International Archives of Photograminetry and Remote Sensing. Vol XXXII Part 7C2, UNISPACE III, Vienna 1999
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I5PR5
UNISPACE III - ISPRS Workshop on
“Resource Mapping from Space”
9:00 am -12:00 pm, 22 July 1999, VIC Room B
Vienna, Austria
I5PR5
agencies. The Moderate Resolution Imaging Spectroradiometer
(MODIS) will be one of the new sensors for providing data on
the Earth’s biosperic dynamics. A MODLAND team is
developing remote sensing algortihms for deriving time series
data products on various terrestrial geophysical parameters
including spectral albedo, land cover, vegetation indices, snow
and ice cover and surface temperature using MODIS as a
measurement device (Running et al., 1994). The bio-physical
variables contain leaf area index (LAI) and fraction of absorbed
photosynthetical active radiation (fPAR) meant for the
calculation of APAR, evaporation and net primary' production.
MODIS is developed by NASA in framework of the Mission to
Planet Earth and is a radiometer covering the 0.405 to 4.08 pm
wavelengths including two thermal infrared channels, with a
spatial resolution from 250 m to 1 km at nadir. The revisit time
is 1 to 2 days only. MODIS will fly onboard EOS-AM1, which
is scheduled for launch on October 15, 1999. The AM-1 satellite
will also contain the Advanced Spacebome Thermal Emission
and Reflection radiometer (ASTER) for monitoring at moderate
spatial resolutions. ASTER has four 15 m wide bands in the
0.52 to 0.86 pm spectral region, six 30 in bands in the 1.6 to
2.43 pm part and five 90 m bands in the 8.125 to 11.65 pm
spectral range (Schmugge et al., 1999). ASTER’s ability to
serve as a zoom lens for local scale resource management
evaluations can be particularly relevant for evaluating local
agricultural practices. The ASTER Science Team is composed
of members from the United States and Japan, as well as from
France and Australia. NASA’s EOS policy is to provide satellite
data free of charge, and value added data will become
worldwide accessible through the Earth Observing System Data
Information System (EOSDIS). This must be regarded as a
major breakthrough for evaluating land and water resources,
especially in developing countries.
The European Space Agency (ESA) will launch the ENVISAT
satellite having the 15 bands MEdimn Resolution Imaging
Spectrometer (MERIS) and the 7 bands Advanced Along Track
Scanning Radiometer (AATSR) sensors for studying land
surface conditions. MERJS will have different resolution
modes, varying between 250 to 1000 m (0.39 to 1.040 pm
spectrally). AATSR will have a spatial resolution of 1000 m
with bands in the visible, near- and thermal infrared. The second
generation Meteosat (MSG) has, with a 15 minute time interval
between two consecutive images, paramount potential for
monitoring hydro-biospheric processes with rapidly changing
cloud conditions. MSG will get 12 channels with a spatial
resolution of 1 km. It may therefore be regarded as a
geostationary AVHRR type of sensor.
The newest opportunities to get access to I km resolution
images for river basin scale analyses are outstanding and should
not be missed. To increase the use of remote sensing in
operational water resources management in developing
countries, education needs to be fostered and demonstration
projects established. There is a need for international monetaiy
assistance to establish long-term remote sensing skills (Rango
and Shalaby, 1998). A professional team consisting of water
resources managers exploring space data should exchange the
technical capabilities and limitations, and should be regarded as
an important asset for extracting the maximum possible
information at acceptable confidence intervals from space
platforms. The framework and spirit of MODLAND (Running
et al., 1994) can be considered as a good example, and should
perhaps be expanded by a team emphasizing global water
resources conditions.
5. CONCLUSIONS
Demand pressure on water resources from agriculture, industry 1 ,
the domestic sector and from environmental conservation, lias
increased dramatically in the past decades. The world wakens to
the reality that water is a resource that is finite and becoming
increasingly scarce. Competition for limited water supplies
between users, sectors and countries, poses a greater challenge
to manage our natural resources better. There is hardly a
scientific consensus on the large scale water balance and the
water consumption of agro-ecosystems, and this makes water
management evaluations in the context of river basins difficult
to realize with conventional hydro-meteorological networks.
Many developing countries do not have the financial resources
or the organizational capabilities to benefit from the available
remote sensing technologies. Most of the problems limiting the
operational application of remote sensing in hydrology are
either financial or organizational in nature. As the NOAA-
AVHRR data are freely available on the internet one day after
image acquisition for the entire globe, the results of the case
study in Pakistan briefly presented has potential scope for
application in other countries and irrigation schemes. The
Satellite Active Archive has an address at the world wide web
(/www.saa.noaa.gov/) from where the data can be downloaded.
It is expected that this will be followed up by data from new
space platforms.
Remote sensing developments should become more demand
driven, which is only feasible if the end-user is aware of the
technical possibilities. Literature compilations together with
demonstration projects and proper educational programs can
improve the exploration of the added value of earth observation
data in land and water resources management. Ultimately,
remote sensing can help monitoring food security and alleviate
unequal access to the resources of disadvantaged people, but it
requires improvements in financial, educational and technical
aspects.
REFERENCES
Bandara, K.P.M.S., 1998. Water needs and w'ater use of agro
ecosystems in the Kirindi Oya watershed, Sri Lanka, a remote
sensing approach, M.Sc. Thesis, ITC, Enschede, The
Netherlands: 51 pp. and appendices.
Bastiaanssen, W.G.M., 1998. Remote sensing in water
resources management: the state of the art, International Water
Management Institute, Colombo, Sri Lanka: 118 pp.