Magesh Nagarajan

Disseminating a warning message to evacuate: A simulation study of the behaviour of neighbours

Large-scale evacuations are a recurring theme on news channels, whether in response to major natural or manmade disasters. The role of warning dissemination is a key part in the success of such large-scale evacuations and its inadequacy in certain cases has been a ‘primary contribution to deaths and injuries’ (Hayden et al., 2007). Along with technology-driven ‘official warning channels’ (e.g. sirens, mass media), the role of unofficial channel (e.g. neighbours, personal contacts, volunteer wardens) has proven to be significant in warning the public of the need to evacuate. Although post-evacuation studies identify the behaviours of evacuees as disseminators of the warning message, there has not been a detailed study that quantifies the effects of such behaviour on the warning message dissemination. This paper develops an Agent-Based Simulation (ABS) model of multiple agents (evacuee households) in a hypothetical community to investigate the impact of behaviour as an unofficial channel on the overall warning dissemination. Parameters studied include the percentage of people who warn their neighbours, the efficiency of different official warning channels, and delay time to warn neighbours. Even with a low proportion of people willing to warn their neighbour, the results showed considerable impact on the overall warning dissemination.

Domestic Water Demand During Droughts in Temperate Climates: Synthesising Evidence for an Integrated Framework

In the upcoming years, as the population is growing and ageing, as lifestyle changes create the need for more water and as fewer people live in each household, the UK water sector will have to deal with challenges in the provision of adequate water services. Unless critical action is taken, every area in the UK may face a supply-demand gap by the 2080s. Extreme weather events and variations that alter drought and flood frequency add to these pressures and there is therefore a need to develop evidence-based drought scenarios models for water management purposes. However, little evidence is available about householders’ response to drought and there are few if any studies that have synthesised this evidence. In response, this paper discusses the current empirical literature on the factors driving domestic water consumption under both ‘normal’ and drought conditions. The paper identifies the limited availability of evidence on the many different and evolving factors affecting domestic consumption under both ‘normal’ and drought conditions and stresses the need for the inclusion of inter and intra household factors as well as water use practices in future demand forecasting models. The paper then presents ‘Water Cultures’ as an integrative modelling framework to combine the limited evidence that is available on the interactions of social norms, practices and material cultures. This enables the paper both to capture both the uncertainty and heterogeneity of individual and/or household level variation and also outline the research gaps that need to be addressed.