The month of November can be described as having had two parts. The first half of the month was categorised by regular severe weather warnings with large thunderstorms occurring over large parts of the summer rainfall region. The last part of the month was dryer, with intermittent thunderstorms with the month ending in with the second heat wave being declared over large parts of the Free State, North West... Read more
Monthly Overview
The month of November can be described as having had two parts. The first half of the month was categorised by regular severe weather warnings with large thunderstorms occurring over large parts of the summer rainfall region. The last part of the month was dryer, with intermittent thunderstorms with the month ending in with the second heat wave being declared over large parts of the Free State, North West, Northern Cape and Gauteng. On 7 November there was flooding over parts of Pretoria and the East Rand with large hail being reported over the East Rand. On the 9 of November, there was massive flooding again, but this time over Johannesburg. It was reported that at least 8 people died due to weather related incidents on the 9th. On the 11 November there were reports of a tornado in the Viljoenskroon area. A day later, there were reports of a tornado that destroyed houses in Ennerdale, south of Johannesburg. Storms with large hail were reported over the East Rand on the same day. There were also reports of a funnel cloud near Standerton, but it is unclear if it ever touched down to form a tornado. On 15 November, there was a report of a tornado in the Grootvlei area near Balfour. The rest of the month was relative quiet on the storm front with intermittent thunderstorms. There was reports of a large sandstorm that hit parts of Gauteng on 18 November. November ended off with the second heat wave of this summer season during the week of 29 November to 2 December. The World Meteorological Organisation released a statement in November declaring that 2016 was set to become the hottest year on record.
Rainfall
Large parts of the summer rainfall region received good rainfall during November. Mpumalanga received the highest recorded rainfall for the month with some areas exceeding 250mm. Southern Limpopo, northern North West, Gauteng, the northern Free State and KZN received between 100 to 150mm. Northern Limpopo received up to 80 mm with the north eastern part only receiving 60mm. The Vaal Dam stood at 25% capacity at the beginning of the month, but after water was released from the Sterkfontein dam and some good rains in its catchment area, levels improved to 36% month-end.
Figure 1: Total rainfall estimation in millimetres for 1 to 30 November 2016
Figure 2: Percentage difference - rainfall for 1 to 30 November 2016.
Figure 2 gives a perspective of the rainfall for November 2016. The majority of the summer rainfall region received more than 100% of it's normal rainfall for the month. North eastern Limpopo was dryer than normal and the region received less than 100% of its normal rainfall. Isolated areas south of Richardsbay, to just south of Durban, also received less than 100% of its normal rainfall. The north western region of the Northern Cape received more than 500% of its normal rainfall, and an area stretching between Sprinbok and Calvinia received more than 100% of normal rainfall. The rest of the country remained dry with little, or no rainfall.
Figure 3: Cumulative rainfall from 1 June 2016 to 30 November 2016 in millimetres.
The cumulative rainfall map (Figure 3) for 1 June to 30 November highlights areas that received more than 150mm during the last 6 months: Light green colours indicate areas receiving between 150 to 200mm; dark green colours indicate areas that received between 200 and 300mm; areas that received more than 400mm are indicated with the blue colours. KZN received good rainfall over the last 6 months. Northern Limpopo received less than 150mm over the last 6 months and is in need of good rainfall this season.
Figure 4: Percentage difference - rainfall for 1 June to 30 November 2016.
Figure 4 highlights the areas of South Africa that received below-normal and above-normal rainfall over the last 6 months. The yellow to light brown colours highlight areas of concern. These areas include the Northern Cape, southern Free State, the Eastern Cape and the Western Cape - these areas received less than 100% of their normal rainfall. Northern Limpopo is another area of concern with less than 100% of its normal rainfall. The majority of the summer rainfall region has received more than 100% of its normal rainfall over the last 6 months. If this positive trend continues, an improvement in the dam levels and drought conditions throughout the region can be expected.
El Nino/La Nina
Background: Periods of below normal rainfall in South Africa are often linked with the El Nino event while above normal rainfall is usually linked to La Nina. The latest predictions issued by the Australian Bureau of Meteorology indicate neutral conditions. (Figure 5). Current model predictions show the possibility of near La-Nina conditions have decreased. Forecasts issued by the South African Weather Service (23 November) indicate that wetter conditions will continue through December, January and February but, some degree of uncertainty remains since there is no clear indications of La Nina developing this season.
Figure 5: Current model predictions for Sea Surface Temperature in the Pacific.
NDVI
Figure 6: ProbaV difference map for November 2016 compared to the long-term (19-year) average.
Figure 6: The map was created by calculating the difference between November 2016 and the long-term (19 year) average for November. Figure 6 is dominated by normal vegetation activity (beige colour). Areas of concern with below-normal vegetation activity (red colours) can be seen in the southern Eastern Cape, eastern Mpumalanga and small isolated areas in Limpopo. Higher vegetation activity can be seen from East London stretching northward along the KwaZulu-Natal coast, northern Free State, Gauteng, Mpumalanga and southern Limpopo.
Figure 7: Percentage of Average Seasonal Greenness for the last 6 months ending in November 2016.
Drought is a long term phenomenon. Focusing on longer time-periods is a more reliable method to monitor and map drought. Areas of concern include the southern Kruger National Park in north-eastern Mpumalanga. Below normal vegetation conditions can also be seen in northern KwaZulu-Natal. The western part of the Eastern Cape as well as the western part of the Northern Cape show below-normal vegetation activity.
General Discussion
Maize is produced mainly in North West province, the Free State, the Mpumalanga Highveld and the KwaZulu-Natal Midlands. Rainfall has been good during this last month especially in Mpumalanga Highveld and the KwaZulu-Natal Midlands and this has favoured maize plantings in these areas; the optimum date for planting many maize varieties is from the middle to the end of November. However, the recent extreme heat may have affected maize that has already germinated and emerged.
Farmers plan to sow 2.44-million hectares with maize, up from the 1.947-million hectares planted last year (Business Day 25th October estimate from trading houses surveyed by Reuters). This reflects optimism in the forecasts predicting good rains in the 2016 - 17 season.
While the summer rainfall regions are receiving abundant rain, there is much concern for the drier winter rainfall regions particularly the Western Cape where water is severely limited and water restrictions have been implemented due to low dam levels. The dry and hot conditions favour veld fires and farmers should continue to watch weather and fire warning reports and plan accordingly. In hot and humid areas, farmers should watch for signs of heat stress, particularly in pigs, chickens and dairy cattle.
Flooding can also have a severe impact on livestock farmers. Animals can be moved to higher grounds when there are warnings of heavy rains. Farmers should ensure animals are all marked correctly with legal markings to identify displaced animals. This will also assist police in cases of stock theft. The price of meat is expected to rise with the increase in demand over the festive season and the limited supply of stock due to farmers rebuilding their herds after the drought.
Acknowledgements:
SPOT Vegetation Data: The product was generated by the land service of Copernicus, the Earth Observation program of the European Commission. The research leading to the current version of the product has received funding from various European Commission Research and Technical Development programs. The product is based on VEGETATION data ((c) CNES).
PROBA-V Data: The product was generated by the land service of Copernicus, the Earth Observation program of the European Commission. The research leading to the current version of the product has received funding from various European Commission Research and Technical Development programs. The product is based on PROBA-V data ((c) ESA).
El-Nina/La Nina predictions: POAMA graph provided by courtesy of the Australian Bureau of Meteorology, (c) 2016.
Rainfall Estimation (RFE): Data provided by the National Oceanic and Atmospheric Administration (NOAA), Centre for Weather and Climate Prediction. http://www.cpc.noaa.gov/...
Click here for a .PDF Version of this information.
Wishing all our readers a wonderful holiday period and a blessed 2017.
