICULTURAL MANAGEMENT: A perspective from Southern Africa
Lead Authors:
Hector Chikoore[1], Leonard Unganai[1]
Introduction
Recent advances in understanding El Nino Southern Oscillation (ENSO) based seasonal climate forecasts have raised hopes for better agriculture management in Southern Africa (Phillips et al, 2001). With most economies in southern Africa being agro-based great potential exists to minimize and maximize impacts of adverse and favorable interannual climatic fluctuations. However, connecting these forecasts with agricultural decision-making remains a research problem.
“Using climate forecasts to better manage climate sensitive sectors such as agriculture … is a new frontier, with potentially very significant implications for humankind” (IRI, 2000). An efficient climate information system requires close collaboration between natural and social scientists and institutions such as academic institutions, government and non-governmental organizations (Podesta, 2000). Seasonal climate forecasts and applications require further integration (Unganai, 2000).
Pilot studies were undertaken in many parts of the SADC region with objectives to assess the access to seasonal climate forecasts by smallholder farmers, use of these forecasts in decision-making and identification of limiting constraints and opportunities for advancement in agricultural management.
Integration of climate forecast information with agricultural management would better equip farmers to make informed decisions and reduce food insecurity (increasing production) and improve livelihoods.
SYSTEM DESCRIPTION
Climate of Southern Africa
Southern Africa experiences a wide variety of climatic regimes. The southwest sections of the sub-region experience Mediterranean Climate characterized by winter rainfall due to the passage of the westerly waves of the middle latitudes. Rainfall is inhibited by subsidence virtually throughout the year in the arid Namib and Kalahari Deserts. Cloud bands from the west in the early part of the season are the main source of precipitation in the southwestern regions. Moderate to heavy precipitation associated with the Inter-Tropical Convergence Zone (ITCZ) characterizes the tropics and subtropics. The mean climate of southern Africa is further modified by topography with the highland areas of eastern Zimbabwe, Lesotho and the Drakensberg of South Africa receiving more orographic rainfall. Strong teleconnections have been found to exist between seasonal rainfall of the region and the behavior of the tropical Oceans of the Pacific and Indian Oceans. The ENSO effects are dominant over the region with generally below normal rains associated with an El Nino event. Drier conditions are evident in figure 1 in the southwestern section which is semi arid while the heavier precipitation exceeding 800 millimeters is received in the northern and central sections.
Figure 1 – Mean rainfall for SADC region from October – December and from January to October (1961 – 1990)
Source- Drought Monitoring Center, Harare
Agricultural Systems
The majority of the rural populations are subsistence farmers by trade and their lives largely depend on agriculture. The agriculture is mostly rain fed. The main crops grown are tea, coffee, tobacco, sorghum, millet maize and rice. Any climatic extremes would impact negatively not only on agriculture, but also on livelihoods.
The recurrent Droughts and Floods
Figure 2 – A buffalo carcass during a drought in Zimbabwe and Floods that ravaged Mozambique after Cyclone Eline in Feb 2000
Source- Drought Monitoring Center, Harare
The recurrent droughts and floods are among the many challenges facing agriculture and environmental management in Southern Africa. In response to these environmental challenges, a number of national and regional structures and processes for seasonal climate monitoring and prediction have evolved since 1990.
Current State of Long Range Forecasts
Consensus on the long-term prospects of each rainfall season is established through regional climate outlook fora. These attract climate experts from global and regional climate prediction centers. This is the mandate of the Southern Africa Development Community’s Drought Monitoring Center (DMC) based at Harare.
The seasonal climate forecasts are based on empirical diagnostic analyses with Global SST anomaly patterns, the sate of ENSO, NAO and upper level winds being the main predictors. The forecasts are issued in terciles, below normal, normal and above normal with the probability of rainfall being in each of three categories as stated. In addition, these forecasts are issued for relatively large homogeneous rainfall regions extending over three month periods. A typical example of a seasonal forecast is shown in the figure below for October to December 2001 and January to March 2002. However the probabilities are only for use by the climate scientists and not given to the press.
Figure 3 - Seasonal Climate outlook for the SADC region for OND 2001 and JFM 2002
Source- Drought Monitoring Center, Harare
The national forecasts are disseminated late September/early October through radio/TV, printed press, the Internet and Climate bulletins. Radio broadcasts are the most efficient means of communicating climate forecasts to rural communities in southern Africa, while the Internet is least efficient. The flow of seasonal climate forecasts from the regional forecast to end users of climate information is shown in fig. 4.
Fig 4 – Seasonal climate forecast dissemination system
Farmers Climate Information requirements
How have our forecasts been useful to the end user? Pilot studies were undertaken in many parts of the SADC region to investigate the utility of climate information in agricultural management.
