Managing complex Food-Energy-Water systems: an integrated technology-environment-economics model of nutrient cycling in the U.S. Corn Belt watersheds

Abstract:

Food production, water supply, water quality, energy supply, economic growth and financial stability in Corn Belt depend on each other while competing for resources. Traditional modeling approaches usually use individual disciplinary models to address these interconnected problem piece by piece. Those approaches do not fully consider the food, energy and water (FEW) nexus relations that exist at certain spatial scales, and thus cannot capture the interconnected influence of measures taken across the FEW systems. To facilitate understanding and decision making in this context, we will present an integrated technology-environment-economics model (ITEEM) considering interactions within the FEW systems in Corn Belt watersheds. The developed ITEEM is a product from collaborative efforts that fill critical knowledge gaps in the interrelations between environment, technology, and economics of the interdependent systems. We will present how the ITEEM is formulated as a spatially semi-distributed dynamic simulation model that quantifies the impacts of various management strategies, technologies, and policy interventions. Specifically, process models for grain processing and water and wastewater treatment (technology); a watershed model simulating hydrology, nutrient cycling and water quality, and crop production; and an economic model assessing market and non-market values of the various technologies and practices are built via the various software programs based on discipline-specific knowledge. To integrate these models into the framework of ITEEM, different surrogate techniques are applied, including the response matrix method, machine learning, look-up table, and empirical numerical equations. The surrogates and empirical models and the interactions between the components are integrated in a unified computational framework using Python, which results in a computationally efficient integrated model. The ITEEM allows to run many what-if scenarios within minutes. We will demonstrate ITEEM with a testbed watershed located in Central Illinois. The ITEEM can be used to quantify the impacts of various technologies, best management practices, and policies, and the tradeoffs among those measures considering the co-benefits of the FEW systems in the Corn Belt.