How floods, displacement and ecological stress are reshaping borders and regional stability
Kolkata:Across India’s Northeast, the traditional boundary between ecological vulnerability and national security is steadily disappearing. Long viewed primarily through the lenses of insurgency, border enforcement and geopolitical competition, the region now faces a more pervasive threat: climate-induced disruption.
The eight northeastern states—Assam, Arunachal Pradesh, Manipur, Meghalaya, Mizoram, Nagaland, Sikkim and Tripura—are exposed to floods, riverbank erosion, landslides, earthquakes and increasingly unpredictable rainfall. These pressures are not confined to the environment. They affect human mobility, infrastructure, border surveillance, military logistics, social cohesion and India’s relations with neighbouring countries.The Brahmaputra and Barak are the region’s two principal river systems. They sustain agriculture, livelihoods, transport and biodiversity, but extreme rainfall, erosion and changing river behaviour are also displacing communities and damaging roads, bridges, embankments and border infrastructure.What was once treated largely as a recurring natural calamity has therefore evolved into a strategic security challenge.
From Seasonal Flooding to Prolonged Displacement
India recorded 5.4 million disaster-related internal displacements in 2024—the country’s highest annual figure since 2012. Approximately 2.4 million of these movements were triggered by severe monsoon flooding, according to the Internal Displacement Monitoring Centre.The organisation separately estimates that the 2024 floods in Assam generated approximately 2.5 million internal displacements. This figure measures movements rather than necessarily representing 2.5 million distinct individuals, as the same person can be displaced more than once during successive flood events.Assam experienced three major waves of flooding during 2024. The Assam State Disaster Management Authority’s flood memorandum reported that all 35 districts were affected, covering 7,794 villages and 42.95 lakh people. Homes, crops, roads, embankments and other public infrastructure suffered extensive damage.Floodwaters eventually recede, but riverbank erosion creates a more permanent form of displacement. The Water Resources Department of Assam estimates that the Brahmaputra and its tributaries have eroded more than 4.27 lakh hectares—approximately 4,270 square kilometres—of land since 1950. This represents about 7.4 per cent of Assam’s geographical area.For families living on chars, or shifting river islands, erosion can erase agricultural land and homes within a single season. It may also destroy land records, identity documents and proof of residence. This is particularly serious in Assam, where land ownership, migration and citizenship have long been politically sensitive issues.Research on riverbank erosion in Assam has linked severe erosion with poverty, loss of livelihoods and both short- and long-term migration. However, the relationship is not automatic: economic insecurity, lack of employment and other social conditions also influence migration.Climate displacement does not by itself become a national-security threat. The danger arises when families remain without durable rehabilitation, documentation, livelihoods or access to public services. Prolonged exclusion can deepen social marginalisation and intensify competition over land and employment.This is where environmental vulnerability begins to intersect with governance and internal security.
When a Changing River Reshapes the Border
India shares a 4,096.7-kilometre international border with Bangladesh. Assam, Meghalaya, Tripura and Mizoram account for substantial portions of this frontier, while the remainder runs through West Bengal.Several northeastern sections of the border pass through rivers, floodplains, forests and densely inhabited areas. River channels shift, chars emerge and disappear, and floods can damage roads, fencing, border pillars and observation posts. Conventional border infrastructure cannot always remain fixed in such a fluid landscape.The Dhubri sector in Assam illustrates this challenge. Here, the Brahmaputra enters Bangladesh through an expanse of river channels and shifting islands where physical fencing is difficult.In March 2019, the Ministry of Home Affairs inaugurated the Border Electronically Dominated Quick Reaction Team Interception Technique, known as BOLD-QIT, under the Comprehensive Integrated Border Management System.According to the Ministry of Home Affairs, the system was designed to integrate surveillance technologies across a 61-kilometre riverine stretch in Dhubri. These include thermal imagers, radar, sonar, ground sensors and real-time command-and-control networks. The government has subsequently reported the continued deployment of technological surveillance, boats and floating border outposts in riverine areas.Such systems improve situational awareness, but climate adaptation must become integral to border planning. Installations designed for stable terrain may not remain effective where rivers change course, embankments collapse or severe weather interrupts communications.Border security in the Northeast will increasingly depend on flexible surveillance, resilient infrastructure, local intelligence and coordination among security forces, disaster-management authorities and water-resource specialists.
