International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol XXXV, Part B7. Istanbul 2004
etc. The mangroves and coral reefs are the most
important and fragile components of the coastal
ecosystems and act as a buffer between the ocean and
terrestrial boundaries. With the built-up of large industrial
infrastructure along the coasts, the frequent monitoring of
the mangrove and coral reefs needs to be a mandatory
activity.
Freshwater ecosystems encompass rivers, lakes and
wetlands; and contain just a fraction- 1/10096 of earth's
water and occupy less than 196 of earth's surface (WRI
2000-2001). Fragmentation of river systems through dam
construction or similar measures has the most significant
impact on freshwater ecosystems. This has and is
adversely impacting the ecosystem through changes in
pattern of sediment and nutrient transport, affecting the
migratory patterns of dependent fish species, altering the
riparian habitat composition, creating migratory paths for
exotic species, and in turn leading to changes in coastal
ecosystems. To conserve and improve the freshwater
ecosystems, holistic approaches are required addressing
aspects like water scarcity (demand and supply),
fragmentation and flows of freshwater systems, quality
and quantity, dependent food systems, and biodiversity.
Besides, one of the biggest challenges to research
towards attaining sustainable development is combating
natural disasters in a multi-pronged way through
prediction and forewarning mechanisms, improving
mitigation procedures (relief, rescue and damage
assessment).
Earth Observation Systems for
Sustainable Development
Earth Observation Systems
Satellite Communication, close weather watch and earth
observations are three important areas in which space
technology plays a significant role towards sustainable
development. The data from EO satellites can contribute
to sustainable development by providing information,
measurements and quantification of natural or artificial
phenomena. The synoptic view provided by satellite
imagery offers technologically the most appropriate
method for quick and reliable mapping and monitoring of
various natural resources, both in space and time
domains. Change detection through repetitive satellite
remote sensing over various temporal and spatial scales,
offers the most economical means of assessing
environmental impact of the developmental processes,
monitoring of bio-species diversity of an ecosystem and
evolution of appropriate -action plans for initiating
sustainable development. Availability of data at different
spatial resolutions (as coarse as 1 km, or as fine as 5 m
or better in multispectral mode) provides a means for
observing the earth simultaneously at macro and micro
levels. Recent improvements in microwave techniques
have provided all weather capability to remote sensing.
Decision-making for sustainable development is a
complex process and often involves studying trade-offs
that need to be made for conflicting goals of different
sectors. GIS provides a convenient platform to integrate
multi-sector data in different formats for analyzing “what-if
scenarios of alternative developments. Spatial decision
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support systems (SDSS) integrating process-based
models with scenario analysis greatly aid the process of
decision-making. There are possibilities of developing
SDSS by tight coupling of GIS tools with those for
modeling, simulation, optimization, statistical analysis,
image processing and expert reasoning (Densham 1991).
Besides allowing spatial analysis, GIS is a powerful tool
for empowering communities by enabling people's
participation in decision-making.
Earth observation covers a wide field of remote sensing
as well as of other sensing methods (in-situ), it
encompasses the earth itself and also the enveloping
environment. With the advent of parallel developments in
the field of electronics, the important achievement is the
ability to observe earth and its environment in the entire
breadth of the electromagnetic spectrum. The first years
of EO were dominated by overall requirements for
repetitive coverage and the need for an operational
capability (Kramer 2002). Since then, EO fraternity all
over the world is contributing to the information needs for
the cause of sustainable development. NASA pioneered
the operationalisation of satellite-based EO through
launch. of Landsat-1/2/3 (1972/75/78; MSS & RBV).
Subsequent launches of Landsat-4/5 (82/84; MSS & TM)
taken up by NOAA enhanced the imaging capability
through improved sensor technologies. NOAA also
launched its workhorse radiometer, AVHRR onboard its
POES series spanning during 1985-2001. In 1999, NASA
again launched the Landsat-7 with ETM+. CNES, France
commenced its operations way back in 1986 through
SPOT-1 (2 HRV), and followed it up with SPOT-2/3/4
(1990/1993/1998). Its recent launch is that of SPOT-5 in
2002 (HRVIR, HRS, Vegetation). Canada launched
RADARSAT-1 in 1995. The ESAs endeavours include
ERS-1/2 (1991/94), and ENVISAT-1 (2000). Indian Earth
Observation Programme started in 1979 with the launch
of experimental satellite ^ Bhaskara |. Operational
programme began in 1988 with IRS-1A (LISS-I & Il) and
its sequel IRS-1B (1991). Its second generation satellites
are IRS-1C/1D (1995/97; WiFS, LISS-III & PAN). This was
interspersed by IRS-P3/P4 (1996/1999; WiFS/OCM &
MSMR). Its recent launch is that of state-of-art IRS-P6 a k
a Resourcesat-1 (AWiFS, LISS-III and LISS-IV). NASDA
launched MOS-1a /.1b (1987/90), JERS-1 (1992; OPS)
and followed this with ADEOS in 1996 (AVNIR) and ALOS
(2003). Russia (erstwhile USSR) too is contributing
through the launches of RESURS series starting from
1985, and followed up with RESURS-01-2 (1988),
RESURS-0-3 (1994), and RESURS-0-4 (1998). Many
other agencies and countries including private enterprise
are also in the field of EO manufacturing and launching
satellites. At present, there are some satellites like
IKONOS-2 and Quickbird (high spatial resolution), Terra
(multiple spectral channel), and Hyperion (hyperspectral)
providing specific and focused information.
Agro ecosystem
In the field of agro ecosystem, first-hand information at
periodic intervals is required on cultivable and non-
cultivable wastelands, post-monsoon and post-winter
agricultural fallows, and potential areas for improved crop
intensity and area or region-specific cropping system for
sustainable development. In addition, measures to
minimize land degradation due to soil erosion, water-
logging, salinity & alkalinity etc. and conservative use of
