Drought risk for agricultural systems in South Africa: Drivers, spatial patterns, and implications for drought risk management

Highlights: • South Africa is highly susceptible to drought impacts on agriculture, given its high water reliance. • Drought risk varies substantially between irrigated and rainfed agricultural systems. • The most extreme drought for rainfed croplands is observed in Northern Cape, North West and Limpopo. • Highest drought risk on time series for irrigated crops is across Limpopo and Eastern Cape. • Our methodology to assess drought risk is transferable to other regions. The regular drought episodes in South Africa highlight the need to reduce drought risk by both policy and local community actions. Environmental and socioeconomic factors in South Africa's agricultural system have been affected by drought in the past, creating cascading pressures on the nation's agro-economic and water supply systems. Therefore, understanding the key drivers of all risk components through a comprehensive risk assessment must be undertaken in order to inform proactive drought risk management. This paper presents, for the first time, a national drought risk assessment for irrigated and rainfed systems, that takes into account the complex interaction between different risk components. We use modeling and remote sensing approaches and involve national experts in selecting vulnerability indicators and providing information on human and natural drivers. Our results show that all municipalities have been affected by drought in the last 30 years. The years 1981–1982, 1992, 2016 and 2018 were marked as the driest years during the study period (1981–2018) compared to the reference period (1986–2015). In general, the irrigated systems are remarkably less often affected by drought than rainfed systems; however, most farmers on irrigated land are smallholders for whom drought impacts can be significant. The drought risk of rainfed agricultural systems is exceptionally high in the north, central and west of the country, while for irrigated systems, there are more separate high-risk hotspots across the country. The vulnerability assessment identified potential entry points for disaster risk reduction at the local municipality level, such as increasing environmental awareness, reducing land degradation and increasing total dam and irrigation capacity.