October started off with mild temperatures over Gauteng after light snowfalls on the Drakensberg mountains, but temperatures gradually increased towards extremely hot conditions - in the high thirties - by the end of the first week. Thunderstorms announced the summer rainfall season on... Read more
Monthly Overview
October started off with mild temperatures over Gauteng after light snowfalls on the Drakensberg mountains, but temperatures gradually increased towards extremely hot conditions - in the high thirties - by the end of the first week. Thunderstorms announced the summer rainfall season on the first day of October 2016 over Mpumalanga, while KZN received good rain throughout the province. The second week of October saw large parts of Limpopo and North West experiencing record high temperatures while the Eastern Cape experienced a strong cold front, and an upper-air trough brought cooler, wet weather during the third week to Gauteng. Strong storms developed during that week bringing widespread rain to the summer rainfall region. Up to 17 mm were recorded in the Vaal catchment area. Good rain also fell over the Free State and North West. The Eastern Cape was saw severe thunderstorms by the end of the week. The last week of October was characterised by scattered thundershowers, hail storms and heat wave conditions throughout the northern region of South Africa.
Rainfall
While the Cape provinces didn't receive much rain during October, large parts of the summer rainfall region received good rains for the start of the season. Isolated areas in the north eastern Free State, parts of Mpumalanga and KZN, indicated in the green colours, received between 80 to 120 mm. Rainfall throughout the summer rainfall region was between 40 to 80 mm. Northern Limpopo, southern North West, and the southern Free State however, did not receive a lot of rain during October.
Figure 1: Total rainfall estimation in millimetres for 1 to 31 October 2016
Figure 2: Percentage difference - rainfall for 1 to 31 October 2016.
Figure 2 gives a better perspective of the rainfall for October 2016. After having a dry 2015/16 season, the start of the 2016/17 season looks promising. Large parts of the summer rainfall region received more than 100% of its normal rainfall for October (green colours). Areas shown in yellow received between 80 and 100% of it's normal rainfall. As can be expected with the change of season, little to no rain fell over the Cape provinces, although the northern and eastern regions of the Eastern Cape received good rainfall during the month. If this rainfall trend continues, and South Africans work together to save water, we might see an improvement in our dam levels during this season.
Figure 3: Cumulative rainfall from 1 May 2016 to 31 October 2016 in millimetres.
The cumulative rainfall map (Figure 3) for 1 May to 31 October highlights areas that have received more than 150mm during the last 6 months. Light green colours indicate areas that received between 150 to 200mm, while dark green colours indicate areas that received between 200 and 300mm. Areas that received more than 400mm are indicated in the blue colours. KZN received good rainfall over the last 6 months, but with the winter rainfall season coming to an end, there are concerns for the Western Cape.
Figure 4: Percentage difference - rainfall for 1 May to 31 October 2016.
Figure 4 highlights the areas of South Africa that received below-normal and above-normal rainfall for the last 6 months. The yellow to light brown colours highlight areas of concern. The Western Cape, western half of the Northern Cape, most parts of the Eastern Cape, northern Mpumalanga and parts of Limpopo received below normal rainfall during the last 6 months. Areas that received normal to above normal rainfall are indicated in the green colours with areas that received well above normal rainfall being shown in the blue shades. Parts of the eastern Northern Cape, Free State, northern Eastern Cape, KwaZulu-Natal and parts of North West and Gauteng show normal to above normal rainfall for the last 6 months.
El Nino/La Nina
Background: Periods of below normal rainfall in South Africa are often linked with the El Nino event while above normal rainfall is usually linked to La Nina. The latest predictions issued by the Australian Bureau of Meteorology indicate neutral conditions. (Figure 5). Current model predictions show the possibility of near La-Nina conditions is less. Forecasts issued by the South African Weather Service (20 October) indicates that wetter conditions will continue through November, December and January. A high degree of uncertainty remains since there is no clear indications of La Nina developing this season.
Figure 5: Current model predictions for Sea Surface Temperature in the Pacific.
NDVI
Figure 6: ProbaV difference map for October 2016 compared to the long-term (19-year) average.
The map in Figure 6 is derived by calculating the difference between October 2016 and the long-term (19 year) average for October. Figure 6 is dominated by normal vegetation activity (beige colour). Areas of concern with below-normal vegetation activity (red colours) can be seen around Pongola, northern KwaZulu-Natal and eastern Mpumalanga. Higher vegetation activity can be seen from East London stretching northward along the KwaZulu-Natal coast, as well as along the southern coast and central Free State.
Figure 7: Percentage of Average Seasonal Greenness for the last 6 months ending in October 2016.
Drought is a long term phenomenon. Focusing on longer time-periods is a more reliable method to monitor and map drought. Areas of concern include the southern Kruger National Park in north-eastern Mpumalanga. Below normal vegetation conditions can also be seen in northern KwaZulu-Natal. The western part of the Eastern Cape as well as the western part of the Northern Cape shows below-normal vegetation activity.
General Discussion
The rain experienced in the summer rainfall region was very welcome, bringing along some greenery to an otherwise very dry country. Livestock may still be in poor condition and farmers are cautioned not to let hungry animals gorge themselves on lush green grass. Farmers should adjust stocking rates so as not to exceed carry capacity of the veld. Additional fodder and licks can be supplied to improve nutritional value of grazing in dry areas.
Thunderstorms and heavy downpours with possible flooding may occur. Farmers are advised to watch weather reports and take steps to protect their animals from adverse conditions. Appropriate shelters protect animals from wind and hail, and moving animals away from rivers and lower ground is essential when flooding is possible. Fences and farm dams should be inspected after such events have occurred.
The high temperatures and rainfall can cause uncomfortably hot and humid conditions. Several animals may be prone to heat stress, especially if night temperatures do not drop sufficiently for animals to recover. Ensure sufficient clean water is available at all times and feed animals during the cooler parts of the day. Avoid handling animals during the heat of the day. Control flies and parasites that may put additional stress on animals.
Livestock prices are expected to rise with the increase in demand for meat products over the festive season. Stock theft is also on the rise and farmers should ensure all animals are marked with the correct identification marks and take steps to protect their animals from stock thieves.
The latest estimations of maize supply and demand for 2016/2017
South African total maize production forecast are at 12.4 million tons in 2016/2017 marketing season, which covers 7 million tons of yellow maize and 5.4 million tons of white maize. According to National Agricultural Marketing Council (NAMC's) South African Supply and Demand Estimates for October 2016, 2.7 million tons of maize are expected to be imported, provided that about 70 000 tons are delivered early with the surplus of 50 000 tons. Total exports are estimated at 760 000 tons of whole maize and 180 000 tons of processed products in marketing season of 2016/2017.
References:
http://www.farmersweekly.co.za/ - Latest maize supply and demand estimate by Annelie Coleman, 4 November 2016
Acknowledgements:
SPOT Vegetation Data: The product was generated by the land service of Copernicus, the Earth Observation program of the European Commission. The research leading to the current version of the product has received funding from various European Commission Research and Technical Development programs. The product is based on VEGETATION data ((c) CNES).
PROBA-V Data: The product was generated by the land service of Copernicus, the Earth Observation program of the European Commission. The research leading to the current version of the product has received funding from various European Commission Research and Technical Development programs. The product is based on PROBA-V data ((c) ESA).
El-Nina/La Nina predictions: POAMA graph provided by courtesy of the Australian Bureau of Meteorology, (c) 2016.
Rainfall Estimation (RFE): Data provided by the National Oceanic and Atmospheric Administration (NOAA), Centre for Weather and Climate Prediction. http://www.cpc.noaa.gov/...
Click here for a .PDF Version of this information.
