Agriculture, in whatever form, has always been dependent on climate, and farming has always been difficult irrespective of the impacts of climate change.
According to Peter Johnston from the Climate Systems Analysis Group at UCT there are cycles which cannot be predicted, droughts are a complex reality, rainfall is, and will always be, variable and the oil price does not make things easier for farmers. In addition, farmers face significant threats from a changing climate.
The Garden Route Area falls within the Gouritz Water Management Area (WMA), which has 275 million m3 of water available per year. The human requirements for this area (for agriculture, urban use, industrial use, golf courses, etc) are 339 million m3 per year. That comes down to a deficit of 64 million m3 of water per year. Important agricultural industries in this area include vegetables, livestock (ostriches, sheep, dairy and beef cattle), deciduous fruit and horticultural crops (e.g. hops).
The greatest demand for water in this area comes from the irrigation sector. Groundwater is of major importance to irrigation in the Gouritz WMA (more than half of the water used is abstracted from groundwater). The warmer and drier climate predicted would increase irrigation demand, with a decrease in water availability.
A significant decline in water quality is expected with the reduction in flows caused by the increase in water demand. Continuance of the current, unsustainable land and irrigation practices, coupled with more erratic rainfall patterns, may result in wide-scale food and water shortages.
Projected climate change patterns for this region with implications for the agricultural industry include:
- Precipitation: a decrease in winter rainfall, a shorter winter rainfall season, an increase in spring and early summer rainfall
- Temperatures: warming trend in nearly every location
- Winds: velocity increase- all seasons
Given these scenarios it is important to note that when a combined effect of two or more factors is experienced at the same time, farming systems experience much greater vulnerability and risk. For example, where higher temperatures are experienced over a longer period of time, there is a potential increase in evaporation and transpiration, and hence in crop water demand. This, coupled with a decrease in rainfall, will put an even greater pressure on water resources.
The aim of the case study is to illustrate how climate change data/ information can be used to identify these vulnerable (exposed) agricultural industries, and develop scenarios of future pressure on land and water resources with the projected climate change information. This will allow us to develop practical, feasible and sensible adaptation strategies.
Climate risk should be considered a normal part of decision making. It becomes increasingly important for decision makers to determine logical, viable and feasible adaptation measures that will encourage the wise and sustainable use of land and water resources within the agricultural sector of the Garden Route.
By Daleen Lötter