GUWAHATI, July 21 - A team of experts of the Department of Water Resources Development and Management of the Indian Institute of Technology (IIT) Roorkee has suggested that entry of sediment to the Brahmaputra should be scrupulously controlled, through comprehensive watershed management as well as development programme to check bank erosion by the mighty river.
Besides, sustainable channelisation, measures are also to be undertaken by effecting closure of the subsidiary channels of the river for the purpose, they said.
The experts of the IIT Roorkee made the above recommendations in their final report of a study on Brahmaputra erosion (Study of Brahmaputra River Erosion and its Control), which was prepared for the National Disaster Management Authority (NDMA) of India and completed in May 2012.
They observed that data analysis and computer simulation studies conducted in the study have concisely brought out that the prime causative factor of stream bank erosion vis-�-vis channel instability process of the Brahmaputra is the inherent �sediment overloading� of the river�s fluvial (stream-related) system, accompanied by the intensification of its channel braiding pattern.
They also suggested creation of a comprehensive data base comprising all pertinent data and information using the latest data management system and establishment of an autonomous well-equipped research and development centre. This centre should be manned by highly competent people for conducting applied research in an advanced manner.
The recommendations of the IIT Roorkee experts are relevant in the present day context. After the recession of the floodwaters, the Brahmaputra and many of its tributaries will now in the post-flood condition, start eroding their banks. Bank erosion by the rivers in the post-flood condition has emerged as a major problem for the people of this narrow valley for the past about six decades.
The IIT Roorkee experts said in one of their recommendations that cost-effective erosion control measures like the multi-tier �RCC Jack Jetty Field System� along with submerged vanes should be deployed as �per the site condition feasibility.�
To start with, they said field pilot studies may be undertaken at two sites � near Sualkuchi in Kamrup district and near Bhuragaon in Morigaon district. For this purpose, they said preliminary designs have been evolved.
They further said that due to the prevalent inadequacy of reliable and consistent field data, modelling in relation to erosion, sediment inflow and flood forecasting may have certain elements of inconsistencies and discrepancies. These may lead to fallacious prediction of the future scenario.
This situation, hence, urgently demands strengthening and upgrading of the existing data acquisition and processing infrastructure at the ground level of the agencies concerned, they said.
The IIT Roorkee experts, who conducted the study, included Prof Dr Nayan Sarma, Dr RD Garg, Archana Sarkar, Md Parwez Akhtar and Neeraj Kumar.