Course Disasters and their Effects ​on the Population: Key Concepts

Each disaster or humanitarian emergency is a unique situation determined by the event that caused it, as well as climate, geography, culture, social structure, and the pre-existing conditions of the affected population. Therefore, national and international organisations should begin with a rapid assessment and avoid the impulse to respond immediately before critical information is available.

Interventions based on assumptions rather than accurate, on-site information are likely to waste time and valuable resources, ultimately increasing the suffering of the affected population. Although similar types of disasters have predictable patterns of disruption, as shown in Table 2, the degree of severity and the type of response required are influenced by local conditions.

An appropriate response should be based on the specific needs of each disaster. Needs should be continuously reassessed at local, community, national, and regional levels.

Unanticipated effects may require urgent attention. For example, a safe water supply may not be directly affected by a strong storm or mudslide. However, if the regional system for water pumping or purification is damaged, access to safe water becomes a critical issue that must be addressed to prevent disease and excessive mortality.

Resources must be used in a timely manner within the time frame dictated by the disaster. For example, trauma is often the leading cause of death immediately after an earthquake. If trauma teams and field hospitals arrive a week later, most trauma-related deaths will already have occurred, and the benefit of these high-cost resources will be limited.

WHO and PAHO have developed guidelines for the appropriate use of field hospitals in sudden-impact disasters. More information is available at  https://www.paho.org/disasters