(388c) A Physical Input-Output Model for the Food-Energy-Water (FEW) Nexus in Indiana

Authors: 
Wachs, E., Purdue University
Singh, S., Purdue University
One of the major obstacles to understand the challenges of managing the production of food and energy while maintaining water availability and resources is the lack of physical insights into the regional economies. Physical Input-Output Table (PIOT) based models provide insights into physical interaction of various production sectors while taking advantage of structural information about the economy, thus quantifying the interdependency of food and energy production [1]. Furthermore, the environmentally extended form of PIOT allows the studying of environmental impacts from production systems by tracking the emissions to water and air by each production system. While few fully developed physical input output tables have been produced, their application has been demonstrated in measuring land footprints, analyzing the structure of the economy, and testing the resiliency of supply chains, all of which are important in FEW systems [2,3,4]. Hence, we developed an initial PIOT model for agro-based industries in Indiana to analyze the interdependency of food and bioenergy production in the state. In particular, the unidimensional flow of nitrogen was tracked as measure of production from various sectors, since N forms the basis of food production and the optimization of its use is critically important to food systems and ecosystem management. Indiana’s agrobased economy is based on corn and soybean production, which together make up over 76.5% of Indiana’s agricultural land [5]. Bioenergy is produced as both determining and co-product from the corn processing sectors. To build this model, we generated process models for each production unit and used the results to generate the PIOT as shown in [6]. For agricultural systems, we performed mass balances on production systems. An algorithmic approach was followed to find the statistical sources for information where available, as well as approximation methods from peer reviewed literature. Once the mass balances were completed they served as the basis for process models that fit into the PIOT building approach described in [6]. The structure of PIOT in Indiana is compared with an earlier PIOT developed for Illinois [7].
[1] Hoekstra, R., & van den Bergh, J. C. (2006). Constructing physical input–output tables for environmental modeling and accounting: Framework and illustrations. Ecological Economics, 59(3), 375-393.
[2] Hubacek, K., & Giljum, S. (2003). Applying physical input–output analysis to estimate land appropriation (ecological footprints) of international trade activities. Ecological economics, 44(1), 137-151.
[3] Altimiras-Martin, A. (2014). Analysing the structure of the economy using physical input–output tables. Economic Systems Research, 26(4), 463-485.
[4] Nakatani, J., Tahara, K., Nakajima, K., Daigo, I., Kurishima, H., Kudoh, Y., Matsubae, K., Fukushima, Y., Ihara, T., Kikuchi, Y. and Nishijima, A. (2017). A graph theory-based methodology for vulnerability assessment of supply chains using the life cycle inventory database. Omega.
[5] United States Department of Agriculture National Agricultural Statistical Service. (2017). 2016 State Agriculture Overview: Indiana. Retrieved from https://www.nass.usda.gov/Quick_Stats/Ag_Overview/stateOverview.php?stat....
[6] Wachs, L. and Singh, S. (2016, November). Computational Approaches in Systems Modeling for Environmental Impacts of Industries Automating Physical Input-Output Tables (PIOTs) Via Aspen Process Modeling. Poster session presented at the 2016 AIChE Annual Meeting, San Francisco, CA.
[7] Singh S, Compton J, Hawkins, T, Sobota D, Cooter E., “A Physical Input-Output Model for Illinois” In Review