Critical infrastructure composes themselves of assets, systems, and physical and virtual networks as labelled by the Cybersecurity and Infrastructure Security Agency. Vulnerabilities to these infrastructures can be characterized as the installation, assets, applications, systems, or any of their dependencies that could degrade or suffer or lose function to its designated function as a result of an attack, threat, or natural disaster. Vulnerabilities have been noted and recognized for a long time. As threats can be natural, accidental or technical, or human-caused, protections must be put into place to reduce the amount of risk that can be aimed towards them. Data from the International Journal of Control and Automation state that over 33 percent of waterborne containers come through the ports of Los Angeles and over 37 percent of freight railcars pass through the state of Illinois as well as 27 percent through the state of Missouri (Robles et al.). For one example to handle the massive amount of the transportation sector to pass through, mitigations of risk need to be put into place as one event or threat could undermine the infrastructure.
Supervisory control and data acquisition, also known as SCADA, are known for monitoring or controlling some of the systems that run behind the scenes. SCADA systems are employed worldwide within numerous types of industries in which the average person does not know about with their critical importance. These systems can control oil and gas pipelines, as well as nuclear facilities or even water plants. As these centralized systems monitor sites, they take in data which can be watched and studied to find outlying data. The Human Machine Interface, or HMI, is the device in which the human can interact with the data given from the SCADA systems database. This is the point in which outlying data can be seen, or automation can be changed within the systems, or even simply showing an alarm or normality can be on the display. Other hardware, such as terminals or supervisor stations will be in place as well.
The mitigation of risk comes to play when the human factors can receive the data from these systems and implement change. Seeing the data enables fixes, as well as puts automations into play so the infrastructure can continue working if there is a degradation. As more threats begin to emerge, changes to the systems and interfaces will appear as well to continue to mitigate the potential threats.

References
Critical Infrastructure Vulnerability Assessments. (n.d.). Retrieved November 08, 2020, from https://www.cisa.gov/critical-infrastructure-vulnerability-assessments
Robles, Rosslin J., et al. “Common Threats and Vulnerabilities of Critical Infrastructures.” International Journal of Control and Automation, http://article.nadiapub.com/IJCA/ Accessed 7 November 2020
SCADA Systems. (n.d.). Retrieved November 07, 2020, from http://www.scadasystems.net/