The Govt. of India is aggressively pursuing the National Waterway No. 2 (NW2) as an infrastructure project for the development of the North-East, particularly for the State of Assam. It is an extremely ambitious project with plans of multi-modal transport systems and multiple other diplomatic agendas such as taking our neighbouring nations on-board for the development of the region. Such ambitious projects raise the stakes for all the stakeholders and demand high-end measures to ensure reliable operational availability at all times.

The NW1 and NW2 are also a part of the trans-boundary Inland Water Transport (IWT) between India and Bangladesh. The IWT network promises to provide an efficient system for multi-modal connectivity between India and its eastern neighbourhood.

Bharat-Bangladesh Protocol Route. Source: IWAI

The NW2, over the Brahmaputra River, faces some very unique challenges. The Brahmaputra carries the world’s highest sediment load. Both physical and chemical erosion rates in the Brahmaputra Basin are higher than the world average.

The Namche Barwa or Eastern Syntaxis Zone in upstream Brahmaputra is the major source of sediments, accounting for 45% of the bulk sediment flux which arises from only 20% of mountain area. The sediment deposited in the Brahmaputra varies from 150 tonnes per sq km in Tibet to 1495 tonnes per sq km in Arunachal Pradesh.

The Inland Water Transport (IWT) project is highly sensitive to such siltation as it severely impacts the navigability of waterways. Thus, any planning of the IWT project must factor in the rapid rate of siltation and devise ways to safeguard vessels from any consequent damage.

In a typical river, the sediment rate is directly proportional to its channel geometry i.e. size and shape of the channel in which the river’s water flows. However, for a river like the Brahmaputra, the channel geometry itself keeps on changing. The course of the Brahmaputra has many variations ranging from steep gorges to wide channels with gentle slopes, probably due to its tectonics-driven gradient changes. This makes it extremely challenging to effectively estimate the sediment load.

If we are to better understand the water discharge and sediment load, we must know the channel geometry, but measurements can be made only at specific points and at limited frequency. The task can be done using an Artificial Intelligence (AI) based technique involving an Artificial Neural Network (ANN).

If we put in the sediment grain size and water discharge rate, the ANN can tell us the width, depth, and slope of the channel of the river. AI techniques give us a significant advantage as they allow us to make real-time computations and also improve the accuracy of the estimation.

ANN Flow for Estimation of River Channel Geometry. Source: Author

The existing models of estimating total sediment load are based on direct and indirect methods, however, both ultimately bring us to the next task of applying the knowledge to the aid of navigation of IWT vessels.

In the late 1990s, the Technical Committee of the International Maritime Organization (IMO) developed the Automatic Identification System (AIS), which has been a critical development in the maritime sector. AIS data gives complete static and dynamic inputs on the vessel and its voyage. Today, AIS data is freely available and thanks to it, multiple researchers have built algorithms for varied applications.

One critical input required for our application here is the draught of the vessel. Based on the present draught of the vessel and the estimation of sediment load using techniques discussed, we have developed a unique aid for the navigation of IWT vessels.

This is a state-of-the-art, AI-based tool that takes real-time inputs on the ground situation, performs extensive computations to derive real-time sediment load, and then maps it on to the draught of the ship for evaluating the navigational hazards. The aid will serve as a tool to assess, in real time, the siltation in a specific area and send out an early warning to the navigator of the vessel.

The Maritime Research Centre at Pune has researched multiple aspects of this topic. During this study, it has established that there is ample scope to take this study as the aid which they have developed forward into multiple areas such as – defence applications, monitoring of the environment and ecosystems, effective realisation of UDA (underwater domain awareness) framework, more effective formulation of the Blue Economy policy, and oceanographic studies in both, the Brahmaputra river basin and across the IOR.

(This post first appeared here in The Tilak Chronicle.)

Dr Arnab Das
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Dr Arnab Das is a former Naval Officer and has obtained a PhD on Underwater Technology from IIT Delhi. He is Founder & Director of Maritime Research Centre (MRC), Pune and also runs a startup called M/S NirDhwani Technology Pvt Ltd (NDT). Both MRC and NDT focus on the Underwater Domain Awareness (UDA) Framework.


The views and opinions expressed in the above article belong to the author(s) and do not necessarily represent the official opinion, policy or position of Lokmaanya.


1 comment

  1. The fact remains that a very large percentage of silt will make its way to the sea in Bangladesh.
    The residual silt will deposit on the river bed , increasing the water level during monsoon, leading to more floods in the Assam valley.

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