Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

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


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.

This is a preview of subscription content, access via your institution

Access options

Rent or buy this article

Get just this article for as long as you need it


Prices may be subject to local taxes which are calculated during checkout

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 λt) under the CWFs model.
Fig. 4: Bayesian credible intervals of the spatially lagged effects on λt) 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.

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.


  1. Kallis, G. & Zografos, C. Hydro-climatic change, conflict and security. Climatic Change 123, 69–82 (2014).

    Article  Google Scholar 

  2. Zografos, C., Goulden, M. C. & Kallis, G. Sources of human insecurity in the face of hydro-climatic change. Glob. Environ. Change 29, 327–336 (2014).

    Article  Google Scholar 

  3. Mach, K. J. et al. Climate as a risk factor for armed conflict. Nature 571, 193–197 (2019).

    Article  CAS  PubMed  Google Scholar 

  4. European Security Strategy: A Secure Europe in a Better World, Vol. 94 (Council of the European Union, 2003).

  5. McGowan, A. H. The environment and national security. Environment 49, 10–25 (2007).

  6. Hsiang, S. M., Burke, M. & Miguel, E. Quantifying the influence of climate on human conflict. Science 341, 1235367 (2013).

    Article  PubMed  Google Scholar 

  7. Schleussner, C. F., Donges, J. F., Donner, R. V. & Schellnhuber, H. J. Armed-conflict risks enhanced by climate-related disasters in ethnically fractionalized countries. Proc. Natl Acad. Sci. USA 113, 9216–9221 (2016).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  8. Von Uexkull, N., Croicu, M., Fjelde, H. & Buhaug, H. Civil conflict sensitivity to growing-season drought. Proc. Natl Acad. Sci. USA 113, 12391–12396 (2016).

    Article  Google Scholar 

  9. IPCC Climate Change 2007: Mitigation (eds Metz, B. et al.) (Cambridge Univ. Press, 2007).

  10. Harari, M. & Ferrara, E. L. Conflict, climate, and cells: a disaggregated analysis. Rev. Econ. Stat. 100, 594–608 (2018).

    Article  Google Scholar 

  11. Couttenier, M. & Soubeyran, R. Drought and civil war in sub‐Saharan Africa. Econ. J. 124, 201–244 (2014).

    Article  Google Scholar 

  12. Seter, H., Theisen, O. M. & Schilling, J. All about water and land? Resource-related conflicts in East and West Africa revisited. GeoJournal 83, 169–187 (2018).

    Article  Google Scholar 

  13. Abel, G. J., Brottrager, M., Crespo Cuaresma, J. & Muttarak, R. Climate, conflict and forced migration. Glob. Environ. Change 54, 239–249 (2019).

    Article  Google Scholar 

  14. Bernauer, T., Böhmelt, T. & Koubi, V. Environmental changes and violent conflict. Environ. Res. Lett. 7, 15601 (2012).

    Article  Google Scholar 

  15. Gizelis, T. I. & Wooden, A. E. Water resources, institutions, & intrastate conflict. Polit. Geogr. 29, 444–453 (2010).

    Article  Google Scholar 

  16. Roche, K. R., Müller-Itten, M., Dralle, D. N., Bolster, D. & Müller, M. F. Climate change and the opportunity cost of conflict. Proc. Natl Acad. Sci. USA 117, 1935–1940 (2020).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  17. Galli, N., Dell’Angelo, J., Epifani, I., Chiarelli, D. D. & Rulli, M. C. Socio-hydrological features of armed conflicts in the Lake Chad Basin. Nat. Sustain. 5, 843–852 (2022).

    Article  Google Scholar 

  18. Selby, J. Positivist climate conflict research: a critique. Geopolitics 19, 829–856 (2014).

    Article  Google Scholar 

  19. Ide, T., Brzoska, M., Donges, J. F. & Schleussner, C. F. Multi-method evidence for when and how climate-related disasters contribute to armed conflict risk. Glob. Environ. Change 62, 102063 (2020).

    Article  Google Scholar 

  20. Allan, J. A. Virtual water: a strategic resource global solutions to regional deficits. Ground Water 36, 545–546 (1998).

