Why we should care about dying indigenous weather systems

Since time immemorial, local people have used traditional weather and climate forecasting to guide them in making important decisions to enable them to cope and adapt to climate change-induced extreme weather variations. For many local communities in Zimbabwe and other parts of Africa, traditional weather and climate forecasting remains the most accessible and affordable source of weather and climate information. In this report, Sifelani Tsiko (ST), Agric, Environment & Innovations Editor speaks to Juliet Gwenzi (JG), a meteorologist and researcher in the Department of Space Science and Applied Physics at the University of Zimbabwe about why enabling policies and a myriad of other forward – looking initiatives are vital to save beliefs, practices and customs that connect indigenous weather forecasting systems to our collective past and the present.

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ST: Are local communities in Zimbabwe still using indigenous climate services in the country?

 JG: Farmers in Zimbabwe still use indigenous knowledge systems to some extent

ST: How widespread is this?

JG: The practice is more common in rural communities and even more so in marginalised areas where they hardly access scientific forecasts.

ST: Which kind of weather forecasting does the majority of the people in Zimbabwe use — the one done by the Meteorological Services Department (MSD) when it issues seasonal climate forecasts (SCFs) or the indigenous climatic observations done in local communities?

JG: The use of SCFs has increased over the years and it’s a product that many people in climate sensitive sectors look forward to accessing. In communities IKS observation is a continuous process and farmers combine with SCFs to make decisions where possible.

ST: Indigenous knowledge systems have over the past decade gained currency alongside seasonal outlooks given by the MSD. Do you think IKS in climate services is recognised in Zimbabwe? Are there any studies that are being done to highlight its importance in filling the gaps that are left by scientific forecasting?

JG: There has been growing interest in IKS in recent years. Studies available have not covered the whole country. Most such studies have focused on documenting IKS and uses. No studies have gone further to ascertain the sensitivity of IKS. It’s also important to highlight that IKS is location specific. Sensitivity studies will require some reasonable funding so that research is done in many locations. Sometimes the indicators mean opposite outcomes in different locations.

ST: Indigenous knowledge weather forecasting systems have for years used a number of indicators to signal normal, drought and above normal seasons. Local communities have assessed local weather and climate through prediction and interpretation using locally observed variables and experiences such as plants, animals, insects and meteorological and astronomical indications. Can you tell us more about the examples of IKS indicators used in various parts of Zimbabwe?

 JG: Trees used include muchakata / mobola plum (Parinari curatellifolia), muzhanje / wild loquat (Uapaca kirkiana), musika/Tamarind (Tamarindus indica) and mumbumbu (Lannea discolour). Birds and insects used include shuramurove, haya, nhowa, nyenze and dzvatsvatsva. Atmospheric observations include the prevalence of whirl winds, wind direction and pre-season heating.

A study done in Uzumba — Maramba — Pfungwe district in Mashonaland East, shows that when muzhanje and muchakata trees have average or few fruits, locals believe there will be a good rainfall season while if mango trees have many flowers which fall off, there will be a poor rainfall season. When the musika tree has too many fruits it means a poor rainfall. When forecasting poor seasons, farmers grow more small grains and short season varieties for maize. Where there are indications of a good season, they grow medium maturity crops and maintain land for small grains. When locals observe shuramurove (Abdim stork) birds flying in large numbers, it means there are prospects of a good rainfall season.

The Haya sounds can mean rainfall is imminent while the continuous singing of the nyenze insects mean the rain season is approaching. Locals say when the Dzvatsvatsva ants run all over especially at night, rains will come within three days and when they open their holes, dry conditions will persist. Through atmospheric and astronomical indicators, delayed August winds (Nyamavhuvhu) may mean delayed onset of rains while high pre-season temperatures may mean good rainfall season with severe hailstorms. Indicators depend on the specific location of a community. In some areas, high fruitage of the muuyu (baobab) indicates drought while high fruitage of mutohwe (snot apple) indicates above normal rainfall and low fruitage indicates a drought. Signals vary from one place to another.

ST: How effective are IKS weather forecasting systems given the fact that local communities do not measure and record climatic data like in formal climate monitoring?

JG: Atmospheric observations can be explained using science. Strong south-easterly winds bring cold air over the country which stabilises the atmosphere. If a high pressure system (Botswana Upper High) is dominant in the middle levels (5.5 – 7km above the surface) dry conditions are experienced (if observed during the rainfall season). Drizzle may occur early in the morning depending on the strength of the south-easterly winds. The other IKS have not been tested/checked for accuracy, as a result, there is no record on how good they are. So far it’s merely acceptance of community experiences. No percentage value can be attached to the accuracy of each of the indicators, let alone the differences in meaning from location to location.

ST: How do local communities use observations based on life long experience in their area to help do forecasting and actions they should take to adapt to the seasonal changes?

 JG: Communities relate observations to past events and their evolution. However, the memory is not able to store intricate details about how events unfolded. Observations help communities make choices of crop varieties or provide basic information on whether the season is good or bad. Details available on community response to indigenous indicators rarely go beyond actions on choice of crop varieties and land preparation. Farmers are not proactive in seeking information much like they do with SCFs. Many are content with getting information on seasonal climate outlook.

ST: The art of indigenous weather forecasting is under threat of disappearing due to lack of documentation of the knowledge and lack of coordinated research to investigate the accuracy and reliability of IK forecasts. What do you think needs to be done to save the IKS weather forecasting systems?

 JG: Countrywide documentation of IKS and meaning should be done. Once documented, the next stage will be checking the physical science associated with the observations, testing for sensitivity and accuracy of the indicators. There is a need for concerted effort to preserve remaining IKS through enabling national policies. Obviously a lot of money will be required for the research to be done satisfactorily.

ST: What can be done to promote IKS weather forecasting systems alongside the mainstream scientific weather forecasting systems?

JG: Currently most processes are revolving around science. The results on sensitivity and accuracy of IKS will make the method believable by the young generation. Whilst IKS exists and is in use, promotion alongside scientific forecasts will be possible when there is enough evidence on accuracy of IKS. If the physical science behind the characteristics observed in trees and behaviour of other indicators is understood, promotion could start by carrying out awareness campaigns on the importance of the IKS.

ST: Given the numerous challenges facing the IKS weather forecasting systems, what then is the future of this system in Zimbabwe? Can it survive the onslaught of extinction?

JG: Preservation of IKS cannot be overemphasised. However this cannot be done apart from having an enabling environment supported by relevant policies. Survival is certain if the importance and conservation of biodiversity and functional ecosystems remains a priority.