Understanding Natural Hazards and Disaster Prevention

Natural Hazards

Natural hazards represent the probability of an area's population experiencing damage or catastrophe due to a natural event. UNESCO defines risk as the probability of human and property loss from natural or human-caused phenomena.

Key Concepts

• Dangerousness of a Natural Process: This estimates the potential of a natural process to cause environmental transformations, regardless of social context.
• Interference: This refers to the degree of interaction between a natural process in a specific area and human activities.
• Damage: This encompasses the types of transformations caused, considering economic, cultural, and production-related impacts.
• Social Catastrophe: This is the actual realization of a risk, measured by the resulting economic cost.

Types of Natural Hazards

Hazards Related to Internal Dynamics

• Seismic activity
• Volcanic eruptions
• Ground deformations

Hazards Related to External Dynamics

• Erosion
• Gravitational processes
• Geological characteristics of the subsoil
• Periglacial, nival, and glacial processes
• River dynamics
• Coastal processes
• Atmospheric dynamics

Hazards Associated with Internal Processes

• Ground and Building Shaking: Building collapse is the leading cause of death in earthquakes.
• Surface Displacement of Soil: This occurs along fault lines.
• Landslides: A violent earthquake can trigger thousands of landslides.
• Tsunamis and Tidal Waves: These waves travel at high speeds from the seabed, propelled by a vertical force.

Natural Disaster Prediction, Forecasting, and Prevention

This involves identifying processes and risk factors that may endanger a population. Prediction pinpoints where, when, and with what intensity a phenomenon will occur. Forecasting defines the statistical probability of a phenomenon's occurrence and its intensity levels, identifying the frequency of potentially catastrophic events. Prevention involves implementing activities to avoid the harmful impacts of dangerous phenomena. When unavoidable, measures should be taken to minimize the effects.

Earthquake Risk Prediction

The most effective earthquake prevention strategy is identifying high-risk zones and mitigating potential harm. Prevention must ensure the integrity of equipment and infrastructure to guarantee support and services after an earthquake.

Volcanic Hazard Prevention

Prevention relies on constant volcano monitoring to detect pre-eruption phenomena.

Hazards Associated with External Processes

Erosion

Erosion is the detachment and removal of materials from an area due to agents involved in external geological processes.

• Loss of Resources: The most significant loss is fertile land, vital for vegetation growth.
• Action of Mobilized Materials: Sediment transport poses a risk by potentially filling dams or hydroelectric power plants.