Search results for "Idrologia"

Critical analysis of the thermal inertia approach to map soil water content under sparse vegetation and changeable sky conditions

2012

The paper reports a critical analysis of the thermal inertia approach to map surface soil water content on bare and sparsely vegetated soils by means of remotely sensed data. The study area is an experimental area located in Barrax (Spain). Field data were acquired within the Barrax 2011 research project. AHS airborne images including VIS/NIR and TIR bands were acquired both day and night time by the INTA (Instituto Nacional de Tecnica Aeroespacial) between the 11 th and 13 rd of June 2011. Images cover a corn pivot surrounded by bare soil, where a set of in situ data have been collected previously and simultaneously to overpasses. To validate remotely sensed estimations, a preliminary prox…

Prediction of soil texture distributions using VNIR-SWIR reflectance spectroscopy

2013

Abstract Reflectance spectroscopy provides an alternate method to non-destructively characterize key soil properties. Different approaches, including chemometrics techniques or specific absorption features, have been proposed to estimate soil properties from visible and near-infrared (VNIR, 400-1200 nm) and shortwave infrared (SWIR, 1200-2500 nm) reflectance domains. The main goal of this study was to test the performance of two distinct methods for soil texture estimation by VNIR-SWIR reflectance measurements: i) the Continuum Removal (CR) technique that was used to correlate specific spectral absorption features with clay, silt and sand content, and ii) the Partial Least-Squares Regressio…

Tetti verdi multistrato per lo sviluppo sostenibile di città resilienti: quattro casi studio italiani

2021

Negli ultimi anni le inondazioni in ambito urbano sono state sempre più frequenti, provocando notevoli danni sia livello sociale che a livello economico. Questo fenomeno è in parte determinato da un aumento di urbanizzazione causato dalla crescita della popolazione, che tende sempre più a spostarsi dalle zone rurali alle aree urbane, che si espandono molto velocemente, spesso con infrastrutture idrauliche inadeguate. Inoltre, a causa di cambiamenti climatici, soprattutto nelle aree mediterranee, si può osservare un aumento di lunghi periodi di siccità, intervallati da piogge di breve durata, ma di sempre più forte intensità e frequenza. La presenza di questi fenomeni di pioggia intensa, in …

DORA algorithm for network flow models with improved stability and convergence properties

2001

A new methodology for the solution of shallow water equations is applied for the computation of the unsteady-state flow in an urban drainage network. The inertial terms are neglected in the momentum equations and the solution is decoupled into one kinematic and one diffusive component. After a short presentation of the DORA (Double ORder Approximation) methodology in the case of a single open channel, the new methodology is applied to the case of a sewer network. The transition from partial to full section and vice versa is treated without the help of the Preissmann approximation. The algorithm also allows the computation of the diffusive component in the case of vertical topographic discon…

Daily streamlow prediction with uncertainty in ephemeral catchments using the GLUE methodology

2009

Abstract The Generalised Likelihood Uncertainty Estimation (GLUE) approach is presented here as a tool for estimating the predictive uncertainty of a rainfall–runoff model. The GLUE methodology allows to recognise the possible equifinality of different parameter sets and assesses the likelihood of a parameters set being acceptable simulator when model predictions are compared to observed field data. The results of the GLUE methodology depend greatly on the choice of the likelihood measure and on the choice of the threshold which determines if a parameters set is behavioural or not. Moreover the sampling size has a strong influence on the uncertainty assessment of the response of a rainfall–…

Probabilistic characterization of flood hazard using bivariate analysis based on copulas

2014

This study presents an innovative approach to obtain flood hazard maps where hydrological input (synthetic flood design event) to a 2D hydraulic model has been defined by generating flood peak discharges and volumes from a bivariate statistical analysis, through the use of copulas. Synthetic hydrographs were generated by means two different approaches: an indirect one, where rainfall were generated by a stochastic bivariate rainfall generator to be entered a distributed conceptual rainfall-runoff model that consisted of a soil moisture routine and a flow routing routine; and a direct one, where stochastic generation of flood peaks and flow volumes have been obtained via copulas, which descr…

Development and analysis of the Soil Water Infiltration Global database

2018

27 Pags.- 11 Tabls.- 8 Figs. © Author(s) 2018. This work is distributed under the Creative Commons Attribution 4.0 License.

State and parameter update in a coupled energy/hydrologic balance model using ensemble Kalman filtering

2012

Summary The capability to accurately monitor and describe daily evapotranspiration (ET) in a cost effective manner is generally attributed to hydrological models. However, continuous solution of energy and water balance provides precise estimations only when a detailed knowledge of sub-surface characteristics is available. On the other hand, residual surface energy balance models, based on remote observation of land surface temperature, are characterised by sufficient accuracy, but their applicability is limited by the lack of high frequency and high resolution thermal data. A compromise between these two methodologies is represented by the use of data assimilation scheme to include sparse …

Caratterizzazione idrologica dei bacini siciliani col metodo del Curve Number

2010

RUNOFF CURVE NUMBER METHOD IN SICILY: CN DETERMINATION AND ANALYSIS OF THE INITIAL ABSTRACTION RATIO

2010

The Curve Number method is widely used in hydrology because it’s simply based on a single parameter, CN, that represents the basin absorption. In this paper CN is evaluated at basin scale from rainfall-runoff multi-daily events (Mockus, 1964), in the observation period 1940-1997 (record length mean equal to 20 years), for 61 Sicilian basin with three different methods: NEH4 method, Asymptotic fitting method (Hawkins, 1990, Hawkins et al., 2002, Hawkins et al., 2009), Least squares method (Woodward et al., 2006, Hawkins et al., 2009). A first analysis of Sicilian watershed behavior indicates a major occurrence of standard CN response (42 basins), rather than complacent response (11 basins) a…