Study of Multihazard on urban habitats of India: A case study of Ahmedabad City
STUDY OF MULTIHAZARD ON URBAN HABITATS
OF INDIA: A CASE STUDY OF AHMEDABAD CITY
Nilesh S. Jha
Dr. R. K. Gajjar
“Applied multi risk mapping of natural disasters for impact
assessment” to develop a new approach to produce integrated multi
risk maps to achieve more effective spatial planning procedures in
areas prone to natural disasters in Europe by DSS.
Multi Hazard Mitigation Plan for Columbia County, covers each of the
major hazards that pose risks. The objective of mitigation is to reduce
negative impacts of Future Disasters on community.
“Disaster Prevention in Urban Environment” focuses on disaster
prevention policy in Netherland, implementation issues and gaps and
failure of local and national authorities’ preventative policies.
Comparisons are also made with the implementation of Strategic
“Multi Hazard risk assessment using GIS in urban areas: case study
of Costa” is based on formulating a digitized map for city and its
surrounding and based on historical information, a GIS database was
generated which was used for mapping multi hazards.
LITERATURE REVIEW CONT’D.
“Urban multi Hazard risk analysis using GIS and Remote sensing:
Case study of Kohima, Nagaland”, “presents a guideline for
preparing a multi hazard map by GIS and Remote Sensing
considering various building elements at risk and population at
risk is calculated but limited to landslides, earthquakes and fire.
Management/Evaluation of Urban Disaster Risk by Norio Okada
focuses on management. Research focuses on development of
methodologies for evaluation of UDR and effective utilization of
Promoting Safer Building Construction by V. Suresh lays
emphasis on need for evolution of safer habitat which can
respond and resist the loads, forces and effects due to natural
Risks influences and sustainable multi hazard design on built
environment by Razvan Oprita. In this paper approach has been
made for investigation of built environment affected by EQ, Flood,
Wind and Fire.
LITERATURE REVIEW CONT’D.
Quality of life, Sustainable Civil Infrastructure, and Sustainable
Development: Strategically Expanding Choice by Jamie
Montague Fischer and Adjo Amekudzi reviews the role of QOL
in civil infrastructure decision making.
Urban Runoff Mitigation by a Permeable Pavement System
over Impermeable Soils by Elizabeth A. Fassman and Samuel
Blackbourn suggests that Permeable pavements can mitigate
conventional large design storm flows, but care must be taken
during installation to ensure proper function.
Knowledge-Enabled Decision Support System for Routing
Urban Utilities by H. M. Osman and T. E. El - Diraby presents
a Web-based system for supporting the selection of the most
suitable routes for buried urban utilities. The aim of the
proposed system is to support (not make) decisions through a
collaborative semi automated environment.
LITERATURE REVIEW CONT’D…
Urban Hazard Mitigation: Creating Resilient Cities by David R.
Godschalk This research considers the relationship between
resilience and terrorism, and discusses why resilience is important
and how to apply its principles to physical and social elements of
Built Environment Hazards in Urban Habitats by Farzad Naeim &
Marshall Lew provides a basic understanding of major EQ
performance issues of importance worldwide. This paper
contributes to the critical understanding of issues and action to
reduce the damage caused by them during future EQ.
Structural and Non structural seismic vulnerability assessment for
schools & hospitals: case study in Central America and India by
D. H. Long, M. I. Verbicaro, Y. Singh, JSR Prasad, D. Wong Diaz,
M. Gutierrez has formulated a standardised questionnaire which
allow a priority ranking and identification of most vulnerable
features by advanced technology.
In most of the developed and developing countries
research has been conducted on hazards planning
and authorities take the effect of multi hazards for
planning of urban habitats.
Till date we have been conducting research generally
on a particular hazard in isolation but a hazard is
always coupled with other systems failure which
exacerbates the disaster. Eg. Bhuj EQ Utilities like
power failure, communication failure etc.
Evacuation procedures and routes required in case
of hazard for public buildings are not defined.
RESEARCH GAP CONT’D….
Urban hazard mitigation is not accounted for - during
the planning stage. e.g. Ahmedabad flash rains,
Mumbai bomb blasts.
Earthquakes are followed by fires but its effect is not
accounted during the planning stage of multi-storied
buildings in India. This effect of multi-hazard leads to
premature failures of multi-storied buildings.
