Natural Disasters of India

Subject: Geography | Unit: Climate & Weather | Topic: Natural Disasters Exam: AP Group 2 (APPSC)

Introduction

India is one of the most disaster-prone countries in the world — approximately 85% of India's land is vulnerable to one or more natural hazards. The country faces earthquakes along the Himalayan arc, cyclones on its vast coastline, floods in river basins, droughts in semi-arid regions, and landslides in hilly terrain. For AP, cyclone vulnerability along the 974 km coastline and drought in Rayalaseema are the most critical disaster concerns. Disaster management has become a significant exam topic since the enactment of the Disaster Management Act 2005.

Context

India's vulnerability stems from its geological position (Indian Plate collision with Eurasian Plate), long coastline exposed to Bay of Bengal cyclones, monsoon-dependent agriculture, and rapid urbanization in flood-prone areas. The 2004 Indian Ocean Tsunami was a watershed moment that led to the establishment of comprehensive early warning systems and the NDMA framework.

Core Content

India's Vulnerability Overview

Seismic Zones of India (BIS)

Major Historical Earthquakes

Cyclones

Formation requirements: Sea surface >27 deg C, Coriolis force >5 deg latitude, moisture convergence, unstable atmosphere, weak vertical wind shear.

Bay of Bengal vs Arabian Sea: Ratio 4:1 — Bay of Bengal significantly more cyclone-prone (warmer, more moisture convergence).

Cyclone-Prone States:

Major Recent Cyclones:

Floods

• Flood-prone area: ~40 million hectares (12% of India)
• Most flood-prone: Brahmaputra basin (Assam), Bihar (Kosi — "Sorrow of Bihar"), UP, West Bengal
• Kosi 2008: river changed course; displaced 3.3 million
• Kerala 2018: worst floods in a century; 483 deaths
• Uttarakhand 2013: cloudburst + glacial outburst; 5,000+ deaths

Droughts

Drought-prone regions: Rajasthan (most drought-prone), Rayalaseema (AP), Marathwada (Maharashtra), Gujarat interior, Bundelkhand.

Tsunamis

• 2004 Indian Ocean Tsunami: 9.1 magnitude earthquake near Sumatra
• Hit India's east coast: Tamil Nadu, AP, Andaman & Nicobar; ~12,000 deaths in India
• Indian Tsunami Early Warning Centre (ITEWC) established in Hyderabad (2007)

Disaster Management Framework

• Disaster Management Act: 2005
• IMD (India Meteorological Department): cyclone and weather warnings
• CWC (Central Water Commission): flood forecasting

AP Connection

• AP coast is highly cyclone-prone: Hudhud (2014, Vizag), Titli (2018, Srikakulam)
• Rayalaseema is drought-prone: Anantapur, Kurnool most affected
• AP falls in Seismic Zone II-III (moderate risk); relatively stable peninsular region
• 2004 Tsunami affected AP coast: ~100+ deaths
• ITEWC (Indian Tsunami Early Warning Centre) located in Hyderabad
• APSDMA coordinates state-level disaster response
• Cyclone-vulnerable districts: Srikakulam, Vizianagaram, Visakhapatnam, East Godavari, Krishna, Nellore
• Krishna and Godavari river floods affect delta districts periodically
• Budameru rivulet caused devastating Vijayawada floods (2024)

Key Points Summary

1. ~85% of India is vulnerable to one or more natural hazards
2. Seismic Zones range from V/VI (highest risk, Himalayas) to II (lowest, Peninsular interior)
3. BIS introduced Zone VI (2025) for entire Himalayan arc
4. Bay of Bengal has 4x more cyclones than Arabian Sea
5. Cyclone formation requires sea surface temperature >27 deg C
6. Kosi = "Sorrow of Bihar"; Damodar = "Sorrow of Bengal"
7. 2004 Tsunami led to ITEWC establishment in Hyderabad
8. Disaster Management Act 2005 created NDMA-SDMA-DDMA framework
9. NDMA chaired by PM; SDMA by CM; DDMA by District Magistrate
10. NDRF is the specialized disaster response force with 12 battalions
11. Drought types: meteorological (rainfall), agricultural (soil moisture), hydrological (water resources)
12. Rajasthan is most drought-prone; Rayalaseema (AP) is also highly drought-prone
13. Latur 1993 earthquake was significant as a rare peninsular India event
14. AP is in the 2nd most cyclone-prone position (79 cyclones 1981-2002)
15. Hudhud (2014) and Titli (2018) devastated AP's coast

Exam Strategy

• Seismic zones: Know the 5-zone system and which states fall where; AP = Zone II-III
• Cyclone frequency: Bay of Bengal 4:1 over Arabian Sea; east coast more vulnerable
• AP disasters: Hudhud 2014 (Vizag), Titli 2018 (Srikakulam), Rayalaseema drought
• Framework: NDMA (PM) > SDMA (CM) > DDMA (DM) > NDRF (specialized)
• Trick: 85% of India vulnerable to hazards but only 12% is flood-prone

Key Terms Glossary