    Article  CAS  Google Scholar 

  21. D’Odorico, P. et al. The global food–energy–water nexus. Rev. Geophys. 56, 456–531 (2018).

  22. Bernauer, T. et al. Climate variability, food production shocks, and violent conflict in Sub-Saharan Africa. Environ. Res. Lett. 10, 125015 (2015).

    Article  Google Scholar 

  23. Dell’Angelo, J., D’Odorico, P., Maria & Rulli, C. The neglected costs of water peace. WIREs Water 5, e1316 (2018).

    Google Scholar 

  24. Allan, J. A. The Middle East Water Question: Hydropolitics and the Global Economy (Bloomsbury Academic, 2012).

  25. Alcamo, J., Dronin, N., Endejan, M., Golubev, G. & Kirilenko, A. A new assessment of climate change impacts on food production shortfalls and water availability in Russia. Glob. Environ. Change 17, 429–444 (2007).

    Article  Google Scholar 

  26. Regional Data Bank for Statistical Follow-up to the SDGs in Latin America and the Caribbean (ECLAC & UNDP, 2021).

  27. Nett, K. & Rüttinger, L. Insurgency, Terrorism and Organised Crime in a Warming Climate (Adelphi, 2016).

  28. Maria, A., Acero, J. L., Aguilera, A. I. & Garcia Lozano, M. Central America Urbanization Review: Making Cities Work for Central America (World Bank, 2017);

  29. Gotlieb, Y., Pérez-Briceño, P. M., Hidalgo, H. & Alfaro, E. The Central American Dry Corridor: a consensus statement and its background. Rev. Yu’am 3, 42–51 (2019).

    Google Scholar 

  30. Bonilla Vargas, A. Patrones de Sequía en Centroamérica. Su Impacto en la Producción de Maíz y Frijol y Uso del Índice Normalizado de Precipitación para los Sistemas de Alerta Temprana (Global Water Partnership, 2014);

  31. Magrath, J. Coffee Rust Fungus Threatens Employment Collapse in Central America (Oxfam, 2014).

  32. CEPALSTAT (CEPAL, 2022);

  33. Vargas, R. et al. EDE Climate risk and food availability in Guatemala. Environ. Dev. Econ. 23, 558–579 (2018).

    Article  Google Scholar 

  34. Cattaneo, A. et al. Economic and social development along the urban–rural continuum: new opportunities to inform policy. World Dev. 157, 105941 (2022).

    Article  Google Scholar 

  35. Cattaneo, A., Nelson, A. & McMenomy, T. Global mapping of urban-rural catchment areas reveals unequal access to services. Proc. Natl Acad. Sci. USA 118, e2011990118 (2021).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  36. Chiarelli, D. D. et al. The green and blue crop water requirement WATNEEDS model and its global gridded outputs. Sci. Data 7, 1–9 (2020).

  37. CHIRPS v2.0 (Climate Hazards Group, 2015);

  38. Harris, I., Jones, P. D., Osborn, T. J. & Lister, D. H. Updated high-resolution grids of monthly climatic observations - the CRU TS3.10 dataset. Int. J. Climatol. 34, 623–642 (2014).

    Article  Google Scholar 

  39. Allen, R. G., Pereira, L. S., Raes, D. & Smith, M. Crop Evapotranspiration: Guidelines for Computing Crop Water Requirements (FAO, 1998).

  40. The State of Food Security and Nutrition in the World 2020 (FAO, IFAD, UNICEF, WFP & WHO, 2020);

  41. Doorenbos, J. & Kassam, Amir. Yield response to water. FAO Irrigation and Drainage Paper 33 (1979).

  42. Salehyan, I. et al. Social conflict in Africa (SCAD): a new database. Int. Interact. 38, 503–511 (2012).

    Article  Google Scholar 

  43. Arab, A. Spatial and spatio-temporal models for modeling epidemiological data with excess zeros. Int. J. Environ. Res. Public Health 12, 10536–10548 (2015).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  44. FAO. Human energy requirements: report of a joint FAO/WHO/UNU Expert Consultation. Food Nutr. Bull. 26, 166 (2005).

    Google Scholar 

  45. Bazzi, S. & Blattman, C. Economic shocks and conflict: evidence from commodity prices. Am. Econ. J. Macroecon. 6, 1–38 (2014).