The assessments were done in terms of terminology, precision and influence on decision-making. From the pilot studies, it was found that farmers require information about the following in order to make decisions on agricultural management:
q Onset date of the main rains
q Quality of the rainy season (rainfall amount)
q Cessation date of the main rains
q Temporal and spatial distribution of the main rains
q Timing and frequency of active and dry periods (wet and dry spells)
q Agronomic recommendations in terms of which crop varieties to grow and so on
The most useful forecast information according to the farmers are the early warnings of a poor season, the commencement of the season and whether the rains would be adequate (Phillips et al, 2001). It is probable for people living in low rainfall zones that seasonal forecasts for wetter years are of greater value than warnings of a poor season (Phillips, 1998). Above all “the forecast needs to be stated in a language and in terms the user understands” Unganai (2000)
Decision Support Tools
The Zimbabwe Meteorological Services is collaborating with Australian scientists with a view to adopt the Strategic Drought Management System of the Grassland and Rangeland Assessment by Spatial Simulation as decision support tools. The Grass Production Model (GRASP) uses real time data (rainfall, temperatures, humidity and evaporation), historical climate data and data about soils, pasture type, stocking rate and tree cover. It produces information about soil moisture and biomass utilization which can be used to produce land degradation alerts and feed deficit alerts. The GRASP model, coupled with rainfall decile analyses and greenness maps from NOAA satellite data, allows extension, policy and decision-making.
DISCUSSION AND CONCLUSIONS
Current seasonal climate forecasts do not provide adequate information required for decision making. For example there’s no information about the intra-seasonal character of the rainfall season i.e. the active and break periods. No information is given either with regard to the onset and cessation dates. The demarcation of areas is often difficult for farmers who lie on the boarder line because the forecast changes abruptly thereon. Besides, There is limited understanding of climate forecasting science among agricultural practitioners and this makes it difficult for smallholder farmers to interpret and use them. It should be realized that seasonal climate forecasts are not the only tools required for decision-making. However, there are other important factors needed in decision making such as “labor, inputs, government policy, farmer skills and market trends” (Unganai, 2001).
There is need
for expertise in the form of trained staff in climate modeling, producing climate resource champions for the region and use of dynamic climate models to improve the forecast skill. The IRI in its Summary and Proposals for Action (2001) recommended the need to distinguish “between the roles of end users and intermediaries”; intermediaries are such organizations as government, non-governmental organizations, extension officers and others. The involvement of middlemen such as extension officers would allow them to cascade the climate information to the end users making their own agronomic input in the process. These recommendations could include adjustment of planting dates, crop sequences and mixes.
With regard to integrating climate science with agriculture and policymaking, the Harare DMC has brought scientists and stakeholders together from around the SADC region training them in seasonal climate prediction every year. Involvement of the end users and their intermediaries should be increased because if people took part in the forecast process, they would own the forecasts and would very easily believe them.
The involvement of the media in their role as the source of information was recommended (IRI, 2001). The DMC has recently invited journalists to participate in the RCOF process. Capacity building for journalists allows them to inform the public (or users) with authority, without misinforming them.
Acronyms
DMC Drought Monitoring Center
ENSO El Nino Southern Oscillation
GRASP Grass Production Model
ITCZ Inter-Tropical Convergence Zone
NGO’s Non-governmental organizations
NOAA National Oceanic and Atmospheric Administration
RCOF Regional Climate Outlook Forecast
SADC Southern Africa Development Community
SARCOF Southern Africa Regional climate Outlook Forecast
References:
International Research Institute for Climate Prediction, 2001: Coping with the climate: a way forward, Summary and Proposals for Action, International Research Institute for Climate Prediction
Phillips, J.G., 1998: Comparing Optimal Use of ENSO Forecast Information in two socioeconomic contexts. Invited Talk at the American Association of Geographers Annual Meeting, Boston, MA, March 1998.
Phillips, J.G. et al, 2001: Current and Potential Use of Climate Forecasts for Resource-poor Farmers in Zimbabwe. American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Madison, USA. Impact of El Nino and Climate Variability on Agriculture. ASA Special Publication no. 63
Podesta, G., 2000: Experiences in Application of ENSO-related Climate information into the Agricultural Sector of Argentina, Proceedings of the International Forum on Climate Prediction, Agriculture and Development, International Research Institute for Climate Prediction.
Unganai, L.S., (2000): Application of long range rainfall forecasts in agricultural management: a review of Africa’s experiences. Proceedings of the International Forum on Climate Prediction, Agriculture and Development, International Research Institute for Climate Prediction
[1]
[1] Zimbabwe Meteorological Services, P.O. Box Be 150, Belvedere, Harare, Zimbabwe