Seismicity studies for walled city, 08.06.04

Professor VS Ramamurthy

Secretary, DST, Technology Bhavan, New Mehrauli Road, New Delhi - 110016

Sub: Walled City imperatives – request for opinion / clarifications

Ref: Chandni Chowk houses won’t survive quake, The Hindustan Times, 31.05.04

As per the report under reference DST’s micro-zonisation study categorizes the Walled City as probable high-death-toll-zone, with 70 to 80 per cent of the buildings unlikely to survive an earthquake measuring 5 on Richter Scale. I seek DST opinion on the following questions:

1. Does high-death-toll probability not call for urgent mitigation measures and stopping other initiatives at least till criteria are set out for ensuring they do not increase this probability? I ask because Walled City ideas of last 2-3 years, ranging from small projects to ‘visions’ and proposals to modify laws, do not reflect the seriousness of the risk at all.
2. Does high-death-toll probability have anything to do with local geological factors? I ask because the news item makes reference to loose Yamuna soil and other features, I understand, also contribute to earthquake vulnerability / damage, such as pockets of chalk, pocket aquifers being depleted / collapsing, subterranean interferences, etc.
3. Does high-death-toll probability in the Walled City arise from buildings being more unsafe than in other parts of the city or from densities being several times higher? I ask because the news item suggests the former (in a manner consistent with ideas for redeveloping the Walled City after substantively modifying existing law that requires its conservation), while the statutory Delhi Master Plan (DMP) suggests the latter.

I also seek DST opinion on a basic question: would it suffice, for purpose of normalizing death-toll-probability, to shift manufacturing, wholesaling, warehousing, government, etc, uses (which account for large share of total use) and restore the traditional built form in the Walled City? I ask because DMP sets out de-densification as pre-requisite for other Walled City interventions – so that infrastructure inputs match desired use levels rather than ‘facilitate’ the overuse problem, heritage conservation initiatives have sufficient elbow room, etc – with ample space elsewhere for uses to be shifted. DMP statutory solutions for Walled City have remained elusive because of lack of will about the de-densification pre-requisite, though a few possibilities have now arisen from Supreme Court judgment for industries in the context of UPA NCMP. If DST has also identified de-densification as an imperative from earthquake safety perspective, the convergence of imperatives could become very useful.

I am enclosing an old paper that dwells on the de-densification imperative and I do look forward to hearing from you.

Yours sincerely

Gita Dewan Verma / Planner

B.Arch (SPA, gold medalist); M.Planning (SPA, gold medalist); PG Dip-Research (IHS-Rotterdam, top rank); Dip-Training (DoPT)

Formerly: Senior Fellow (HUDCO-HSMI), Visiting Faculty (SPA, TVB SHS), Consultant (DfID, IHSP, Nuffic, UNICEF, etc)

Currently: Independent researcher / writer and consultant to citizens’ groups synergising on Master Plan Implementation Support Group

Encl. as above, Inner City Renewal: Lessons from the Indian Experience, Habitat Intll 17(1), 1993

cc: (in cont. of correspondence re ground water, earthquake risk / heritage and DMP imperatives)

• Member Secretary, CGWA
• Secretary, Delhi Science Forum
• Head of Department of Conservation Architecture, School of Planning and Architecture