The month of September started with high temperatures in the northern regions of the country. Temperatures reached the high thirties at the end of the first week of September. In the second week of September it was slightly cooler with the first summer thunderstorms brought some relief... Read more
Monthly Overview
The month of September started with high temperatures in the northern regions of the country. Temperatures reached the high thirties at the end of the first week of September. In the second week of September it was slightly cooler with the first summer thunderstorms brought some relief to large areas of the Free State and Gauteng. A strong cold front moved over the country during the weekend of 17 & 18 September resulting in rainfall and colder temperatures for a large part of the country. This was the sixth cold front to pass over South Africa, against the five experienced last year. Rainfall in the Western Cape was normal to below normal for most of the winter rainfall season, despite a high number of cold fronts. Temperatures recovered during the third week of September and ended with thunderstorms over large parts of the summer rainfall region. Limpopo and Mpumalanga received welcome relief with intense thunderstorms over these areas.
Rainfall
September was largely a dry month with the eastern Free State, KwaZulu-Natal and the northern Eastern Cape receiving between 40 to 60 mm. Isolated areas along the southern coast, George and Port Elizabeth areas, received more than 100 mm. The Western Cape received scattered showers, well below the expected normal rainfall for this period.
Figure 1: Total rainfall estimation in millimetres for 1 to 30 September 2016
Figure 2: Percentage difference - rainfall for 1-30 September 2016.
Figure 2 gives a better perspective of the rainfall for September. Rainfall over the Western Cape was mixed during September with some areas receiving normal to above normal rainfall (green to blue colours), but some areas received below normal rainfall. KwaZulu-Natal, the eastern Free State and northern Eastern Cape received normal to above normal rainfall for this period. Large parts of North West received normal to above normal rainfall. Rainfall over Gauteng and Limpopo was mixed with dryer conditions dominating. Most parts of Mpumalanga received normal rainfall with the eastern regions receiving above normal rainfall while the central regions remained dry. The western region of the Northern Cape received above normal rain, with areas around Upington, Prieska and De Aar receiving normal rainfall.
Figure 3: Cumulative rainfall from 1 April 2016 to 30 September 2016 in millimetres.
The cumulative rainfall map (Figure 3) for 1 April to 30 September highlights areas that have received more than 150mm during the last 6 months. Light green colours indicate areas that received between 150 to 200mm, while dark green colours indicate areas that received between 200 and 300mm. Areas that received more than 400mm are indicated in the blue colours.
Figure 4: Percentage difference - rainfall for 1 April to 30 September 2016.
Figure 4 highlights the areas of South Africa that received below-normal and above-normal rainfall for the last 6 months. The yellow to light brown colours highlight areas of concern. The Western Cape, western half of the Northern Cape, most parts of the Eastern Cape, northern KwaZulu-Natal, Mpumalanga and Limpopo received below normal rainfall during the last 6 months. Areas that received normal to above normal rainfall are indicated in the green colours with areas that received well above normal rainfall being shown in the blue shades. Parts of the eastern Northern Cape, Free State, northern Eastern Cape, southern KwaZulu-Natal and parts of North West show normal to above normal rainfall for the last 6 months.
El Nino/La Nina
Background: Periods of below normal rainfall in South Africa are often linked with the El Nino event while above normal rainfall is usually linked to La Nina. The latest predictions issued by the Australian Bureau of Meteorology indicate neutral conditions. (Figure 5). Current model predictions show the possibility of near La-Nina conditions is less. This supports the South African Weather Service's warning of a low likelihood of high rainfall during the spring months. There is a high uncertainty in current climate models as to the likelihood of higher than normal rainfall over the summer rainfall region.
Figure 5: Current model predictions for Sea Surface Temperature in the Pacific.
NDVI
Figure 6: ProbaV difference map for September 2016 compared to the long-term (19-year) average.
The map in Figure 6 is derived by calculating the difference between September 2016 and the long-term (19 year) average for September. Figure 6 is dominated by normal vegetation activity (beige colour). Areas of concern with below-normal vegetation activity (red colours) can be seen around Calvinia, northern KwaZulu-Natal and eastern Mpumalanga. Higher vegetation activity can be seen from East London stretching northward along the KwaZulu-Natal coast, as well as along the southern coast.
Figure 7: Percentage of Average Seasonal Greenness for the last 6 months ending in September 2016.
Drought is a long term phenomenon. Focussing on longer time-periods is a more reliable method to monitor and map drought. Areas of concern include the southern Kruger National Park in north-eastern Mpumalanga. Below normal vegetation conditions can also be seen in northern KwaZulu-Natal. The western part of the eastern cape as well as the western part of the Northern Cape show below-normal vegetation activity.
General Discussion
Maize is the staple diet for most people in the country so changes in the price caused by the drought will have a significant effect on their personal finances. It can be seen from figure 8 below that there has been a steady increase from 2014 when the price was below R 2 000 per ton to over R 4 500 per ton in 2016.
White maize is the staple of choice for human consumption and yellow maize is used mainly as livestock feed. The shortage and demand for white maize has been particularly apparent in 2016; this is shown by a 30% higher price for white maize than yellow maize during 2016, while in the past prices have been very similar.
At the same time, from 2014 to 2016, the Rand exchange rate has weakened considerably further increasing the cost of living for everyone (in figure 9).
Internationally the price of maize (shown by USD price / ton) has decreased but this has not affected local prices at all.
Much of the country is still very dry with a few areas showing concern receiving below normal rainfall for this time of year. This is especially true for the Western Cape that lies in the winter rainfall region. The little bit of rain that was received in many areas was welcomed but it did not make an impact and dam levels remain low in many areas.
Several Municipalities have been forced to implement water restrictions which affect many crop and livestock farmers. It is important for farmers to comply with these water usage regulations and put an effort into preserving our water resources. Water related infrastructure in poor states should be fixed or replaced to prevent leaks and to reduce any further water loss.
Acknowledgements:
SPOT Vegetation Data: The product was generated by the land service of Copernicus, the Earth Observation program of the European Commission. The research leading to the current version of the product has received funding from various European Commission Research and Technical Development programs. The product is based on VEGETATION data ((c) CNES).
PROBA-V Data: The product was generated by the land service of Copernicus, the Earth Observation program of the European Commission. The research leading to the current version of the product has received funding from various European Commission Research and Technical Development programs. The product is based on PROBA-V data ((c) ESA).
El-Nina/La Nina predictions: POAMA graph provided by courtesy of the Australian Bureau of Meteorology, (c) 2016.
Rainfall Estimation (RFE): Data provided by the National Oceanic and Atmospheric Administration (NOAA), Centre for Weather and Climate Prediction. http://www.cpc.noaa.gov/...
Click here for a .PDF Version of this information.
July started with an intense cold front that moved from the Western Cape towards the north-east of the country bringing new record low temperatures. Temperatures in parts of Gauteng dropped to below 0 for the first time this winter. The lowest temperatures for this winter season were recorded on the... Read more
Monthly Overview
In the summer rainfall areas of South Africa, August is known for being a dry and windy month. On voting day in August, strong winds caused havoc with temporary voting stations in the Eastern Cape. Strong winds were also present over Gauteng and the northern region of the country. Temperatures dropped dramatically towards the end of the week after due to a cold front moving in the country. During the week of 8- 12 August temperatures climbed to the same highs last experienced in May and after two weeks of mild weather, another major cold front passed over the country on 22 August causing temperatures to drop drastically. After the cold front, temperatures increased dramatically over the country with new record highs for this time of year recorded in parts of the Eastern Cape. The South African Weather Service issued a warning at the end of August of expected hotter than normal temperatures in September, with a low likelihood of high rainfall during the spring months.
Rainfall
August 2016 was generally dry with only the Western Cape and KwaZulu-Natal receiving rain of up to 80 mm in places for the month, while some areas in the interior did receive a little rain as cold fronts passed over the country.
Figure 1: Total rainfall estimation in millimetres for 1 to 31 August 2016
Figure 2: Percentage difference - rainfall for 1-31 August 2016.
