JNTU B.Tech III DISASTER MANAGEMENT Previous Question Paper (October - 2020 - R16)

A disaster is a serious disruption of the functioning of a community or society at any scale due to hazardous events interacting with conditions of exposure, vulnerability, and capacity, leading to widespread human, material, economic, and environmental losses. It occurs when a hazard exceeds the coping capacity of the affected population.

The primary approaches to disaster management include:

• Relief and Response Approach: A reactive strategy focusing on immediate search, rescue, and provision of emergency services after a disaster occurs.
• Mitigation and Prevention Approach: A proactive strategy aimed at reducing the severity of disasters by strengthening infrastructure, land-use planning, and implementing early warning systems.
• Developmental Approach: Integrates disaster risk reduction into long-term national development policies to ensure that new infrastructure does not create new risks.
• Community-Based Disaster Risk Management (CBDRM): Empowers local communities to identify risks and build resilience using local knowledge and resources.

Major damage during an earthquake is rarely caused by the ground shaking alone; it is typically the result of the interaction between seismic energy and human-made structures. Key factors include:

• Building Design and Construction Quality: Poorly designed or non-engineered structures, particularly those made of unreinforced masonry or brittle concrete, are highly susceptible to collapse. Lack of seismic detailing, such as insufficient steel reinforcement, is a primary cause of failure.
• Geological and Soil Conditions: Soft soils and loose sediments can amplify seismic waves, leading to more intense shaking. Furthermore, saturated sandy soils are prone to liquefaction, where the ground loses its bearing capacity, causing buildings to sink or tilt.
• Proximity to Fault Lines: Structures located directly on or near active fault lines experience the highest peak ground acceleration and permanent ground displacement.
• Secondary Hazards: Earthquakes trigger secondary disasters such as landslides in hilly regions, tsunamis in coastal areas, and fires caused by ruptured gas lines or electrical short circuits, which often cause more damage than the initial tremors.
• Urban Density and Infrastructure: High population density combined with narrow streets and poor urban planning hinders rescue operations and increases the scale of casualties.