Clear cut zoning guidelines are not formulated that
identify areas and localities within urban habitats
which may be subjected to hazards like faults, fire,
To study the effect of multi hazards i.e. earthquake and fire on
public multi-storied buildings and population affected in nearby
locality due to multi-hazard.
Formulation of multi hazard maps using Geographic Information
To study the existing practice (planning, design and
construction) followed by local body for earthquake and fire and
formulate a check list for existing limitations and disparity in
development for multi-storied buildings.
Formulation of guidelines for practicing engineers and
formulating road map for setting safety standard for multi-
storied buildings for hazards like earthquake and fire.
Multi-storied public buildings of Ahmedabad city are
taken as case study and are mapped in GIS by finding
locational details by GPS.
GIS maps for earthquake hazard are created for multi-
storied buildings considering various parameters like soil
profile, N – value, shear velocity (Vs), fault lines,
lineaments, ground water table and zoning guidelines.
Fire hazard map for buildings are developed considering
underground pipelines of water and gas, historic fire call
record, household units, road networks, location of fire
station and CNG stations, industrial estates and
Effect of earthquake is studied on multi-storied buildings
and only those buildings that are vulnerable to
earthquake are further analyzed for hazard of fire.
Mitigation strategies existing for the hazard of earthquake
and fire specifically for multi-storied buildings are studied
in developed countries like US and Europe.
Existing practices adopted by local authority like
Municipal Corporation and urban authority for the hazard
of earthquake and fire for buildings.
Study and comment on design features for earthquake
resistance and fire safety measures of selected buildings.
Are the multi-storied buildings in India safe from
the effect of multi-hazards such as earthquake and
A primary survey has been conducted within the
city limits of Ahmedabad City wherein data is
collected for desired parameters of Earthquake
Respective Maps for the hazard of earthquake is
formulated in Geographical Information System
Qualitative information is converted into
quantitative data based on experience and
consultation with professionals, academicians
and experts of the subject and a table of values,
METHODOLOGY CONT’D ….
Location details of the buildings under study are
generated by GPS and fed in GIS.
Similar methodology as mentioned in steps 1 to
3 is adopted for generation of hazard map for
The methodology adopted is not experimental
and techniques adopted are both qualitative and
ABOUT AHMEDABAD CITY
The city limit extents to the area of @ 464 sq. km.
The entire city is distributed into Six Zones for
Administration purpose which is further sub divided
into various election wards based on population.
As of date, City is divided into 64 wards
Total population within the city is @ 45.0 lac
As per the records of AMC, there are as many as
12.91 lac Residential Buildings and 3.96 lac Non
Residential Buildings = 16.87 lac Total Bldgs.
City has @ 622 Govt. & Semi Govt. Buildings
From the tax bills of Corporation, 76
Government Multi-storied Buildings
have been identified and is
considered for study purpose
The exact location of these buildings
along with the height above GL have
been found by GPS.
Based on the parameters like;
Fault lines and Lineaments
Land Use or Zoning Guidelines of AMC or AUDA
N – Value
Shear Value (Vs)
Ground Water Table depth below the surface
And Depending on the severity of the above
parameters on buildings during earthquake,
some weightage is given
Parameters A = 20.0 B = 15.0 C = 10.0 D = 5.0
N - Value 1 - 8.0 8.1 - 15.0 15.1 - 22.0 > 22.0
Type of Soil CI/MI CL/ML SM SC
Ground Water Table
(m) 1 - 8.0 8.1 - 12.0 12.1 - 18.0 > 18.0
Shear Velocity Vs
(m/sec) 139.0 - 173.5 173.6 - 208.0 208.1 - 242.6 > 242.6
Land Use Regulation
City / Central
Zone (1/2/3) Others
for Faults (m)
Within 150.0 m
- 200.0 m
200.1 - 225.0
for Lineaments (m)
Within 50.0 m
Between 50.1 -
75.1 - 100.0
A refers to Extremely High Risk
B Refers to High Risk
C Refers to Moderate Risk
D Refers to Low Risk
DETAILS OF RISK RANKING CALCULATION
Finally, Five Buildings
L. G. Hostel Block
Sales Tax Bhavan
Have been identified as Vulnerable to Earthquake based
on the above parameters.
M. S. Building - Vastrapur (New) is also taken into
consideration for calculation of Risk as it is newly
constructed building with sensors and smoke detectors.
Apna Bazar located in the heart of city is also studied as
population density is maximum in that locality.
