Rapid urbanization and climate change together increase the vulnerability of poor urban communities to natural hazards, undermining urban resilience. It is therefore critical to identify and deepen our understanding of the main variables, and the complex interactions between them, producing and shaping the vulnerability of poor urban communities to natural hazards. Identifying factors that challenge or support the efforts of these communities in responding to hazards is also helpful in policymaking for urban resilience. To develop this understanding, it is necessary to conduct detailed research at the local scale. This paper aims to contribute to this knowledge by applying participatory modelling techniques to a particular case study of an informal settlement in Durban, South Africa. The aim is to elucidate how this detailed empirical research can contribute to broader theoretical knowledge on urban vulnerability and resilience in the face of climate change and rapid urbanization. Keywords climate change / Durban / informal settlements / system dynamics / urbanization / vulnerability I. IntroductIon Rapid and unplanned urbanization, in combination with the impacts of climate change, increases the vulnerability of the urban poor to natural hazards. Currently 3.9 billion people, or just over half of the world's population, reside in urban areas. (1) This number is projected to rise to 6.3 billion by 2050, when 66 per cent of the world's population will be considered urban. In absolute terms, this represents an addition of approximately 2.4 billion people to the global urban population. (2) This rapid urbanization process, which will largely take place in cities and towns of the global South, poses significant challenges to both authorities and ordinary citizens, as the majority of these fast-growing urban areas already have high levels of poverty, unemployment, informality and environmental risk, as well as housing and service backlogs. david samuel williams is a junior researcher at climate service center Germany (GerIcs) and specializes in the field of local governance and climate change. Further research interests include the management of hydrological extremes and sustainable development. Address: climate service center Germany (GerIcs), Helmholtz-Zentrum Geesthacht-economy and climate Impacts,