This paper explores the advantages of simulation to raise the question of how digital and social networks affect the mobility in a pastoralist artificial society in the context of environmental degradation. We aim to explore mechanisms and develop scenarios, which are going to be validated through further research. We use a model of a simple pastoralist society in a world without borders to migration by adding the possibility of experiencing the effects of social structures (such as family and friends) and technological networks (e.g., social media). It appears obvious that pastoralist mobility depends on other dimensions as land tenure and traditional knowledge; however, isolating these two effects and experimenting in a simple society allow us to filter the multidimensionality of mobility decisions and concentrate on comparing scenarios in several different social structures and technological network combinations. The results show an expected behavior of more connection and more mobility, and a non-linear emergent behavior where pastoralists wait for a longer amount of time to mobilize when they interact using powerful social and technological networks. This occurs until they decide to move, and then, they mobilize more quickly and strongly than they did when communication was non-existent between them. The literature on migration explains this emergent non-linear behavior.

<p>We develop a single-agent-based model in Netlogo of a coastal city facing climate change, using the VIABLE framework. The coastal city is threatened by damages from sea level rise and subsequent extreme sea level events. The agent, representing an urban planner, uses capital generated by the city to mitigate these damages by investing into one of two adaptation options available to it- developing coastal defenses or relocating the vulnerable coastal territories of the city inland. As the simulation progresses, gradually rising sea levels and randomly occurring extreme sea level events incur damages, and the agent alters its investments to optimize its value, resulting in dynamic reactive behavior. We track the response of this agent to the changing system through its investment patterns.</p>

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Coastal flood risk and sea-level rise require decisions on investment in coastal protection and, in some cases, the relocation of urban areas. Models that formalize the relations between flooding costs, protective investments, and relocation can improve the analysis of the processes and issues involved and help to support decision-making better. In this paper, an agent-based model of a coastal city is represented in NetLogo. This model is based on the VIABLE modeling framework and describes adaptive dynamic agent behavior in a changing system. The hypothetical city faces damage caused by gradually rising sea levels and subsequent extreme sea-level events. To mitigate these risks, an “urban planner” agent has two adaptation measures at their disposal: developing coastal defenses or, as a more extreme measure, relocating vulnerable areas inland. As the simulation progresses and the decisions change with rising sea levels, the agent alters investments in these two measures to increase its value function, resulting in dynamic reactive behavior. Additionally, gradual sea-level rise is implemented in various modes, along with extreme sea-level events that cause severe short-term damage. The results of simulations under these modes and with multiple scenarios of agent action are presented. On average, agent behavior is quite reactive under limited foresight. Individual simulations yield a ‘priming’ effect when comparing different timings of extreme sea-level events, wherein an earlier extreme event primes the agent to adapt and thus be better prepared for subsequent events. Agent success with adaptation is also found to be sensitive to the costs involved, and these varying degrees of adaptation success are quantified using three parameters of adaptation success.

<p>An agent-based model (the VIABLE framework) of a coastal city is represented in Netlogo, describing adaptive dynamic agent behavior in a changing system. Rising sea levels and subsequent extreme sea level events incur damages to the city which an “urban planner” agent can mitigate through two adaptation pathways: developing coastal defenses, or as a more extreme measure, relocating vulnerable areas inland. Capital generated by the city can be directed as investments towards these pathways, with the remainder being consumed. The agent’s control variables are thus the amount of capital invested, and the ratio of investments allocated to the two pathways. As the simulation progresses and the system changes with rising sea levels, the agent alters these control variables to optimize its value, resulting in dynamic reactive behavior. Additionally, sea level rise is implemented in various modes, along with extreme sea level events that cause severe short-term damages.</p>