- Specialized weather forecasting for Angora goat farmers
|Last update: March 26, 2012 02:53:52 PM|
Specialized weather forecasting for Angora goat farmers
Grootfontein College of Agriculture
Private Bag X529
Angora goats are sensitive to adverse weather and deaths can result if goats are not given sufficient protection during crucial times of the year, especially during shearing and kidding (Wentzel, Viljoen & Botha, 1979; Fourie, 1984).
If goats can be kraaled in time when unfavourable weather is expected, many of these animals can be saved. The Weather Bureau was therefore approached for its co-operation in issuing of warnings to Angora goat farmers of approaching adverse weather.
The initial information that the Weather Bureau required was:
Identification of weather conditions affecting the goats adversely, the area most affected by adverse weather and the dates when goats died during spells of adverse weather, so that the implications of the synoptic situations can be analysed.
From the weather conditions responsible for goat deaths on 122 separate dates in the past, it was found that a daily average temperature of 10 °C and less accompanied by 5 mm or more rain were causing deaths among unprotected goats (Rowswell, 1985).
These criteria are associated with cool to cold and wet conditions, which are the result of either general rain from cut-off low-pressure cells or from frontal systems. Wind direction and speed, although being important factors affecting the goats, could not be evaluated for several reasons (Rowswell, 1985).
These criteria were used by forecasters at the Weather Bureau to formulate weather warnings for Angora goat farmers of expected inclement weather.
During consultations -with Angora goat farmers it became evident that there were recommendations, which could be of great value to improve the weather forecasting service.
After the television weather forecasts took on a new format and when Algoa Radio Regional Service came into being, a follow-up survey was conducted with the co-operating farmers to evaluate the change in the forecasts.
An initial questionnaire was sent out to farmers to determine their views and recommendations.
Three hundred and seventy-three- farmers responded to the following questions:
Which weather forecast services are made use of by the farmers?
How does the farmer grade the television weather forecast?
Does the farmer know in which forecast region he belongs?
Does the weather forecast warn the farmer in time to bring in his goats?
Which weather forecast does the farmer listen to when deciding whether to bring in his goats?
Is the information supplied in the forecast sufficient?
Would a percentage chance of bad weather assist the farmer?
Would the farmer like a warning of all possible chances of adverse, weather?
Comments and recommendations were also requested.
The initial questionnaires revealed that the farmers would like:
Warnings of all possible adverse weather
The region split up into smaller zones so that more detailed forecasts can be given
A percentage probability that rain will occur
The warning to be given not only at 20:30 on television, but also at 13:30 which would give the farmer time to bring in his animals
The Sunday forecasts to be improved for this forecast region.
With the inauguration of the Algoa Radio Regional Service broadcasting from Port Elizabeth, a new forecasting schedule and approach were planned to cater for the forecasting needs of the Angora goat industry. With this new approach the Weather Bureau has split the Eastern Cape into several climatic zones as illustrated in Fig. 1. This is then used by the weather forecaster in Port Elizabeth to:
1. Supply a rainfall probability for each zone (RR)
2. Give an estimated maximum and minimum temperature for the following day (TX, TN)
3. Give the prevailing wind speed and direction for the period concerned (wind)
4. Remark in the bulletin on the possibility of threatening weather expected in this region for the near future.
This information can be seen on a typical Weather Bureau report (Appendix 1).
In 1986 a follow-up survey was conducted. The following questions were put to the farmers:
1.1 How do you rate the change in the presentation of the television forecasts?
1.1.1 At which time do you prefer the television weather forecast to be broadcast?
1.2 Do you consider these forecasts to be a helpful medium to warn you on the approach of adverse weather for Angora goats?
1.3 Is the information supplied in these forecasts sufficient?
2.1.1 Do you listen to Radio Algoa weather forecasts?
2.1.2 If Yes, which forecast do you consider the most convenient: the 06:40, 13:40 or the 16:40 broadcast?
2.1.3 If your answer is No to 2.1.1 and 1.2 how would you like the warnings to be given?
2.1.4 Is the information supplied in Radio Algoa forecasts sufficient for your needs?
2.1.5 If not, what other information would you require?
2.2.1 If you do not receive Radio Algoa weather forecasts, which radio station do you listen to for warnings of adverse weather?
2.2.2 Does this radio station supply sufficient information?
In the same questionnaire the farmer was given a scale + 1.0 (excellent) to -10 (very poor) to use in evaluating the change in the weather forecasting services.
