Satellite Earth Observation for Disaster
Risk Management
Disasters: A Growing Concern
Natural disasters are of increasing
frequency and severity in the modern world.
Over the past decade, some 4130 disasters
resulting from natural hazards were
recorded, causing over 1100000 deaths and a
minimum of US$1195 billion in recorded
losses. In 2011 alone, 302 disasters claimed
around 30000 lives, affecting 206 million
people and generating an estimated US$366
billion in damages.1 Rapid growth in the
global population and continued urbanisation
have brought a dramatic rise in population
densities and placed pressure on the
development of areas previously undeveloped
because of their exposure to risk. Over the
past 30 years, the portion of the world’s
population living in flood-prone river
basins has increased by 114%, and that of
those living along coastlines threatened by
cyclones has increased 192%. Today, over
half of the world’s cities of 2-15 million
people are in areas of seismic risk. In
parallel, anticipated climate change will
likely bring further environmental impacts
that will compound existing threats to
coastal and flood-plain settlements, as well
as increase wildfire hazards and bring
stronger and more frequent hurricanes and
cyclones. The world’s population has never
been exposed to such a high level of risk,
and this is likely to grow in the coming
years as the same trends continue.
The IPCC Special Report on Managing the
Risks of Extreme Events and Disasters to
Advance Climate Change Adaptation addresses
how integrating expertise in climate
science, disaster risk management and
adaptation can inform discussions on how to
reduce and manage the risks of extreme
events and disasters in a changing climate.
It evaluates the role of climate change in
altering characteristics of extreme events.
According to the report, increases in some
extreme weather and climate events have been
observed in some parts of the world. Further
increases are projected over the next
decades. For instance, the frequency of
heavy precipitation will likely increase in
the 21st century over many regions; in other
regions, extreme drought has brought renewed
risk of wildfires; it is also likely that
the average maximum wind speed of tropical
cyclones (also known as typhoons or
hurricanes) will increase throughout the
coming century, although possibly not in
every ocean basin. As far as losses are
concerned, the report indicates that
economic losses from weather- and
climate-related disasters have increased,
but with large spatial and inter-annual
variability. The increased losses are due to
increased exposure to risk.
Whether it is the Japanese tsunami in March
2011, the devastating 2010 Haiti earthquake,
the Indonesian tsunami of 2004 or the South
Asian earthquake hitting Pakistan and India
in 2005, catastrophic events leave a mark on
our collective memory. Yet these events
overshadow other major disasters that arise
almost every week. Flooding alone causes
dramatic effects annually in China,
Bangladesh, Mozambique and other nations.
Natural disasters are caused by the impact
of natural phenomena on society and the
built environment. Re-insurer MunichRe
classifies hazards as:
− Geohazards (earthquakes, volcanoes and
landslides);
− Hydrometeorological events (windstorms,
flooding and avalanches);
− Climatological events (extreme temperature,
drought and wildfires); and
− Human-made disasters (from direct human
intervention: industrial accidents, chemical
spills and nuclear accidents).
Phases of Disaster Risk Management.
Disaster risk management (DRM) aims to reduce
the loss of life and damage to property from
disasters. This involves both disaster risk
reduction (DRR) such as
mitigation/preparedness, prevention/warning
activities and other phases such as emergency
response, recovery, rehabilitation and
reconstruction. Satellite data, particularly
Earth observation data, can provide valuable,
unique information supporting both research
into natural hazards and their causes and
operational decision-making tied to both
planning and response.
One of the key challenges to address in DRM is
the ability to make meaningful contributions
to each phase of the disaster management
cycle. Limiting contributions to one aspect
will necessarily weaken the impact as the
phases are interlinked. Indeed, one of the
most significant hurdles to further
technological contributions to DRM lies in the
weak institutional relationships between
solution providers and the disaster-management
community. These links are best forged between
events, in the context of disaster mitigation
activities. CEOS and its member space agencies
are seeking to develop stronger ties with
international and regional coordinating
agencies such as UN International Strategy for
Disaster Reduction (UNISDR) or the World Bank
and the Global Facility for Disaster Reduction
and Recovery, in order to promote better use
of Earth observation.
