A societal metabolism approach to effectively analyze the water-energy-food nexus in an agricultural transboundary river basin

Unidad de excelencia María de Maeztu CEX2019-000940-MWe implemented the semantically open conceptual framework 'Multi-Scale Integrated Analysis of Societal and Ecosystem Metabolism' (MuSIASEM) to deal with nexus challenges in agricultural production systems in transboundary river basins, using the Iranian Aras River Basin as a case study. The performance of the agricultural sector was characterized for relevant typologies of crop production using metabolic profiles, i.e., inputs and outputs per ton of crop produced, per hectare of land use, and per hour of labor. This analysis was contextualized across hierarchical levels of analysis, including the agronomic context at the regional level (rainfed versus irrigated cultivation), the socio-economic and political context at the national level (food sovereignty; urbanization), and the hydro-ecological context of the larger transboundary river basin (water constraints, GHG emissions). We found that the simultaneous use of two different interrelated logics of aggregation-the productivity of land and labor (relevant for the agronomic and socio-economic dimension) and the density of flows under different land uses (relevant for the hydrological and ecological dimension)-allowed for the identification of trade-offs in policy deliberations. In the case of Iran, it showed that striving for strategic autonomy will exacerbate the current water crisis; with the current cropping patterns, agronomic improvements will not suffice to avert a water crisis. It was concluded that the proposed approach fills an important gap in nexus research, but to effectively guide nexus governance in the region, a co-production of the analysis with social actors as well as more complete data sets at the river basin level would be essential