GUWAHATI, March 20 � Undoubtedly, the seismic survey proposed in the riverbed of the Brahmaputra for oil exploration, would have adverse impacts on the aquatic animals of the river.
This was the observation of Dr Sarada Kanta Sarma, Emeritus Reader of Engineering Seismology and Research Investigator at the Imperial College, London. Dr Sarma is an internationally recognised expert on engineering seismology and earthquake engineering. His Sarma Method of analysing the seismic stability of earth dams and slopes is much admired. He was talking to this correspondent here recently.
To him, it is also important to note that if oil is struck on the riverbed, then how safe and eco-friendly would be its extraction. As, he said, the Brahmaputra is a fault line and it is important to know what impact of such oil extraction will have on the overall seismicity of the region.
On the issue of the proposed NE mega hydel dam projects, he said that technologically mega dams are feasible even in seismically very sensitive regions.
However, he said, proper monitoring by impartial agencies of the project activities must be a part of the country�s policy while going for such projects.
If the designs of the mega dams are old, these should be checked and re-designed at the construction stage, he said, when told that the designs of some of the dams, like the underconstruction Lower Subansiri Project, are allegedly old.
Moreover, impacts of such projects should be assessed thoroughly at inter-state level to avoid dam-induced disasters. It must be a part of the country�s hydel projects� designs to ensure that silt and water flow through the proper channels of the rivers.
The rivers should be dredged regularly downstream of the dams to maintain proper flow. This must be a part of any hydel project, he said.
On high-rise buildings, he said that the present popular attitude towards high-rise buildings in Guwahati or any other place of NE region needs to be reviewed basing on the modern technological advancements and construction practices.
Such structures are possible even in highly active seismic zones, he said, adding, even in highly active seismic American city of San Francisco, such buildings are built.
Of course, proper soil investigation, structural analysis, designs and proper quality monitoring system are mandatory to make such structures safe, he added.
�We ought to have a national character as do the people of the developed countries have, to solve all the problems connected with such structures,� he emphasized.
Moreover, he said, our codes for construction should also focus on the �don�ts��that is, what we should not do.
Generating awareness among the people on safe structures is very important and academics and people who matter in the administration should undertake the responsibility in this respect, he said.
Further, he said, our engineering colleges should send their students and teachers to study the impacts of earthquakes whenever and wherever they occur, to gather practical knowledge of such phenomena.
In this connection, he said that improvement in the State�s lifeline engineering is required to prepare the State for pre-disaster management, he maintained.
Improvement in lifeline engineering includes widening of the roads, improvement in the electrical installations and overground and underground structures etc. Without these, all post-disaster management efforts are bound to fail, said the renowned engineer.
He also laid stress on working out the population-hospital bed ratio taking into consideration the required infrastructure and accessible distance of such facilities.
It is also important to assess the safety of the hospital buildings and the subsequent steps to correct the defects, if there are any, in such structures.
Equally important is the improvement of the landline telephone network. As, the mobile phone towers located atop the multi-storey structures may develop problems under the impact of any major earthquake, he said.
Dr Sarma delivered a lecture on earthquake engineering in the city organised jointly by the Guwahati Chapter of Indian Society of Earthquake Technology and the Institution of Engineers, India, Assam State Centre.