Fire Monitoring Examples Using
Satellites
Fire risk monitoring providing
daily fire risk indexes
combining meteorological and
EO-based vegetation information
at low or medium resolution to
provide global estimates or to
support fire prevention and
firefighting services with more
accurate risk information.
Envisat MERIS image of 29
July 2010 illustrating
burning peat fields near
Moscow. The city is in the
bottom left corner of the
image. The smoke plumes
stretch over several
hundred kilometres and,
combined with other air
pollutants, can raise
pollution levels by a
factor of ten (ESA
2010).
Fire monitoring to detect
and monitor fires using
medium-resolution satellite
data to provide a ‘global
view’ of ongoing large fires
in support to fires
management at regional
level, and
transregional/transnational
cooperation of firefighting
services.
Rapid mapping with
on-request mapping of burnt
areas, at high resolution
just after the event.
Burn scar mapping providing
seasonal mapping of burnt
areas and damage assessment,
for better damage
assessment, risk assessment,
planning and land use
management.
Identifying the Information Need and
Associated Benefits
There are many different actors involved in
the DRM process at local, national, regional
and international levels. Their capacity to
integrate technology and information changes
on a geographic and development basis, and
their different mandates determine the nature
of their varying needs for data and
information.
The Group on Earth Observations Secretariat
has worked closely with CEOS to understand
better the needs of the global disaster
management community for satellite-based data.
These needs span multiple disaster types, the
various phases of the disaster cycle and many
satellite data, including:
− medium- and high-resolution optical data;
− medium- and high-resolution microwave radar
data (C-, L- and X-band);
− interferometric synthetic aperture radar
(SAR) data products;
− infrared and thermal data;
− meteorological datasets and models.
No single organisation or government has a
responsibility to meet international
requirements for satellite-based DRM data.
CEOS can serve a meaningful role in federating
diverse requirements and defining key
contributions for member agencies to make on a
best-effort basis. Working with user
organizations to identify resources to
leverage initial ‘in-kind’ contributions of
data, the international community can make
meaningful progress towards increasing the use
of Earth observation in DRM. This may enable
the purchase of commercial imagery and
ultimately increase the number of satellites
designed and built to support disaster
management.
It is clear from the texts of agreements such
as the UNFCCC or other related conventions on
biodiversity and desertification that
satellite data can help to develop a wealth of
information to address monitoring and
verification needs. United Nations agencies
are currently planning for the post-2015
framework to succeed the Hyogo Framework for
Action, with renewed emphasis on concrete
action to implement recommendations. In this
new framework, satellites may play a critical
role, particularly in reducing the underlying
risk factors and strengthening disaster
preparedness for effective response. Satellite
data can supply regular, detailed updates on
the status of hazards on a global, regional or
national basis.
Reducing the severity of disasters requires
the integration of observations, exploiting
predictive modelling and disseminating timely
and accurate information needed by all actors
involved in response and risk mitigation.
Earth observation’s contribution to the
provision of refined risk assessment
includes up to date localisation and
characterisation of the asset at risk;
information to support prevention plan
elaboration; supporting anticipation (for
instance, forecasting and early
warning/alert) as well as crisis management
operations (rescue, recovery) and to help
understand the resulting environmental
damages and natural recovery mechanisms
better.
