Risk has been defined, for management purposes, as the potential economic, social and environmental consequences of hazardous events that may occur in a specified period of time. In the past, the concept of risk has been defined in many cases in a fragmentary way, according to each scientific discipline involved in its appraisal. A framework and a multidisciplinary risk evaluation model is proposed in this article that take into account not only the expected physical damage, the number and type of casualties or the economic losses, but also the conditions related to soial fragility and lack of resilience which favor second order effects (or indirect effects) when an earthquake strikes an urban centre. Thus, the mentioned evaluation is holistic, that is based on an integrated and comprehensive approach, made by using indicatos andoriented towards guiding decision-making. Th conceptual framework and the model proposed are also valid for their applicationto multihazard risk evaluation, although this article has been focused on the evaluation of the seismic riskk. The first step in obtaining the Urban Seismic Risk index (USRi) consists of calculating a Physical Risk index for each unit of analysis starting form existing physical risk scenarios. An impact factor, associated with a set of socio-economic and lack of resilience conditions of the community, is applied in a second step to the physical risk index in order to obtain the USRi. It has been demostrated that the proponed holistic evaluationmodel of the seismic risk in robust, provideing stable and reliable values of the USRi. Finally, numerical simulation results of the seismic risk obtained with the proposed model are given in the article for the cities of Bogota (Colombia), Barcelona (Spain) and Manila (The Phillipines)
