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Exploring the water–food nexus reveals the interlinkages with urban human conflicts in Central America

Nature Water volume 1, pages 348–358 (2023)Cite this article

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Abstract

Hydroclimatic extremes have been shown to enhance conflict in fragile societies. Quantitative research in this field has historically focused on rainfall anomalies, without accounting for their effects on the water–food system. Here we explore the water–food nexus and its interlinkages with urban conflicts in Central America. We use an agrohydrological model to assess the effects of drought on water availability and food production, accounting for regional food trade. A biophysical parameterization is then coupled with an econometric Bayesian zero-inflated Poisson model to detect dynamic spatial relations among social and hydrological variables. We find that drought-induced water deficit affects food security in major cities in the region and is correlated with the rise of conflict. Moreover, low population density and higher human development enhance the probability of permanent absence of conflict. Our analysis reveals the crucial role of food redistribution between rural and urban areas and its association with livelihoods and urban violence.

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Fig. 1: Conflict, food security and food trade flows in Central America for the period 2014–2016.
Fig. 2: Descriptive statistics for the variables included in the CWFs model.
Fig. 3: Bayesian credible intervals of the standardized direct spatial effects on λ (βt) under the CWFs model.
Fig. 4: Bayesian credible intervals of the spatially lagged effects on λ (γt) under the CWFs model.
Fig. 5: Food security and green water availability trends and conflicts in San Salvador city.
Fig. 6: The envelope of food security and the nature of conflicts occurring around the capital cities.

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Data availability

Input data used in this analysis were retrieved from publicly available sources that are cited in the text. Results data are available in the Supplementary Information. Additional data are available from the correpsonding author upon reasonable request.

Code availability

The code used for the Bayesian econometric analysis is available from the corresponding author on reasonable request.

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Acknowledgements

M.C.R. acknowledges support from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie Action (MSCA) Innovative Training Network (ITN) grant agreement no. 861509–NEWAVE. M.C.R. and N.G. are supported by ENI Enrico Mattei Foundation (FEEM), Cariplo Foundation (SusFeed project no. 0737 CUP D49H170000300007) and Regione Lombardia (RUD0CONV01/ASSO project D44I20002000002).

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Authors and Affiliations

  1. Department of Civil and Environmental Engineering, Politecnico di Milano, Milan, Italy

    Martina Sardo, Nikolas Galli & Maria Cristina Rulli

  2. Department of Mathematics, Politecnico di Milano, Milan, Italy

    Ilenia Epifani

  3. Department of Environmental Science, Policy, and Management, University of California, Berkeley, Berkeley, CA, USA

    Paolo D’Odorico

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Contributions

M.C.R., I.E., P.D. and M.S. conceived and designed the research. M.S. and N.G. collected and analysed data. M.S. wrote the paper with input from all co-authors.

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Correspondence to Paolo D’Odorico.

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Supplementary Methods, Notes, Figs. 1–32 and Tables 1–8.

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Supplementary Data 1

Full dataset of the variables used in the Bayesian econometric model.

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Sardo, M., Epifani, I., D’Odorico, P. et al. Exploring the water–food nexus reveals the interlinkages with urban human conflicts in Central America. Nat Water 1, 348–358 (2023). https://doi.org/10.1038/s44221-023-00053-0

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