South Africa remains in the grip of its worst drought in decades. The combination of a poor 2014-2015 season, the extremely dry early agricultural season (October to December) and forecasts for continuing hot and drier-than-average conditions through mid-2016, suggest a scenario of extensive, regional-scale crop failure[i]. The impact of regional-scale crop failure is disastrous for the economy. Being able to localise and quantify the damage done as quickly as possible is essential for timely mobilization of resources and appropriate assistance to the worst affected areas. eLEAF BV from the Netherlands has done an analysis quantifying the impact of the current drought, using their satellite based PiMapping® technology.
The figure below visualises the percentage of agricultural production lost during the 2015-2016 South African summer when compared to the 2014-2015 season. The analysis is based on actual biomass production (kg/ha) from August to January. Three areas are looked into in more detail: 1) The Free State, 2) the Vaalharts irrigation system, and 3) Kruger National Park.
Looking at the Free State where a large part of the rainfed summer crop is grown, we see an average biomass production of 8,000 kg/ha for the period Aug-Jan in the 2014-2015 season. The same period this year shows and average production of 4,000 kg/ha. This is a 50% production drop compared to the 2014-2015 season which already saw a lower than average production.
Although rainfed crops are hardest hit, irrigated areas have also seen a significant drop in crop production. The Vaalharts irrigation system in the Northern Cape Province saw a significant, 20% drop in biomass production from 17,500 kg/ha last year, to 14,000 kg/ha in the same period in the 2015-2016 season. This same trend is visible when we consider Kruger National Park where the growth of natural vegetation was 37% lower than last year. The water available for crop growth (expressed as evapotranspiration) declined by nearly 100 mm over the Aug-Jan period, from 276 mm to 178 mm. Being a natural reserve, this has a devastating effect on the wildlife in Kruger Park. Andrew Desmond from South African National Parks (SANParks) states that hippopotamus have started dying in large numbers due to the shortage of water for the animals at the park, forcing them to consider culling some of the animals[ii].
The ongoing drought is said to be the worst in a century. While such events are hard to forecast, we can use state of the art satellite technology to identify emergency areas and quantify losses in a timely manner. Such information gives authorities unparalleled insight into the effects of the drought allowing them to implement mitigation measures in the most effective way.
[i] Retrieved from: http://www.fao.org/news/story/en/item/382932/icode/