Introduction
India's unique geo-climatic setting renders over 85% of its geographical territory vulnerable to one or more natural hazard risks. Among these, landslides, droughts, floods, and cyclones represent recurring extreme events that disproportionately impact vulnerable populations, agrarian livelihoods, and socio-economic infrastructure.
1. Landslides
Landslides denote the downward and outward movement of slope-forming materials including rock, soil, and artificial fill under the direct influence of gravity.
- Triggers and Vulnerability: Primarily induced by heavy precipitation, slope undercut for infrastructure, tectonic activity, and deforestation. According to ISRO’s Landslide Atlas of India, approximately 12.6% of the country’s landmass is vulnerable, concentrated heavily in the fragile Himalayas and the Western Ghats.
- Mitigation Measures: Geological Survey of India (GSI) susceptibility mapping, rainfall threshold-based early warning systems, slope bio-engineering, and restricted hill-slope construction.
2. Droughts
Drought is a slow-onset, progressive natural disaster characterised by extended deficiency in precipitation, evolving across meteorological, hydrological, and agricultural dimensions.
- Triggers and Vulnerability: Initiated by erratic monsoon patterns, El Niño phenomena, over-extraction of groundwater, and shifting agro-climatic conditions. The National Disaster Management Authority (NDMA) estimates that nearly 68% of India's cultivable area is susceptible to drought, with chronic hotspots in Vidarbha, Marathwada, and Rayalaseema.
- Mitigation Measures: Promotion of micro-irrigation under PM Krishi Sinchayee Yojana (PMKSY), adoption of drought-hardy millets, watershed development, and construction of check dams and rainwater harvesting structures.
3. Floods
Flooding constitutes the temporary submergence of normally dry land due to river overflow, dam releases, storm surges, or cloudburst events compounded by poor urban drainage.
- Triggers and Vulnerability: Siltation of riverbeds, intense precipitation events, glacial lake outburst floods (GLOFs), and concretisation of floodplains. The Central Water Commission (CWC) classifies approximately 40 million hectares (~12% of the national area) as flood-prone, recurrently affecting the Indo-Gangetic-Brahmaputra plains and urban agglomerations.
- Mitigation Measures: CWC real-time basin forecasting, embankment maintenance, catchment area treatment, and wetland rejuvenation through sponge-city urban planning.
4. Tropical Cyclones
Cyclones are intense low-pressure warm-core weather systems originating over tropical oceans, driven by sea surface temperatures exceeding 27°C and Coriolis force.
- Triggers and Vulnerability: Associated with high-velocity gale winds, torrential rainfall, and destructive storm surges. Around 5,700 km of India's 7,516 km coastline across nine coastal states is prone to cyclonic disturbances, with the Bay of Bengal being particularly prone.
- Mitigation Measures: Early warning dissemination via IMD Doppler weather radars, expansion of multi-purpose cyclone shelters under the National Cyclone Risk Mitigation Project (NCRMP), and restoration of coastal mangrove bioshields.
Conclusion
Transitioning from reactive post-disaster relief to proactive climate-resilient risk governance is imperative. Mainstreaming the Sendai Framework for Disaster Risk Reduction priorities and adhering to the Coalition for Disaster Resilient Infrastructure (CDRI) standards will ensure systemic preparedness and sustainable development across hazard-prone regions.