Dr. D.R. Kapoor
Jammu, situated in the Outer Himalayan belt, falls in Zone IV. Around Jammu there are four tectonic breaks i.e., Panjal Trust (PT); Murree Thrust (MT); Main Boundary Fault (MBF) and Himalayan Frontal Fault (HFF). Presence of these tectonic breaks in the north and south of Jammu make the region vulnerable to earthquakes.
Keeping in view the nature of litho logical character of an area, 4 zones of ground with respect to vibration amplification of earthquake waves in sediments have been identified.
Zone-1: Recent Muds – Most Unstable Zone-3: Thin Drift Cover – Slightly Stable
Zone-2 : Thick Drift Cover – Unstable Zone 4: Bedrock Outcrop – Relatively stable
Old Jammu city Area: The old city of Jammu is situated on Boulder Conglomerate Formation (approximately 2, 20,000 to 17,20,000 years old) consisting of spherical to ellipsoidal boulders embedded in loose clay, sand, pebbles and gravel.
Critical Points: The lithology is susceptible to readjustments due to seismic activity.
* Raghunath Bazaar and Kanak Mandi are commercial areas. Ornamental appendages and faulty alignments of structures would not stand the quakes.
* Constructions on slopes near the new road (Thandi Sarak) areas in and around Peer-kho and adjoining areas are highly susceptible to destruction with minor quake.
* In this area, haphazardly and unplanned buildings have come up.
* There are highly unconsolidated, non-rigid, non-resistant risk areas.
* In case of any eventuality, narrow lanes, irregular and unplanned construction would Choke all escape routes.
The damage/destruction is likely to be maximum and rescue works would be almost impossible to execute. Rapid evacuation may involve more causalities than eventual earthquake damage.
Talab Tillo and Adjoining Areas: Lithologically these areas consist of boulder bed (sand/clay/boulders/gravel/pebbles etc) overlain by a 2 to 3 meters thick soil cover. Soil cover acts as buffer zone between the engineering structures and the underlying boulder bed.
Critical Points : The soil horizon of this area holds good amount of water content (vadose zone) which reduces its capacity to withstand the load of heavy engineering structures.
* The soft soil does not dampen ground vibrations but amplify them as seismic waves pass beneath them.
* Some sediment in these areas has the potential to liquefy or behave more like liquids than soils during intense ground shaking.
* Structures on wet soil suffer much worse earthquake damage than those on bedrocks.
* Narrow lanes and by-lanes would hamper the rescue work.
* In some parts of these areas the traffic movement for rescue operation would be impossible.
There will be a massive loss of human lives and property in case of seismic activity.
Gandhi Nagar, Trikuta Nagar, Channi Himmat, Sidhra, Bathandi, Greater Kailash and Sainik Colony Areas
* Critical Points: These areas are in part lithologically similar to old city area.
* Boulder bed is covered by average thickness of soil.
* There is much less amount of wetness as compared to Talab Tillo area.
* The threat of earthquake is as large as elsewhere in the region.
* The rescue work will be comparatively easier as compared to other areas.
* These are planned colonies. Network of roads and connectivity will major plus point in the rescue operation. However, buildings have not been constructed as per shock proof design.
Disaster Management Preparedness
* All dilapidated buildings should be identified and to be cleared especially in old city areas;
* Structural design should have appropriate safeguards for earthquake;
* Construction in vulnerable should be strictly according to approved plan and encroachment of lane and drains should not be allowed;
* Construction on sloppy (more than 50 degree) land should not be approved for construction;
* Construction on wetland should be restricted keeping in view opinion of the structural engineer;
* Emergency management plans and procedures should include the identification of appropriately trained staff members responsible for decision-making when an emergency occurs.
* Training plans should include internal people, contractors and civil protection partners, and should state the nature and frequency of training and testing.
* Testing of a plan’s effectiveness should occur regularly.
* Pre-planning of communications is critical. Miscommunication can easily result in emergency events escalating unnecessarily.
* The steps necessary should be prioritised to ensure critical functions are operational as soon as possible
* A comprehensive assessment evaluating the level of impact and its financial implications should be undertaken.
* Intra-and inter-organizational coordination between organizations, from organizations to the public, from the public to organizations, and within systems of organizations should be streamlined.
(The author is former KAS Officer)
Follow our WhatsApp channel
