A new study reveals that India has the largest number of slum dwellers—over 158 million—living in flood-prone areas, primarily concentrated in the Ganga river delta. Globally, 33% of informal settlements in the Global South (445 million people) are in flood-exposed regions. The study highlights that low-income households are often forced into floodplains due to cheaper land, despite the high risk. This disproportionate exposure is exacerbated by failing infrastructure and lack of drainage. The findings underscore the urgent need for human-centric risk management strategies, community collaboration, and skill improvement in sanitation and waste management to enhance resilience, aligning with the UN's Sustainable Development Goals by 2030.
- India has the highest number of slum dwellers (over 158 million) residing in flood-prone areas, mainly in the Ganga river delta.
- Globally, 33% of informal settlements in the Global South are exposed to floods.
- Low-income populations are often pushed into floodplains due to affordability and lack of other viable options.
The article discusses India's preparation for Glacial Lake Outburst Flood (GLOF) events, highlighting recent catastrophic events in Nepal and the increasing risk in the Himalayas due to rising temperatures and glacial melt. India's National Remote Sensing Centre identifies 28,000 glacial lakes in the Indian Himalayan Region (IHR), with two main types: supraglacial and moraine-dammed. The National Disaster Management Authority (NDMA) has shifted from post-disaster response to proactive risk reduction, initiating a national program to prioritize and mitigate risks from 195 at-risk glacial lakes. This includes hazard assessment, installing early warning systems, and community engagement.
- GLOF events, like recent ones in Nepal, pose increasing threats in the Himalayas due to glacial melt and rising temperatures.
- The Indian Himalayan Region (IHR) contains 28,000 glacial lakes, primarily supraglacial and moraine-dammed types.
- The National Disaster Management Authority (NDMA) has adopted a proactive strategy for GLOF risk reduction, moving beyond post-disaster response.
The NASA-ISRO Synthetic Aperture Radar (NISAR) satellite is a joint mission designed to observe Earth's changing surface with high detail. Utilizing L-band and S-band radars, it will provide data every 12 days to monitor ecosystems, ice sheets, farmlands, and volcanoes. NISAR's mission is crucial for understanding natural hazards like earthquakes, tsunamis, and volcanic eruptions, and for tracking changes in land surface, groundwater, and forest cover. The data will significantly aid disaster management, climate change studies, and resource management globally, offering a "Smart Way to Succeed" in various administrative applications and environmental monitoring efforts.
- NISAR is a collaborative NASA-ISRO mission focused on detailed observation of Earth's surface changes.
- It employs L-band and S-band radars to provide high-resolution data every 12 days for monitoring various environmental features.
- The satellite's data is vital for understanding natural hazards, climate change impacts, and managing natural resources.
The article highlights that human activities such as mining, groundwater extraction, impounding water behind dams, and injecting fluids into the ground can induce seismic activity, leading to human-induced earthquakes. These activities cause strain accumulation between tectonic plates. A 2021 study linked shallow earthquakes in the National Capital Region to excessive groundwater extraction. Large dams, like the Koyna hydroelectric dam, have also been associated with significant earthquakes. India's growing energy demand, met through hydropower and oil/gas extraction (including fracking), further increases this risk. Scientists emphasize the need for scientific management of groundwater, proper evaluation before dam construction, and strong seismic networks to monitor these activities.
- Human activities like groundwater extraction, dam construction, and energy extraction can induce earthquakes.
- These activities alter the stress regime in the Earth's crust, leading to seismic events.
- Examples include earthquakes linked to groundwater depletion in Delhi-NCR and the Koyna dam.
The Environment Impact Assessment (EIA) study for the ₹72,000-crore Great Nicobar Infrastructure Project (GNIP) downplays the risk of future mega-earthquakes and tsunamis, stating the probability is "low." This contradicts some scientists who point to uncertainties in earthquake prediction and insufficient site-specific studies in the highly geo-dynamic Andaman-Sumatra fault line region. While the EIA cites a 2019 IIT-Kanpur study on return periods for mega-earthquakes (420-750 years), it omits the study's caveat about uncertainty due to a 2,000-year gap in sediment history. Experts like C.P. Rajendran emphasize the non-linear nature of earthquake recurrence and the presence of unknown parallel rupture lines, urging site-specific analysis for vulnerable infrastructure projects like the proposed transshipment port and international airport.
- The EIA for the Great Nicobar Infrastructure Project (GNIP) assesses the probability of mega-earthquakes and tsunamis as "low," despite the region's high seismic activity.
- Scientists express concern over the EIA's downplaying of risks, citing uncertainties in earthquake prediction and insufficient site-specific studies.
- The EIA selectively uses findings from an IIT-Kanpur study, omitting caveats about the unpredictability of future earthquakes.