Understanding Natural Hazards and Disaster Risk Reduction
Natural Hazards and Their Impact
Natural hazards are the probability of harmful consequences occurring due to physical phenomena motivated by natural forces: hydrological, geological, or atmospheric. These events can lead to disaster. They are not only a cause of death but are also usually accompanied by disease, famine, and poor drinking water supply. In many cases, the affected areas are located in underdeveloped countries, where infrastructure and measures to prevent disasters are scarce or nonexistent because financial resources are insufficient. For this reason, the rapid response of international aid is vitally important. Even though these disasters keep happening and mankind cannot stop them, it is in our power to minimize their consequences. For all these reasons, we support research and policy measures for sustainable management with appropriate information campaigns for the population.
Factors That Increase Disaster Risk
A question we must ask is whether this increase in the number and the virulence of disasters is related to human action and how it evolves. Yes, disasters are profoundly linked to how humanity has chosen to develop. Currently, we suffer further effects of natural disasters due to high population growth, demographic density, migration, environmental degradation, climate change, and development mismanagement.
Disaster Risk Index (DRI)
The DRI is an instrument used to calculate the average risk of fatalities occurring because of earthquakes, cyclones, or floods. It can also identify indicators of vulnerability to natural hazards. It has been found that people have different vulnerabilities to a threat. It is for this reason that the term ‘vulnerability’ refers to development actions provided by humans that can influence increased threat.
Disaster Risk in Development Planning
Management to reduce disaster risk must be integrated into development planning in the medium and long term. However, at present, humanitarian aid is essential to mitigate the consequences of catastrophes.
Frequent Disasters
- Floods: A flood occurs when the ground’s water assimilation capacity is exceeded due to heavy rainfall, seawater invasion, or snowmelt. Floods are the natural disasters that cause the greatest number of casualties in the world. Human activity also increases the risk of flood disaster: paved surfaces prevent water from being absorbed by the land, as do deforestation and urban sprawl.
- Earthquakes: Earthquakes occur mainly due to the movement of the Earth’s tectonic plates. When they collide, they generate a lot of energy that is released as seismic waves from the focus or hypocenter. One of the most detrimental factors to the death toll in an earthquake is undoubtedly the dangerous union of rapid and uncontrolled urban growth, breach of construction rules, and overcrowding.
- Tropical Cyclones: These usually occur in countries with tropical climates. Countries with the greatest population exposed to the threat of tropical cyclones are characterized by densely populated coastal areas and river deltas.
- Drought: Drought is a less spectacular and slower phenomenon than the winds of a tornado or the violence of an earthquake. Unlike what happens in the earlier cases, deaths by drought do not reflect well enough the magnitude of such a serious risk. To measure the virulence of a drought, its duration (which may be many years) and the scarcity of rainfall are taken into account, unlike the above phenomena, in which intensity and frequency are considered.
- Tsunamis: These usually occur in coastal areas. An undersea earthquake causes water movement, known as tidal waves or tsunamis.