Integrative Analysis and Modeling of Interdependent Systems

The special collection on Integrative Analysis and Modeling of Interdependent Systems is available in the ASCE Library (https://ascelibrary.org/joeedu/integrative_modeling_interdependent_systems).

Modern socio-environmental systems have evolved into complex networks of nested systems with social institutions and organizations, engineering infrastructures, and natural processes (Levin et al. 2013; Preiser et al. 2018). Due to uncoordinated management and failure to account for cross-scale interactions, solutions to issues with one system may lead to unintended consequences in other respects or systems. Well-intended policies and efforts to promote sustainability or green technologies may lead to more resource consumption, pollution, or social injustice. For example, policies promoting the conversion of corn to ethanol that aim to enhance energy security and lower carbon emissions posed a threat to water security from both the quantity and quality perspectives and resulted in higher food prices throughout global markets, leading to social unrest (NRC 2008; Lagi et al. 2015). Electric vehicles promoted in inappropriate timing and locations may result in higher life-cycle emissions due to the electrical grid’s high fossil fuel reliance and/or inefficient local battery manufacturing and disposal processes (Sterman 2000).

Managing interdependent systems for efficient and reliable provision of critical services (e.g., water, food, energy, mobility, ecosystem functions) remains a grand challenge due to our limited understanding of the feedback among physical, natural, and human components. Thus, integrative analysis and modeling of interdependent systems is considered a key research need and has been emphasized and supported by various institutions and programs globally. More importantly, this field of research is very relevant to environmental engineering because the protection of public health and environmental quality is a core objective. Achieving this objective requires understanding the interactions between social, engineering, and natural systems and their interdependency as well as designing and implementing solutions that address these systematic challenges. This special collection covers topics related to integrative analysis and modeling of the interdependent systems, particularly through the lens of water and wastewater infrastructure management, to inspire effective, sustainable, and resilient solutions.

Systematic inequalities in water infrastructures call for a collective understanding of physical interdependencies, environmental conditions, and social contexts. To unravel this multifaceted problem, Wakhungu et al. (2021) developed a novel vulnerability assessment framework that integrates the geographical information analysis of environmental hazards (e.g., floods and contaminated properties), sociodemographic data, and network analysis of water distribution networks. The framework was implemented for the City of Tampa, Florida. The study found that the unequal distribution of water infrastructure vulnerability is associated with race, social class, and environmental hazards, which contributes to low resilience capacity in communities.

To identify effective strategies for improving the community management that can provide sustainable water services, Cannon et al. (2022) developed a system dynamics model that captures the critical feedback loops between community management and water system service. The model-estimated water service performance was validated based on monitoring data in Bolivia and Colombia. A set of alternative strategies were further evaluated and a shift from fix-on-failure corrective maintenance to preventive maintenance was suggested as a good strategy to sustain high performance. This study illustrated a quantitative system model to understand the dynamics of community-based systems and design high-impact interventions.

Through a participatory approach, Libey et al. (2022) developed a system dynamics model to investigate the influence of budget allocation on the functionality of water supply infrastructure in two developing regions. Compared with the status quo, their analysis revealed the importance of significantly increasing funds for infrastructure repair and maintenance rather than new installations to achieve improved functionality and water access rates. This study exemplifies how a participatory modeling approach can be used to inform policy making in a practical setting that enables critical social benefits.

To advance the knowledge on the use of systems approaches and guide the future research within the water, sanitation, and hygiene (WASH) sector, Walters et al. (2022) conducted a multiround survey with a panel of WASH sector experts. The study identified the consensus on the attributes of systems approaches and revealed several needs in WASH systems research including understanding the barriers to adoption of systems mapping approaches, improving the efficacy of collective action approaches, and applying systems approaches across geopolitical scales.

In a case study for Tampa Bay Water, a potable water supplier for over 2 million people in southwest Florida, Wang et al. (2022) quantified the system’s reliability as a result of future treatment infrastructure expansion. The study estimated a number of “industry understood” reliability metrics that could be potentially implemented in other potable water systems around the world. This study showed that proposed future infrastructure expansion scenarios would ease the duration and magnitude of water shortages for projected future water demand for 2028–2040.

Integrating crowdsourced water quality monitoring, pre- and post-survey, and statistical analysis, Jakositz et al. (2022) quantitatively evaluated the extent of engaging participants and improving scientific literacy through citizen science methods. The study showed the improvement in literacy related to key lead information, increased likelihood to communicate water quality issues, and self-assessed educational benefits to the participants. This study demonstrates how the methods from different fields can be combined to address a traditional environmental problem while providing educational and behavioral benefits.

Considering the importance and various challenges of small wastewater systems, Hall et al. (2022) developed a wastewater decision support tool to assist in the selection of treatment alternatives. The tool includes 12 sustainability metrics considering economic, environmental, and social performance and was applied to compare three on-site wastewater treatment systems in Florida. This study highlights the importance of considering triple bottom line sustainability and stakeholders’ value in wastewater treatment system evaluation.

Various studies related to water and wastewater are presented in this special collection, with the intention of integrating the methods and tools from engineering and social sciences to explore the dynamics of socio-environmental systems. The knowledge gained through these studies will help environmental engineering communities understand the interdependency of natural, engineering, and social systems and facilitate the use of an integrative systems approach to find the holistic solutions to many pressing environmental problems.

The guest editors would like to thank the Journal of Environmental Engineering team and reviewers for their support of this special collection.