Figure 2 gives a better perspective of the rainfall for August. Many areas over the Northern Cape and southern Free State received unseasonably high rainfall in August. Parts of the northern Eastern Cape stretching into KwaZulu-Natal received higher than normal rainfall as well. The north and north-eastern Limpopo as well as areas around Mbombela and Ermelo in Mpumalanga received above normal rainfall. Gauteng, North West, western Mpumalanga and northern Free State received little to no rainfall during August. Rainfall was normal to below normal in the Western Cape with the west coast receiving little to no rainfall.
Figure 3: Cumulative rainfall from 1 March 2016 to 31 August 2016 in millimetres.
The cumulative rainfall map (Figure 3) for 1 March to 31 August highlights areas that have received more than 150mm during the last 6 months. Light green colours indicate areas that received between 150 to 200mm, while dark green colours indicate areas that received between 200 and 300mm. Areas that received more than 400mm are indicated in the blue colours.
Figure 4: Percentage difference - rainfall for 1 March to 31 August 2016.
Figure 4 highlights the areas of South Africa that received below-normal and above-normal rainfall for the last 6 months. Areas of concern (orange to brown colours) following the drought of the 2015/2016 season include North West, Gauteng, southern Limpopo, west and north-western Mpumalanga as well as the Eastern Cape and west coast region. Rainfall in the Western Cape has been mixed. Some areas in the region have received normal (yellow) to above-normal rainfall (green). Large parts of the province received below-normal rainfall.
Areas that received above normal (green to blue colours) include large parts of the Northern Cape province as well as the southern Free State. The northern region of the Eastern Cape as well as most of KwaZulu-Natal received above normal rainfall. North and north western Limpopo also received above normal rainfall.
El Nino/La Nina
Background: Periods of below normal rainfall in South Africa are often linked with the El Nino event while above normal rainfall is usually linked to La Nina. The latest predictions issued by the Australian Bureau of Meteorology indicate El Nino conditions have ended (Figure 5). Current model predictions show the possibility of near La-Nina conditions developing from September 2016. This supports the South African Weather Service’s warning of a low likelihood of high rainfall during the spring months. There is a high uncertainty in current climate models as to the likelihood of higher than normal rainfall over the summer rainfall region.
Figure 5: Current model predictions for Sea Surface Temperature in the Pacific.
NDVI
Figure 6: ProbaV difference map for August 2016 compared to the long-term (19-year) average.
The map in Figure 6 is derived by calculating the difference between August 2016 and the long-term (19 year) average for August. Figure 6 is dominated by normal vegetation activity (beige colour). Areas of concern with below-normal vegetation activity (red colours) can be seen around Calvinia. Higher vegetation activity can be seen from Mthatha stretching northward along the KwaZulu-Natal coast.
Figure 7: Percentage of Average Seasonal Greenness for the last 6 months ending in August 2016.
Drought is a long term phenomenon. Focussing on longer time-periods is a more reliable method to monitor and map drought. Areas of concern include the southern Kruger National Park in north-eastern Mpumalanga. Below normal vegetation conditions can also be seen in northern KwaZulu-Natal. The western part of the eastern cape as well as the western part of the Northern Cape show below-normal vegetation activity.
General Discussion
The effects of the dry season have had some negative effects on the grapefruit exports but they have also had some benefits. Grapefruit is in demand in many markets at the moment, partly due to an early stop in supply from Israel and Turkey, and because of the slow start to the South African season. The slow colour development means that fruit must be picked from each orchard 3 or 4 times which is very labour intensive. On the positive side it will enables all packable fruit to be harvested and ensures consistent supply over a longer period.
At the start of the season there were expectations was that the grapefruit volume would be around 30% lower as a result of the hail at the end of last year and extreme temperatures at the beginning of 2016, but the actual loss in production might be less. Although volumes are lower than previous years, the conditions have resulted in fruit with a higher brix, and good internal quality and colour. The markets are also now receiving fruit that has not been stored for long.
With most of the country still in the grips of the drought, livestock farmers will need to continue to feed supplements and licks. Farmers should be on the lookout for poisonous plants that may attract hungry animals. Many of these plants sprouts at a time when no other green grass is available and newly emerging shoots are often more toxic than mature plants.
Farmers should continue to watch weather reports to plan management activities such as dipping and vaccinating. Spring is the time to start vaccinating against several diseases and before the breeding season begins. The warm weather is also accompanied by an increase in activity of ticks and parasites. Animals already stressed from the drought and lack of feed are more susceptible to parasites and diseases and thus should be dipped, dosed and vaccinated accordingly.
References:
Fresh Plaza. FruitOne South Africa. August 2016: Cobus van Graan
Acknowledgements:
SPOT Vegetation Data: The product was generated by the land service of Copernicus, the Earth Observation program of the European Commission. The research leading to the current version of the product has received funding from various European Commission Research and Technical Development programs. The product is based on VEGETATION data ((c) CNES).
PROBA-V Data: The product was generated by the land service of Copernicus, the Earth Observation program of the European Commission. The research leading to the current version of the product has received funding from various European Commission Research and Technical Development programs. The product is based on PROBA-V data ((c) ESA).
El-Nina/La Nina predictions: POAMA graph provided by courtesy of the Australian Bureau of Meteorology, (c) 2016.
Rainfall Estimation (RFE): Data provided by the National Oceanic and Atmospheric Administration (NOAA), Centre for Weather and Climate Prediction. http://www.cpc.noaa.gov/products/international/data.shtml
Click here for a .PDF Version of this information.
July started with an intense cold front that moved from the Western Cape towards the north-east of the country bringing new record low temperatures. Temperatures in parts of Gauteng dropped to below 0 for the first time this winter. The lowest temperatures for this winter season were recorded on the... Read more
July started with an intense cold front that moved from the Western Cape towards the north-east of the country bringing new record low temperatures. Temperatures in parts of Gauteng dropped to below 0 for the first time this winter. The lowest temperatures for this winter season were recorded on the 4th of July. Mild temperatures returned midway through July with higher than normal temperatures dominant over Gauteng in the week of 17 July. An intense Cut-off low developed over the country during the weekend of 23 July bringing a return of colder temperatures and rainfall to most parts of South Africa. Intense thunderstorms developed over Gauteng on 25 July and these storms intensified on 26 July into a large hailstorm over south western Gauteng. These storms also led to the development of a tornado that caused damage in Tembisa, to the east of Midrand. There were reports of flooding in Durban as a result of intense and continued rainfall. Temperatures reached new lows in Gauteng on 27 July.
RFE or Rainfall Estimation data was developed and implemented by the National Oceanic and Atmospheric Administration (NOAA). Information provided by NOAA will be added to this monthly report to provide important information on the monthly rainfall totals as well as the deviation from the normal, to highlight areas affected by drought conditions. Both monthly and 6-monthly cumulative maps will be provided, as well as maps indicating the deviation from the long term average as a percentage of the NDVI and PASG maps.
Figure 1: Total rainfall estimation in millimetres for 1 to 31 July 2016
Figure 1 shows that large parts of the Western Cape received good rainfall in July. Between 50 to 100 mm of rain fell over large parts of the province. The northern Eastern Cape received good rainfall while KwaZulu-Natal experienced flooding with more than 250mm recorded. Unseasonably high rainfall also occurred over parts of the Free State.
Figure 2: Percentage difference - rainfall for 1-31 July 2016.
Figure 2 gives a better perspective of the rainfall for July. Rainfall had been above normal in some parts of the province (green colours) while other areas remain drier than normal (orange and brown colours). Isolated areas in the Northern Cape received good rainfall, but most of the province remained dry. The western parts of the Eastern Cape received low rainfall while the eastern parts of the province received rainfall well above normal. Above normal rainfall also occurred over KwaZulu Natal, the Free State, North-West, Gauteng and Mpumalanga. The southern parts of Limpopo as well as areas from Musina southward received above normal rainfall. The rest of the province remained dry with below normal rainfall.