Displacement, Documentation and Social Stability
Most climate-related displacement in Northeast India remains internal. Families affected by floods, erosion and landslides often move towards district headquarters and cities such as Guwahati and Silchar, or settle on embankments, government land and environmentally sensitive fringes.These movements place pressure on housing, healthcare, education, employment and urban infrastructure. They can also intensify friction in areas where land, indigeneity and political representation are historically contested.Sanjib Baruah’s scholarship on displacement and political belonging in Northeast India shows how people uprooted within national borders can remain socially and politically insecure despite being citizens. His 2003 paper, “Citizens and Denizens: Ethnicity, Homelands, and the Crisis of Displacement in Northeast India,” provides a more defensible basis for examining this relationship than the untraceable source cited in the original manuscript.The security implications do not arise from displaced people themselves. They arise from inadequate rehabilitation, contested documentation, prolonged exclusion and failures of governance.Assam already has a rehabilitation policy for erosion-affected families. Existing disaster-relief norms also provide limited assistance for eligible small and marginal farmers who lose substantial portions of legitimate land because of changes in river courses.The policy requirement is therefore not simply to “recognise” erosion. It is to make existing assistance more accessible, strengthen rehabilitation, restore documents, provide secure housing and create durable livelihood alternatives.
Why Climate Resilience Matters to India’s Security
The Northeast’s strategic significance extends far beyond disaster management. The region borders China, Bangladesh, Myanmar and Bhutan and is connected to the rest of India primarily through the narrow Siliguri Corridor.Floods and landslides can disrupt national highways, railway lines, bridges, airports, power systems, fuel supplies and telecommunications. Such interruptions affect civilians as well as the movement of security personnel and essential supplies towards sensitive frontier areas.Climate resilience is therefore connected to strategic mobility. All-weather roads, resilient bridges, protected communication networks, decentralised supply centres and alternative transport routes are security assets as much as development projects.The same principle applies to India’s Act East Policy. Projects intended to connect the Northeast with Bangladesh, Myanmar and Southeast Asia depend on reliable roads, railways, inland waterways and border facilities. If climate risks are not incorporated into their design, strategically important connectivity projects may repeatedly suffer damage or disruption.Border villages also have an important role. Livelihood security and reliable public services help sustain communities in remote frontier areas. When ecological stress forces people to leave, the resulting depopulation can weaken local economic activity and the state’s everyday presence.The security of the Northeast consequently cannot be measured only through military deployments or border installations. It must also be measured through the resilience of its infrastructure and communities.
China, the Brahmaputra and the Transparency Deficit
The Brahmaputra originates as the Yarlung Zangbo on the Tibetan Plateau before entering Arunachal Pradesh and flowing through Assam into Bangladesh. This geography connects the environmental security of Northeast India with upstream developments in China and downstream consequences in Bangladesh.China formally began construction of a major hydropower project on the lower reaches of the Yarlung Zangbo in July 2025. According to the Chinese government’s announcement, the project will comprise five cascade hydropower stations.Beijing maintains that the project will not adversely affect downstream areas and says it will continue cooperation on hydrological data, flood prevention and disaster reduction. Nevertheless, its scale and location have generated understandable concerns in India over dam safety, ecological consequences, sediment movement, emergency notification and the availability of reliable operational information.The issue should not be reduced to unverified claims of deliberate “water weaponisation.” The more immediate strategic concern is the transparency deficit in a transboundary river basin exposed to earthquakes, landslides and extreme weather.Even a project designed principally for electricity generation can affect sediment transport, seasonal flows, aquatic ecosystems and disaster-management calculations. These consequences require independent scientific assessment rather than either alarmism or unquestioning reassurance.India and China have previously maintained mechanisms for sharing hydrological information. The scale of the new development, however, strengthens the case for continuous data exchange, advance communication about major operational changes, dam-safety information and credible downstream impact assessments.Uttam Kumar Sinha’s Riverine Neighbourhood: Hydro-politics in South Asia provides an identifiable scholarly foundation for this argument. His work examines how transboundary rivers connect ecological interdependence with diplomacy, sovereignty and regional security.
