The document discusses the seismic risk and earthquake preparedness in Meghalaya, focusing on the frequency and potential magnitude of earthquakes in the region, particularly the likelihood of significant events greater than 8.0 on the Richter scale. It emphasizes the importance of compliance with earthquake-resistant construction codes and guidelines, along with the need for community awareness and capacity building among professionals involved in disaster management. The text also outlines various strategies and recommendations for enhancing structural safety and mitigating the impacts of potential earthquakes.

1. By
S.Ahmed
Faculty Head, DMC,
Meghalaya Administrative Training Institute

2.  We need to study :-
 Frequency of earthquakes in the region
 The probability of a particular magnitude of
earthquake occurring
 The Vulnerability of the area under
consideration

3.  “Our findings show that great earthquakes-
those with a magnitude of 8.2 or greater – can
re- rupture Himalayan regions that already have
ruptured in recent smaller earthquakes, or those
with a magnitude of 7.8 or below”.
 “The current conditions might trigger at least
four earthquakes greater than 8.0 magnitude,
but if they delay, the strain accumulated during
the centuries provokes more catastrophic mega
earthquakes.”

4.  “Moderate magnitude to great earthquakes in
the northeast India region is found to be
preceded, generally, by well defined
earthquake swarms and quiescence periods”
 Based on this, Dr. Gupta made specific
predictions in 1986- the 7.5 R magnitude
Indo-Myanmar earthquake which occurred in
1988

8.  The Probability of a Major Earthquake
is----?
 HIGH
 Magnitude?
 About 8 on the Richter Scale

9.  Disaster Risk
= Hazard X Vulnerability
 Vulnerability – Social, Economical, Physical,
Structural

11.  Magnitude of an earthquake is a measure of
the energy released at the focus
 Intensity is the effect caused by the
earthquake at a particular place
 Magnitude of earthquake is same no matter
which observatory measures it
 Intensity usually reduces with distance from
the epicentre

12. Magnitude
Intensity

13.  7R≈ IX MSK intensity earthquake, at
epicentral area;
 General panic among people, damage to
furniture, animals run to & fro in confusion
and cry;
 General damage to buildings occur, large
cracks in walls of R.C.C. buildings are seen;
chimneys break or fall off; and many stone
masonry houses collapse;
 Cracks of about 10 cm width are seen in the
ground; Landslides occur; old dry wells
become renewed and existing wells may dry
up

14.  General Destruction of buildings
 Gaps in walls, parts of many R.C.C. buildings
may collapse; Most of stone masonry houses
totally collapse;
 Critical damage to dykes & dams; severe
damage to bridges; underground pipes brake
 Cracks in the ground of width upto 1.0
metres may occur; Considerable landslides
possible; new lakes occur

15.  Intensity of Earthquake?
 It is unpredictable!
 Where will the Epicentre be?
 At what depth will the focus of the
earthquake be?
 What will the Vulnerability be then?!!

16.  According to a hazard map by the Global
Seismic Hazard Assessment Programme and
other scientific studies, the State can expect
to have a peak gravitational acceleration
(PGA) of 0.24g to 0.48g.
 The region where the highest PGA can be
expected is along the State's border with
Assam, the site of the Great Shillong
earthquake of 1897.

18. Intensity IX –
30,000 sq miles
Intensity X –
“Mexican – hat” of
11,000 sq miles
greatest intensity
mapped by Oldham

19.  Area of greatest earthquake intensity= 3.5
x size of Meghalaya
 Area of greatest earthquake intensity= 40 x
size of Shillong City
 Epicentral distance ≈100 km

20. In the Shillong plateau, the focal depth is mostly
within 60 km.
The prominent structural discontinuities in the
plateau are Dudhnai, Kulsi, Samin, Dawki and
Dhubri faults and Dapsi and Barapani thrusts.
Here earthquakes of upto MM intensity IX can be expected. In
this region earthquakes come with landslides, flood and along
with series of smaller magnitude earthquakes.

21.  Ground was fissured & sand vents spewed
fountains of sand
 Many Streams changed courses
 River Brahmaputra affected causing floods
 Bed of River Krishnai subsided and Lake
Dekachang formed (15km long x1.5 km)
 Landslides occurred- hills stripped of forest
for 30 km

22.  Vertical movement of 10m at Chedrang Fault
 Telegraph poles displaced by about 5 metres
 Many houses sank, due to liquefaction of soil
during earthquake, with roof only visible
 Geography changed
 TYPICAL DESCRIPTION OF INTENSITY XII

23.  INTENSITY IX may be adopted as the
minimum level of Risk
 Provided Vulnerability does not increase

25.  Risk is the expected loss, in terms of :
 Number of people who may die
 Number of people who may be affected
 Number of buildings/structures likely to
collapse
 Services likely to be disrupted
 Loss in monetary terms