Figure 3: ProbaV difference map for July 2016 compared to the long-term (19-year) average.
The map in Figure 3 is derived by calculating the difference between July 2016 and the long-term (19 year) average for July. Figure 3 is dominated by normal vegetation activity (beige colour). Areas of concern with below-normal vegetation activity (red colours) can be seen around Mbombela and the southern Kruger National park. An area with low vegetation activity also stretches along the south western parts of Eastern Cape.
Figure 4: Cumulative rainfall from 1 February 2016 to 31 July 2016 in millimetres.
The cumulative rainfall map for 1 February to 31 July highlights areas that have received more than 150mm during the last 6 months. Light green colours indicate areas that received between 150 to 200mm, while dark green colours indicate areas that received between 200 and 300mm. Areas that received more than 400mm are indicated in the blue colours. The north western region of the country received below 150mm.
Figure 5: Percentage difference - rainfall for 1 February to 31 July 2016.
South Africa was severely affected by El Nino in the 2015/2016 summer rainfall season. Current long-term rainfall indicates that there has been an improvement in the rainfall received over the last few months, especially in southern KwaZulu-Natal, the northern Eastern Cape, eastern Free State, Gauteng and the areas surrounding Gauteng. Areas affected by lower than normal rainfall in the last 6 months are highlighted with the different shades of brown. Areas of concern include the Northern Cape, North West, the eastern Western Cape and the western Eastern Cape, as well as northern KwaZulu-Natal, north-eastern Mpumalanga and the western Free State.
Cumulative time series analysis further enhances the mapping of drought conditions. Data accumulated over a number of months, compared to the same period in history, can highlight the severity of drought conditions. The Percentage of Average Seasonal Greenness (PASG), Figure 3, is an example of how long-term data can be used to monitor and map drought affected areas.
Figure 6: Percentage of Average Seasonal Greenness for the last 6 months ending in July 2016.
Drought is a long term phenomenon. Focussing on longer time-periods is a more reliable method to monitor and map drought. Since large part of the country received higher than normal rainfall the last 6 months, as discussed in figure 5, there has been an improvement in vegetation conditions throughout the country. Areas of concern, highlighted in the red and orange colours include the southern Kruger National park, northern KwaZulu-Natal, the southern and western Free State, isolated areas in North West and the Northern Cape. The eastern Western Cape and western Eastern Cape also show below normal vegetation activity. The majority of South Africa is dominated by normal vegetation conditions (beige colour). Higher vegetation activity (green colour) is visible around Upington in the Northern Cape.
Figure 7: Current model predictions for Sea Surface Temperature in the Pacific - El Nino.
Background: Periods of below normal rainfall in South Africa are often linked with the El Nino event while above normal rainfall is usually linked to La Nina. The latest predictions issued by the Australian Bureau of Meteorology indicate El Nino conditions have ended (Figure 7). Current model predictions show the weakened possibility of La Nina conditions developing later in the year. There is, however, largely uncertain - as seen in the various prediction models. If La Nina conditions do develop, it is expected not to be as strong as previous La Nina events.
The changes from the norm in weather patterns can have a negative impact on livestock productivity. Animals stressed from the effects of the drought may be further stressed by uncharacteristic weather changes. Stress factors can influence average daily weight gain, and milk and egg production amongst other things.
The changes in weather and rainfall patterns can have an influence on disease and parasite distribution. Stressed animals are more susceptible to these diseases and parasites. Livestock owners are cautioned to limit stress as much as possible by avoiding unnecessary handling and ensuring animals have access to sufficient feed, water and shelter. Very cold areas can result in drinking water freezing and floods may affect access to feed. Some licks, especially those containing urea, are affected by rain. Power loss from adverse weather conditions can impact housed animals such as pigs and poultry that rely on controlled housing conditions.
Care should be taken with pregnant animals that may abort, and very young and old animals that are more vulnerable to adverse conditions such as very cold winds. Farmers should also be on the lookout for veldfires, especially in very dry areas when strong winds are present.
As usual during the winter period much of the fresh produce comes from the frost-free areas of the country. Although some vegetables can tolerate frost, production is more rapid and greater in frost-free conditions. In Gauteng much of the produce is grown in Limpopo particularly the Tzaneen area, Thohoyandau region and the Limpopo valley, and transported to the city markets. Winter-conditions favour the production of cabbages, carrots, beetroot, onions and potatoes, in particular.
Frost-free areas along the eastern coast line to the Cape facilitate fresh produce production, while winter rains in the Western Cape enable cultivation of winter wheat.
Acknowledgements:
June kicked off with cold weather across the country with a cold front that brought rain to large parts of the summer rainfall regionfrom the end of May. An intense cold front reached the Western Cape on 9 June causing temperatures in the interior to drop to new lows... Read more
June kicked off with cold weather across the country with a cold front that brought rain to large parts of the summer rainfall regionfrom the end of May. An intense cold front reached the Western Cape on 9 June causing temperatures in the interior to drop to new lows during that weekend with snowfall on the high lying regions of the Eastern Cape and the Drakensberg. This was the 3rd and strongest cold front of the season and many parts of Gauteng experienced their lowest temperatures for this winter.
Temperatures gradually increased during the rest of the month for most parts of South Africa, while another intense cold front is expected in the beginning of July.
Figure 1: ProbaV difference map for June 2016 compared to the long-term (19-year) average.
The map in Figure 1 is derived by calculating the difference between June 2016 and the long-term (19 year) average for May. Figure 1is dominated by normal vegetation activity (beige colour) with small areas showing higher vegetation activity (green colours) in the central region of the country. Areas of concern with well below-normal vegetation activity (red colours) can be seen between Lephalale in Limpopo, eastern South Africa from the southern Kruger National park southwards to Richards Bay. An area with low vegetation activity also stretches along the Southern cape towards the Eastern Cape.
Cumulative time series analysis further enhances the mapping of drought conditions. Data accumulated over a number of months, compared to the same period in history, can highlight the severity of drought conditions. The Percentage of Average Seasonal Greenness (PASG), Figure 2, is an example of how long-term data can be used to monitor and map drought affected areas.
Figure 2: Percentage of Average Seasonal Greenness for the last 6 months ending in June 2016.
Drought is a long term phenomenon. Focussing on longer time-periodsis a more reliable method to monitor and map drought. The overall long-term vegetation conditions over South Africa look extremely negative due to the drought experienced during 2015/2016. With winter settling in, rainfall had little impact over the summer rainfall region.
Severe drought conditions are still present in North West and the Free State provinces, with the eastern side of South Africa from the Kruger Park to Richards Bay also showing severe drought conditions. Vegetation conditions around Upington and along parts of the Orange river in the Northern Cape are well above average.
Figure 3: Current model predictions for Sea Surface Temperature in the Pacific - El Nino.
Background: Periods of below normal rainfall in South Africa are usually linked with the El Nino event while above normal rainfall is usually linked to La Nina. The latest predictions issued by the Australian Bureau of Meteorology indicate El Nino conditions have ended (Figure 3). Current model predictions show the weakened possibility of La Nina conditions developing later in the year. There is, however, a large uncertainty - as seen in the various prediction models. If La Nina conditions do develop, it is expected not to be as strong as previous La Nina events.
It is estimated that the national production of grain and oilseeds will be 8.8 million tons this year. This means that 4.2 million tons of these crops will need to be imported (this excludes wheat and rice). Of the 4.2 million tons, 91% is maize and the remainder are soybeans, groundnuts, sunflower and sorghum. South African ports can cope with 5 million tons of imported grain per year.
Maize production was down by 28% compared with 2015 and was 50% less than 2014. This is a direct effect of the drought.