It is true that many of the current
generation of satellite systems were not
designed specifically for DRM activities,
with notable exceptions such as the Disaster
Monitoring Constellation. However, the rapid
pace of technology advance has led to the
launch of increasingly flexible and powerful
systems. These missions are now
multi-purpose and offer exceptional coverage
and scope. Taken collectively, the world’s
satellite systems offer a unique tool for
DRM. CEOS has identified a number of key
data requirements for disaster information
that can be met by existing systems. For
example, the requirements of disaster
management centres concerning plain flood
hazard have been gathered in consultation
with national civil protection authorities:
reference mapping are needed within the day
of the hazard impact, while rapid mapping of
the flood extent is needed within a few
hours or within a day, every day. Similar
analysis has produced a characterisation of
requirements for other hazard types and
other phases of DRM such as early warning –
for a range of different
hydro-meteorological or geophysical hazards
– situational awareness during and after
disasters, precise damage assessment and
support to recovery and reconstruction.
Satellite EO-based Earthquake Damage
Assessment
GIS layer produced by the European
Centre for Training and Research in
Earthquake Engineering (EUCENTRE) for
the Italian Civil Protection
Department. The coloured polygons
represent an estimate of the seismic
damage level in three categories of
damage intensity (up to 10% damage,
greater than 10%, greater than 30%).
The estimate is based on
damage-related statistics from spatial
features in a post-event very high
resolution Cosmo-SkyMed image of the
area.
Credits: EUCENTRE, ASI
In the specific area of disaster response,
the International Charter ‘Space and Major
Disasters’ has established a system to
respond to global disasters on a best-effort
basis, providing satellite-based information
at no cost to disaster-management agencies
and the UN. Initiated by ESA, the French
space agency CNES and the Canadian space
agency CSA, the Charter began operations in
2000 and today has 14 members worldwide.
Further to the International Charter,
mechanisms such as Sentinel-Asia and SERVIR
address similar concerns on a regional
basis. In Europe, the European Commission
has established Emergency Management
Services to address the integration of
satellite data for emergencies and is
currently collaborating with the
International Charter to provide
value-adding services to support the
exploitation of imagery supplied via the
Charter to European organisations for
response in areas pertinent to the policy
sectors of Europe, primarily in its
territories and in regions where
humanitarian assistance is invoked.
The use of satellite data for response is
now well-established for both natural or
man-made disasters. Indeed, it is hard to
imagine how response to such man-made
catastrophes as the Deepwater Horizon oil
spill in the Gulf of Mexico would be
possible without the synoptic overview
offered by satellite Earth observation.
Satellite imagery can be used to track the
extent and direction of oil flows for
containment and, over time, to identify
coastal wetlands adversely affected by the
accident.
In the immediate aftermath of a disaster,
the primary issue is timeliness. Satellites
can provide rapid situational awareness over
a large area, typically on a daily basis.
This objective, synoptic view of the theatre
of operations offers the DRM community a
powerful tool to support recovery over the
days and weeks that follow a major
catastrophe. After the Asian Tsunami of 26
December 2004, the Indian, French and German
authorities and the United Nations invoked
the Charter and thousands of images from
SPOT, Envisat, ERS, IRS, Radarsat, Landsat
and US commercial satellites were acquired.
Partners produced more than 300 Earth
observation-based maps on scales ranging
from 1:400 000 to 1:10 000 over Sri Lanka,
the Indian coast, the Andaman islands,
Africa, the Maldives, Myanmar, Thailand and
Indonesia. These mapping actions supported
not only relief, but a host of recovery
activities. Typically, needs can be as
diverse as getting people back to work,
getting children back to school, supporting
community-driven reconstruction, rebuilding
houses, roads, bridges, ports and airports,
and reconnecting people: electricity and
telephones, reviving the economy, rebuilding
irrigation systems, bringing clean water and
sanitation, rebuilding health services,
restoring damaged ecosystems and protecting
the environment, restoring local and
provincial governments, managing
reconstruction transparently, and developing
a disaster-mitigation strategy.
Examples of support provided by the
satellite community include the city map of
Banda Aceh produced by the GSE Respond
project led by Infoterra UK using satellite
imagery, hard copies of which were
distributed in the streets; and Earth
observation-based debris monitoring maps
elaborated by the German space agency (DLR
ZKI) to help national authorities and aid
actors identify and locate debris for
removal.
