In the past few years, the field of dam safety has approached risk informed methodologies throughout the world, combining the probability of undesired events with their consequences. Reflecting this, the International Commission on Large Dams (ICOLD) has issued a bulletin exclusively dedicated to the topic and has also devoted one of the sessions of the last International Congress on Large Dams to it as well. In terms of performing specific analyses, these have ranged from the most simplified and qualitative to complete quantitative applications.

With all this in mind, the main objective of this work is to develop a complete tool for risk analysis applicable to any dam or system of dams. For this purpose the work has been divided into 5 parts, which are summarized below.

The first part presents the theory behind Risk Analysis and treats each one of the variables which are part of a risk model and their relationships in a systematic manner. A whole chapter is devoted to each variable, reviewing the state of the art of its modeling and providing the knowledge and perspectives that have been gained through the development of this work. This part of the work also has the intention of serving as a guideline for Risk Analysis. Consequently, a general procedure for conducting Risk Analyses is proposed and the existing guidelines for risk tolerability are discussed.

In the second part, a conceptualization of risk models is developed which is general enough to be able to capture any risk model which could be used in dam safety but also sufficiently intuitive and compact for it to be effective in its application to real world cases. This conceptualization is based on influence diagrams and risk models specified with it can be automatically calculated by a software routine. The algorithms which are used are explained and a new methodology for the calculation of systems of dams is proposed. Finally, there is chapter for the verification of the developed algorithms, contrasting the results they offer with previously published results. The methodologies developed in this part have been implemented in a software code, which has been used for the calculations of this work.

In the third part, all of the above is applied to perform a risk analysis to 5 dams pertaining 2 different systems. The Carrión system has two dams in series: Camporredondo and Compuerto. The Pisuerga system has three dams in Y: Requejada, Cervera and Aguilar de Campoo. This part also includes a proposal of new indexes combining efficiency and equity concepts, useful for the prioritization of risk reduction measures in systems of dams.

The fourth part details the conclusions and possible future research directions and the fifth part includes the appendixes.