ABSTRACT
Rainfall does not provide a constant source of water; it is characterized by remarkable inter-annual and seasonal variability. Drought is a temporary anomaly, more or less prolonged, during which rainfall is below normal, resulting in a significant reduction of water resources (National Drought Mitigation Center, 2015). Drought is a natural risk. It is particularly common and extreme in the semi-arid regions such as in Tucson, where aridity, the systematic lack of moisture and water, make it a natural feature that defines the local climate. Climate change is expected to increase the risk of drought because rising temperatures incrementally increase the evaporative potential of the air, which combined with erratic rainfall fosters less water availability and longer dry periods that may be very intense (Limones, 2013). Drought usually leads to water scarcity, but not necessarily, because it is possible to mitigate the negative environmental and social effects with proper planning and management tools (WWF, 2012). In order to understand the interaction of droughts and water shortages, it is necessary to analyze the variables that influence the social response to different aspects of the water cycle. Additionally it is necessary to take into account the whole hydro-social system to further develop potential prediction methods of physical and social system response.
