HR: 1340h
AN: H33E-1431    [Abstracts]
TI: Rainfall Spatial Patterns and Catchment-Scale Geomorphic Hydrologic Response
AU: Nic•tina, L
EM: ludovico_81@yahoo.it
AF: Dipartimento di Ingegneria Idraulica Marittima e Geotecnica and International centre for Hydrology "Dino Tonini", Universit… di Padova, Padua, Italy, Via Loredan 20, Padua, I-35131 Italy
AU: * Uccelli, A
EM: uccelli@idra.unipd.it
AF: Dipartimento di Ingegneria Idraulica Marittima e Geotecnica and International centre for Hydrology "Dino Tonini", Universit… di Padova, Padua, Italy, Via Loredan 20, Padua, I-35131 Italy
AU: Settin, T
EM: settin@idra.unipd.it
AF: Dipartimento di Ingegneria Idraulica Marittima e Geotecnica and International centre for Hydrology "Dino Tonini", Universit… di Padova, Padua, Italy, Via Loredan 20, Padua, I-35131 Italy
AU: Botter, G
EM: botter@idra.unipd.it
AF: Dipartimento di Ingegneria Idraulica Marittima e Geotecnica and International centre for Hydrology "Dino Tonini", Universit… di Padova, Padua, Italy, Via Loredan 20, Padua, I-35131 Italy
AU: Rinaldo, A
EM: rinaldo@idra.unipd.it
AF: Dipartimento di Ingegneria Idraulica Marittima e Geotecnica and International centre for Hydrology "Dino Tonini", Universit… di Padova, Padua, Italy, Via Loredan 20, Padua, I-35131 Italy
AU: Marani, M
EM: marani@idra.unipd.it
AF: Dipartimento di Ingegneria Idraulica Marittima e Geotecnica and International centre for Hydrology "Dino Tonini", Universit… di Padova, Padua, Italy, Via Loredan 20, Padua, I-35131 Italy
AB: This paper focuses on the spatial accuracy required in the description of rainfall forcings for modelling the hydrologic response. Patterns of precipitation in space and time are usually achieved by means of geostatistical techniques (i.e. ordinary Kriging) based on point rainfall observations. The above procedure obviously requires an observation network, whose density affects the spatial resolution adopted to estimate the rainfall field. The choice of a spatial resolution is related to the physical dimensions of the catchment and to the degree of detail suited for hydrologic purposes. High resolutions may lead to heavy computational burdens and are often prevented by the lack of a dense observation network. On the other hand, low resolutions may produce a significant underrepresentation of rainfall spatial heterogeneity and errors in the simulation of the relevant hydrologic processes. Here we explore the effects of different spatial resolutions in the description of the rainfall forcing on the geomorphic hydrologic response, in a spatially distributed framework capable of accounting for arbitrary patterns of rainfall in space and time. In particular, we focus upon rainfall fields at resolutions ranging from the hillslope to the catchment scale (i.e. from 0.01 km2 up to 8000 km2) by means of numerical up-scaling. We explore applications to two basins of widely different areas (1500 km2 and 8000 km2) located in Northern Italy. Using well-tested geomorphological models of the hydrologic response we progressively upscale the rainfall fields of actual events and address the ensuing changes in the modelled responses. We relate such differences to changes induced by different resolutions in the estimated total rainfall volume impinging on the basins and to the varying features of rainfall heterogeneity captured at different resolutions. The results from a wide variety of events demonstrate the major role played by the total rainfall input to the basin, particularly for relatively small and medium-sized basins, and the increasing influence of an accurate representation of rainfall heterogeneities as the size of the basin is increased.
DE: 1804 Catchment
DE: 1854 Precipitation (3354)
DE: 1860 Streamflow
SC: Hydrology [H]
MN: Fall Meeting 2005