Abstract:
Water-related hazards usually occur as causes and consequences of large water cycle
fluctuations on global and regional scales, while disasters and damages due to these hazards
happen through strong linkage with human activities on a local scale. The observations and
predictions of water-related hazards and their damages can be enhanced by combining global
Earth observation and prediction systems and local information. In this context, downscaling
of the water cycle from global to regional and local scales is a key integration function.
General circulation models currently used for predicting weather and climate have coarse
spatial resolution and thus cannot capture the details of topography and land use nor resolve
important cyclonic disturbances or similar-sized circulation features. This precludes an
accurate representation of precipitation on the scales of individual grid boxes. The method to
obtain regional-to-local scale information from larger-scale general circulation model data is
referred to as downscaling. The flash flood control system of the Global Earth Observation
System of Systems takes maximum advantage of global Earth observations and predictions
and develops a downscaling system coupled with satellite-based data assimilations and
distributed hydrological models to disseminate usable information on a river basin or smaller
scale for decision making in disaster mitigation and water resource planning.