  46. Central America – Livelihood Zones (FEWS NET, 2016).

  47. Gleick, P. H. Water, drought, climate change, and conflict in Syria. Weather Clim. Soc. 6, 331–340 (2014).

    Article  Google Scholar 

  48. Müller, M. F., Yoon, J., Gorelick, S. M., Avisse, N. & Tilmant, A. Impact of the Syrian refugee crisis on land use and transboundary freshwater resources. Proc. Natl Acad. Sci. USA 113, 14932–14937 (2016).

    Article  PubMed  PubMed Central  Google Scholar 

  49. Taylor, M. J., Aguilar-Støen, M., Castellanos, E., Moran-Taylor, M. J. & Gerkin, K. International migration, land use change and the environment in Ixcán, Guatemala. Land Use Policy 54, 290–301 (2016).

    Article  Google Scholar 

  50. Aguilar-Støen, M. Between a rock and a hard place: rural transformations and migrant communities in Guatemala. Can. J. Dev. Stud. 41, 57–73 (2020).

    Article  Google Scholar 

  51. Conceicao, P. & Kim, N. The economic crisis, violent conflict, and human development. Int. J. Peace Stud. 15, 29–43 (2010).

    Google Scholar 

  52. Hoeffler, A. in Conflict, Political Accountability and Aid 1–34 (Routledge, 2013).

  53. Satyanath, S., Sergenti, E. & Miguel, E. Economic shocks and civil conflict: an instrumental variables approach. J. Political Econ. 112, 725–753 (2012).

    Google Scholar 

  54. Müller, M. F. & Levy, M. C. Complementary vantage points: integrating hydrology and economics for sociohydrologic knowledge generation. Water Resour. Res. 55, 2549–2571 (2019).

    Article  Google Scholar 

  55. Miguel, E. & Satyanath, S. Re-examining economic shocks and civil conflict. Am. Econ. J. Appl. Econ. 3, 228–232 (2011).

    Article  Google Scholar 

  56. Brück, T. et al. The Relationship Between Food Security and National Security (International Security and Development Centre, 2016).

  57. Martin-Shields, C. P. & Stojetz, W. Food security and conflict: empirical challenges and future opportunities for research and policy making on food security and conflict. World Dev. 119, 150–164 (2019).

    Article  Google Scholar 

  58. Elhorst, J. P. Spatial Econometrics From Cross-Sectional Data to Spatial Panels Vol. 16 (Springer, 2014).

  59. Gelman, A., Meng, X. L. & Stern, H. Posterior predictive assessment of model fitness via realized discrepancies. Stat. Sin. 6, 733–807 (1996).

    Google Scholar 

  60. Famine Early Warning Systems Network – Markets and Trade (FEWS NET, 2012).

  61. Hoekstra, A. Y. & Mekonnen, M. M. The water footprint of humanity. Proc. Natl Acad. Sci. USA 109, 3232–3237 (2012).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  62. Doorenbos, J., Kassam, A. H., Bentvelsen, C. & Uittenbogaard, G. in Irrigation and Agricultural Development (ed. Johl, S.) 257–280 (Elsevier, 1980).

  63. Marsal, J. Crop Yield Response to Water (FAO, 2012).

  64. Guha-Sapir, D., Below, R., Hoyois, P. EM-DAT (CRED, 2019).

  65. Hijmans, R., Kapoor, J., Garcia, N., Wieczorek, J. & Mandel, A. GADM v.2.8 (GADM Maps and Data, 2015);

  66. Human Geography Map (ESRI, 2021);

Download references


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).

Author information

Authors and Affiliations



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.

Corresponding author

Correspondence to Paolo D’Odorico.

Ethics declarations

Compliance with ethical standards Competing interests

The authors declare no competing interests.

Peer review

Peer review information

Nature Water thanks Marc Muller, Molly Brown and Hadi Jaafar for their contribution to the peer review of this work.

Additional information

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary information

Supplementary Information

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

Reporting Summary

Supplementary Data 1

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

Rights and permissions

Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.

Reprints and Permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

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).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:

This article is cited by


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing