Training Module-II

NATURAL DISASTERS Preparedness, Mitigation and Management

‘Building a safer and prosperous Sikkim’

Disaster Management Faculty, Sikkim

G. B. Pant Institute of Himalayan Environment & Development

Sikkim Unit, Pangthang (Gangtok)

in collaborative with

Supported by

Land Revenue and Disaster Management Department, Govt. of Sikkim

National Disaster Management Division, Ministry of Home Affairs, Govt. of India

Training Module-II

NATURAL DISASTERS: Preparedness, Mitigation and Management

'Building a safer and prosperous Sikkim'

Compiled ByVarun Joshi

Ashok Kumar SharmaKireet Kumar

For Further Details Contact

Disaster Management Faculty

G.B. Pant Institute of Himalayan Environment & Development

Sikkim Unit, Post Box-24, Gangtok, East Sikkim-737 101

Phone: (03592) 237189, 237328, Fax: 237415

Published byG.B. Pant Institute of Himalayan Environment & DevelopmentKosi-Katarmal, Almora - 263 643, UA, INDIAPhone : 05962-241041/ 241154, Fax : 05952-241150/ 241014

Natural Disasters: Preparedness, Mitigation and Management© G.B. Pant Institute of Himalayan Environment & Development, 2007

Designed and Printed at:Venus Printers and PublishersB-62/8, Naraina Industrial Area, Phase-II, New Delhi-110 028Tel. : 91-11-25891449, 25815063, Mob. : 9810089097, 20274098E-mail : pawannanda2000@yahoo.co.in; pawannanda@gmail.com

Foreword

The dwellers of the Himalayan region are encountering many natural hazards. Earthquake,

landslide, cloud burst, flash floods, high intensity rainfall, floods, forest fire and avalanches are

the common natural disasters that have been occurring and causing tragedies, specially in

populated areas of the Himalayan region. In order to minimize losses through concerted

international actions, the United Nations observed the last decade of the Millennium i.e. 1990-

2000 as the International Decade of Natural Disaster Reduction (IDNDR). Formulation of

natural disaster mitigation programme, optimal land use and provision of insurance for disaster

integrated with developmental programme of all the nations, particularly the developing

countries, are some of the major thrust areas spelled out in IDNDR. A switch from post-disaster

life management programme to preparedness, mitigation and management has become the new

focus. Awareness generation through training, mass media, education, strengthening the

government support and early warning system are the key areas of the programme.

In a populous country like ours, people will have to live in disaster prone areas, therefore

ways and means need to be evolved to protect their lives to ensure that their social and economic

activities are not adversely affected. While making efforts to further strengthen the disaster

preparedness, the disaster management strategy should focus on building mitigation content into

the overall development plans for minimization of the impact of disasters. Knowledge on

construction of earthquake resistant buildings, landslide stabilization, appropriate planning of

transport network, fire control systems and proper land use methods can also reduce the physical

vulnerability to a great extent.

As elsewhere in the Himalayan region, Sikkim state is also highly vulnerable to mountain

specific disasters like earthquakes, landslides, cloud burst and flash flood, etc. Preparation for

any form of natural disaster is the foremost need of the region. This publication is a compilation

of information related to natural disaster preparedness and mitigation. It is hoped that, with due

reasoning and application, this training module will be very helpful to a range of stakeholders

working at various levels in the management of the natural calamities in Sikkim state and other

parts of the Himalaya.

I wish to place on record deep sense of appreciation to my colleagues who have compiled

this publication.

(Uppeandra Dhar)Director

Acknowledgements

This training module is the outcome of compilation of Resource Material for Natural Disaster

Mitigation and Preparedness by Ministry of Home Affairs (Govt. of India), other

agencies/organizations working on same line and the experience and informations gained during the

trainings/field work carried out in different phases in the state also incorporated. We gratefully

acknowledge the support, encouragement and guidance of Dr. Uppeandra Dhar, Director, G.B. Pant

Institute of Himalayan Environment and Development, Kosi-Katarmal, Almora in preparing this

training modules. Thanks are also due to Drs. A. P. Krishna, H. K. Badola, K. K. Singh, Y.K. Rai, Shri

R.Joshi, L.K. Rai, R. K. Das, J.N. Dhakal, P.K. Tamang and other staff member of Sikkim Unit for

their scientific and technical help at various levels. Disaster Management Division, Ministry of

Home Affairs (Govt. of India) is acknowledged for financial support to Disaster Management

Faculty Sikkim and Land Revenue and Disaster Management Department, Govt. of Sikkim to

facilitate the programmes in the state.

Foreword i

Acknowledgments iii

Introduction 1

Earthquake: Mitigation and Preparedness 7

Landslide: Mitigation and Preparedness 23

Flood: Mitigation and Preparedness 35

Forest Fire: Mitigation and Preparedness 47

Avalanche: Mitigation and Preparedness 56

Bibliography 63

Contents

1

2

3

4

5

6

Introduction

Sikkim, the small but beautiful state in year 1976 acceded to Indian Union as 22nd state. It is situated

in the Eastern Himalayan region extending around 114 km from North to South and 64 km. from East 0 0

to West, having a total geographical area 7096 sq. km. The State is situated between 27 04' to 28 07' 0 0

North latitudes and 88 01'to 88 55' East longitudes. Nepal bound the state in the west, vast stretches

of the Tibetan plateau, in the north, Bhutan and Chumbi valley of Tibet in the east and Darjeeling

district of West Bengal along the southern boundary. Teesta and Rangit, which originates

respectively, from Cholamu Lake (Zemu Glacier) and Rathong Glacier, are the two major rivers of

the state.

Location map of Sikkim

1

11

SIKKIM AT A GLANCE Total area 7096 sq.km.

2

Khangchendzonga/Kangchenjunga is the third highest mountain in the world with an altitude of

8,586 / 8,598 metres is located in the Sikkim - Nepal border as part of the Himalayan mountain

range. The huge third highest mountain in the world derived its name from the Tibetan words'

Kanchen' and 'Dzonga' mean “five treasuries of the great snow”. The five peaks of Kangchenjunga

are the five Treasures of the Eternal Snow, a belief beautifully interpreted by the great Lama Lhatsun

Chenpo: “The peak most conspicuously gilded by the rising sun is the treasury of gold, the peak that

remains in cold grey shade is the storehouse for silver and other peaks are vaults for gems, grains and

the holy books”. The people of Sikkim regard “Kanchenjunga as their Gardien Deity”. Glimpse of

the peak from various locations is the main attraction of tourist in the state.

Profile of land elevation of Sikkim

Rainfall

Mean annual rainfall varies from 2000 mm

to 5000 mm with intensity ranging from

drizzling to torrential rain. Rainfall is heavy

and well distributed from May to September

during which July is the month in most of

places. North-West Sikkim gets very little

rainfall. This area has mostly snow -covered

mountains. It is generally low rainfall in the

months November to February. Rainfall

pattern is basically monsoonal. Due to the

wide variation of sharp edged mountains

present through out the State, there is a large

variation of rainfall. Some part of south

district is under rain shadow zone.

ClimateThe climate of the state varies generally from sub-tropical to alpine depending upon the elevation of the place. Within the same catchment watershed of a stream, sub-tropical or even tropical climate is often observed at the lower end watershed in the valley, while temperate climate prevails in the upper reaches of the stream (widerange of elevation is shorter distance). Climatically, Sikkim experiences change-able temperature with summer in the foothills and freezing winter on the high mountains. For most of the period in a year, the climate is cold and humid as rainfall happens in every month. The area experiences heavy rainfall due to its nearness to the Bay of Bengal.

Type of Land Level of Elevation

Lower Hills Altitude ranging from 270 m to 1500 m

Mid Hills Altitude ranging from 1500 m to 2000 m

Higher Hills Altitude ranging from 2000 m to 3000 m

Alpine Zone Altitude above 3900 m

Snow Bound LandVery High Mountains without vegetation and with Perpetual Snow cover up to 8580 m

3

Temperature

Temperature varies with altitude and slope

aspects - it generally decreases with

increases in altitude. The maximum

temperature is recorded generally during

July and August and minimum during

December and January. Maximum summer o o

temperature goes up to 24 C, minimum 13o

C and winter maximum temperature 10 C, o

minimum 2 C. Fog is a general feature in the

whole state from May to September and

sometimes in winter. Snowfall is common

in high altitude areas during winter.

Population

The population of Sikkim included three

main groups of people i.e. the Lepchas,

Bhutias and Nepalese, makes 75% of the

population. The total population of Sikkim

State 540,851 as per the Census of India

2001. District wise population of the state

North 41030, East 245040, West 123256

and South 131525. Sikkim's population

predominated by Nepalese origin people.

The minority groups are Bhutias, Lepchas

and Limbus. The overall density of

population in the state is 76 per sq. km.

Geology

The geological setup and stratigraphic position of the rock unit of Sikkim Himalayas are still

under academic debate, evaluation and re-evaluation, because of tectonic complexity,

polyphase metamorphism and unfossiliferous nature of most of the litho-units. The geological

formations from South to North are disposed in a reveres tectonic order.

The state is mostly covered Precambrian metamorphites of low to medium grade (Daling

Group), high grade gneisses (Darjeeling Gneiss and Kanchendzonga Gneiss), Chungthang

Formation (quartzite, calc-silicate rocks, marbles, graphite schist's and occasionally

amphibolites) with intrusive granites (Lingtse granite gneiss) and Phanerezoic rocks including

Gondwana and Tethyan sedimentaries. The Paleozoic and Mesozoic (Tethyan) sequence in the

northern and north-western part of Sikkim are fossileferous.

The Gondwana super Group consist of sandstone, shale and carbonaceous shale with

occasional thin bands of coal and pebbly shale horizon.

Daling group of rocks can be classified into three formations:

a. Gorubathan Formation: characterized by quartz-chloride-sericite sehists, phyllite and

quartzite's.

b. Reyang Formation: characterized by quartzite's (occasionally calcareous), phyllite

interbanded with carbonaceous slate.

c. Buxa Formation: characterized by presence of dolomitic limestone occasionally

interbanded with phyllite and development of organo sedimentary structure

(stromatolites).

4

The Kanchendzonga Gneiss comprises mainly high-grade gneiss The Chungthang gneiss is a

quartz-biotite gneiss .A streaky sheared granite gneiss known as “Lingtse Gneiss” occur as a

NE-SW to N-S trending strip of rocks and forms a general line of separation between the Daling

and high grade Kanchendzonga Gneiss. The Tethyan sedimentaries, exposed in the northern

part of Sikkim represent Everest Phyllite series (shale's/phyllite), Mount Everest Limestone

series, Lachi Formation (conglomerate with thick diamictite base) and Tso Lhamo Formation

(calcareous shale, limestone band, calcareous sandstone).

Geological map of Sikkim (Source: GSI, Sikkim Centre, Gangtok)

5

Landuse

Sikkim is well known for its rich

biodiversity. The vegetation consisting of

broad and coniferous evergreen trees,

grasses, and bushes extends up to 4000m

MSL only. At elevations above 5000 m MSL

hardly any vegetation is found. Distribution

pattern of natural vegetation in the State

may be divided into 5 mixed forest zones.

F Lower Hill Forest (<900m): It consists

of three main types viz. sal forest, dry

mixed forest and wet forest. Teesta and

Rangit valleys are rich in sal forest

Pakasaj, Lampatey, Simul, Chilawne,

Lali are some of the important associate

species.

F Middle Hill Forest (900-1800 m): This

range of elevation is dominated by trees

like Musre Katus and Dalne Katus.

Walnut is also noticed.

F Upper Hill Forest (1800-2450 m):

Species like Mawa, Rani Champ etc. are

common at this elevation.

F Rhododendron and Oak Forest (2450-

3350 m): At this elevation, the main

trees are Book, Sunguray Katus mostly

mixed with Kapasay, Rhodonendron

etc. 36 species of Rhododendron

(Guras) (highest in India) occupies the

middle storey in the entire conifer forest

of Sikkim.

F Conifer Forest (>3350 m): The

distribution of conifer forest is

dependent on precipitation. Most

conifers are found in the low rainfall

zone of North district.

F Alpine Pastures: It comprises of dwarf

junifers and Rhododendron, exclusive

grassy meadow with Dischampsia sp.

caespitosa, Salix silkkimonses, Roscoea

sp. etc.

Sunrise, Kangchenjunga

Cold desert, North Sikkim

Rhododendron maddeni Rhododendron decipiens

6

2Earthquake: Earthquakes are considered to be one of the most disastrous natural hazards

causing colossal loss of life and property within fraction of time. The beginning of this

occurrence is usually sudden with little or no warning. It is a sudden shift of the earth's crust blow

or at the surface that results in ground vibration and the potential collapse of buildings and

possible destruction of life and property, if the quake is of sufficient magnitude. Earthquakes are

considered to be one of the most disastrous phenomenon. It is not yet possible to predict

earthquakes and to make preparation against damages, collapse of buildings and other man

made structures.

Earthquake: Mitigation and Preparedness

Causes of Earthquake: Earthquakes are

caused by natural tectonic interactions

within the earth's crust and it is a global

phenomena. May arise either due to the

release of energy from strained rock inside

the Earth or tectonic movements or volcanic

activity. The sudden release of accumulated

energy or stresses inside the earth or sudden

movement of massive land areas on the

earth's surface cause tremors, commonly

called earthquakes.

Earthquake Hazards in India

History of earthquake in India is since time immorial. About 80% of the population and 56% of

the total area (Zone-V- 12%,-IV-18%, III-25%, II-45%) of our country is in the high or moderate

seismic risk zone. The country is divided into five zones on the basis of seismicity. About half of

India's total area of 3.3 million sq. km falls in the seismic zone. This is even higher than the

seismic areas of Japan and California (USA) put together. The most earthquake prone areas

belong to the Himalayan belt in the northern region from Kashmir to Arunachal Pradesh in the

east, the earthquake prone areas are all eight state on NE region, Uttarakhand, Gujrat, H.P, J&K,

part of Bihar-Nepal border and Kutch region.

7

Main Seismic Regions of India

D Kashmir and Western Himalayas

D Central Himalayas

D Northeast India including Sikkim

D Indo Gangetic Basin and Rajasthan

D Cambay and Rann of Kutch

D Peninsular India including Islands of

Lakshadweep

D The Andaman and Nicobar Islands

Impact and Effects of Earthquake

Disasters

F Loss of Life

F Injury

F Damage to and Devastation of Property

F Damage to and Devastation of Sub-

sistence and Cash Crops

F Devastation of Production

F Devastation of Lifestyle

F Loss of Livelihood

F Disruption to Essential Services

F Damage to National Infrastructure and

Disruption to Administrative and

Organization Systems

F National Economic Loss

F Sociological and Psychological after-

effects

F Liquefaction failures and Landslides

F Spread of Epidemics

Earthquake Hazard Zoning Map of IndiaSource: BMTPC

House Census of India, 1991

20 May 2007 Earthquake damage TashidingMonastery, Sikkim

14 February 2006 Earthquake - Sikkim

State

Andman and NicobarMizoramArunachal PradeshMeghalayaNagalandAssamSikkimManipurTripura

House (in %)Earthquake Safe

97.4 97.0 93.8 91.7 86.7 84.1 78.7 66.6 50.5

8

Earthquake Disaster Mitigation in India

Ministry of Home Affairs, Government of India, is responsible for providing help at the time

of emergency. The Government helps the population in distress due to any natural calamity

through relief and rehabilitation programs, loans and subsidies. The respective state

government coordinates the Disaster Management programme. A number of Voluntary

Agencies also come forward in a big way during emergency situations in a district. The District

Collector coordinates their efforts in a most suitable manner.

Earthquake Mitigation

F Follow Building codes.

F Enforcement of Compliance with codes Requirements and Encouragement of Higher

Standards of Construction quality.

F More Emphasis should be given to Engineering of Structures to withstand vibration forces.

High Standard of Engineering design of all Public Buildings (Hotels, Schools and Hospitals

etc.).

F Reduce Population/Construction Densities in High Seismic Zones.

F Strengthening of Existing Buildings, Monuments in the vulnerable areas.

F Encouraging Insurance.

F Community Participation in Constructing Safe Houses from Seismic forces, Creating

Awareness of What to do and What not to do at the time of Earthquake.

F Community Action Groups in Fire-Fighting, First-Aid and Rescue Operation, and Regular

Earthquake Mock Drills in the area.

Measures for Earthquake Risk Reduction

Earthquakes strike without warning and cause widespread damage to various man-made

structures and systems. These can neither be prevented in terms of their magnitude, place and

time of occurrence. Therefore, the most effective measures of risk reduction are pre-disaster

mitigation, preparedness and preventive measures for reducing the vulnerability of the built

environment and expeditious effective rescue and relief actions immediately after the

occurrence of an earthquake. The main purpose of earthquake disaster management is to

mitigate sufferer as well as to find out their causes and solutions.

9

Earthquake in Sikkim

All districts of the state of Sikkim lies in

Zone- IV. The earthquake happenings in this

region are due to the movement of Indian

plate pitching (thrusting) under the Eurasian

plate. The state is mountainous and

underlain by some major thrust/ regional

faults. Most important are the Main

Boundary Thrust (MBT), the Main Central

Thrust (MCT) and the Himalayan Frontal

Thrust (HFT).

- Indo-Nepal Border

region, Moment Magnitude-8.0, time -

14:21:25 IST / 08:43:25 UTC, 26.50

North, 86.50 East Nearly 10,500 people

were killed in Bihar and Nepal. Damage

was also reported from many places in

Sikkim.

- West of Gangtok

(Indo-Nepal Border region), 6.1 (TS)

time-13:32:24 UTC, 27.60 North- 88.00

East.

- Near Gangtok

(Sikkim-West Bengal Border region),

6.1 Surface Wave Magnitude, time-

19:00:46.9 UTC, 27.39 North-88.75 East

17 kms depth. Eight people were injured

in Gangtok and minor damage also

reported from the city. The quake was

also felt in eastern and north-eastern

India, Bangladesh, Bhutan and Nepal.

Major Earthquakes in Sikkim

G 15 January 1934

G 12 January 1965

G November 1980

G 21 August 1988

G 14 February 2006

G 31 December 2006

G 20 May 2007

- Udaipur Gahri, Nepal

(Indo-Nepal Border region), Moment

M a g n i t u d e - 6 . 8 ( N E I C ) t i m e -

23:09:09 UTC / 04:39:09 IST, 26.755

North - 86.616 East. Nearly 900 people

were killed in the border districts of

Nepal and Bihar, India. Damage was also

reported from Kathmandu and Sikkim.

Felt in Northern and Eastern State of

India and most of the part of Nepal.

North Sikkim,

Moment Magnitude-5.3, 27.377 North -

88.362 East, Depth: 20.1 kms, Origin

Time - 00:55:23 UTC, 06:25 IST. mode-

rate earthquake hit Sikkim Himalayas

ensuing two deaths and minor damage to

property in Sikkim. Two Indian Army

soldiers were killed, when traveling a

vehicle hited by a rock fall at Sherathang

near the border outpost at Nathu-La. Two

people were injured in East Sikkim by

this earthquake.

An earthquake of low

moderate intensity 2.1, local time- 12.49

P.M.

- Moderate intensity 5.0,

West Sikkim, 17:48 hrs (IST). Damage to

Tashiding Monastery. Two more tremours

thmeasuring 4 and 4.6 recorded on 16 and

th18 May 2007, respectively. No causality

reported.

-

-

10

Earthquake Preparedness

Disaster Preparedness helps people in coping with disaster situation. Pre-disaster preparedness

should also be maintained taking in account likely damage scenario in probable earthquake

occurrences and estimate of extent of efforts required. In the fight against devastation, some tools to

handle earthquake disaster more effectively are as follows:

Planning Measures

This involves demarcation of potential risk

as high risk and low risk areas, taking into

consideration population densities, econo-

mic importance, strategic needs, etc;

determination of local seismicity by micro-

seismicity techniques; planning new

settlement and colonies according to

earthquake safety principles.

Earthquake Catalogues and Seismic

Zoning Maps

Geological Survey of India studies

earthquake damages. Indian Meteoro-

logical Agency operates seismic instru-

ments. National Geophysical Research

Institute studies the cause of earthquake.

And the Bureau of Indian Standards has

released the seismic zoning map of India.

Earthquake Resistant Design

Earthquake resistant structure must be

designed and constructed in earthquake

prone zone; codal provisions must be

implemented/Denforced new construc-

tions. Vulnerability atlas and hazard maps

must be studied carefully as it shows geo-

tectonic characteristics, soil and bedrock

conditions which will determine the

behavior of the building during the

earthquake. Public should be informed

through mass media and demonstrations

regarding simple and economical

resistance features for their otherwise

traditional constructions.

11

Education and Training

Vulnerability can be reduced to a great extent

through appropriate awareness through

education and training of the whole

community. Research and development

work, education and training in the institute

of higher learning must be carried out.

Earthquake engineering subject must be

included in the curricula of engineering

colleges. The Police Force, Fire Services,

Civil, Defence, Home Guard and selected key

members of the public shall be trained

regularly and in case of necessity, their

services may be requisitioned at short notice.

? Training is the most appropriate and

effective tool for preparing people to

cope with disasters to mitigate and create

awareness.

? Training enhances the skill of the

personal to cope up at the time of

disasters.

? All citizens to be trained, frequent mock

drills would help in fighting disaster.

? The district administration according to

its vulnerability has to impart training to

the people and officials.

? School wise awareness through training

on First-Aid, Do's/Don'ts on disaster

safety culture to be conducted.

12

Research

Research work is to be carried out for

developing and implementing engineering

intervention and improving regulatory

mechanism, developing instrumentation

for hazard monitoring, forecasting, early

warning, etc. Research must be carried out

for sesmic micro-zonation and to develop

measures for the assessment, prediction,

prevention and mitigation of earthquake

disaster.

Insurance

The State Governments should make life

and property insurance mandatory for the

persons residing in the recurrent earthquake

prone zone. Insurance is a very effective

risk-mitigating instrument as it not only

helps to mitigate the economic effects but

also works to affect market forces, which

eventually improve the quality of

Management of Rescue and Relief

Search and rescue of people who are

trapped and injured is the first and foremost

task after the disaster. This is a highly

specialized task, which requires specially

trained and equipped teams. The teams

should be equipped with elements of

rescue, first aid, fire fighting, communi-

cation and administration. Mobile first-aid,

surgical trauma and evacuation teams have

to be deployed in the area to provide first-

aid treatment to the casualties and to

arrange for immediate evacuation of the

seriously injured, old and infant.

Arrangement should also be made for

mobile surgical teams along the mobile

operation van for major injury cases that

may require immediate life saving surgery.

Along with the search and rescue teams,

specially trained dogs also supplement

detection human causalities where search

and recovery operations are hampered.

Rehabilitation

The rehabilitation process requires a lot of

emotional and psychological support in

addition to physical and material

assistance. Thus Psychologists and

Psychiatrists play a very important role in

the post disaster scenario. The effort should

be to make the people self-reliant,

optimistic and confident to face the future.

At the same time, restoration of essential

services such as communication, water and

power supply should be made as early as

possible. There are many role players in the

rehabilitation period, the universities,

colleges and schools possess vast

potentiality and with some training to

students, a lot of rehabilitation work can be

done after earthquake. NGOs also play a

very important role in rehabilitation period

due to their linkages with the community

and flexibility in procedural matters.

13

Phase of Earthquake Disaster Management

Earthquake Disaster

Pre-disaster Management

Post-disaster Activity

l

l

l

Prevention

Preparedness

Protection

l Rescue Relief Rehabilitation Reconstruction Repair Renewal

Pre Disaster Preventive Measures

Long Term Measures

u Re-framing the building codes, guidelines, manuals and bye- laws and their proper

implementation. Stricter legislation for highly seismic areas.

u In high-risk areas, all buildings should incorporate earthquake resistant features.

u Public utilities like water supply system; communication network, electricity lines, etc must

be earthquake proof to reduce damages to the infrastructure facilities. Besides alternative

arrangement for the same must be developed.

u Identification of community buildings and buildings used for gathering of large number of

people like, schools, dharamshalas, hospitals, prayer halls, etc must be made earthquake

resistant.

u Research and Development in various aspects of disaster mitigation, preparedness and

prevention and post disaster management should be encouraged.

u Improving educational curricula in architecture and engineering institutions and in technical

training life polytechnics and schools to include disaster related topics.

u Earthquake insurance for building and structures to reduce the economic impact on people.

u Community participation in constructing safe houses from seismic forces, creating

awareness of What to Do and What Not Do at the time of earthquake.

u Reduce urban densities in High Seismic Zones.

u Routine awareness campaign.

l

l

l

l

l

14

Medium Term Measures

u Retrofitting of the weak structures in the highly seismic zones.

u Preparation of a list of Do's and Don'ts in local languages for the building constructions and

earthquake safety.

u Prepare a family Disaster Mitigation Plan, indicating whom to contact and where to go.

u Getting the community involved in the process of disaster mitigation by providing them

proper education and awareness.

u Supporting local technical institutions/colleges/schools to conduct research, training and to

organize exhibitions, etc for public awareness.

u Networking of local NGOs working in the area of disaster management.

u Maintenance of law and order, prevention of trespassing and looting.

u Evacuation of people

u Recovery of dead bodies and their disposal.

u Medical care for the injured.

u Supply of food and drinking water.

u Provision of temporary shelters like, tents and metal sheds.

u Restoring lines of communication and information.

u Restoring transport routes.

u Quick assessment of damage and demarcation of damaged areas according to grade of

damage.

u Cordoning of severely damaged structures that are liable to collapse during after shocks.

u Temporary shoring of certain precariously standing building to avoid collapses and damage

to other adjoining buildings.

u Immediate action to prevent chain- reaction from developing, such as release of water from

the reservoir behind a damaged dam to avoid flooding of the area if the dam fails. Also

emptying of containers of toxic or inflammable liquid and gases, treatment of environment

for preventing spread of epidemics, etc.

Post Disaster - Preventive Measures

15

Consolidation and Reconstruction Phase

Guidelines for Reduction of Seismic Vulnerability

l Detailed damage assessment of building and decision regarding repair, restoration,

retrofitting and strengthening or demolition;

l Repair, restoration and seismic strengthening or demolition;

l Selection of sites for new settlements;

l Adoption of strategy for new construction such as, through contractors, self help,

construction of core-houses or supply of construction materials, etc;

l Execution of the reconstruction programme;

l Review of existing seismic zoning maps and risk maps;

l Review of seismic codes and norms of construction;

l Training of personnel, engineers, architects, builders and artisans;

l Statistical studies regarding earthquake.

l To ensure that the structure possesses at least the minimum strength to withstand minor

earthquakes.

l To resist moderate earthquakes, with an once-in-a-lifetime occurrence probability, without

significant damage, although some minor structural damage may occur.

l To enable the structure to withstand without collapse, a major earthquake having Maximum

Potential in that area.

Site Selection

l Stability of the slope: In general, level sites are preferable to those on slopes or hillsides.

Stable slopes should be chosen to locate the buildings.

l Rock falls: Sites prone to rock falls are to be avoided as they as dangerous for human

settlement.

l Reclaimed or filled sites: Such sites should be avoided, particularly in seismic prone areas.

l Soil Testing and Microzonation: Where available, microzonation information should be

obtained to ascertain the probable maximum intensities, which could be experienced

during an earthquake.

16

Materials and Quality of Construction

Construction material and technology affect the seismic performance of a building. A building

constructed of brick in cement mortar will behave much better than brick in mud mortar,

provided all other parameters remain the same. The suitability of materials for construction is

dependent on the characteristics of the materials themselves as well as their combination with

other materials. From earthquake safety view point, the suitability of materials for construction

could be classified as follows:

u

u

u

u

Highly suitable: Steel, Wood and RCC.

Moderately suitable: Brick, block, dressed stone masonry with good mortar, compacted

abode construction if appropriately reinforced.

Slightly suitable: Un- reinforced brick, block, stone masonry with good mortar.

Unsuitable: Un-reinforced masonry with mud mortar, earthen walls without reinforcement.

In all seismic zones, the following measures should be adopted as per IS-4326 (revised in 1993)

for walls built using rectangular units in cement mortar and as per IS-13828 (subjected-1993)

for walls of coarsed rubble masonry or other masonry built using mud mortar.

u

u

u

u

u

u

u

u

u

u

Control on length, height and thickness of wall in a room.

Control on size and location of openings.

Control on material strength and quality of construction.

Seismic band at plinth level (maybe omitted if founded on rock or hard soil).

Seismic band at ceiling level of floors or roofs consisting of jointed prefab elements.

Seismic band at door-window lintel level in all cases.

Seismic band at eave level of sloping roofs.

Seismic band at the top of gable wall and ridge wall top.

Bracing in roof structure of trussed as well as rafted roofs.

Stiffening of prefab elements in roofs/floor where used.

17

Vulnerability of Sikkim State in terms of Seismic Zoning Map: Seismic Zones

The Himalayan region has been rocked by both moderate and large earthquakes with a magnitude of

about eight on the Richter scale. Seismicity is high along both the MBT and the MCT. Seismicity

maps show that the Indo-Nepal border registers the largest number of earthquakes per year. Sikkim,

thin the Eastern Himalayan region also falls in the high earthquake prone area, i.e. the IV seismic

zone.

Seismic Zone - IV

Sikkim State Seismic Zone -IVSeismic Zone map of India Source: BMTC

Zone V: Covers the areas liable to seismic intensity IX and above on Modified Mercalli Intensity

Scale. This is the most severe seismic zone and is referred here as Very High Damage Risk Zone.

Zone IV: Gives the area liable to MM VIII. This zone is second in severity to zone V. This is

referred here as High Damage Risk Zone.

Zone III: The associated intensity is MM VII. This is termed here as Moderate Damage Risk

Zone.

Zone II: The probable intensity is MM VI. This zone is referred to as Very Low/Low Damage

Risk Zone.

18

Do's and Don'ts in Earthquake Disaster Situation

19

Before the Earthquake Disaster

l Firstly learn about the causes and effects of the earthquake.

l Prepare a family Disaster Mitigation Plan indicating whom to contact and where to go.

l Prepare an Emergency kit and place it in a safe place. Kit should contain-dry food and water

adequate for a day, battery operated radio, torch or match stick and candles, bandages and

basic medicines, directory and telephone numbers to be called during emergency, etc.

l Keep a handy torch and a portable transistor radio.

l Identify safe places in the house that can provide cover during an earthquake like inner

corner, doorway, etc.

l Arrange your home in such a way that it is possible to move more easily, keeping corridors

clear of furniture, sleeper, shoes and toys.

l Shelves for bookcase, etc., should firmly fixed to the walls. Remove heavy objects from

shelves above head level. Do not hang plants in heavy pots that could swing free of hooks.

Bookcases, cabinets or wall decorations can topple over and fall.

l Place heavy and bulky objects on the floor or on the lowest shelves.

l Consider retrofitting your house with earthquake safety measures. Reinforcing the

foundation and frame could make your house earthquake resistant.

l Teach all members of your family how to turn off the electricity, water and gas supply.

l Prepare special plan for children, physically handicapped and aged persons.

l Locate beds away from the windows and heavy objects that could fall. Don't hang mirrors or

picture frames directs over beds.

l Secure applications that could move break of gas or electrical lines. Know location of master

switch and shut-off valve.

l Make sure that overhead lighting fixture are well secured to the ceiling and move heavy

unstable objects away from exit routes.

l Knowledge of seismicity of area. Must know you are residing in an earthquake prone area, if

so what is the Seismic Zone: Zone-II, Zone-III, Zone-IV or Zone-V.

During an Earthquake

If In-Door

l Keep calm and keep others calm.

l Be ready to face the situation and over

come.

l Drop, cover and hold on.

l Do not rush to the doors or exits; never

use the lifts; keep away from windows,

mirrors, chimneys and furniture.

l Stand in the doorway, under doorjambs

or in the corner of the room.

l Go under a table or other sturdy

furniture; kneel, sit or stay close to the

floor. Hold on to furniture legs for

balance.

l Protect yourself by standing under the

lintel of an inner door, in the corner of a

room, under a table or even under a bed.

l If on the upper floor of the building,

don't jump from windows or balcony.

If you are Driving

l Stop the vehicle away from buildings,

walls, slopes, big tree, electricity wires

and stay put in the vehicle.

l Don't attempt to cross bridge/flyover.

If you are on the Street

l Walk towards an open place in a calm and

composed manner, do not run and wander

round the streets.

l Keep away from buildings, especially

old, tall or detached buildings, electricity

wires, slopes and walls, which are liable

to collapse.

l Do not re-enter damaged buildings and

stay away from badly damaged

structures.

20

After an Earthquake

t Check yourself for injuries first before attending to

others.

t Keep calm, switch on the transistor radio and obey any

instructions you hear from the radio.

t Don't create panic or rumors.

t Keep away from beaches and low banks of rivers.

t Expect aftershocks.

t Turn off the water, gas and electricity.

t Do not smoke and do not light matches or use a cigarette

lighter.

t Use a torch.

t If people are seriously injured, do not move them unless

they are in danger.

t Immediately clean up any inflammable products that

may have spilled.

t If you know that people have been buried, tell the rescue

teams. Do not rush and worsen the situation of injured

persons or your own situation.

t Avoid places where there are loose electric wires and do

not touch any metal object contact with them.

t Do not drink water from open containers without

treatment.

t Do not re-enter badly damaged buildings and do not go

near damaged structures.

t Do not walk around the streets to see what has happened

and cause congestion. Keep clear of the streets to enable

rescue vehicles to pass.

t Examine walls, floors, doors, staircases and windows to

make sure that the building is not in danger of collapsing.

t Check for sewage and water line damage.

t Use telephone only to report life-threatening

emergencies. They need to be clear for emergency calls to

get through.

Emergency Phone No.

(Toll Free)

Police : 100

Fire : 101

Ambulance : 102

21

Global Positioning System (GPS) Based

Active Tectonic Studies in Sikkim

The kinematics of active deformation in

Sikkim- Darjeeling Himalaya is being

carried out using GPS instruments by

GBPIHED, Sikkim Unit. Strike- slip

earthquakes of magnitude around 6.0 have

dominated the earthquakes recorded in the

region so there is a need to look at the nature

and the mechanism of active tectonics in the

region. This area has also not experienced

any high magnitude earthquakes and that

makes the earthquake potential in the region

extremely high. A campaign - mode study

setting up GPS station at various locations

in the state is going on to understand the

deformation and later the potential seismic

hazard. The permanent GPS station at

Sikkim Unit campus is being used as

reference station for campaign-mode study.

The outcome of the present study will be

utilized for the formulation of future

strategies to cope up from any seismic

hazard in the region.

Seismic hazard and microzonation atlas of

the Sikkim Himalayas has been developed

by Prof. S.K. Nath, IIT. Kharakpur. It is

described that the microzonation is a

process that involves incorporation of

geologic and geotechnical concerns into

economically, sociologically and politically

justifiable and defensible land use planning

for earthquake effects so that architect and

engineering can site and design structures

that will be less susceptible to damage

Microzonation provides general guidelines

for the types of new structures that are most

suitable to an area.

The seismic ground motion hazard is

mapped in the Sikkim Himalayas with local

and regional site conditions incorporated

through Geographical Information System.

Seismical hazard map evolved using

seismological themes i.e. Site Response

(SR), Peak Ground Acceleration (PGA) and

Predominant Frequency (PF). The overall

SR, PGA and PF show an increasing trend in

the NW-SW direction peaking at Singtam in

the lesser Himalaya. For the geometrical

central frequency 2.5 Hz the probabilistic

Seismic Microzonation map identifies six

major zones, the maximum risk is attached

at Singtam and its neighborhood. At the

geometrically central frequency 7.5 Hz six

major zones are mapped, the maximum risk

is attached at Mangan and its immediate

neighborhood. The Probabilistic Seismic

Microzonation map at the geometrically

central frequency 15 Hz identifies five

major zones; the maximum risk is attached

in the region encompassing Singtam,

Gangtok and Mangan.

GPS Permanent station, Sikkim Unit

GPS field Campaign, East Sikkim

22

3

Landslide: Landslide is simply defined as the mass movement of rock, debris or earth in down

slope and have come to include a broad range of motions whereby falling, sliding and flowing

under the influence of gravity dislodges earth material. A landslide is a result of shear failure

along the boundary of moving soil or rock mass. A shear failure occurs when average shear stress

along a potential sliding surface becomes equal to the shear strength of soil or rock.

Landslide: Mitigation and Preparedness

Causes of Landslides:

Causes for Landslides are Natural or Manmade

Natural

Manmade

Himalaya, the youngest mountain range in the world, is highly erosion

prone. It is brutally lashed by intense rainstorms and thus constitutes an ecosystem primed for

disaster. Landslides are common all over the Himalayan ranges and Sikkim is no exception. The

region is highly susceptible to these calamities. The state experiences the ever-perennial

problem of landslides and other mass movements at various locations. These are further

compounded by increasing population and the developmental needs of the dwellers. The rugged

mountain topography of Sikkim has an altitude range of 300 to 8500 masl. The average annual

rainfall varies from 2000mm to 5000mm. High rainfall and flashes of cloudburst are the frequent

trigging factor for new slides and re-activators of old landslides in the Sikkim Himalayas.

n Increase in the mass of weak rocks, clay and other debris likely to slide.

n Loosening or breaking of rocks and soil by wetting due to rainfall, weathering, erosion,

deforestation, earthquake, tremors and similar other events.

n High intensity precipitation and steep slopes - coincidence of dip direction of steeply

dipping bedding plane of strata with slope direction.

n Denudation of natural vegetation.

n Agricultural operations/slope modifications.

n Infrastructural development like roads, dam, irrigation channels, hydroelectric power

channels, etc

23

Landslide Prone areas in India

Landslide causes extensive damage to roads, bridge, human dwellings, electricity, telephone,

agricultural lands, orchards, forest etc., resulting in loss of property as well as life. Degradation of

hill areas has also been on the increase due to greater frequency of occurrence of landslides.

Landslides incidences in India and proximate causes

Landslide Disasters Mitigation and

Preparedness

§ Identification of Active Landslide spots.

§ Avoid commercial and residential

constructions in hazard prone areas.

§ Making strong foundations of structures.

§ Contribution in slope stabilization

through terracing and engineering/

bioengineering.

§ Making rock-fall barriers.

§ Preparing Landslide Hazard Zonation

Maps.

§ Creating sufficient drainage system.

§ Monitoring and warning.

§ Community education, training and

awareness. Engineering/bioengineering measures in Mamring Landslide

24

Potential causes for Landslides in Sikkim

s Heavy and incessant rains on geologically fragile formation with steep topography leading

to over saturation of the slopes. The soil cover in most areas is shallow and lies over soft,

quick weathering rock thus leading to slope failures as well as landslides

s Toe-cutting and erosion- by the over swollen Teesta and other rivers.

s Many locations on major roads are subjected to hill cutting and blasting for widening of the

road. But work remains unfinished due to early monsoons and this contributes in increased

road blockages on the highway.

s Further aggravation in already sinking and subsiding zones due to unchecked plying of

heavy vehicles.

Activating Factors for Landslides

in Sikkim

n Gravity of the slope materials and other

structures present on the slope acting

vertically downward.

n Prolonged heavy rainfall, which is very

common in the summer monsoon.

n Melting of snow in the high altitude area.

n Seismic waves propagation by natural

shocks (earthquakes) and blasting which

give rise to induced landslides.

n Undercutting of toe portion of fringe

slopes, either due to river erosion or man

made action.

n Violent storm and cloudburst with heavy

and persistent rain.

n Supersonic sound waves produced by

thunderbolts (high lightening zone) in a

period of heavy and prolonged rain.

25

Impacts of Landslides in Sikkim State

Highways in Sikkim bristle with landslides

causing extensive damage to roads in the

region and throwing the normal activities of

the inhabitants out of gear. Numerous

landslides continue to occur every year

dislocating the communication system and

blocking the road network. The roads remain

closed for long periods causing hardships to

the villagers who get their basic supplies and

provisions from the neighboring areas

through road transport.

Landslides very often disrupt water source

and cause disruption in the water supply

system. Water sources are breached from

several places and are choked by debris, thus

resulting in water shortages in the region.

The water channels being affected results in

no water for irrigation purposes and hence

agriculture suffers. Telephone and electric

cables are often disrupted by frequent

sliding, causing great inconvenience to the

inhabitants.

Landslides are a great hindrance/setback to

the Tourism Industry of the State. The

snapping of road network adversely affects

the commercial activities of the state as

travelers experience great difficulties in

commuting to their destinations during

landslides.

This leads to a dip in tourist inflows and

consequently a drop in the government

treasury and the businesses of the people

specially during monsoon period.

Landslides contribute to soil erosion in the in

the state and wash away the rich topsoil of

the slopes. The fertility of the soil is washed

away leaving the land unproductive and

barren. They destroy terraced agricultural

fields, which cannot be easily renovated or

made productive again. Deforestation is

often blamed for landslides, but forests can

only inhibit shallow landslides, they have

little effect on deep landslides. Contrary to

the belief that the conservation of forest can

act as both prevention and protection against

landslides, there are instances in Sikkim to

show that landslides occur even in very

dense forests. Thus in a geologically fragile

state like Sikkim, an integrated approach to

landslide prevention is required.

Landslide in dense forest, North Sikkim

26

Recent Landslide Disaster in

Sikkim Himalaya

In the recent past, the people of Sikkim faced

such kind of natural disaster, which still

haunts the minds of the effected people even

today. The thundering rainfall subsequently thtriggering of landslide in the night of 24

September, 2005 turned out to be a total

nightmare for the people residing in the

capital and the surroundings areas.

Bakthang-Burtuk, loose and soft sandy

soil causes subsidence of road.

Retrofitting measures are going on like

construction of supporting wall adjacent

to road side.

Gurdum landslide trigged after heavy thrainfall on 24 Sept, 2005, collapse the

main state Highway Bridge on Samdong-

Gangtok road. The landslides area was so

heavy that the road leading to Samdong

Gangtok has been totally blocked.

Basement of a house at Seven mile

(Samdur) washed away, resulting

collapse of house.

A Temple collapsed at Ranipool as a

result of landslide.

thRate Chu landslide on 6 June, 2006,

damage of main water supply system of

Gangtok city crises of water remains for

more than two weak.

l

l

l

l

l

27

l On July10, 2006, the retaining wall of

PNT quarters collapsed due to heavy

rain, cause threat is the building.

l In monsoon season of 2007 (up to

August) eight people lost their life at

various places of the state. Sereve

landslides trigged in Gangtok, forced

more than 30 families to evacuate their

houses.

l One of the most disastrous and famous

landslide triggered in Gangtok on the

thnight of 8 June 1997. The landslide was

result of high intensity rainfall, which

started as light showers in the afternoon,

and extended to heavy rainstorm by

evening and night. About 50 people were

reported dead and large number of

houses were devastated or affected.

l Heavy rainfall trigged Chandmari

thlandslide on 8 June, 1997, 8 people lost

their life and heavy damage to adjacent

building and parked cars.

t hl Heavy landslide trigged on 5

September, 1995 in Deorali, causing

damage to houses, reported loss of 30

lives.

Major Landslides in Sikkim

28

B2 Landslide: The B2 slide located 13.4 km

north of Gangtok on North Sikkim Highway

(NSH) has been an active slide since last four

decades. It has been observed that this

particular slide is an extremely dynamic one

and has prograded up slope in a conspicuous

rate. Since the NSH is aligned entirely within

this unconsolidated debris failures, creep

and subsidence occur at various elevations

during monsoon causing severe distressing

and failure of road bench. The NSH form the

lifeline of the state, connecting the border

areas and the Headquarters of North District

has strategic importance. In recent years, the

pressure on said communication routes has

increased because of expanding urbani-

zation, tourism and upcoming of river valley

projects. The frequent occurrence of mass

movements along these communication

routes not only isolate Sikkim from rest of

the country during rains/monsoons but also

create problem for tourists and delay the

planning and execution of the development

projects.

Threat of Landslide in Sikkim Himalayas

District Very Severe

Severe Moderate Total

29

Risk Reduction Methods

Landslide Hazard Zone Mapping

Land Use Regulation

Site Selection

Information Technology

u Landslide prone areas are to be delineated by integrating

multiple databases, e.g. topographical map, geological

map, remote sensing data, ground truth and geotechnical

investigations. Landslide hazard zone mapping is a

relatively new tool being used for identifying landslides

susptiable areas, forecasting and early warning.

u Land use controls can be enacted to prevent hazardous areas from being used for

settlements, developmental activities or as sites for important structures.

u Permanent settlements should be avoided in high-risk zones.

u Site selection even in moderately safe zones, should be made with all precautions.

u Diversion of stream channels in upper slopes, especially above settlements should be

strictly disallowed.

u Adequate provision should be made to ensure drainage of storm water away from high

sloping terrain to reduce over saturation.

u Any contour bunding or terracing adopted for seasonal cultivation or initiation of

plantations in slopes of >16 above settlements should have sufficient provision for storm

water drainage.

u Landslides can be predicted with proper and systematic studies and with adoption of

suitable remedial measures, damage can be minimized and averted for a long time. Modern

techniques and methods based on Remote Sensing (RS) and Geographic Information

System (GIS) are widely used to meet the requirements of synthesizing the available

information and contribute to effective natural disaster management. RS/GIS data help in

the development of hazard Zonation map, early hazard warning system and landslide

disaster preparedness measures.

30

Insurance

Community-Based Risk Reduction Measures

o Insurance programs may reduce losses related to landslides by spreading the expenses over a

larger base and including standards for site selection and construction techniques.

o The most damaging landslides often occur as a result of anthropogenic activities. Thus prior

to the disaster, public education awareness programmes should be initiated to the people

which will make them understand the causes and consequences of landslides in addition

helping them to identify unstable areas and avoid construction of house there. Communities

should be trained to recognize potential land instabilities, identify active landslide areas and

avoid hazardous locations for settlements.

Landslide Control Techniques

Shallow Erosional Slides

Check dams, bally benching

Asphalt mulch

Use of natural fibre gride (such as juite or

coir)

Bio-engineerings

Use of synthetic grids

Surface Drainage

Catch-water drains

Road side drains

Chutes

Sub-Surface Drainage

Horizontal drains

Sub-surface trench drains

Restraining Systems

Retaining walls

Rock bolts

Prestressed anchors

Grouting

w

w

w

w

w

w

w

w

w

w

w

w

w

w

Other Control Measures

w Re-grading of slope

w Benching of slope

w Provision of fill at the toe

w Relocating or changing the location of

facility to avoid landslide prone areas.

w Revetment, spurs, dykes, groins to

protect slopes against river and stream

erosion.

w Display Boards for public awareness that

areas prone for landslides to avoid

accidents.

w Plan barren and sloppy areas in hills with

suitable bio-engineering measures.

w Conducting a skill development

programmes for persons engaged in the

construction sector.

w District Administration should study the

vulnerable areas and take appropriate

preventive steps.

31

Before the Landslide Disaster

l Do not construct houses near steep slopes,

close to mountain edges, near drainage

ways, or natural erosion valleys.

l Get a ground assessment of your property.

l Be particularly observant of your

surrounding area before or during intense

storms that could heighten the possibility

of landslide or debris flow.

l If you are at risk from a landslide talk to

your insurance agent, get insurance on

your land.

l Contact with Local Authority working on

Earth Movement to assist you for take

precautionary measures for your home.

Contacting persons should be Geotech-

nical, Structural or Civil Engineer.

l Learn to recognize landslide-warning

signs

u Doors or windows stick or jam for the

first time.

u Outside walls, walks or stairs begin

pulling away from the building.

u New cracks appear in plaster, tile,

brick or foundations.

u Underground utility lines break.

u Bulging ground appears at base of the

slope.

u Water breaks through the ground

surface in new locations.

u Fences, retaining walls, utility poles,

or trees tilt or move.

u The ground slopes descending in one

direction and may begin shifting in

that direction under your feet.

Do's and Don'ts in Landslide Disaster Situation

Pelling Town

32

During a Heightened Threat of Landslide

During Landslide Disaster

u Listen to radio or television for warning of intense rainfall.

v Be prepared to evacuate if instructed by local authorities or if you feel threatened.

v If possible distance yourself from the direct path of the debris flow and landslide debris.

u Be alert when intense short bursts of rain follow prolonged heavy rains or damp weather,

which increase risks of debris flows.

u Listen for any unusual sounds that might indicate moving debris, such as trees cracking or

boulders knocking together.

u If you are near a stream or channel, be alert for sudden increases or decreases in water flow and

for a change from muddy to clear water. Such changes may indicate landslide activity

upstream.

u Be especially alert when driving. Embankments along roadsides are particularly susceptible to

landslides.

u Quickly move away from the path of a landslide or debris flow.

u Areas generally considered safe include:

v Areas that has not moved in the past.

v Relatively flat-lying areas, away from drastic changes in slope.

u If escape is not possible, curl into a tight ball and protect your head.

u Quickly switch of the electricity and gas, etc. if possible.

u Contact your local fire, police, or public works department. Local officials are the best persons

able to assess potential danger.

u Inform affected neighbors. Your neighbors may not be aware of potential hazards. Advising

them of a potential threat, may help in saving lives. Help neighbors who may need assistance

to evacuate.

u If at home, move to a second story if possible to distance yourself from the direct path of the

landslide or debris flow.

33

After the Landslide Disaster

u Stay away from the slide area. There may

be danger of additional slides.

u Check for injured and trapped persons

near the slide, without entering the direct

slide area.

u Help a neighbor who may require

assistance.

u Listen to local radio or television stations

for the latest emergency information.

u Landslides and debris flow can provoke

associated dangers such as broken

electrical, water, gas and sewage lines

and disrupt roadways.

u Watch for flooding, which may occur

after a landslide or debris flow. Floods

sometimes follow landslides and debris

flow.

u Replant damaged ground as soon as

possible since erosion caused by loss of

ground cover can lead to flash flooding

and additional landslides in the near

future.

u Contact yours local emergency

authorities immediately District Control

Room, Fire Service, Police, Hospital etc.

for emergency rescue and relief.

u Try to find the advice of a geotechnical

expert for evaluating landslide hazards or

designing remedial techniques to reduce

landslide risk. An expert will be able to

advise a the best ways to prevent or

reduce landslide risk, without creating

further hazard.

34

4Flood:

Types of Floods

Flood occurs when surface water covers land that is normally dry or when water

overflows normal confinements. It can arise from abnormally heavy precipitation, dam failures,

rapid snow melts, river blockages and other related causes.

v Flash Floods

v River Floods

v Coastal Floods

Flood: Mitigation and Preparedness

Causes of Flood Disaster

Floods are excessive accumulation or flow of water which results from heavy rainfall, cloud

burst, snow melt, glacier lake outburst or high tides and causes such as dam burst, embankment

failure etc. They include flash floods which are rapidly rising and falling of river level and

overland flows resulting from the rapid run off of rainfall from upland areas. River floods in

which river water spills over adjoining areas, tidal flooding usually saline from the backflow of

sea into coastal rivers at high and tides storm surge floods associated with the passage of tropical

cyclones. Normally floods are caused by high rainfall or more snow melt on the higher altitude

of mountains. This raises the level of rivers than its normal level, leading to floods.

Impact and Effects of Flood Disaster

v Loss of life, settlements and property.

v Damage to and devastation of subsistence and cash crops.

v Devastation of production.

v Devastation of lifestyle.

v Loss of livelihood.

v Disruption to essential services.

v Damage to national infrastructure.

v National economic loss.

v Damage to roads, electric and communication lines.

35

Flood Prone areas in India

India is one among the most flood prone countries in the world.

India accounts for one-fifth of global death count due to floods. Over 30 million people are

displaced annually.

The most flood prone states are Utter Pradesh, Bihar, West Bengal, Assam and Orissa. The flood

affected areas are also serious in Andhra Pradesh, Gujarat, Haryana, Punjab, Rajasthan, Tamil

Nadu and North-Eastern States.

Floods have ravage portions of India from time immemorial, though floods are one of the very few

well recorded natural phenomena.

Source: BMTPC

36

Flood in Teesta River

The Teesta flowing through the Sikkim and

Darjeeling hills is possibly the wildest river

in the Himalaya with a valley extremely

prone to cloudbursts flowed by landslides

and flash floods. The Teesta has the highest

sediment yield of all the Himalayan rivers

bringing down approximately 98 cum of silt

per hectare of its catchments per year,

giving a high denudation rate.

The explosive character of the Teesta valley

can be attributed more to intense rainstorms

than earthquakes. Monsoon rainfall is

greater in the eastern Himalaya than in the

western Himalaya. And even in the eastern

Himalaya, it is particularly intense in the

Teesta valley. The area experiences rainfall

varying from 3000 mm to 6000 mm every

year. Often the intensity of the rainfall is so

high that within 10 minutes of its

commencement can reach a burst of 750

mm per hour. The highest rainfall (4032

mm/day) recorded in year 1977 (in June) in

Teesta valley.

Three factors prevailing in Sikkim

Himalaya exacerbate the destabilizing

impact of high rainfall. Firstly, hills in the

region are extremely fragile.

The strata consists of sandstone, shale,

mica-schist and quartzite, which are in a

disintegrated condition in many places and

folded and thrusted with a number of fault

planes. Secondly, the topography is such

that it leads to enormous erosion, toe cutting

and landslides. Also about one-third of the

Teesta catchment is under perpetual snow.

Sikkim is mainly drained by the Teesta,

which travels through the centre of the state

in an almost north-south axis. The Burhi

Rangit, which drains a good part of western

Sikkim, merges into the Teesta just south of

Melli Bazaar in the Kalimpong hills. Due to

New Vong landslide river Teesta was

blocked for 20 minutes in year 1966, later

caused flash flood in downstream. Teesta

flood of 1968 caused a colossal loss to life

and property in Sikkim. It is estimated that

some 20,000 landslide took place. The 50

km road between Siliguri and Darjeeling

was cut in 92 places and approximately

20,000 people were killed, injured or

displaced. All bridges, including one with

just a four meter clearing above river level

but situated two km above Rangpo, remain

intact. A Number of bridges were washed

away and traffic was closed for 32 days.

37

Rangpo's lower market, which was well

above the river before 1968, came under

two meters of sand after the flood and is now

almost at the same level as the river's flood

plain. A bridge on Tumthang Khola (stream)

of 30 m long buried under the silt of the

flood. This bridge was exposed in the 1969

rains and then it was excavated. The bridge

is still in service at the same site. There were

major floods in 1973 and 1975.

38

Record of Cloud Burst in Teesta Valley

Year Date Recorded Rainfall Rate,mm hr-1 Rate,mm day-1

39

Flood Reduction Measures

Structural Measures

Land use controls will be of limited use in

already developed floodplains. Therefore,

structural measures must be implemented to

reduce a community's vulnerability to flood

damage. The most commonly used options

involve measures for flood reduction and

diversion and flood proofing and may be

used in combination with land use controls.

In short term,

on an annual basis timely cleaning,

distilling or deepening of natural water

reservoirs and drainage channels must be

taken up. Well designed watershed

development planning to reduce runoff

and silt load.

- aims to decrease the

amount of runoffs, usually by altering the

watershed. Typical treatments include

reforestation or reseeding, contour

ploughing or terracing and protection of

vegetation from fire, overgrazing and

clear-cutting.

- include levee and dam

construction and channel improvements.

Levees, embankments and dykes restrict

floodwaters to low value and on the flood

plain and are relatively cheap to

construct.

? Watershed Management:

? Flood Reduction

? Flood Diversion

? Flood Proofing:

? Natural Water Retention Basins:

Temporary measures

include blocking or sealing entrances or

windows and the use of sandbags to keep

floodwaters away. Permanent measures

include use of hazard resistant design

such as raising living and working spaces

high above the possible flood levels.

Houses may be elevated by structural

means (stilts) or by raising the land using

landfill. Buildings should be set back

from water bodies. Land surrounding

buildings and infrastructure should be

protected against erosion. Streambeds

should be stabilized with stone masonry

or vegetation especially near bridges and

erosion prone areas.

Inspect and strengthen where necessary

all flood protection embankments, ring

bounds and other bounds.

? All engineering structures to withstand

flood forces and design for elevated floor

level and construction over stilts.

Construction of reservoirs, dams, dykes,

retaining walls, constructing alternate

drainage courses are structural methods

of flood mitigation.

40

Non-Structural Measures

The non-structural measures aim at

modifying the susceptibility to flood

damage as well as modifying the loss

burden.

Flood plain

management is achieved by flood plain

zoning and regulation. The basic map is

combined with other maps and data to

form a complete picture of the

floodplain. Other inputs include

frequency analysis, inundation maps,

flood frequency and damage reports,

slope maps and other related maps such

as land use, vegetation, population

density and infrastructural maps. Remote

sensing techniques provide an alternative

to traditional techniques of floodplain

mapping and can be equally or more cost

effective as they allow estimates of data

otherwise requiring labor intensive

collection methods.

- Floods

often cause or occur in conjunction with

or result from other hazards. A multiple

hazard map serves to highlight areas

vulnerable to more than one hazard. It is

an excellent tool for designing a multiple

hazard mitigation and emergency plan.

v Mapping of Floodplain:

v Multiple Hazards Mapping

v Land Use Control:

v Drainage Management:

Land-use control

planning to avoid use of injudicious

f lood plains for residential or

commercial purpose.

Ø Reduction of densities

Ø Prohibiting specific functions

Ø Relocation of elements that block the

flood way

Ø Regulation of building materials

Ø Flood forecasting and warning systems

Ø Provision of escape route

Ø Community preparedness

l Issuing warnings at the local level

l Participating in flood fighting by

organizing work parties to repair

embankments or clear debris from

drainage areas, stockpile needed

materials, etc

l Facilitating agricultural recovery

l Planning emergency supplies of flood

and clean drinking water

l Identifying traditional mitigation and

preparedness measures

At many

places drainage overloading in the

aftermath of flooding is major hazard.

Drainage control development can help

in prevention of water from entering in a

level site from either rainfall or runoff

from upstream watersheds.

41

Flood Preparedness

Flood Preparedness of the Department Concerned:

By the State and District Administration

ö Pre Monsoon Inspection of all roads, canals, drains by respective departments.

ö Regular clearance of the drains from silt and weeds to make the drainage system fully

functional and restoration of natural drainage blocked by roads, debris and garbage etc.

ö Regular maintenance of embankments of rivers, canals, distributors, etc and regular checks of

the canals and clearing of silt.

ö Clearing of storm water and sewage drains in towns before monsoon.

ö Constitution of committees comprising of heads of all emergencies services, medical, police,

transportation and the district administration to ensure proper coordination during the crisis.

ö Convening a meeting of the District Level Committee on natural calamities.

ö Functioning of the control rooms.

ö Review of contingency plan.

ö Contingency plan can be modified/ updated if necessary.

ö Co-ordinate with NGOs/CBOs.

ö Review and visit to likely places for evacuation to ensure their functional availability.

ö Make people aware of the warning dissemination mechanism.

ö Do's and Don'ts.

Response Mechanism

Pre-Disaster

On receipt of a warning of an impending disaster, the people have to be immediately warned.

Dissemination through print and electronic media as well as informing the authorities concerned

is very essential. The District Administration is responsible in informing to the masses those have

no access to mass media modes. This could be by beat of drums, sounding of sirens, village gongs

or by rumor.

42

Dissemination of Warning

Doordarshan

All India Radio

High priority

Telegram

Bulletins in the press

Satellite based Disaster

Warning Systems

Telephone

Government Channel

Teleprint/Telex

During Disaster

Administration of Relief Search and Rescue

Evacuation, Rescue, Provision of Food, Clothing, Shelter, Drinking Water, Medical Care, Restoration, etc

Post Flood Management

ö Speedy restoration of roads and the postal services.

ö Normal water supply in the affected areas either by arranging tankers or by fire tenders.

ö Repair in the power, telephone and sewerage lines.

ö Proper arrangements for the supply of food, shelter and clothing to the victims.

ö Constitution of a survey team to assess the loss and compensation to be given to the affected

population.

ö Assistance of repair/building of private properties.

ö De-silting and dewatering of the inundated areas.

ö Taking up suitable events according to Contingency Plan for the agriculture sector.

43

Before a Flood: Individual Preparedness

E Insure crops and household.

E Plan and practice evacuation routes.

E Reinforce your house and make it flood proof by filling sand bags and putting them around the

house.

E Identification of safer shelter places.

E Move to safer places and highlands with food provisions and potable water on receipt of

warning at least for a week.

E Keep drinking water in covered vessels and jugs.

E Listen to radio/TV to get updated information.

E Emergency telephone numbers like, Fire, Police, and Hospital should be known to all family

members.

E Build of stock of emergency provision i.e. medicines, torches, spare battery cells, plastic

sheets, sand bags, hammer, saw, etc before a disaster.

E Teach all family members how to turn off gas, electricity and water.

E Construct barriers to stop flood waters from entering the building like sand bags, bamboo

weaves, etc.

E Seal basement walls with water proof compounds to avoid seepage.

E Ask an out of the - state friend or relative to be in your contact. Make sure that everyone in

your family has the emergency number.

_ Update the entire resource inventory.

_ Control Room should be functional for round the clock.

_ Identify all the shelter places where people could be evacuated.

_ Activate all the First Aid and Rescue and Evacuation team.

_ Ascertain the availability of dry food, drinking water and medicines.

_ Identify all the Relief Centres.

_ Inspect, strengthen and repair all the approach roads and culverts.

_ Prepare maps of alternate route, resources available.

Government Preparedness

Do's and Don'ts in Flood Disaster Situation

44

During Flood

E If indoors, stay inside. Don't move out.

E If outdoors, climb to higher ground and stay there. Don't attempt to wade through floodwaters,

as it could be dangerous.

E If you are in a vehicle and come to a flooded area, turn around and go another way. If your car

stalls in floodwaters abandon it immediately and climb to high ground. Don't attempt to take

vehicles through flooded areas as you could be swept away and get drowned.

E Listen to radio to get the updated information.

E Follow the instructions of the local authorities and follow the recommended evacuation route

and if needed, do so immediately.

E Wear a life jacket if you have one. If not, you can use other things that float like inner tubes, big

empty plastic containers, wood log or banana trees as buoys, if you have to move into a flooded

area.

E Turn off utilities at the main switches. Disconnect electrical appliances. Do not touch electrical

equipment if you are wet or standing in water.

E Be alert of streams, drainage channels and other areas known to flood suddenly. Flash floods

can happen in hill areas with or without such typical warnings as a result of cloudburst or

heavy rain.

E Get your emergency supplies ready to take with you if you have to evacuate.

E Drink boiled water. Use halogen tablets to purify water before drinking.

E Keep your food covered, don't eat heavy meals.

E Move furniture, clothing and appliances, where possible, to high shelves or to second stories if

time permits.

E Be careful of snakes. Snakebites are common during floods.

_ Carry out rescue and evacuation.

_ Operation of control room and provide warning update.

_ Coordination at various levels and agencies.

_ Mobile health units to be made available.

Government

45

After Flood

E Continue to listen to radio/TV and return to shelter only when the authorities indicate that it is

safe to do so. Always remember, flood danger does not end when the floodwater recedes.

E Be ready to volunteer help, particularly to infants, women and the aged. Ask the Red Cross

Volunteers or health workers to check the water quality and to clean your wells before you use

it again.

E Seek necessary medical attention if injured.

E Inspect your house to check the cracks for damages. Make sure that the house is not in the

danger of collapsing.

E Throw away food that has come into contact with flood water.

E Disinfect drinking water before use and keep the food covered always.

E Don't drink floodwater, instead collect rainwater to drink and boil it before drinking.

E Pump out water from the basement to avoid structural damage.

E Use mosquito nets while sleeping.

E Plant bamboos or appropriate trees around your house to protect it against floods.

E Return home only when authorities indicate it is safe.

E Use intense care when entering buildings; there may be hidden damage, particularly in

foundations.

_ Rescue people who are stranded.

_ Restore road and power supply.

_ Provide safe drinking water.

_ Check outbreak of any epidemics.

_ Take help of NGOs.

_ Carry out damage assessment.

_ Ensure that adequate, timely and speedy credit is available to the farmers for purchasing

agricultural inputs and cattle.

Government

46

Forest Fire : Forest Fire constitutes typical disaster phenomena, origin of which can be either

natural or manmade. In their ferocity and destructive potential, these are notoriously dangerous.

Forest Fire which may caused by natural processes sometimes but most of the time, these occur

and spread due to human negligence. Fire can be classified into two types:

� Natural Fire (Wild/Forest Fire)

� Man-made Fire

Forest Fire: Mitigation and Preparedness

Causes of Forest Fire

The amount of vegetation cover and other combustible material such as dead wood, dry leaves,

determine the nature and extent of forest fire. High atmospheric temperatures, dryness (low

humidity), the strength of the prevailing wind and the slope of the ground are important factors

in the spread of forest fire. Forest fire could be both natural and manmade.

l Sparks produced on account of fiction of Rolling Stones.

Lighting during Thundering Storms.l

During the Volcanic Irruptions.l

l Careless throwing of cigarette, bidi stubs, match sticks by travelers.

l Carelessness in extraction of honey and other forest product, using lighted torches.

l Negligence in camp and cooking operation near camping ground and fairs.

l Negligence in protecting the crops from the wild animals.

l Negligence during the construction of the roads/resurfacing or repairs.

l For clearing the forest paths by the villagers.

l Negligence in extracting resin from the chir pine tree.

l For obtaining green flush of grass for grazing the animals.

l For burring the pine needles to clear the ground from carpet of needles.

l For concealing the illegal felling.

Sifting cultivation.l

Natural Forest Fire

Manmade Forest Fire

47

5

Types of Forest Fire

Forest fires are basically of four types depending upon their nature and size:

This is the most common type of forest fire. It burns undergrowth and dead

material along the floor of the forest and is useful to the vegetation and help more than harm.

This fire burns roots and other material on or beneath the surface. This is more

damaging than surface fire because it can destroy vegetation completely.

This is most unpredictable fire and burns the tops of trees and are spread rapidly

by wind.

A fire storm is the most damaging to the forest cover. It is basically an intense fire

over a large area. As the fire burns, heat rise and the cold wind from outside rushes in, causing

the fire to grow rapidly. More wind inflow makes the fire spin very violently like a storm.

Temperatures inside this type of forest fire can reach up to 2,000 degrees Fahrenheit.

ö Surface Fire:

ö Ground Fire:

ö Crown Fire:

ö Fire Storm:

Impacts of Forest Fire Disaster

n Loss of valuable timber and minor forest produce resources.

n Degradation of water catchments areas resulting in loss of water.

n Loss of biodiversity and extinction of plants and animals.

n Loss of wild life habitat and depletion of wild life.

n Loss of natural regeneration and reduction in forest cover and production.

n Global warming resulting in rising temperature.

n Soil erosion affecting productivity of soils and production.

n Ozone layer depletion.

n Indirect effect on agricultural production.

n Health problems leading to diseases.

n Degradation of microclimate of the area making unhealthy living conditions.

n Increase in percentage of carbon dioxide in the atmosphere.

48

Forest Fire in India

The most vulnerable stretches of the world are the youngest mountain ranges of Himalayas.

About 50 percent of forest areas in the country are fire prone, ranging from 33 percent in states to

90 percent in the others. The forests of Western Himalayas are more frequently vulnerable to

forest fires as compared to those in Eastern Himalayas. In India, the hilly areas vulnerable to

forest fires lie in the states of Arunachal Pradesh, Assam, Himachal Pradesh, Jammu and

Kashmir, Manipur, Meghalaya, Mizoram, Nagaland, Sikkim, Tripura and Uttarakhand. Forest

fires are not new for the forests, they have bummed across the earth for millions of years. But in

recent past the incidences of forest fire have increased tremendously due human induced

activities. In comparison to other parts of country the forests of Himalayan region particularly of

Western Himalayas due to various biotic and geographic reasons are more prone to forest fire.

Forest Fire Situation in Sikkim

The Sikkim Himalaya is one of the hot spot for biological diversity in India. From October to

January, winter with slight rain or snowfall the hills of Sikkim have been going through a dry

spell, which caused the forest fire. Dry weather conditions coupled with carelessness by the

people may have triggered off the forest fires. Major source of forest obliteration is forest fires,

caused also accidentally or by villagers for growing fresh grass for fodder.

Petrol Pump Fire, Gangtok (12 August, 2007) Vehicle Fire, Gangtok (October 2005)

49

Recent Forest Fire in Sikkim

The incidents of forest fire in Sikkim are generally reported during winter months.

q 3 January 2006 - The fire broke out in a steep hill called 'Siyo Bhir' near Tingvom in Upper

Dzongu of North Sikkim. (Source: http://www.thestatesman.net )

q 06 January 2006- A forest fire on a hill at the Sinbong Num Reserve affects a forest reserve in

North Sikkim. (Source: http://www.fire.uni-freiburg.de)

q 09 January 2006 - A forest fire broke out at Sombaria forests in West Sikkim natural habitat of

Red Pandas at Barsey Rhododendron Sanctuary. (Source: The Telegraph - Jan. 11, 2006)

q 10 January, 2006 - The devastating fire in the forest at upper reaches of Barshey

Rhododendron Sanctuary which began on 8 January was finally brought under control at

around 4.00 P.M. (Source: http://www.thestatesman.net )

q 22 January, 2006- A forest fire had hit Rajat Bhir near Chungthang guest house in North

Sikkim and a day later another forest fire broke out at Noushou Bhir, about one km from

Geyzing, the west district headquarters. (Source: http://www.thestatesman.net )

PREVENTION

DETECTION

SUPRESSION

Training of Local People and Staff

Fire Line

Other Silviculture Practices

Watch Tower

Fire Watcher

Other Techniques

Surfacial Methods

Arial Methods

STEPS IN FOREST FIRE MANAGEMENT

Managing Forest Fire

50

Forest Fire Risk Management

Prevention Planning and Management

Incident Management Technique

Prevention

As prevention is better than cure. It is of

utmost significance that necessary

preventive measures are taken to manage the

forest fire in an area.

ÄCutting of forest fire line is the traditional

and old method which is very successfull

in preventing the forest fire.

ÄAgricultural tradit ional shift ing

cultivation in which a part of land is

cleared by fire in order to use it for the

agricultural purpose.

ÄAttitude of the people towards

environment in particulararly those

people who whichever live in these

forests or these forms the means of

livelihood for them.

ÄEducating the people about the do's and

don't to prevent forest fire is very

important. They must be made aware of

damages by fire to environment.

ÄAwareness Programmes should be

conducted for the villagers at Panchayat

and Block level.

Planning and Management

It is a focal point in developing plans to react

to a disaster once it threatens or has occurred.

With proper planning and management, the

impact of the forest fires could be reduced to

a great extent.

The areas prone to forest fire

disaster should be identified.

A complete

assessment with the help of volunteer

force and available technology.

l Direct Method - Where the effort is

put directly on or immediately

neighboring to the limit of fire.

l Indirect Method Where the control

line is located along favorable

topographic breaks or natural breaks

and area between the fire limit and

control line is burned off (control

fire).

ÄZoning and Mapping of Vulnerable

areas:

ÄAssessment of Fire Hazard:

ÄFire Fighting

51

ÄFire Line Procedure

ÄEducation and Training:

l Fire should be attacked where it meets

fresh fuel.

l Fire guard should be dug down to mineral

soil.

l Firewood or roots extending across the

line should be cut and pulled out from

burned area to prevent fire avoidance

through them.

l Any fire that has move down into the

roots should be grubbed out.

An education

and training programme should be carried

out. This can act as an effective tool for

pre and post disaster's planning and

management. The community is to be

divided into three groups for the

education and training at their group

level;

l General Public

l Volunteers/Social Workers

l Experts

ÄFast Detection and Message:

ÄFire Brigade Force:

ÄStrengthening of Forest Staff:

ÄCommunication and Transport:

Forest fire

disaster mitigation can be achieved

through quick detection of occurrence

and prompt passage of communication

without loss of time in dealing with the

occurrence.

It should be

stationed near the hazard prone area. Fire

brigades should be well equipped with

modern equipment and the fire personal

trained to expert in the fire repression

techniques.

The

pressure on the forests is mounting up due

to increase in population along with the

developmental activities. Hence there is a

need to strengthen the forest conservation

staff to have effective patrol. A committee

of the experts should be made depending

of the area and type of forest. During the

fire season additional staff be engaged to

for special squad to deal with fire to avoid

any major incident.

An

effectual communication and transport

system shell be worked out.

52

Petrol pump Fire, Gangtok (12 August, 2007)

Incident Management Techniques

ÄNodal Agency:

ÄHigh Power Committee at State Level:

ÄCoordination Action Committee at

District Level:

A nodal agency

constituting of District Commissioner/

District Magistrate should be formed to

coordinate the activities of the various

departments in case of forest fire disaster.

As soon as any information is received by

the District Magistrate, the same shall be

passed on to Fire Officer/ Divisional Fire

Officer as well as District Police Officer.

A high power committee should be

constituted at the state level of the

concerned departments, under the

chairmanship of the Chief Secretary to

review the situation and make policy

decisions.

An action committee

should be formed at the district level to

take immediate actions against the

disaster hit areas. This committee should

be formated under the chairmanship of

the District Commissioner/District

Magistrate.

ÄStage of Action:

ÄWarning Systems:

ÄSetting up of Control Rooms:

Action Committee

normally forms three stages; (i) Alert

(ii) Preparatory (iii) Operational

A proper warning

system should operate to give warning

and information to public. This would

help in avoiding panic and ensure that the

public is aware of the situation and take

the necessary safety actions.

For better

coordination and controlling the situation

control rooms shall be set up;

l District Control Room

l Police Control Room and Fire Control

Room

l Departmental Control Room

53

Do's and Don'ts in Fire and Forest Fire Disaster

Before a Fire and Forest Fire

E Remove inflammables, clear items that

will burn around the house including

wood masses, lawn furniture, barbecue

grills, oilcloth coverings, etc.

E Check the electrical wiring in yours

residence. Install electrical lines

underground, if possible.

E Water attaches garden hoses; fill any

ponds, hot tubs, garbage cans, tubs or

other large containers with water.

E Ask fire authorities for information about

forest fires in your area. Request that they

inspect yours residence and property for

hazards.

E Evacuate your pets and all family

members who are not essential to

preparing the home. Anybody with

medical or physical limits, children and

the aged should be evacuated right away.

E Take away combustibles. Clear items that

will burn around the house, including

wood piles, grass furniture, barbecue

grills, tarp cover, etc.

E Make sure all of the family members

know what to do in case of a fire. Have

everybody learn the emergency phone

number of the fire department. (101 toll

free and common for whole country).

E Install smoke detectors on every level of

your home. Test your detectors one time

every month, replace the batteries once

a year and replace the detector every ten

years.

E Make and practice Fire Exit Drills;

everybody from adults to children needs

to know what to do in a fire. Remember

to meet outside at a selected spot; do not

reenter the home for any reason.

E Many renters do not have insurance,

renters insurance is relatively cheep and

we advise having some. Know how to

contact your landlord and keep the phone

numbers with your residence inventory.