3.1.1 How would you grade the Radio Algoa weather forecasts? Give a value (A) for the old service and a value (B) for the new service.
3.1.2 How would you evaluate the improvement in the forecast time on the broadcasted weather forecasts? Give a value (A) for the old service against (B) for the new Algoa Radio Service.
3.1.3 How would you evaluate the change in the television weather forecast presentation? Give a value (A)-for the old presentation and (B) for the new way the weather forecast is presented.
By January 1987 177 (47%) of the questionnaires were returned.
From these questionnaires it was found that 70% of the farmers fell in the Radio Algoa reception area, while most of the remaining 3096 fell within the Radio Good Hope reception area. Of the 70% farmers in the Radio Algoa reception area only 58% listened to Radio Algoa while most of the remaining 1296 were not aware of this forecasting service. According to the mohair production figures for the summer of 1986 (Mohair Board, 1986) it was found that from the top 50 mohair production districts in South Africa, 2396 (a clip of R18 million) was produced in the Radio Good Hope reception area.
Most of the farmers who do not listen to the regional radio stations listen to Radio South Africa weather forecast directly after the news on the English station (13:15) and at 13:00 in Afrikaans.
Regarding question 2.1.2., it was found that out of the farmers who listen to Radio Algoa, all prefer the 13:40 forecast time, while 37% also listen to the 06:40 broadcast. Very few (7%) listen to the late afternoon bulletin.
With respect to the content of the Radio Algoa forecasts, 87% were satisfied, and many thought it an excellent service. The service was evaluated by the farmers using the scale + 10 to -10 for the present service against the previous one. In their opinion the service is on average 250% better than the previous weather forecast services.
Farmers' attitudes towards the television forecasts were varied:
Forty per cent said they were good, 36% said they were fair and 12% thought they were poor. There is still a great deal of criticism concerning the forecasts. Here is a list of general comments:
1. The forecasts are 12 - 24 hours late. The farmers call them "Postcasts" or "Aftercasts"
2. The forecasts are generalised
3. The farmers feel medium term forecasts (2 – 3 days ahead) are of great value
4. They would like the speed of the front to be given, i.e. the approximate time it will pass over certain towns
5. The presenter should be more aware of the causes of goat deaths and if he does give a warning then it should be mentioned in which area the goats will be affected (there are goats throughout South Africa)
The farmers' opinion concerning the television forecast reveals that the forecasts have improved by 67%.
Seven per cent of the farmers would like a warning at approximately 07:00 on the new television programme, Good Morning South Africa. The majority, 74%, are satisfied with the present time (20:25) and 4% would like the weather forecast at 19:55, just before the news.
Radio Algoa is now broadcasting the weather forecast for the zones three times a day: at 06:40, 13:40 and at 16:40. This is a vast improvement on the generalised forecast by the previous services.
From the follow-up questionnaire it is evident that there is merit in zoning the Angora region of the Radio Good Hope reception area to promote weather forecast warnings to the 23% farmers in this region.
It is evident that for the majority of farmers the weather forecast broadcasts are crucial in planning for the short and medium term.
Many recommendations for improved television forecasts were received from the Angora goat farmers. If carried out, these recommendations can make the future television forecasts more meaningful.
Many of the television forecast problems could be resolved if the Weather Bureau presented the forecasts on a real time base. The situation at present is that although the Weather Bureau compiles the forecast from the 14:00 synoptic map, SA TV leaves the presentation to a freelance presenter to fill a 4 min time slot at 20:25.
With regard to the radio forecasts, Radio Algoa is doing an excellent job for the Angora goat farmers in the Eastern Cape. If Radio Good Hope could serve the western interior, Angora farmers in these areas would benefit.
It is evident that to meet the weather forecast needs of this particular field of agriculture, a monitoring system must be introduced. Data from such a system will provide motivation for more specialised forecasts. This will ensure a more acceptable and reliable service.
FOURIE, T.J., 1984. 'n Vergelykende studie van die effek van koueblootstelling op die hitteproduksie van angora- en boerbokke. M.Sc. thesis, University of Port Elizabeth.
MOHAIR BOARD, 1986. Summer 1986 mohair production figures. Unpublished.
ROWSWELL, D.I., 1985. Weather related danger regions in the Angora goat industry. Karoo Agric 3 (5), 10 - 16.
WENTZEL, D., VILJOEN; K.S. AND BOTHA, L.J.J, 1979. Physiological and endocrinological reactions to cold stress in the Angora goat. Agroanimalia II.. 19 - 22.
Karoo Agric 3 (8), 35-38