‘Managing nucleus of Ganga sand bed could control flood’

Varanasi: As Varanasi and other places in the Gangetic plain faced flood fury, eminent river engineer and former head of the department of civil engineering at IIT-BHU Prof. UK Choudhary has claimed that “floods can be controlled if the nucleus of the river sand bed is properly managed before the rainy season”.
“The flood is not a natural calamity, but is like human’s vomiting phenomenon caused by growth of tumour in the stomach,” said Prof. Chaudhary, explaining further that this is the function of excessively enhanced drag forces of the convex-bank side floodplain of undilutedly rising sand-bed having the reverse slope as compared to that of the river bed.
“The sand bed has a nucleus, which is the highest level of the bed responsible for damping out the turbulence in the most vigorous way causing heavy deposition of sand. This ensures conversion of kinetic energy into potential energy, the enhancement in flood height,” he added.
According to him, in Varanasi, the nucleus of the sand bed in the Ganga lies in front of Ramghat/Panch Ganga Ghat. Its height and location changes every year. Usually, the maximum height remains between 7 to10 m above the maximum level of the bed in front of the Assi Ghat. This nucleus with its surroundings is causing the dissipation of kinetic energy of the stream and its conversion into the enhanced potential energy. The integration of this energy loss in the upstream region defines the flood in Varanasi, he explained.
“The flood height in Varanasi can be well minimized if the nucleus of sand bed here is properly managed before the rainy season,” said Prof. Chaudhary, adding that the friction, form and pressure drag forces of the sand bed are the responsible factors for flood.
“The control over the mechanics of sand bed formulation is not within the human endeavour as it is a function of sinuosity of the river and the strength of the secondary circulations. But minimization of drag forces is well within human control when the flood plain is in lean period,” he added.
“As such, flood is not a natural calamity. The theory is known as flood plain management technology for flood control. This is similar to removing the tumour from the human stomach and to manage the digestive potential and to control the vomiting,” he said and added that the management of the nucleus of sedimentation is the technology for flood mitigation.
“This is known as the outflow management for flood control,” said Prof. Choudhary, who is also the founder director of the Mahamana Malaviya Institute of Technology for Ganga Management (MMITGM) in Varanasi.