E Keep all trees and hedge plant branches

trimmed so they do not come into contact

with electrical wires house or hang over

your chimney.

E Keep trees neighboring to buildings free

of dead or dying branches.

E Keep battery operated radios and

flashlights with extra batteries.

E Cut back all lower branches eight feet

from the ground.

E Keep rain sewer clear of garbage at all

times.

54

During a Fire and Forest Fire

E If you have a step, support it against the

house so you and firefighters have access

to roof.

E If hoses and sufficient water are available

set them up. Fill buckets with water.

E Move upholstered furniture away from

windows and sliding glass doors.

E Be ready to evacuate all family members

and pets when requested to do so.

E Use water or a fire extinguisher to put out

small fires. Do not try to put out a fire that

is getting out of control. If you're not sure

that you can control it, get everyone out of

the residence and call the fire department

from a neighbor's residence.

E Never use water on an electrical fire. Use

only a fire extinguisher approved for

electrical fires.

E Stay out formerly you are safely out. Do

not reenter. Call 101 (Fire service).

E If advised to evacuate, do so immediately.

Choose a route away from the fire

hazards. Watch for changes in the speed

and direction of fire and smoke.

After a Fire and Forest Fire

E Check with fire officer before attempting

to return to your home.

E Use caution when reentering a burned

area flare-ups can happen.

E Check grounds for “hot spots” on fire

stumps and vegetation. Use your buckets

of water.

E Consult local experts on the best way to

restore and replant your land with fire

safe landscaping.

E If you are with burn injured, or are a burn

casualty, yourself give first aid where

needed and after that call Ambulance 102

or your local emergency number; cool

and cover burns to reduce chance of

further injury.

E Take photographs of the damage. You

may need these to verify insurance claims

afterward.

E Check your household electric wiring

before the current is turned on.

E Normally, the fire department will see

that utilities are either safe to use or are

disconnected before they leave the site.

Do not attempt to turn on utilities

yourself.

55

6Avalanche: Mitigation and Preparedness

Avalanche prone area, North Sikkim

Avalanche prone area, North Sikkim

56

Avalanche prone area, North Sikkim Avalanche prone area, North Sikkim

57

Causes of Avalanche

Terrain

Slope angle

Slope direction

- Generally avalanches occur on

slopes between 30 and 45 degrees, but can

happen on any slope angles given the proper

situation. Extremely soggy snow will be well

lubricating with water, meaning it might

avalanche on a slope of only 10 to 25 degrees.

Very dry or granular snow will most likely

avalanche on a slope close to the 22 degree

angle of repose.

- However avalanches will

sprint on slopes opposite any direction,

mainly avalanches run on slopes opposite

north, east, and northeast. As the sun is at

such a low angle, mostly during winter, a

colder and deeper snow pack increases.

Slopes that are under shadow all through

most of the day are suspect because the snow

pack remains cooler, without much of the

melting and bonding that can make the snow

layers stronger.

Snowfall

Temperature

Rain

- Fresh snowfall puts extra stress on

the existing snow pack, especially if it does

not sufficiently bond to the pre-existing

surface layer. The extra weight of new snow

alone can reason a block to break rotten and

fall down the slope, particularly in storm-

induced avalanches.

-As snow is a good insulator,

slight temperature changes do not have much

effect on snow pack as bigger or longer

changes perform. For example, shadows

from the sun crossing the snow surface

during the day will not considerably vary

snow pack stability. Changes that last several

hours or days, such as a warm front moving

through, can slowly increase temperatures

that cause melting within the snow pack. This

can critically weaken some of the upper

layers of snow, creating increased avalanche

potential, particularly in combination with

other factors.

- In the short-term causes instability

through additional load and possible

lubrication of lower layers. Avalanche also

occurs if the upper snow layer is moved. Rain

reduces friction in the snowpack.

Weather

- Avalanches are probably to run either

during or immediately after a storm where

there has been significant snowfall. The 24

hours following a heavy snowfall are the

most dangerous.

58

Wind - Wind usually blows up one side of a

slope or mountain and down the other.

Blowing up the windward slope, wind will

"scour" snow off the surface, carry it over the

summit and put it on the leeward side. What

this does, is pack snow unevenly on the

leeward side, making it more prone to

avalanche.

Vegetation - On a snow-covered slope,

heavily forested areas are much safer than

open spaces, but don't suppose any

vegetation at all will be defensive. Single

trees, bushes, or big rocks on a mountainside

can sometimes weaken the stability of the

snow pack. A break row might run from a

lone tree to a rock to another tree.

Avalanche areas in India

Avalanches occur during winter months in

the snowbound belt of Western and Central

Himalaya and to some extent in Eastern

Himalaya. From the main Himalayan belt,

the mountain system is divided into three

principle zones which have marked

orographic features. These are the Great

Himalaya, Lesser Himalaya and the Outer

Himalaya. The Himalaya has about 43,000

2km of permanent ice bound area. In India,

Jammu and Kashmir (J&K), Himachal

Pradesh (HP), Uttarakhand and part of

Sikkim and north western Arunachal Pradesh

are the avalanche prone states.

Avalanche in Sikkim

Many severe avalanche incident takes place

in Sikkim, but the encounter with people,

especially, during winter months is

negligible. They generally trigger in

uninhabited areas or border areas where our

army is deployed.

- An avalanche in Thanggu area

in state killed 19 soldiers tire trapped under

ice, could recovered, six solders injured.

High winds reportedly triggered the

avalanche.

- At Dongkong in North

Sikkim, 5 members of the Expedition Team

including the team leader ADGP of Punjab

Police lost their lives.

April 1, 1998

September 25, 2005

Avalanche prone area, North Sikkim Avalanche prone area, North Sikkim

59

Avalanche Safety: What you should do to prepare yourself

_ What was the weather conditions been over the past few days? Recent heavy snows?

_ Can you observe any wind loading on the slopes?

_ Do you have a good sense of the snow pack? Have you performed any snow pit or shear tests?

_ Have you noticed many fracture lines, heard "humping" or cracking sounds, or hollow

noises in the snow pack?

_ Are you keeping an eye on the orientation and steepness of the slopes as you cross them?

_ Are you lingering in gullies, bowls, or valleys?

_ Noticed any recent avalanche activity on other slopes similar to the one you are on?

_ If a slope looks suspect, are there any alternative routes?

Hazard Specific Preparedness Steps

ö Check out area avalanche conditions before you venture out.

ö Tell family/friends where you are going, what route you will be taking and when you expect

to return.

ö Complete a Wild Trip Plan and give it to a family member or friend before you leave.

ö Bring along the appropriate equipment and supplies for winter conditions and the activity

you're involved in. Be prepared in the event you get lost or separated, including a method for

communication such as a two-wave radio. Pack dry clothing, waterproof matches and

paraffin fire starters with you.

ö Pay attention to and abide by posted signs and regulations.

ö Stay aware of your surroundings. Learn the indicators and signs for avalanche and know

what to do if you're caught in.

ö Be prepared to take emergency shelter.

ö Keep an updated disaster supply kit in your vehicle.

ö Establish meeting places and phone numbers in case family members are separated and your

home is impacted.

ö Be sure to keep at least a half-tank of gas in your vehicle at all times. Someone may need it to

get help, or you could be delayed for long periods of time or have to reroute, if a pass is

temporarily closed for avalanche control.

60

Preparedness Steps

ö Have and practice a family disaster plan.

ö Establish meeting places and phone numbers in case family members are separated.

ö Identify an out-of-state contact to call during a major disaster or emergency; it will be easier

to call out of the area if local lines are tied up.

ö Keep your disaster kits up to date. Make sure you have kits for your home, vehicle, work and

school.

ö Teach all family members when, where and how turn of utilities. Make sure you have the

appropriate equipment, such as a wrench, etc.

ö Preplan alternate transportation routes to and fro and for other important destinations.

ö Know ahead of time what you should do to help family, friends or neighbors who are elderly

or have special needs.

ö Know what kinds of weather and snow conditions are likely to cause avalanches.

ö If you have to cross a slope that appears unsafe, close your jackets tightly and put on hats and

mittens.

ö If you have a rucksack, carry it in your hands and hold it in front of your face to get some

breathing space under the snow.

During an Avalanche

_ Try to take hold of a tree or stone.

_ If there is nothing to hang on to, swim! Swimming motions usually keep the body to the top

of the snow.

_ Don't panic!

_ Push one arm as high as possible overhead. This might alert rescuers to your position if

you're buried.

_ Cover your mouth and nose with your other hand.

61

Avalanche Hazard Mitigation and Management Plans

Avalanche Hazard are a recurring phenomenon. The complete control of avalanches is possible

only through active methods comprising essentially of the erection of suitable structures,

afforestation and by artificially-controlled triggering. However, these methods, besides being

expensive, are very difficult to execute. At some places, these methods cannot be implemented

at all because of the logistic problems.

Structural Control

The structural control method

provides a very high degree of

protection from avalanche danger.

The structural control can be carried

out in the formation zone by

buildings retaining barriers and drift

control, in middle zone by diversion

walls, wedges and galleries and in

the runout zone by catch dams and

mounds.

Afforestation

Forest arrest the formation of avalanches in a number

of ways. A forest with a thick growth of high trees in

the starting zone inhibits the formation of avalanches.

The trees provides anchor to the potential slab

avalanches. This eliminates the snow drift and retains

the snow on tree canopies and releases it more

gradually.

Control Artificial Triggering

This method attempts at triggering

of descent of an avalanche by

explosive, or by controlled skiing

before it occurs naturally. This pre-

emptive method inhibits the build-

up of snow cover on slopes to

disastrous proportions. This method

is generally adopted in conjunction

with avalanche forecasting. Though

this techniques is simple and

economical, it requires great amount

of planning, co-ordination and

training for successful execution.

The another method for avalanche mitigation is

awareness, timely forecasting of the danger of

avalanches and imparting training on safety and

rescue methods.

There is a general lack of awareness among

backcountry travelers about the avalanche

phenomenon and safety and rescue measures to be

followed against. Due to avalanche hazard there is

adverse effect on winter tourism, sports and other

commercial activity. Therefore, there is a need of

awareness campaign about various aspects of the

avalanche disasters. Following maybe the awareness

programmes:

Ø Pre-Winter avalanche awareness programme

Ø Mid-Winter appraisal report

Ø Post-Winter appraisal report

Ø Publication of hazard maps and avalanche atlases

Ø Multimedia and user's guide

Awareness

62

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65

Nobile Orchid Rhododendrom Neveum

Red Panda Blood Pheasant

Other Training Module of Related Interest:Action Plan for Disaster Mitigation,

Prevention and Preparedness

For Further Details Contact

Disaster Management FacultyG.B. Pant Institute of Himalayan Environment & Development

Sikkim Unit, Post Box-24, Gangtok, East Sikkim-737101.Phone: (03592) 237189; 237328, Fax: 237415