DATA COLLECTED FOR EQ FOR SPECIFIC BUILDING
..BISAGDetails of BldgBuilding Details.xlsx
Sources of Fire due to Earthquake
Electric Short Circuit
FIRE HAZARD MAP FORMULATION
Historic data of last 7 years of the entire city related
to the events of fire.
Gas pipe line details and network of the entire city
Locations of the nearest fire stations
Population density of the area
Location of the Industrial areas which are more
Water pipeline distribution network
Zoning regulations of AUDA
Historic data has been collected from
Ahmedabad Municipal Corporation (AMC)
Past 7 years data of Fire Call
Data is sorted Ward wise (64) based on the
Address of Call and the outcome is ….
..FireFire Details Locality.xlsx
WATER PIPELINE DETAILS
Pipeline network of the entire
Ahmedabad City has also been digitized
for the possibility of liquefaction in case
of EQ Hazard
MAP OF ONE OF THE SAMPLE BUILDING (APNA BAZAR)
RISK CALCULATION FOR VARIOUS PARAMETERS FOR FIRE
Parameters High Risk Moderate Risk Low Risk
Gas Pipe line Area &
Water Trunk main Area ≥ 100% 99.9 % – 50 % < 50%
Population ≥ 50000 49999 - 25000 < 25000
Household ≥ 20000 19999 - 10000 < 10000
Historical Incident data
(Fire Call) ≥ 100 99 – 50 < 50
River < 10% 10 % - 19.9 % ≥ 20%
Road Other District Road MDR
Fire Station ≥ 8.0 KM 4 – 7.9 KM < 4. 0 KM
GIDC / Major Industries
GIDC Outskirts GIDC ≥ 1.0 KM from GIDC
TABLE SHOWING RISK ASSESSMENT AND RANKING
Pipe Total Popln.
Distn. Pop_Dis HH_Dis
Bullding 314 52 80 132 95000 100
0 7 42 279 113 106918 24760 2
Building 314 43 0 43 77000 150
0 0 14 1265 25 19113 3475 5
Bhavan 314 0 66 66 60000 80
0 17 21 209 150 90144 18029 3
Bhavan 314 48 51 99 50000 80
0 21 32 716 44 21927 4385 4
Bazar 314 0 70 70 110340 78
2 20 22 212 148 163428 20072 1
Further survey of those buildings that are found
vulnerable to EQ have also been conducted for
hazard of Fire. (Building Specific)
For Fire Hazard;
Height of Each Floor
Approach to Road
Distance of Building from Fire Station
Distance between adjacent buildings
Availability of open space
No. of Exit in given Building
Provision of fire safety
Whether fire fighting equipment installed ?
Provision of Pantry?
Fuel used in Pantry
Gas pipeline in vicinity
Population likely to be affected
No. of potential users of building
RISK ASSESSMENT BASED ON INTERNAL PARAMETERS (BUILDING SPECIFIC)
..BISAGDetails of BldgBuilding Details.xlsx
622 Government buildings were identified in Ahmedabad
City through GPS out of which 76 multi-storied buildings
were study building. Analysis of these study buildings
based on various parameters considering earthquake as
base hazard in GIS environment leads to 5 buildings
vulnerable with risk ranking more than 60 % (Value 90 or
After generation of fire map in GIS based on related
parameters and further analysis of these 5 sample
buildings, population at risk is maximum (1.60 lacs) in the
radius of 1 km for Apna Bazar (one of the sample
CONCLUSION CONT’D ….
During the planning phase of multi-storied building for the cases
in which earthquake load is governing criteria as per codal
provisions, as earthquakes are followed by fires, in case of multi-
storied buildings load combination of earthquake and fire gives
worst combination. This is not addressed in IS codes. This needs
appropriate attention in design.
Multi-hazard map formulated for the city of Ahmedabad can be
used by local authorities by mentioning latitude and longitude of
the said location where the building is to be constructed, in GIS.
Once this is done, all the discussed external parameters for the
hazard of earthquake and fire can be assessed immediately. The
related risk ranking can be calculated and population at risk can
be known within 1 km radius buffer created. The procedure can
be adopted for old and new buildings.
Newly constructed multi-storied public buildings are
designed as earthquake resistant and further fire fighting
equipment, smoke detectors and automatic devices such
as sprinklers are also installed. However periodic
checking/operation and services are lacking. In case of
emergency, for the operation of fire fighting equipment
and sprinklers, skilled and trained person is required
hence basic equipment operation training should be
given to the permanent users of the building. Mock drills
should also be organised at regular intervals