26.  Risk = ∲ F, D, P, L, VV
 F – Frequency of disaster
 D- type of disaster
 P- Probability of occurrence
 L- Level of Disaster (Intensity)
 VV – Value of Vulnerable Elements
 L = ∲ ( V)
 V- Vulnerability of Elements that are affected

27. Stone Masonry structure

28. Stone Masonry structure

29. Stone Masonry structure

30. Stone Masonry structure

31.  Pictures are taken from the book “From
Residency to Raj Bhavan- History of the
Shillong Government House” by Imdad
Hussain,
 and published by Regency Publications,
20/36-G, Old Market, West Patel Nagar, New
Delhi 110008

33. Residence of Late Amjad Ali,
Laban, Shillong

34. Present Day All Saints Church

35. RAJ BHAVAN rebuilt in 1904

36. A Stone Masonry House in Sohra

37. 2001 Census

38. Bamboo- thatch houses

39. The Iing Sad at Smit, Meghalaya, constructed by
the King of Hima Khyriem, in 1928

40. Assam Type Houses

42. Well built
house in
tact
Pancake
collapse due
to poor
design &
construction

44.  All new construction to comply with
earthquake-resistant building codes and
revised town planning bye-laws, land use
zoning, Development Control Regulations &
building codes

45.  Central & State Govt. to implement & enforce
relevant standards for seismically safe design
and construction of buildings, bridges,
flyovers, ports and harbours, and other
lifeline and commercially important
structures
 Consider using incentives and disincentives,
and compliance reviews

46.  State Govt/SDMA will organise capacity
building programmes among professionals
and masons
 Faculty members in engineering &
architecture colleges, and polytechnics,
Industrial Training Institutes, will be provided
with adequate exposure

47.  State Govt. will incorporate earthquake –
resistant features in standard designs of
schools, primary health centres, anganwadi
centres and panchayat buildings
 These will serve as pilot projects

48.  Design of all new buildings and structures to
be scrutinised by competent authorities
before issuing building approval
 Third party audit of the design and
construction of major construction works to
be undertaken

49.  Develop inventory of existing built environment
 Assess vulnerability of these constructions
 Prioritise structures found vulnerable
 Develop seismic retrofitting measures
 Undertake construction work to strengthen
vulnerable structures

50.  Initial focus for structural safety audit &
retrofitting will be on Govt. & public bldgs.
 The State Govt./SDMA to take up selected
critical lifeline structures as pilot projects in a
phased manner
 The State Govt./SDMA in consultation with
their State Eq Management Committee &
Hazard Safety Cell review existing built
environment & prepare such lists

51.  Cluster approach to be adopted in priori-
tising – building types like RCC, stone
masonry,etc- primary schools, PHCs etc. – so
as to encourage consultations, demonstration
& possible replication.

52.  State Government Buildings
 Buildings of Central Government Offices/
Organisations
 Legislatures
 High Courts
 Cantonment
 Private Buildings

53.  Administrative & residential Government buildgs.
 Hospitals
 Schools
 Electric Power Plants
 Water Supply Works
 Telephone exchange
 Cinema Halls and Malls
 Libraries and Auditoriums
 Heritage Buildings
 Dams, Bridges, Bus Stations, Airports, etc

54.  Reinforced Cement Concrete (RCC) multi-
storeyed buildings
 Steel Structures
 Timber structures (Assam Type Buildings)
 Buildings with a Combination of RCC &
Timber
 Stone or brick masonry structures
 Houses of bamboo, tin sheets etc

55. Prioritization for Structural Safety Audit
1. Raj Bhavans, Legislatures, High Courts, State
Secretariats, Power Plants, Water Works,
Heritage Buildings
2. Schools & Colleges, and Hospitals
3. Reservoirs & dams, bridges, bus stations
4. Office of the D.C. & S.P.; Financial
Institutions
5.Multi-storeyed buildings with five or more
floors in residential apartments, office and
commercial complexes

56.  Rapid Visual Screening
 Detailed Vulnerability Assessment

57.  Detailed methodology for RVS for different
types of buildings and standardised
procedure for vulnerability assessment will be
prepared at the National level to clarify the
process and issues involved in seismic
retrofitting

58.  Techno-Legal Framework
1. BIS Guidelines for Seismic Vulnerability
Assessment of Structures – multi storeyed
R.C.C. Framed buildings, are rquired.
2. Rules & Regulations, Building Bye-Laws are
required incorporating these Guidelines

59.  A standardized procedure for vulnerability
assessment will be prepared at the national
level………………………in line with the
relevant national standards

60.  Adoption of Model Town Planning Bye- Law
by State Govt. by revising existing Acts &
Zoning Regulations, & Building Bye-Laws
 BIS will revise/update Codes in two years
 (i) IS: 1893(Part 2): Elevated and ground
supported Liquid Retaining Structures
 (ii) (Part 3) : Bridges & Retaining Walls
 (iii) IS: 4326: Earthquake Resistant Constn