With the cold fronts making their way in over the countryside, small stock owners especially,are advised to be extra vigilant of extreme cold conditions that can have a detrimental effect on young lambs and goat kids. Young animals are especially vulnerable and losses can occur due to cold weather conditions. Older animals and those in poor condition (especially after the recent droughts) are also at risk. Farmers are advised to build shelters and watch weather reports and take preliminary action to protect young and vulnerable animals.
With most of the country still suffering the effects of the 2015/2016 drought, which is expected to take a long time to recover, farmers are advised to continue feeding licks and supplements in affected areas.
Acknowledgements:
May 2016 started with cold temperatures across the country due to a cold front that moved over large parts of the country. Some of the coldest temperatures for 2016 so were recorded on the night of 1 May. A cut of low produced widespread rainfall over... Read more
May 2016 started with cold temperatures across the country due to a cold front that moved over large parts of the country. Some of the coldest temperatures for 2016 so were recorded on the night of 1 May. A cut of low produced widespread rainfall over large parts of the country around 14-15 May, causing temperatures to remain low. The development of a ridging high caused rainfall and cold temperatures in Gauteng around 26 May. Gauteng temperatures dropped to new lows for 2016 on 28 & 31 May.
Figure 1: ProbaV difference map for May 2016 compared to the long-term (19-year) average.
The map in Figure 1 is derived by calculating the difference between May 2016 and the long-term (19 year) average for May. Figure 1 is dominated by normal vegetation activity (beige colour) with small areas showing higher vegetation activity (green colours) in the central region of the country. Areas of concern with well below-normal vegetation activity (red colours), can be seen between Lephalale and Modimolle in Limpopo, eastern South Africa from the southern Kruger National park southwards to Richards Bay. An area with low vegetation activity also stretches along the Southern cape towards the Eastern Cape.
Cumulative time series analysis further enhances the mapping of drought conditions. Data accumulated over a number of months, compared to the same period in history, highlight the severity of drought conditions. The Percentage of Average Seasonal Greenness (PASG), Figure 2, is an example of how long-term data can be used to monitor and map drought affected areas.
Figure 2: Percentage of Average Seasonal Greenness for the last 6 months ending in May 2016.
Drought is a long term phenomenon. Focussing on longer time-periods is a more reliable method to monitor and map drought. The overall long-term vegetation conditions over South Africa look extremely negative because of the drought of 2015/2016. With winter approaching, there was little or no rainfall over the summer rainfall region. Severe drought conditions are still present in North West and the Free State provinces, with the eastern side of South Africa from the Kruger Park to Richards Bay also showing severe drought conditions.
Figure 3: Current model predictions for Sea Surface Temperature in the Pacific - El Nino.
Background: Periods of below normal rainfall in South Africa are usually linked with the El Nino event while above normal rainfall is usually linked to La Nina. The latest predictions issued by the Australian Bureau of Meteorology indicate El Nino conditions have ended (Figure 3). Current model predictions show the possibility of possible La Nina conditions developing later in the year. There is, however, a large uncertainty - as seen in the various prediction models. The prediction models should give a clearer picture in the next few months on the likelihood of La Nina conditions developing.
As can be seen in figure 2, much of the country is suffering from the effects of the drought. The lack of vegetation or quality of vegetation, as well as increased feed prices still has a negative impact on livestock farmers. In areas with no grazing, farmers will need to supplement their animals. Animal nutritionists may be able to advise farmers on cost effective feeds and ingredients that will provide the minimum requirements for livestock. In areas where there is some grazing, farmers can provide licks to make up for nutrient deficiencies and increase utilization of low quality roughage as experienced during winter months when grasses become dormant.
With the prospect of La Nina conditions developing over the second half of the year, rainfall for the 2016/2017 summer season can be expected to increase providing a normal to higher amount of rainfall in the summer rainfall region. This can have a more positive outlook for livestock farmers when maize production and veld conditions improve.
In the meanwhile farmers in the summer rainfall region should be on the lookout for veld fires and adhere to any fire warnings, while farmers in the winter rainfall region can begin to plan for the summer fire season.
The effects of the drought will be felt in the fruit industry going into the latter half of 2016. Most fruit is harvested and exported from May onwards; it is expected that there will be a decline in exports compared to that of 2015.
Citrus, apples and pears are likely to be most affected. Production of table grapes, exported towards the end of the year, is likely to be at normal volumes.
Grapefruit volumes are down 30% not only because of the drought, but also the effects of the hail in late 2015. A positive effect on grapefruit has been the high brix (sugar) content and good colour. The harvest has also been delayed by the drought, avoiding the need for storage, which means the market is benefiting from fresh, high-quality fruit.
Acknowledgements:
April 2016 started with the first major cold front of the year moving over South Africa. Minimum temperatures dropped to below 10°C in many areas. The frontal system also brought rainfall to parts of our country. The rest of the month remained dry with... Read more
April 2016 started with the first major cold front of the year moving over South Africa. Minimum temperatures dropped to below 10°C in many areas. The frontal system also brought rainfall to parts of our country. The rest of the month remained dry with temperatures gradually increasing. At the end of April, the next major cold front had moved in, causing minimum and maximum temperatures to drop drastically with snow reported in the Eastern Cape.
As a matter of interest, the SA Weather Service expects this winter to be between 0.5 - 1°C warmer than normal.
Figure 1: ProbaV difference map for April 2016 compared to the long-term (19-year) average.
The map in Figure 1 is created by calculating the difference between April 2016 and the long-term (19-year) average for April. Figure 1 is dominated by normal vegetation activity (beige colour) with small areas showing higher vegetation activity (green colours). Areas of concern with well-below-normal vegetation activity (red colours), can be seen around Mahikeng in North West, Springfontein in the southern Free-State, significant parts of the southern Kruger National Park, the areas north of Richards bay in KwaZulu-Natal and the Eastern Cape in the Cacadu district municipality.
Cumulative time series analysis, further enhances the mapping of drought conditions. Data accumulated over a number of months, compared to the same period in history, highlight the severity of the drought conditions. The Percentage of Average Seasonal Greenness (PASG), Figure 2, is an example of how long-term data can be used to monitor and map drought affected areas.
Figure 2: Percentage of Average Seasonal Greenness for the last 6 months ending in April 2016.
Drought, as is often explained, is a long-term phenomenon and by focussing on longer time-periods, proofs to be a more reliable method to monitor and map drought. The rain received during February & March 2016 had a positive effect on the 6-month PASG map, but the effect of the low rainfall earlier in the season is still clearly visible over large parts of the summer rainfall region. Lower vegetation activity due to low rainfall over South Africa during the last 6 months, is shown in the red and orange indicators - Figure 2. The Free State and North West, provinces are dominated by lower vegetation activity. Parts of Limpopo, Mpumalanga, Northern Cape, Gauteng, KwaZulu-Natal and the Eastern Cape show general lower vegetation activity. Only along the coastline of the southern Cape do we find areas with positive vegetation activity - green.
Figure 3: Current model predictions for Sea Surface Temperature in the Pacific - El Nino.
Background: Periods of below normal rainfall in South Africa are usually linked with the El Nino event while above normal rainfall is usually linked to La Nina. The current global climate is affected by one of the strongest El Nino events on record. The latest predictions issued by the Australian Bureau of Meteorology indicate El Nino conditions will end in April 2016 with neutral Sea Surface Temperatures expected in May 2016 (Figure 3). Current model predictions show the possibility of possible La Nina conditions developing later in the year. There is, however, a large uncertainty – as seen in the various prediction models. The prediction models should give a clearer picture in the next few months on the likelihood of La Nina conditions developing.
The Department of Agriculture, Forestry, and Fisheries (DAFF) will be conducting an investigation into the devastating effects of the drought on informal traders and communal farmers. There is a general concern in South Africa about the informal traders and communal farmers who depend on sales of produce to support their families.
