Simulating Urban Modifications on Rainfall Using Satellite Observations and
Background and Rational
Understanding of urban effects on rainfall is far from complete. First,
most of the previous research used the ground observations to study one or
few selected cities. However, urban effects vary with the micro-scale
features of individual city. Globally studying urban climate is necessary
in order to generalize the most important characters of urban effects.
Second, previous studies, via different approaches, reached rather
controversial understanding on urban-rainfall relations. It is reported
that urban reduces rainfall due to cloud microphysics (Rathemanthen et al.
2001), although other studies showed that urban enhances the intensity of
storm significantly and increases downward rainfall (Huff and V ogel 1978,
Changnon 1978, Shepherd et. al. 2002). Third, urban simulation is one of
the weakest parts of current land surface modeling (Bonan, 2002 personal
communication). As one extreme example of land cover and
land use changes due to human activities, urban climate must be precisely
understood and predicted
(Changnon 1992, IPCC 2001).