Bangladesh and Basin-Wide Cooperation
India and Bangladesh share 54 cross-border rivers. Heavy rainfall and runoff originating in Northeast India can affect downstream areas in Bangladesh, while ecological disruption across the wider Ganges-Brahmaputra-Meghna basin can affect livelihoods and mobility on both sides.The two countries cooperate through the Joint Rivers Commission and share flood-related information. However, extreme weather increasingly tests the adequacy of existing arrangements.During the August 2024 flooding in Tripura and eastern Bangladesh, allegations circulated that the disaster had been caused by a deliberate release from the Dumbur Dam on the Gumti River. India rejected that claim, stating that exceptionally heavy rainfall across the shared catchment was primarily responsible. The Ministry of External Affairs also reported that an automatic power disruption had interrupted part of the data-transmission system.The episode demonstrated how quickly a disaster can become a diplomatic controversy when information is delayed and public trust is weak.Real-time river data, harmonised forecasting systems, direct communication among local authorities and joint disaster-response exercises could reduce both physical risk and misinformation.Climate vulnerability in Bangladesh is relevant to India, but the relationship between climate change and cross-border migration must be approached carefully. Environmental pressures generally cause internal displacement first. International movement is influenced by several economic, social and political factors and cannot be assumed solely from climate projections.Security policy must distinguish evidence-based mobility patterns from politically charged speculation.
Towards an Integrated Climate-Security Strategy
India has undertaken flood-management, climate-adaptation and border-surveillance initiatives, but responsibilities remain divided among ministries, state governments and security agencies. A coherent climate-security strategy for the Northeast requires greater integration.First, erosion must be treated as permanent loss rather than only as a temporary flood emergency. Relief should be followed by rehabilitation, restoration of documents, secure housing and livelihood support. Assam’s existing rehabilitation policy must be implemented transparently and reviewed for adequacy.Second, infrastructure must be designed for future climate conditions rather than historical rainfall averages. Roads, bridges, railways, telecommunications and border installations should account for heavier rainfall, slope instability, erosion and repeated flooding. Strategic networks require alternative routes and built-in redundancy.Third, India should strengthen hydro-diplomacy. With Bangladesh, the priorities should be real-time data exchange, coordinated forecasting and joint basin-management mechanisms. With China, India should continue seeking greater transparency over upstream construction, dam safety and emergency operations.Fourth, structural measures such as embankments must be combined with wetland restoration, protection of natural drainage channels, catchment treatment, afforestation and responsible floodplain management. In October 2025, the Centre approved a ₹692.05-crore project to restore and rejuvenate 24 wetlands across nine Assam districts, explicitly linking wetland capacity with flood and erosion mitigation.Fifth, border agencies should incorporate climate-risk expertise into operational planning. The Border Security Force, local administrations, disaster-management authorities and water-resource departments need shared maps, communication systems and contingency exercises.Finally, local communities must be treated as partners. Residents possess valuable knowledge of river behaviour, erosion patterns, evacuation routes and changing landscapes. Their participation can strengthen early-warning systems, disaster response and border governance.
Reframing the Northeastern Frontier
Climate change is not replacing the conventional security challenges confronting Northeast India. It is intensifying them.Floods damage transport networks. Erosion displaces communities and destroys livelihoods. Landslides interrupt strategic roads. Shifting rivers complicate border surveillance. Upstream infrastructure generates diplomatic uncertainty, while downstream disasters can create tensions between neighbouring countries.The answer is not to securitise every environmental problem or portray vulnerable communities as threats. It is to recognise that ecological resilience, human security and national preparedness are now inseparable.India’s northeastern frontier will be shaped not only by military preparedness, but also by how effectively the country manages rivers, protects displaced communities, builds climate-resilient infrastructure and cooperates with its neighbours.Climate resilience is no longer separate from national security. It has become one of its defining pillars.
Author
Hridbina Chatterjee is a policy analyst specialising in South Asian geopolitics, maritime security, India’s strategic autonomy and the strategic significance of India’s Northeast. She holds an M.A. in International Relations from Jadavpur University, where she secured First Class First.Her research also explores climate security, critical-mineral geopolitics, gender-inclusive peacebuilding and emerging policy challenges across the Eastern Himalayas and the broader Global South. Her articles have appeared in Global Strategic & Defence News, Asian Confluence, the Nepal Institute for International Cooperation and Engagement, India Way, Samvada World and The Dialectics. She has also contributed chapters to ISBN-registered edited volumes.The views expressed in this article are those of the author.