The investigation will include:
Some earlier informal observations, with market agents and vendors, found that:
On a more positive note, the high temperatures have resulted in better quality citrus, where farmers have been able to irrigate. The high temperatures lead to excellent fruit and eating quality, with high brix- levels. The acid-brix ratio is also high, making for an improved shelf-life. In Citrusdal, favourable night temperatures (10 to 16°C), ensured good colour development, relatively disease-free crops (clean crops) - thus more, export-quality fruit. However, good winter rains are needed to replenish dam levels before the next season.
The effect of the drought continues to have a negative impact as livestock farmers are experiencing feed shortage. The price of maize and wheat (two essential components of livestock diets) is expected to increase further with the expected import of maize and wheat. Farmers should, however, be cautious of flooding. There are predictions of possible La Nina conditions and accompanying flooding developing, with more negative impact on feed prices, with the possibility of changes in disease outbreak patterns.
Acknowledgements:
For our previous Climate Watch articles we used MODIS Terra data. Unfortunately, MODIS Terra stopped receiving and processing data during February 2016 but we are fortunate to be able to replace MODIS data with PROBA-V data, received from the Copernicus... Read more
For our previous Climate Watch articles we used MODIS Terra data. Unfortunately, MODIS Terra stopped receiving and processing data during February 2016 but we are fortunate to be able to replace MODIS data with PROBA-V data, received from the Copernicus European Earth-monitoring programme. The Flemish Institute for Technological Research (VITO) in Belgium distributes the data received on a 10-day-cycle, which they process to monthly composites. Although higher resolution PROBA-V data is available, we use the 1 km product due to its comparability to the 1km VEGETATION dataset processed and distributed by VITO. We create our NDVI derived maps by using both the PROBA-V and VEGETATION datasets.
March 2016 started off with widespread heavy rains across the summer rainfall region. Large areas in Gauteng, Limpopo, and Mpumalanga reported localised flooding while areas in North West, KwaZulu-Natal and the Free State provinces received exceptionally good rains.
Figure 1: Proba-V difference map for March 2016 compared to the long-term (19-year) average.
The map in Figure 1 is derived by calculating the difference between March 2016 and the long-term (19-year) average for March. Figure 1 shows the positive impact of the heavy rainfall experienced in early March over large parts of the summer rainfall region. Only small areas in Mpumalanga, KwaZulu-Natal, and the Free State show below normal vegetation activity - indicated by the red and orange colours.
Cumulative time series analysis further enhances the mapping of drought conditions. Data accumulated over a period, compared to the same period in history, can highlight the severity of drought conditions. The Percentage of Average Seasonal Greenness (PASG), Figure 2, is an example of how long-term data can be used to monitor and map drought affected areas.
Figure 2: Percentage of Average Seasonal Greenness for the last 6 months ending in March 2016.
Drought is a long-term phenomenon. Focussing on longer time-periods certainly is a more reliable method to monitor and map drought. The good rainfall received in March 2016 had a positive effect on the 6-month PASG map although the effect of the low rainfall earlier in the season is still clearly visible over large parts of the summer rainfall region. Lower vegetation activity due to low rainfall over South Africa during the last 6 months, can clearly be seen in the red and orange indicators - Figure 2. The Free State and North West provinces are dominated by lower vegetation activity while parts of Limpopo, Mpumalanga, Northern Cape, Gauteng, KwaZulu-Natal and the Eastern Cape show lower vegetation activity. It is only in the southern Cape, along the coastline, that we find areas with positive vegetation activity (green).
Figure 3: Current model predictions for Sea Surface Temperature in the Pacific - El Nino.
Periods of below-normal rainfall in South Africa are usually linked to the El Nino event while we associate La Nina with above-normal rainfall. The global climate is currently affected by one of the strongest El Nino events on record. Latest predictions by the Australian Bureau of Meteorology indicate El Nino conditions will continue until June 2016 (Figure 3). With neutral Sea Surface Temperatures predicted from July 2016 onwards, the possibility of a normal summer rainfall season in 2016/2017 looks promising.
Crops
The good rains in March helped to replenish water reservoirs and improve underground water levels in some areas. However, despite the slight increases in dam water volumes in provinces such as Limpopo, Gauteng, the North-West, and Mpumalanga, a number of dam levels have not risen.
The long-term effects of the drought will be felt for some time to come. Fresh vegetable prices on the markets have reportedly increased by as much as 30% since December 2015, and higher prices are likely to persist until the summer-rain season. An example of rising prices as a result of drought, is Sandveld in the Western Cape (the biggest potato growing area in South Africa), where they experienced dry conditions coupled with severe heat, resulting in significantly reduced yields. The effect? Potato prices in January were the highest ever recorded. The negative influence of the drought on fresh fruit and vegetable prices are likely to persist until the year-end while shortages of local maize will prevail until the crops are harvested in 2017. One positive forecast is an expected normal summer rainy season for 2016/17.
Livestock
The recent rain in the summer rainfall region has improved grazing conditions in the short term, a windfall welcomed by many livestock farmers. However, as the season starts to change, grass quality starts to drop with grasses beginning to produce seeds and moving food reserves from the leaves to the roots in preparation for winter. Veld that has been overgrazed or degraded, especially due to the drought conditions over the past months, will take several months to recover even with good rainfall. It is essential that veld is rested for as long as possible (a full growing season's rest) to allow a full recovery to sustain animal production in future.
With the possibility of a normal summer rainfall season in 2016/2017, farmers will be able to rebuild their herds and improve production levels from what they are currently.
Acknowledgements:
Weather trends noticed in January, continued into February - large parts of the summer rainfall region would experience heat wave conditions - only to be broken the next moment by short periods of rainfall... Read more
Weather trends noticed in January, continued into February - large parts of the summer rainfall region would experience heat wave conditions - only to be broken the next moment by short periods of rainfall.
Figure 1: MODIS difference map for February 2016 compared to the long-term (16-year) average.
The map in Figure 1 is derived by calculating the difference between February 2016 and the long-term (16-year) average for February. Figure 2 gives us insight into the vegetation conditions in South Africa and how the current situation compares to the normal or average conditions. Figure 1 further shows the impact of the drought conditions South Africa has experienced during the current summer rainfall period. Gauteng, Mpumalanga and southern KwaZulu-Natal show normal vegetation conditions as a result of the good rainfall received during the first two months of 2016. Lower vegetation activity dominates the summer rainfall area as indicated on the map (red coloured area), and is indicative of vegetation under stress (not having received enough rain to stimulate growth).
Cumulative time series analysis further enhances the mapping of drought conditions. Data accumulated over months, compared to the same period in history, can highlight the severity of drought conditions. The Percentage of Average Seasonal Greenness (PASG), Figure 2, is an example of how long-term data can be used to monitor and map drought affected areas.
Figure 2: Percentage of Average Seasonal Greenness for the last 6 months ending in January 2016.
Drought is a long-term phenomenon. Focussing on longer time-periods is a more reliable method of monitoring and mapping drought and drought conditions. Lower vegetation activity due to low rainfall over South Africa, during the last 6 months, are clearly shown by the red and orange indicators - Figure 2. The whole of Northern Cape, Free State, North West, Mpumalanga, Gauteng and KwaZulu-Natal, are dominated by lower vegetation activity while parts of Limpopo and the Eastern Cape show lower vegetation activity. It is only the southern Cape that shows normal positive vegetation activity (green).
Figure 3: Current model predictions for Sea Surface Temperature in the Pacific - El Nino.
As indicated before, below normal rainfall in South Africa is mostly linked to El Nino events while above normal rainfall are influenced by the La Nina phenomenon. Global climate is currently affected by one of the strongest El Nino events on record. Latest predictions issued by the Australian Bureau of Meteorology indicate El Nino conditions will continue until June 2016 (Figure 3). With neutral Sea Surface Temperatures being predicted from June onwards, the possibility of a normal summer rainfall season in 2016/2017, looks promising.
