Field Experiments Aimed To The Analysis of Flood Generation Processes
Abstract
The study of the soil moisture dynamics and of the climate-soil-vegetation interac- tion is essential for the comprehension of possible climatic change phenomena, as well as for the analysis of occurrence of extreme hydrological events. In this trend the theoretically-based distribution of floods recently derived by Fiorentino and Ia- cobellis, [ŞNew insights about the climatic and geologic control on the probability distribution of floodsT, Water Resources Research, 2001, 37: 721-730] demonstrated,
by an application in some Southern Italy basins, that processes at the hillslope scale strongly influence the basin response by means of the different mechanisms of runoff generation produced by various distributions of partial area contributing. This area is considered as a stochastic variable whose pdf position parameter showed strong de- pendence on the climate as it can seen in the studied basins behavior: in dry zones, where there is the prevalence of the infiltration excess (Horton) mechanism, the basin water loss parameter decreases as basin area increases and the flood peak source area depends on the permeability of soils; in humid zones, with the prevalence of satu- ration excess (Dunne) process, the loss parameter seems independent from the basin area and very sensitive to simple climatic index while only small portion of the area invested by the storm contributes to floods. The purpose of this work is to investigate the consistency of those interpretations by means of field experiments at the hillslope scale to establish a parameterization accounting for soil physical and hydraulic prop- erties, vegetation characteristics and land-use. The research site is the catchment of River Fiumarella di Corleto, which is located in Basilicata Region, Italy, and has a drainage area of approximately 32 km2. The environment has a rather dynamic geo- morphology and very interesting features from the soil-landscape modeling viewpoint [Santini A., A. Coppola, N. Romano, and F. Terribile. 1999. Interpretation of the spa- tial variability of soil hydraulic properties using a land system analysis. In Modelling of Transport Processes in Soils, J. Feyen and K. Wiyo, eds., p. 491-500, Wageningen Pers, Wageningen, The Netherlands.]. A soil-landscape map was set-up and undis- turbed soil cores, spaced 50 m apart, were regularly collected from the uppermost soil horizons along transects located at the two sides of the river. All cores were subjected to laboratory measurements to determine bulk density, particle-size distribution, or- ganic carbon content, and unsaturated soil hydraulic characteristics. Other field exper- iment have been performed through a non-invasive method of monitoring the spatial 1 and temporal variations of soil water content by using soil resistivity data from elec- trical resistivity tomography and relating the soil resistivity to soil water content. The presence of two pluviometers and a hydrometer permits the evaluation of watershed inflows and outflows at different timescale. 2- Publication:
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EGS General Assembly Conference Abstracts
- Pub Date:
- 2002
- Bibcode:
- 2002EGSGA..27.5453C