The farther along the continuum from relief
to rehabilitation and development, the more
satellite Earth observation has a role to
play: "emergency assistance must be
provided in ways that will be supportive of
recovery and long-term development", as
laid down in UN Resolution 46/182. This
implies that development actors should be
involved in the early stages of aid, and
that satellite imagery acquired at this time
can, and should be, used to support
reconstruction and sustainable
development.
The impact of response activities such as
those of the Charter would be increased by
stronger ties to end users through increased
DRR collaboration, i.e. in non-emergency
activities. This is not without raising
financial and sustainability issues.
Information needs are different from those
of the response phase and require, in
particular, large volumes of data over large
areas, causing an operational challenge for
satellite agencies within the context of
existing systems.
There are three major components to the risk
reduction activities:
− Vulnerability / Risk Assessment. Here, the
central issue is the vulnerability of people
and asset to a set of hazards. Once this
factor has been weighted properly, one can
determine the level of risk that is
acceptable to that community or social
system.
− Mitigation and Prevention Measures. These
are structural or legal/political measures
put in place to limit the impact of hazards
(mitigation) or avoid this impact altogether
(prevention). For example, retrofitting
houses on the coastline to withstand tsunami
waves or storm is mitigation; enforcing a
law that forbids building in the areas of
the coast subject to tsunami and storm is
prevention.
− Preparedness. These are measures directed
to two separate audiences: the population,
in order to make people prepared to react to
warnings and emergency situations (through
drills, exercises, stockpiling, shelters,
etc); and the civil protection forces and
health sector, in order to increase their
ability to respond to disasters (drills,
adapted materials, risk maps, hospital
drills, evacuation procedures, impact
scenarios, GIS, etc).
DRR depends on concrete measures put in
place at the community level by informed
national and local authorities (ministries
of interior, environment, development
planning, land use, agriculture, river
basing administrations, mayors, civil
protection, etc). DRM work relates to
different aspects of development and
territorial management that concern a
variety of domains such as water,
sanitation, habitat, transportation and
energy. They are managed by different types
of organisations with mandates generally
attached to a specific domain, for instance
basin authorities looking at hydrological
risks, geological surveys looking at
geohazards such as landslides. Beyond local
and national actors, international
development organisations such as UNDP and
international financial institutions such as
the World Bank are involved in development
programmes with risk management components.
2014 update: CEOS has
developed a new Disaster Response Management
(DRM) Observation Strategy as a response to
a collection of observation requirements
from the user community to enable the
delivery of three coordinated pilots to be
rolled out over 2014-2016 in three thematic
areas: floods, seismic hazards and
volcanoes. Each of these thematic pilots
aims to serve as a showcase for the
international DRM community, in particular
demonstrating a) the added value and
uniqueness of increased CEOS coordination in
this area; b) benefits of closer ties to
users and ease of access to data; c)
potential for increased roles of space
agencies in DRM beyond the current Hyogo
Framework for Action, for the following
10-year period starting in 2015.
In addition, the Observation Strategy
proposes the establishment of a Recovery
Observatory, which would coordinate the
reaction of volunteer CEOS agencies to a
massive disaster on a scale similar to the
Haiti Earthquake of 2010 or Japanese Tohoku
tsunami of 2011.
Crisis Mapping and Flooding –
Validation Exercise
This exercise was led by a group of
experts supervised by the Institute
of Geomatics (ES) and the Royal
Military Academy of Brussels (BE).
It consisted of a full-scale service
delivery based on historical events
and performed under operational
constraints including 24/7
availability and the rapid mapping
capacity for rush production of
crisis information. As an example,
the large plain flooding of the Red
River (USA, April 1997) was selected
to validate the flood monitoring
service. A total of 14 flood extent
products were rapidly produced
compared to a reference flood map
derived using 2m resolution
air-photos from a survey performed
by the US Army Corps of Engineers.
