# A Modeling of Human Reliability Analysis on Dam Failure Caused by Extreme Weather
## 3 PSFs Analysis  
### The Basic Path of Human Error in Dam Failure  
The basic path of human error in dam failure accidents is the failure path that human behavior patterns will always follow under different causes and for various dam types. Judgments can be made in relation to human information processing paths, which can be divided into two categories: explicit failure paths and implicit ones. In the management of reservoirs, the basic path of explicit failures is caused by manifest failures, mainly the process of unsafe operator behaviors that increase unreliability. Implicit errors, on the other hand, stem from organizational management deficiencies that act on the system's deeper defenses and increase the chances of human error. The discussion in this paper focuses on explicit failure pathways. The process of human influence on dam safety is realized through the manipulation of the human-machine interface. It has been suggested that the manipulator undertakes two main tasks during digitization [31]: type I and type II tasks. Type I tasks, namely, primary tasks, are those performed to fulfill the objectives of the mandate. Type II tasks are interface management tasks, which are tasks that are performed concurrently to fulfill Type I tasks, such as computer interface management, information seeking, and processing. Combining the analysis of human error in other fields with dam safety and referring to the relevant rules and regulations for dam management, the basic path of human error in the dam failure process is constructed, which mainly consists of four parts, including monitoring and awareness, state diagnosis, plan formulation and operation execution, as shown in Figure 2.  
* Monitoring and awareness;  
Figure 2: Basic path of operator behavior. Monitoring and awareness is the process by which reservoir managers obtain information from the situational environment. Abnormal conditions of the reservoir are mainly detected during daily inspections, or abnormal parameters are detected through monitoring equipment, alarms, and other display devices. Monitoring means that the operator checks the various parameters on the computer screen, and in some cases where there is a lack of digital displays, it refers to the checking of the reservoir's appearance, measuring instruments and so on, by the managers. Awareness is when an operator discovers in a timely manner that some data in a computer/measuring instrument are abnormal, or that there are warning signs of distress in a reservoir. Monitoring and awareness is the most frequent and important task of the operator. Therefore, the main human error factors influencing this phase are the human cognitive functioning aspects and psychological factors, which mainly include:  
Individual factors: Physiological factors such as level of vision, color weakness, color blindness, fatigue, level of health; psychological factors such as mental state, concentration, emotions; qualitative factors such as level of skill, experience, level of training, sense of responsibility. Among them, the operator's physiological factors will affect the sensitivity of its perception of information. For example, operators with color weakness and blindness have more difficulty in receiving emergency information, and people in a state of fatigue are inattentive, and so on. Psychological factors such as poor emotional and bad psychological states can distract attention, resulting in cognitive decline and inability to recognize erroneous information in a timely manner. The operator's lack of skill and experience can lead to the creation of an unreliable mental model that reduces human reliability while ignoring many possible signs of malpractice. Technical factors: Display equipment characteristics of the human-machine system display interface; alarm systems; advanced technologies such as water and rainfall measurement, safety monitoring facilities, dam hazard detection technology, and penetrating sensing technology.