HR: 09:45h
AN: NG41A-08 INVITED     [PDF]
TI: Non-homogeneity in rainfall: some considerations
AU: * De Michele, C
EM: carlo.demichele@polimi.it
AF: DIIAR-Politecnico di milano, 32, P.zza L. da Vinci, Milano, I20231 Italy
AB: The homogeneity of rainfall as working hypothesis has widely adopted in hydrologic science. Non-homogeneity can be safely neglected when, at the relevant scales, it has small effect and the random field may be considered homogeneous; in other circumstances homogeneity and non-homogeneity co-exist within the same data set, at different range of scales (e.g. small-scale non-homogeneity and large-scale homogeneity) or in a more complex way. On the other side, it is accepted that rainfall fields exhibit scale invariance properties over a wide range of spatial and temporal windows. This aspect of rainfall is non consistent with its non-homogeneity; namely when the scaling properties are assessed over a range of scales where the homogeneity is a poor approximation, wrong conclusions are drawn. On this route, the presence of non-homogeneity in rainfall is detected through some statistical tests. It is showed how neglecting the non-homogeneity behaviour, some wrong conclusions and unreliable estimate of the scaling exponents can be obtained. Applications to observed and synthetic rainfall data are given and discussed.
DE: 1854 Precipitation (3354)
DE: 1869 Stochastic processes
DE: 3354 Precipitation (1854)
SC: Nonlinear Geophysics [NG]
MN: 2003 Fall Meeting