Christian Klassert

Describing Human Decisions in Agent-Based Social-Ecological Models - ODD+D an Extension of the ODD Protocol

Multiple agent-based models (ABM) on social-ecological systems exist in parallel investigating similar research questions. However, the choice of a particular human decision model is often not sufficiently empirically or theoretically substantiated in the model documentation. Furthermore, model comparison is difficult because model descriptions are often incomplete, intransparent and difficult to understand. Therefore we expand and refine the ‘ODD’ (Overview, Design Concepts, and Details) protocol to establish a standard to describe ABMs which includes human decision making (ODD+D). Since the original ODD is mainly from an ecological perspective, some adaptations are necessary for the social-ecological context. We extended and rearranged the design concepts and related guiding questions to differentiate and describe decision making, adaptation and learning of the agents in a comprehensive and clearly structured way. Furthermore, ODD+D encompasses a section on ‘Theoretical and empirical background’ to encourage that model design and model assumptions are related more closely to theory. The application of ODD+D is illustrated with a description of a social-ecological ABM on water use. We believe that our expansions help to make the ODD protocol a most suitable protocol to describe social-ecological ABMs and may support the review process of related manuscripts. The ODD+D protocol does not only improve the quality of model descriptions but also improves our understanding of models and is an important necessary step forward developing theory respectively frameworks for social-ecological ABMs.

Sustainable Transformation of Urban Water Infrastructure in Amman, Jordan – Meeting Residential Water Demand in the Face of Deficient Public Supply and Alternative Private Water Markets

Rapid urban growth processes pose severe challenges to the existing water infrastructure, particularly in developing countries (see Bedtke and Gawel, Chap. 3 in this volume). Responding to these challenges might exceed the scope of a gradual change and require a sustainability-oriented system transformation (Kabisch and Kuhlicke 2014). This chapter examines the prospects for such an urban transformation in Amman, the capital of the Hashemite Kingdom of Jordan, where the challenges of supplying water to all residents are particularly demanding. Since the year 2000, the population of the greater Amman municipality is estimated to have grown by more than one third (DOS 2014), and this trend can be expected to persist, due to continually high rates of immigration of Syrian refugees. In addition, Jordan is among the most water-scarce countries in the world (Yorke 2013) and is currently overexploiting its renewable groundwater sources by about 65% above the sustainable extraction rate (IRG 2015). Thus, making progress towards a more sustainable use of its freshwater resources is a matter of urgency. The pressing scarcity of water has led Miyahuna, the public water utility of Amman, to introduce a water quantity rationing scheme by which households only receive water for a limited number of hours per week, leading to perceived and actual water quality problems (supply interruptions can, e.g., lead to contaminant infiltration and the development of biofilms; see Hashwa and Tokajian 2004; Yorke 2013; Potter and Darmame 2010). Both the supply intermittency and the quality concerns have forced residents to intensify the use of various coping strategies (e.g., maintaining private storages, ordering private water tankers, purchasing bottled water), which further complicate any targeted steps to initiate a transformation of the public water supply system and water use patterns towards sustainability.