Abstract
While single hazards and risk assessments have been critically scrutinised for many years, research about multiple hazard events and their multiple risk pathways for natural and human systems is still to be addressed. This limitation may have substantial influence on the way how disaster risk reduction activities are addressed and to which extent potential impacts may become reality. This is particularly true for the changing levels of risk due to modified climate conditions. System Dynamics Models (SDM) is a methodology created to improve the understanding of complex systems, their interactions and feedback loops. SDM have been already applied to climate change impact assessments, critical infrastructure interdependencies and in water-food-energy Nexus. However, applications addressing multi-risk assessments are still limited.Here we show an SDM application accounting for multiple impacts coming from interactions and feedbacks among interacting sectors in a mountain catchment.The SDM developed for the Noce river catchment (Province of Trento, Italy) represents an innovative multi-risk tool, combining outputs from physically based models and probabilistic assessments of water flows. Moreover, this study focuses on the water demand from three main sectors relying on the same resource: (i) apple orchards cultivation, (ii) water releases from large dam reservoirs for hydropower production and (iii) domestic and seasonal tourism activities. Results have been validated on historical time series (i.e. 2009-2017) and projected in the future considering RCP 4.5 and 8.5 climate change scenarios for 2021-2050 medium term and 2041-2070 long term. By doing so, it has been possible to explore future unsustainable conditions of water supply and demand leading to multiple impacts. Finally, SDM can be used to identify possible adaptation strategies (e.g. water pricing, drip irrigation and regulation) and integrate decision policies scenarios to tackle climate-related water scarcity.