Spatial quantification framework for Water-Energy-Food security – Applied to South Africa

Water, energy and food (WEF) security is required for general human health and well-being, quality of life and livelihoods, and thus, ultimately, sustainable development [1, 2]. To improve WEF security, sustainable resource management is required, particularly in the context of climate change and its spatial variations. The WEF nexus is an approach to ensure this by accounting for and understanding the interrelations, synergies and trade-offs between WEF systems [1]. It is used to design appropriate solutions to WEF insecurity. For that, the state of WEF security must be assessed and the underlying causes to insecurity identified. Previous research conducting quantitative WEF nexus assessments has focused on i) creating national WEF indices [3, 4]; ii) technical assessments of infrastructural and biophysical aspects of WEF security [2, 5]; or iii) context-specific WEF security and linkages in case-study areas [5]. While these are valuable in providing macro-level understanding of WEF security and linkages, they do not account for socio-economic dimensions of security [2] or spatial heterogeneity within countries [3]. Sectoral approaches encompass a more comprehensive set of security aspects, such as the framework covering availability, accessibility, affordability, and acceptability (the so-called “four As”) originating in energy security literature [6], but these have not been applied to the nexus nor spatially explicitly.

Our objective is to develop a framework mapping WEF security along these four As and to apply the framework at a national level to identify hotspots of WEF insecurity within a country. We cover twelve domains of WEF security: each a combination of one of the four As and one of the three WEF resource systems. For each, household-level indicators were selected that can be quantified for countries at a high spatial resolution (e.g., municipality-level) by using data present in population and household surveys, supplemented with other open-source datasets (e.g., agricultural statistics, hydrological measurements, national utility prices, etc.). Resulting indicator scores for the twelve domains were subsequently combined and spatial patterns analysed to identify WEF insecurity hotspots (i.e., areas where there is concurrence of low scores across multiple domains).

The framework was applied to South Africa, a country with high spatial inequality. Data from national surveys were used to assess the spatial patterns in the WEF security domains across South Africa’s 257 municipalities. Preliminary results indicate concurrence of relatively low scores on several security domains, especially in municipalities in the east of Eastern Cape province, in KwaZulu-Natal, the north-eastern municipalities of Northern Cape and in parts of North West province. These areas are thus hotspots of multi-faceted WEF insecurity and should be prioritized for interventions. The framework proved suitable in highlighting sub-national patterns in WEF security and can thus be applied to other countries to quantify WEF security spatially explicitly.

References:

[1] Mabhaudhi et al. (2019). https://doi.org/10.3390/ijerph16162970

[2] Biggs et al. (2015). https://doi.org/10.1016/j.envsci.2015.08.002

[3] Nkiaka et al. (2021). https://doi.org/10.1016/j.envdev.2021.100655

[4] Nhamo et al. (2019). https://doi:10.20944/preprints201905.0359.v1

[5] Walker et al. (2022). https://doi.org/10.1016/B978-0-323-91223-5.00006-X

[6] Yao & Chang. (2014). https://doi.org/10.1016/j.enpol.2013.12.047