Abstract: Sustainability challenges related to food production arise from multiple nature-society interactions occurring over long time periods. Traditional methods of quantitative analysis do not represent long-term changes in the networks of system components, including institutions and knowledge that affect system behavior.

Here, we develop an approach to study system structure and evolution by combining a qualitative framework that represents sustainability-relevant human, technological and environmental components (HTE), and their interactions, mediated by knowledge and institutions, with network modeling that enables quantitative metrics. We use this approach to examine the water and food system in the Punjab province of the Indus River Basin in Pakistan, exploring how food production has been sustained, despite high population growth, periodic floods, and frequent political and economic disruptions. Using network models of five periods spanning seventy-five years (1947-2022), we examine how quantitative metrics of network structure relate to observed sustainability-relevant outcomes and how potential interventions in the system affect these quantitative metrics.

We find that the persistent centrality of some and evolving centrality of other key nodes, coupled with the increasing number and length of pathways connecting them are associated with sustaining food production in the system over time. Assessment of potential interventions regulating groundwater pumping and phasing out fossil-fuels could alter network pathways and identify potential vulnerabilities for future food production.

Significance Statement: Models for informing sustainability interventions in complex adaptive systems involving nature-society interactions are challenging to construct due to lack of detailed, quantitative data on the changing structure of system interactions. Here, we develop a new approach combining qualitative descriptions of system components and interactions, with network representation for quantitative characterization of system structure. We demonstrate this approach with retrospective and prospective analyses related to food production in Pakistan’s Indus River Basin. Results identify the nodes and increasing number of pathways associated with sustained food production. Future scenarios point to production vulnerability due to conversion of arable land with implications on livelihoods for laborers and small business owners and highlight the importance of coordinating rural and urban water and land-use policies.