HR: 0800h
AN: H31F-1355    [Abstracts]
TI: Impact of Soil Depths on the Catchment-Scale Geomorphic Hydrologic Response
AU: * Uccelli, A
EM: uccelli@idra.unipd.it
AF: Dipartimento di Ingegneria Idraulica, Marittima e Geotecnica and International centre for hydrology "D. Tonini", Universit… di Padova, Padua, Italy, Via Loredan 20, Padua, I-35131 Italy
AU: Catani, F
EM: filippo.catani@geo.unifi.it
AF: University of Florence, Italy, Via LaPira 4, Florence, I-50121 Italy
AU: Marani, M
EM: marani@idra.unipd.it
AF: Dipartimento di Ingegneria Idraulica, Marittima e Geotecnica and International centre for hydrology "D. 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 "D. Tonini", Universit… di Padova, Padua, Italy, Via Loredan 20, Padua, I-35131 Italy
AB: Catchment modelling in areas dominated by geomorphologic active processes is often hampered by the lack of reliable and easily applicable models of sediment production and transfer at the basin scale (e.g. erosion and landsliding). One of the major problems in distributed soil erosion and landsliding models is the correct evaluation of the spatial distribution of the soil thickness (i.e. distance to bedrock). The soil thickness may strongly vary within a single catchment as a function of the vegetation cover, lithology, climate, gradient, hillslope curvature, upslope contributing area and land use. In this paper we focus on the prediction of soil thickness by means of topographic and geomorphologic attributes, such as local topographic gradients, slope curvatures and physiographic types (e.g. patterns of soil catenas and toposequences). The application of the model to a relevant case study (the Terzona creek catchment, central Italy) provides results which are in substantial agreement with observed field data, confirming the capability of the model to enhance the prediction of soil thickness in cases of practical interest. To assess the overall influence of computed soil depths on the ensuing hydrologic response at the basin-scale, the Green-Ampt approach for shallow soils has been incorporated into a geomorphic model of the hydrologic response, exploiting key information (e.g. the spatial distribution of soil uses and textures) obtained from remotely sensed images. The basic geomorphologic assumptions pertain to the different dynamics of runoff production in topographically convergent or divergent sites, with a view to the effect of soil depths as seen through different models of soil production. As such, this class of models represents a useful tool for estimating the hydrologic response of a river basin in a spatially distributed framework. A discussion follows on the application of the model to the Brenta river basin (Northern Italy) and on a comparative analysis between the geomorphic approach described above (where the soil saturation dynamics are linked to the soil thickness) and other classical models of runoff production.
DE: 1804 Catchment
DE: 1826 Geomorphology: hillslope (1625)
DE: 1855 Remote sensing (1640)
DE: 1865 Soils (0486)
SC: Hydrology [H]
MN: Fall Meeting 2005