The overall accuracy obtained by the
six value-adding organisations
ranges from 81% to 87%. All products
were delivered within 28 hours after
the delivery of Earth observation
data and 66% of them within 10
hours.
Flood validation exercise:
Radarsat-1 image of the flood event,
acquired 24 April 1997 (left).
Validation ground truth for the same
date, estimated by the US Army Corps
of Engineers, St. Paul District
(middle). Flood extent estimated for
the same date by one of the Service
Providers involved in the exercise
(right). Radarsat SAR imagery, 1997:
copyright CSA.
Integrated Satellite Earth Observations: A
Vision for the Future
Despite the clear successes of initiatives
such as the International Charter, which has
brought satellite-based Earth observation
into mainstream disaster response
management, much remains to be done. With
regard to conventional methods for improving
disaster risk reduction in particular,
better use could be made of existing and
planned satellite resources. Organisations
such as CEOS encourage the use of
satellite-based data in the assessment of
risk and vulnerabilities. Research
initiatives such as the European
Commission’s 7th Framework Programme have
specifically encouraged the development of
new Earth observation-based solutions that
will allow disaster managers to use
satellite data within the context of either
science investigations to characterise
hazards and risks better or operational
systems to support disaster management
authorities. On a global basis,
organisations such as GEO encourage the
development of an international approach to
forge greater ties between those that
generate satellite-based information and
those that need to use it. This
institutional bridge-building includes both
capacity-development activities and the
elaboration of a systematic approach for
using global datasets in risk-prone areas.
Achieving long-term results requires
commitment both from data providers (in
terms of data continuity, new sensors and
evolving requirements) and from the users,
who are often unfamiliar with the
opportunities afforded by new
technologies.
As DRR activities are increasingly
undertaken with national and regional users,
through the sponsorship and guidance of
international players – be they
international financial institutions such as
the World Bank or development agencies such
as the UN Development Programme – the uptake
of new systems and satellite-based data in
operational support to disaster management
will increase. There is nothing planning can
do to reduce the number and severity of
hazards. Ultimately however, while less
prominent in the eye of the media, the
integration of relevant, timely and
comprehensive datasets into disaster
mitigation activities will be the largest
factor contributing to reducing the loss of
life and damage to property. Improved
understanding of risk and risk extent,
improved planning, better preparedness and
systematic efforts towards risk reduction
based on long-term development and
environmental concerns will achieve the
ultimate goal of reducing the number and
scale of actual disasters caused by
hazards.
Volcanic Hazard Monitoring
Satellite Earth observation data
are used for different facets of DRM
concerning volcanoes and volcanic
ash. Historical analysis using Earth
observation data can help to
identify and characterise eruption
types and their probability of
occurrence. Earth observation-based
monitoring is used to support the
characterisation of the state of a
volcano. This includes terrain
elevation measurements and terrain
deformation monitoring using
spaceborne SAR data. InSAR is now a
recognised technique in the early
detection of magma injection and in
monitoring the stability of the
underlying structure of a volcano.
In addition, infrared and
multispectral sensors are useful for
observations of the thermal output
of an eruption and estimates of the
height and behaviour of the eruption
column and observations of the
movement and extent of the ash
cloud, in particular, thermal
anomalies and estimates of gas and
aerosol composition. (source:
Monitoring Volcanic Ash from Space,
ESA Publication STM-280).
Soufrière Hills volcano,
Montserrat, following the eruption
of 20 May 2006. The image shows SO2
retrievals on seven consecutive
days, from the Atmospheric Infrared
Sounder (AIRS on EOS-Aqua), to
measure atmospheric profiles of
temperature, moisture and trace
gases for climate and weather
prediction applications.
Trajectories from an atmospheric
dispersion model overlaid on the
plot confirmed a high, stratospheric
SO2 cloud. Cloud behaviour was
monitored every 15 minutes using
MSG-SEVIRI data. Credit Fred Prata
(fred.prata@nilu.no)
