A System Dynamics Model to Explore the Water-land-energy-food-climate Nexus in Latvia

Water, energy, food/land use and climate are connected a system defined by complexity, feedback and delay, and are commonly referred to as the nexus which operates across scales. Therefore the characteristics of the nexus change depending on the scale being considered, the location, and the sectors of interest. It is essential to clearly define study boundaries in terms of scale and sectors prior to modelling or assessment. System dynamics modelling (SDM) is an approach developed for studying complex systems, and has found widespread applications elsewhere, especially in the environmental and natural sciences. SDM has seen increasing use, with many recent examples applied to a wide variety of complex (environmental) issues. Due to its flexibility, it is an ideal tool to explore the nexus: many disparate sectors can easily be combined and interlinked in one coherent modelling environment.

SIM4NEXUS (www.sim4nexus.eu) is an ongoing H2020 research project that is developing policy-relevant serious games for 12 case studies in scale from sub-national to global. Quantitative SDM models are being developed for every case in close collaboration with a dedicated case study lead. Here, the SDM and baseline results are presented for the Latvia case study. In this case, the principle nexus sectors of interest are land use (changes), energy generation, and water quality impacts. Of particular interest is the drive towards a low carbon economy through the cultivation of crops for energy (biomass). However, this may hinder other targets such as increasing food security, protection of forested lands, and preserving and improving water quality and biodiversity. The SDM captures these critical elements, dynamically linking the nexus sectors but with a focus towards the biofuel and energy sectors (moving towards biomass and away from fossil fuel reliance), and the concomitant impacts on the water, land and climate sectors (e.g. the impacts of converting crop or forestry land to biocrop areas, and the impacts for water quality and national CO2-e emissions). Policy options, developed with local expert stakeholder groups, are to be included in order to fully assess nexus-wide impacts of current, and potential future, policy directions within Latvia. The model will eventually feed a serious game aiming to elucidate nexus wide impacts to policy makers.