In this exclusive conversation, Dr. Diganta Barman, Head of the Water Resources Division (WRD) at the North Eastern Space Applications Centre (NESAC), shares insights with APAC Media into how science, technology, and geospatial tools are transforming water resource management in India’s Northeastern Region.
He highlights WRD’s work on watershed-based planning, flood early warning systems, river morphology studies, and decision-support platforms that help governments manage complex river systems like the Brahmaputra River and Barak. He also outlines future priorities, including AI-driven flood forecasting, spring rejuvenation, and the use of advanced satellite missions to strengthen water security and climate resilience in the region.
WRD, NESAC works extensively at the river basin and watershed scale. How has this approach helped improve water resource planning and decision-making across the Northeastern states?
If we see scientifically and technically as per the principles of hydrology and water sciences, the watersheds (with their various size-based hierarchies such as basin, sub-basin, watershed, sub-watershed, mini-watershed, and micro-watershed) are the prime planning unit across the world when it comes to the management and development of water resources. This approach helps to manage water resources across transboundary (both interstate and international) river basins. It also helps enormously in both conflict resolution and confidence-building among upstream, midstream, and downstream communities residing in the riparian states and countries for joint development of river basins for achieving common goals aligned with global visions of sustainable development.
Due to this approach, with the participation of both central and state-level agencies (such as NESAC, the Brahmaputra Board, State Water Resources Departments, etc.), basin-level master plans are being prepared with the overall goal of improvement in agricultural productivity, conservation of soil & water, people’s livelihood, etc. in the NER states of India.
Floods and river erosion are recurring challenges in the Northeast. From WRD’s experience, how have tech-based flood early warning systems and river erosion monitoring changed the way state authorities prepare for and respond to such events?
With the advent of geospatial (remote sensing & GIS) technologies supported by modern mathematical (hydrological, hydraulic, hydrodynamic, and physics-based numerical weather/rainfall prediction) modelling, it has become feasible to take flood forecasting and early warning to an all-new level of sophistication with improved accuracy, precision, lead time, and overall actionability.
The Flood Early Warning System (better known as “FLEWS”), conceptualized and developed at the North Eastern Space Application Centre (NESAC), led by me with our team of scientists from the Water Resources Division (WRD) and Space & Atmospheric Sciences Division (SASD), has been the first-of-a-kind operational example of GIS & hydro-met modelling-based flood forecasting in India, which has been giving monsoon season flood alerts in the Brahmaputra and Barak valleys to the disaster management authority in Assam from 2012 onward and has completed nearly one and a half decades of operationalization.
The Assam government has been judiciously using its services for relief, rescue, and other flood management activities with actionable lead time. This activity has also been recognised as a professional good practice by the Department of Administrative Reforms under the Ministry of Public Grievances and Pensions, Government of India. In recent years, we have also been focusing on extending this service to other flood-prone areas of NE India in a phased manner.
Your division develops state and district-level water information systems. How do these systems support day-to-day governance, especially for departments dealing with irrigation, drinking water, and disaster management?
The northeastern region of India is renowned for its hydrology and water resources, being the home of the largest river valleys, such as the Brahmaputra, Barak, etc., with more than two hundred tributaries, sub-tributaries, and rivulets. This enormously high number of river channels, along with a very complex sediment transport regime and fragile, sedimentary, and seismicity-induced geological formations, contributes severely towards management challenges for the government.
The “Assam River Atlas,” which has been developed by the Water Resources Division (WRD), NESAC, at the request of the Assam government, is a state-of-the-art, high-resolution river information system covering the two major river systems of Brahmaputra and Barak in Assam, where we have created a single-window GIS database for use by the relevant line departments in Assam associated with the water sector planning. This query-based database, hosted as a geo-portal in the public domain, is currently being used for preliminary reconnaissance of the rivers for planning and execution of engineering interventions for river restoration by the departments.
The Northeast has highly dynamic river systems. What have been some of the key insights/findings/examples from WRD’s studies on river morphology, and how are these findings being used by states for planning and protection works?
In the last two and a half decades since inception, our division at NESAC has worked on domains related to the hydraulic behaviour of fluvial river channels, identification of erosion hot spots, formation of river islands/sandbars, etc. Some of the key findings are behavioural differences between the north (channel braiding) and south (channel meandering) bank tributaries of the Brahmaputra, the influence of secondary undercurrents on channel erosion in the Brahmaputra main channel and some major tributaries, and the identification of temporally stable and unstable sections of river channels. All these findings have either directly or indirectly contributed to the planning and execution of river restoration works by the line departments.
WRD also supports hydropower planning through installed capacity assessment. How does your work help balance energy development with ecological and downstream water concerns in the region?
India’s northeast is also recognised as the hydropower house of the country; with an estimated power potential of more than fifty thousand megawatts, this region has enormous importance in India’s future energy security. The states of Arunachal Pradesh, with the highest power potential, followed by Mizoram, Nagaland, Sikkim, etc., are front-runners currently towards the augmentation of their power production facilities. Our division at NESAC has been supporting the hydropower agencies with different services such as upstream hydromet monitoring and modelling for optimisation of reservoir gate operations, downstream hydrodynamic impact assessment, and scenario generation for dam spillage for planning and design of flood management and mitigation measures.
What are WRD’s priorities over the next few years to strengthen flood resilience, water security, and science-based planning in the Northeastern Region?
Keeping in view the current challenges of water management in NER in specific and in India in general, we are working on a future road map for short-, medium-, and long-term vision for our division. Apart from expansion of the current activities as mentioned in the answers above, we are also prioritising new water management activities such as spring shed delineation and rejuvenation planning for future drinking water security, artificial intelligence-based flood hazard zonation and flood forecasting for improved and more efficient flood management planning, real-time monitoring of high-altitude glacial lakes and GLOF forecasting, altimetry-based river level monitoring for seasonal river navigation planning and flood monitoring, etc. in the coming years. With the help of new satellite missions such as NISAR, TRISHNA, SWOT, etc., we are having a great future direction towards water management in Northeast India.
