Kingston Armstrong Defends his M.S. Thesis

Kingston Armstrong successfully defended his M.S. thesis “Simulating the Emergence of Institutions that Reverse Salinization: An Agent-Based Modeling Approach” on March 14.  Congratulations on a very inventive thesis! We look forward to Kingston’s long and illustrious career in engineering research.


Salt concentration in global freshwater supplies has increased steadily due to salt input from infrastructure maintenance, agriculture, and resource extraction, leading to the Freshwater Salinization Syndrome (FSS). Freshwater salinization can create negative health consequences for individuals following low-sodium diets and negatively impact aquatic ecosystems. The FSS is a common-pool resource because water bodies have a carrying capacity for a mix of pollutants, and the amount of chemical or biological agents that can be discharged to the environment is limited. To curb the FSS, stakeholders can self-organize to develop institutions, which embody a set of rules or norms that are adopted to limit emissions and control degradation of a resource. In this research, a simulation approach is developed to explore the emergence of institutions that reverse the FSS. An agent-based modeling framework simulates a socioecological system composed of small business owners and the soil-water system. Agents represent private property-owners who apply salt to deice pavement in response to winter weather. Salt enters the vadose zone through infiltration, which is modeled using a transit time distribution approach. As salt in the vadose zone increases, agents can adopt institutions that limit how much salt can be applied. Agents are encoded with rules to represent behaviors, such as voting on institutions and choosing to defect or comply with existing institutions. The agent-based model is applied for a hypothetical subcatchment. Results indicate that stable institutions lead to positive economic outcomes for stakeholders, based on their ability to apply salt during winter events and access high-quality drinking water. Further, the emergence of stable institutions is significantly limited by the number of stakeholders who do not comply with institutions. This research demonstrates how self-organized institutions can lead to sustainable application strategies that prevent long-term economic losses and mitigate the FSS.