Istanbul 2004
MONITORING URBAN AREAS FOR ENVIRONMENT AND SECURITY THROUGH REMOTE
SENSING
Paolo GAMBA, Fabio DELL’ACQUA
Dipartimento di Elettronica, Universitä di Pavia, Via Ferrata, 1, 1-27100 Pavia, Italy
{paolo.gamba,fabio.dellacqua} @unipv.it
Working Group III/6
KEY WORDS: Urban remote sensing, GMES.
ABSTRACT
This paper aims at providing an introduction to the topic of urban area management through remote sensing. It builds over
the experience of the GUS (GMES Urban Service) project, funded by ESA in the framework of GMES Service Elements
(GSE). We explore the potential of Earth Observation data for the extraction of aggregated data (maps, indicators, ...)
useful to urban planners and managers.
More specific results for land use and sealing area mapping are offered to provide a living example of the outputs of the
project and the problems as well as the achievements of current analysis algorithms.
1 INTRODUCTION
Environmental monitoring of urban areas seems to be one
of the main requests by the citizens around the world. In
Europe the Global Monitoring for Environment and Secu-
rity initiative (GMES) recognizes this need and addresses
this topic by means of a project aimed at producing GMES
urban services (GUS, 2004). In USA many projects are
considering urban remote sensing (e. g. UEM, 2004) as a
result of homeland security programs and/or a renewed in-
terest in environmentally aware urban planning.
Despite the number of cases where the technological and
scientific knowledge is successfully incorporated in the ur-
ban planning decision-making processes, there are still gaps
to be filled, especially in terms of technology. We feel that
there ought to be an even more active dialogue between
the scientific community and decision-makers if we want
to accelerate the process of developing new tools and new
techniques to collect and monitor indicators as identified
by policy-makers. For instance, there is no unique defini-
tion of urban areas that could be applied to different fields
and policy implementation. Definitions vary from country
to country (UN-HAB, 2004) and are often based on dif-
ferent parameters. Urban areas may be defined by admin-
istrative boundaries, or number of inhabitants, or some-
times simply referred to as “urban centers”. Remote sens-
ing provides a good tool to define urban areas in a more
consistent way and to produce spatially georeferenced ur-
ban extents. It also allows analysis of physical and demo-
graphic/socioeconomic characteristics of the urban envi-
ronment that can be incorporated in decision-making pro-
cesses at all levels.
Some of the major areas of scientific research in urban re-
mote sensing that have a strong interaction with the policy
cycle and would improve environment and security moni-
toring in these areas include therefore:
e characterization of the urban environment (i.e. delin-
eation, land use classification, differentiation of the
inner structures of cities);
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e measuring and monitoring physical properties of ur-
ban areas (i.e. vegetation, air quality, noise, heat);
e impact analysis and vulnerability assessment (includ-
ing water management issues, contaminated land, mon-
itoring of informal settlements), also by co-analysis
of physical and demographic/socioeconomic charac-
teristics of the urban environment;
e monitoring changes and urban growth over time.
2 EU AND URBAN AREA MANAGEMENT
The goal of GMES is to increase the environmental and
security levels inside and outside Europe by integrating
Earth Observation (EO) and ancillary data. As a matter
of fact, there is a strong interest in developing services ex-
ploiting the potentials of remote sensing for monitoring the
environment and managing the security internal and ex-
ternal to each country. Not only the European Commu-
nity is funding through different calls the research effort
for GMES related fields of applications (Land Cover and
Vegetation, Water Resources, Ocean and Marine Applica-
tions, Atmosphere, Risk Management, Security), but also
the European Space Agency (ESA) is currently funding
10 projects for the implementation of novel services in a
framework called GMES Service Elements (GSE). Among
the useful fields in which the GMES initiative can effec-
tively improve the day-by-day management ofthe environ-
ment, the management of urban areas is certainly included.
This is the main reason why, among the above mentioned
ESA-funded services there is one devoted to this topic, the
GMES Urban Services (GUS) Consortium, lead by Indra
Espacio (ES).
For urban areas, a particularly important framework where
to integrate these efforts is the Urban Thematic Strategy
(UTS), addressed by the recent Communication by the Com-
mission (COM(2004)60, “Towards a Thematic Strategy on
the Urban Environment”). The UTS discusses many of the
problems facing Europe’s towns and cities, such as meet-
ing demanding European air quality standards or urban