Poor vegetation activity over much of the country still indicates the dramatic effects that drought has on the natural vegetation necessitating the need for supplements for veld grazing animals. Farmers should ensure that their animals' vaccinations and deworming schedules are up to date and parasite levels controlled to limit additional stress on their livestock. The shortage and high cost of maize continue to put a strain on pig, poultry and dairy farmers. Those affected should consider consulting with animal nutritionists regarding the use of alternative feed substances without affecting productivity.
The harvesting of citrus is currently under way in many areas. The effects of the drought appear to be variable at this time. In the Hoedspruit area, grapefruit has been affected, and volumes may be down by as much as 2 million boxes compared with last year. Hail damage towards the end of 2015 added to producer's woos in the area. On the other hand, the volumes and quality of lemons are good and seem similar to last year. The harvest of early mandarins is about to begin - growers in the Groblersdal area are positive, but the situation could be different elsewhere. In general, it is too early in the harvesting season to make predictions, but overall results might be slightly lower or similar to last year.
January 2016 started with heat wave conditions over large parts of the summer rainfall region, but fortunately also broken in the second week, when many areas of the summer rainfall region received much-needed rain... Read more
January 2016 started with heat wave conditions over large parts of the summer rainfall region, but fortunately also broken in the second week, when many areas of the summer rainfall region received much-needed rain.
Satellite Imagery for January 2016 will show the impact of the rain received over the summer rainfall region and its impact on the current drought situation South Africa is experiencing.
Satellite Imagery is a practical tool used to monitor drought conditions. NDVI images (Normalized Difference Vegetation Index) describe vegetation activity and show the highest possible "greenness" values measured during a particular period. This relationship makes it possible to monitor stressed vegetation or agricultural drought conditions. Rainfall data cannot show the spatial extent of drought conditions, but remote sensing data, through NDVI's do, by helping to map drought conditions.
Figure 1: MODIS difference map for January 2016 compared to December 2015
To derive the map in Figure 1, we calculate the difference between the NDVI's of January 2016 and December 2015. The resulting map shows areas where the NDVI greenness has either increased or decreased. Figure 1 displays the positive effect (Green colours) of the rainfall that fell in January over the summer rainfall region. North-West, the Free State, Gauteng and large parts of Mpumalanga and KwaZulu-Natal show an increase in vegetation activity. Northern KwaZulu-Natal, northern Mpumalanga and large areas of Limpopo show lower vegetation activity (red colours) as a result of little to no rainfall in these areas. Although the map shows a positive image, it should only be seen as a short-term analysis of the conditions. The actual impact of the rain on the vegetation can only be revealed by comparing the data to a long-term average.
Figure 2: MODIS difference map for January 2016 compared to the long-term (16-year) average.
To derive the map in Figure 2, we calculate the difference between January 2016 and the long-term (16 years) average for January. Figure 2 gives us insight into the vegetation conditions for South Africa and how the current situation compares to the normal or average conditions. Figure 2 shows us the impact of the drought conditions that South Africa has experienced during the current summer rainfall region. Only a small number of areas (beige colour) show an improvement or recovery after the good rainfall received in January. The summer rainfall region is dominated by lower vegetation activity (red colour). The lower vegetation activity is a result of it being under stress for not having received enough rainfall to stimulate growth. South Africa is in dire need for more rainfall in the coming months before we will see any improvement in the vegetation activity over the summer rainfall region.
Cumulative time series analysis further enhances the mapping of drought conditions. Data accumulated over a number of months, compared to the same period in history, can highlight the severity of drought conditions. The Percentage of Average Seasonal Greenness (PASG), figure 3, is an example of how long-term data can be used to monitor and map drought affected areas.
Figure 3: Percentage of Average Seasonal Greenness for the last 6 months ending in January 2016.
Drought is a long-term phenomenon. Focussing on longer time-periods is a more reliable method to monitor and map drought. Lower vegetation activity due to low rainfall over South Africa during the last six months can clearly be seen in the red and orange indicators - Figure 3. The Northern Cape, Free State, North West, Mpumalanga, Gauteng and KwaZulu-Natal provinces are dominated by lower vegetation activity. Parts of Limpopo and the Eastern Cape show lower vegetation activity. Only the southern Cape show normal positive vegetation activity (green).
Figure 4: Current model predictions for Sea Surface Temperature in the Pacific - El Nino.
Periods of below normal rainfall in South Africa are usually linked with the El Nino event while above normal rainfall is usually linked to La Nina. The global climate is currently affected by one of the strongest El Nino events on record. Latest predictions issued by the Australian Bureau of Meteorology indicate El Nino conditions will continue until June 2016 (Figure 4). South Africa is likely to continue to receive below-normal rainfall as we've already experienced since the start of the summer rainfall season. With neutral Sea Surface Temperatures being predicted from June onwards, the possibility for a normal summer rainfall season in 2016/2017 looks promising.
CROPS
The current drought conditions have greatly affected rain-fed crops - dry conditions in November and December had a negative influence on maize germination, and some fields had to be replanted. The effect of the drought on irrigated and partially irrigated crops is also apparent, with damage being caused by high temperatures and diminished water supplies. Prices of the most commonly traded vegetables, such as tomatoes, cabbages, spinach, potatoes and onions have soared. Conditions in some neighbouring countries, such as Swaziland, are worse with some complete crop failures and the import of vegetables from South Africa is becoming non-viable because of the high prices here.
South Africa crop insurers are now not covering high-risk crops such as vegetables planted in the northern regions. Some fruit and vegetable crops affected are citrus, tomatoes, carrots, melons, peppers, spinach and cabbage. South Africa's crop insurance industry is worth about R1.0 billion in annual premiums.
LIVESTOCK
While the recent rains bring some relief from the heat, it does not bring instant relief to the drought-stricken veld. Livestock owners will need to continue to provide their animals with supplementary feeds and licks and allow the veld time to rest. In areas where there has been an increase in vegetative growth, animals, specifically sheep, should be well managed when they are returned to green grass after a long period on dry grass. Pulpy kidney can result in mortalities due to sudden dietary changes and farmers are advised to vaccinate animals against it. Grass staggers, caused by magnesium shortages, also occurs when animals return to green grass. Livestock owners should also be on the lookout for plant poisonings in the grazing veld as well as poisonings that may occur from feeding on crop residues.
Crop residues are a valuable source of feed during times of drought however the quality may be poor and should not be used for lactating or pregnant animals. Possible problems with feeding crop residues include the presence of toxins and poisons. Many crops (most noticeably Sorghum) are prone to regrowth when late rains and high temperatures stimulate plant growth. The young shoots can cause prussic acid poisoning. Prussic acid poisoning can be prevented by feeding a sulphur-containing lick.
Brassicas (Cabbage, cauliflower, Brussel sprouts) produce substances that block the uptake of iodine in animals resulting in iodine deficiencies when these crops are grazed for a continuous period. Toxins including solanin in potato leaves can suppress production. Potato leaves should only be fed during times of severe shortages.
Nitrate poisoning occurs when plant growth is slowed or stopped with plants continuing to take up nitrate from the soil. Under normal circumstances, nitrate is converted to nitrite which is then converted to ammonia and used by rumen microorganisms as a nitrogen source. Excess nitrates in drought stressed plants will result in a higher intake of nitrates which is not broken down to ammonia quickly enough resulting in an accumulation of nitrites in the rumen. Nitrite is rapidly absorbed into the bloodstream affecting the ability of the blood to transport oxygen thus suffocating the animal. Farmers should avoid applying excessive amounts of manure or nitrogen fertilizer and delay harvesting any stressed forages.
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