Guwahati: Researchers at the Indian Institute of Technology-Guwahati (IIT-Guwahati) in Assam along with the Brahmaputra Board, Ministry of Jal Shakti, Government of India developed an indigenous river model BRAHMA-2D (Braided River Aid, Hydro-Morphological Analyzer).
The project was led by Professor Arup Kumar Sarma, Department of Civil Engineering of IIT-Guwahati.
Ready for a challenge? Click here to take our quiz and show off your knowledge!
This comprehensive mathematical model can help to understand the flow of large braided rivers like the Brahmaputra, providing valuable insights to field engineers to design sustainable hydraulic structures like Spurs, Revetment and other river bank protection measures.
Predicting river flow variations across depth is crucial for flood and erosion control, agriculture and water supply intake design and zero head energy production. Traditional measurement methods of flow velocity in deep, large rivers during high monsoons are risky and extremely difficult, prompting the use of mathematical models.
Also Read: Assam: Woman dies after being assaulted for hours by husband in Guwahati
Ready for a challenge? Click here to take our quiz and show off your knowledge!
However, existing models provide only average velocity, underestimating undercurrents at different depths. In braided rivers, the presence of sandbars further complicates accurate three-dimensional velocity computation.
Speaking about the BRAHMA-2D model, Prof Sarma said, “Our mathematical model combines highly complex mathematical modelling with challenging field-based research on large braided rivers. With this quasi-3D river flow model, we can understand how fast the water moves at different depths inside a river and its circulation around a structure like a spur installed for preventing river bank erosion.”
BRAHMA-2D integrates a two-dimensional model of water movement with a theory about entropy and a measure of disorder or randomness. The research also delves into how features like river banks, spurs and sandbars affect the way water moves.
Also Read: Assam: Dr Pranavjyoti Deka wins Sahitya Akedemi Award 2023
Specifically, it observes a dip phenomenon near spurs where the flow of water underneath increases, a phenomenon absent in points away from these structures. The model was successfully validated on the Brahmaputra river near Majuli island, the second largest freshwater river island in the world, that is prone to river bank erosion.
Dr Anupal Baruah, at present working as a post-doctoral fellow at the University of Alabama, USA, highlighted the model’s successful application with the river survey data, using Global Positioning System (GPS) Echo-Sounder for depth and Acoustic Doppler Current Profiler, along with current meters for velocity measurement.
“During my research at IIT-Guwahati, field measurements near the spurs revealed a strong agreement with our model results. This breakthrough can now be applied to compute the vertical velocity profile at any desired location.”
Ongoing research at IIT-Guwahati continues to evolve the BRAHMA-2D model extending its application to estimate velocity changes for different vegetation types and assess the impact of structures like porcupines on flow velocity.
The versatile model has further helped to design bioengineering methods for controlling river bank erosion. It has also been applied to understand the habitat suitability of aquatic species, especially endangered species, based on the availability of required depth and flow velocity.
The novel findings were published in the ISH Journal of Hydraulic Engineering, earning the paper the prestigious ‘ISH Jal Vigyan Puraskar’ (Best Paper in ISH Journal), 2023. The award ceremony took place on Thursday (December 21) this year, at the Hydro-2023 conference hosted at the National Institute of Technology (NIT), Warangal.