61.  BIS will place in public domain including
internet for free download all IS related to
seismic safety
 Periodic revision in 5 years
 Design aspects to be addressed
 (i) Seismic evaluation and strengthening
(ii) Seismic design of tunnels
(iii) Seismic design of buried and above
ground pipelines

62.  (iv) Seismic design and ductile detailing of
bridge piers
 (v) Seismic design, construction and
manufacture of facilities, structures and
components related to electrical power
generation, transmission and distribution
 (vi) Seismic design and ductile detailing of
steel structures, etc

63.  Trained Professionals
1. Human Resource with competence in
Seismic Vulnerability Assessment of built
environment is required
2. Practical training by experienced firms in
actually assessing seismic safety of a
building can be given to professionals
3. Testing Equipments required

64.  Trained Professionals (Capacity Building)
1. Experienced and competent Professionals/
Organisations in the Govt. as well as in the
private sector are required
2. Capacity of existing professionals are to be
built up

65. 1. Different organisations and professional
bodies to be consulted to clarify process
and issues involved
2. Capacity of professionals to be developed
under National Earthquake Mitigation
Project??

66.  Techno-Financial Regime
1. Financial Loan for retrofitting/
strengthening of building with subsidy on
interest rate may be given
2. Refund of loan & interest may be treated in
same way as Housing Loan in Income Tax
Rules

67.  Techno-Legal Framework
 Rules & Regulations for declaring a building
as unsafe and for carrying out its demolition
are required
 District Disaster Management Authority
(DDMA) has powers under the D.M.Act, 2005,
to demolish structures hazardous to the
public; Rules may be framed.

68.  Trained Professionals
 Experienced and competent Professionals are
required for demolition without causing any
disaster.

69.  Techno-Financial Regime
 Rules & Regulations for providing temporary
accommodation or for giving financial help to
affected persons/families may be framed
 National Rehabilitation & Resettlement Policy,
2007, may be extended to cover such cases
or similar rules may be passed

71.  Rational Insurance Policies to cover different
structures exposed to different hazards are
required.
 NDMA Guidelines– The Insurance Sector will be
encouraged to promote risk transfer mechanisms
through insurance in the future
 Incentive to Insurers by way of deduction, of the
amount of premium paid, from Income Tax, may be
offered

72.  NDMA Guidelines– other structures will be
insured against losses during future
earthquakes, while undertaking seismic
retrofitting of critical and lifeline structures

73.  D.M.Act, 2005, stipulates creation of Disaster
Mitigation Fund by every State and each
District
 D.M. Plan needs to be mainstreamed with
development plan so that specific allocation
of funds are made for (i) disaster
preparedness, (ii) for mitigation measures,
including retrofitting

74.  State Govt. to make specific allocations for
carrying out disaster preparedness as well as
disaster mitigation measures, including
retrofitting of selected lifeline structures
 Corporate Sector may be asked to support
mitigation measures as PPP efforts and
Corporate Social Responsibility

75.  Housing development programmes supported
by the GoI and State Govts (like Indira Awas
Yojana) etc will be made to comply with
earthquake resistant design and construction
practices
 Disbursement of funds by banks to industrial
units will also be similarly linked to
compliance of safety norms

76.  State Govts to develop suitable bye-laws
 Local conditions to be considered
 State Govts to regulate all future
constructions to make them earthquake
resistant
 State Govts to issue specific illustrative
guidelines for each type of public building,
like panchayat offices, primary schools, etc

77.  Comprehensive awareness campaign on safe
practices to be followed before, during and
after an earthquake to be implemented
 Mobilise community to carry out earthquake
mitigation measures
 A handbook on earthquake safety will be
prepared

78.  Manual on structural safety audit of
infrastructure and lifeline buildings will be
prepared
 Translations into local languages to be
undertaken
 Video films to be prepared
 Handbook for seismic strengthening &
retrofitting of existing buildings to be prepared
 WHO WILL PREPARE?

79.  Electronic and print media will be used
 Different stakeholders like elected
representatives, civil servants, members of
local administration authorities, school
administrators, members of management
boards of educational institutions and
hospitals, school children, etc will be
targetted

80.  High quality education material will be developed
 Professionals to be equipped with requisite
knowledge & will undergo training programmes
 Special programmes for physically handicapped
and mentally challenged people, women and the
elderly will be developed
 DM to be introduced in school curricula, as well
at higher levels
 DM aspects of medical education at
undergraduate level to be introduced

81.  „all hazard‟ medical management plan to be
prepared
 Will address need to create greater awareness
in all medical teams and the medical
community of most frequent injuries, illness
and other health problems
 Trained Medical First Responders to be
identified

82.  All public health facilities will develop their
own DM plans
 Mobile hospitals and Quick Reaction Medical
Teams will be developed
 Trained trauma and psycho-social care teams
to be identified
 Medical & paramedical staff will carry out
regular exercise based on SOP

83.  Disaster Risk
 = Hazard X Vulnerability - Capacity