Dams are a critical component of infrastructure that provide vital services and protection to human communities and the economy, as well as safeguard from other adverse conditions. In Spain, there are approximately 1225 dams, of which 643 dams are more than 50 years old and 274 dams are located in areas of the high/very high seismic hazard class, and the exposure range is between $356–498 billion. This paper proposes a methodology to estimate the risk grade of collapse for dams that have been subjected to seismic processes. For this, a new set of importance factors (IFs) is identified and analysed. Three main concepts outline the methodology comprehensively: hazard, exposure, and vulnerability. Within this methodology, 5 classes, 17 factors and 47 subfactors were introduced for several dams. The results show that 46 dams could be classified as having a “very high/extreme risk”, with a total cost of repair of approximately $23 million. Currently, technical codes comprise very simplified risk concepts and obsolete IF definitions because they are only based on the construction type and its intended use. This study promotes the adoption of an innovative set of new IFs for the risk assessment of dams under earthquaking in a critical way.

大坝是基础设施的重要组成部分，可为人类社区和经济提供重要的服务和保护，并免受其他不利条件的影响。在西班牙，大约有1225座水坝，其中643座超过50年的水坝，其中274座水坝位于高/非常高地震危险等级的地区，暴露范围在3560至4980亿美元之间。本文提出了一种方法来估算遭受地震作用的大坝的倒塌风险等级。为此，确定并分析了一组新的重要性因子（IF）。三个主要概念全面概述了该方法：危害，暴露和脆弱性。在这种方法中，为几座大坝引入了5个类别，17个因子和47个子因子。结果表明，可以将46个大坝归类为“非常高/极端风险”，维修总费用约为2300万美元。目前，技术规范仅基于构造类型及其预期用途，因此包含非常简化的风险概念和过时的IF定义。这项研究促进采用一套创新的新IF，以一种关键的方式对地震中的大坝进行风险评估。