Stefano Barontini

Flooding Hazard Mapping in Floodplain Areas Affected by Piping Breaches in the Po River, Italy

AbstractIn recent years, flood-related risk has been increasing worldwide, being inundations among the natural disasters which induce the maximum damage in terms of economic losses. In the research reported in this paper, a methodology to map the flooding residual hazard due to levee failure events induced by piping in embankments protecting flood-prone areas is proposed. Ensemble simulations are used to account for uncertainties in location, geometry, and time-evolution of the levee breaches. Probabilistic flooding-hazard maps are generated combining the results of 192 inundation scenarios, simulated by using one-dimensional (1D) and two-dimensional (2D) hydrodynamic models. The methodology is applied considering 96 different locations and sizes of breaches occurred along a 23-km reach protected by the right levee of the Po River, the right levee of the Taro River, and the left levee of the Parma River, which delimit a 100-km2 study area. The influence of obstacles to the flood propagation and consequent...

Microwave radiometric measurements of hydrological parameters in mountain areas

In this paper, an experiment aimed at investigating the water balance after soil thawing and the radiation budget is described. The experiment was carried out by combining microwave remote sensing measurements with ground and meteorological data. The higher frequencies were found to be very sensitive to the characteristics of snow, whereas the lower ones were much more influenced by the soil conditions. The sensitivity to soil moisture was well demonstrated at L-band, although the soil was covered by a thick layer of grass, and, to a minor extent, also at C-band.

Innovative Probabilistic Methodology for Evaluating the Reliability of Discrete Levee Reaches Owing to Piping

AbstractTraditionally, levees are a popular measure widely adopted for flood control, accepted and trusted by populations living in floodplain areas. The presence of levees sometimes might even induce a false sense of safety in the population, influencing their decision to develop further in floodplains, because they feel safer. Thus, failures of levee systems are potentially devastating, as they might induce loss of human lives, damages to properties, and economic loss. This study proposes an innovative methodology to estimate the reliability of levee systems, accounting for different sources of uncertainty, and to divide and classify discrete levee reaches, according to different fragility classes. The reliability analysis is performed by evaluating the probability of failure, as a function of a certain failure mechanism, conditioned by a given hydraulic load. Fragility curves are determined using two different methods: Monte Carlo data generation and the so-called approximate, first-order reliability m...

Steady Lateral Flow in Sloping Soils: Which is the Effect of the Conductivity at Saturation Profile?

The effect of the shape of the decreasing conductivity at saturation profile with depth on the steady lateral flow was investigated. The Zaslavsky transformation provided a synthetic, graphically based, approach which resumes the infiltration thresholds to characterize a perched water table and its thickness. It moreover allowed to easily compare the effect of different conductivity at saturation profiles on the capability of subsurface runoff production of the slope. As a case study, a reconstructed layered soil was described by means of two different conductivity profiles. The effect of the two models on the flow field is presented and discussed.

Dimensionless Numerical Approach to Perched Waters in 2D Gradually Layered Soils

Aiming at better understanding the processes involved in perched water tables onset and in their development, the case of a soil slope characterised by gradually decreasing hydraulic conductivity at saturation with depth was numerically investigated. Different anisotropy factors and steepness values were accounted for. The problem was led to a dimensionless form on the basis of the Buckingham π-theorem. Coherently with a theoretical solution of the 2D sloping case, the simulations evidenced (a) non-monotonic transverse profiles of the pressure head within the perched water, (b) slightly lower infiltration thresholds for perched water onset and for soil waterlogging, with respect to the 1D case. If the slope is long enough, an almost uniform flux can be observed in a branch of its central part.

Lake Garda lemon houses (Italy): Opportunities of a sensitive, marginal area in urban planning

Abstract The lemon houses of Lake Garda provide Ecosystem Services, due to their history and their deep rooting in the landscape. Unfortunately, Urban Planning hasn’t ever taken into account these possible benefits. In fact, it has always allowed their reuse as residences and it has sustained the conservation of the buildings only. The lack of interest in reintroducing lemon growing or other agricultural activities has produced a noticeable impoverishment of the local landscape. To overcome these limits, Urban Planning should be oriented to implement practices, which take root in and bring out the variety of local landscapes. In order to reach this result, Urban Planning may help to bring some lemon houses, especially the abandoned or the most vulnerable ones, back to their original agricultural vocation, reintroducing autopoietic agricultural techniques, which are in balance with the environment. An interdisciplinary approach may be adopted in a profitable way, to strengthen the efficiency of the Urban Planning. Aiming at this interdisciplinary approach the paper reports our first investigations concerning the contribution of different disciplines, which will help Urban Planning to consider, in case of the reuse of Lake Garda lemon houses, immaterial benefits and to reintroduce activities linked to their original vocation.

Structural Residual Risk Due to Levee Failures in Flood Mapping

A conceptual framework considering, in a statistical sense, the residual risk related to possible levee failures in flood hazard mapping is presented. The residual risk is separated into a “design hydraulic residual risk”, RRD, associated to levee failures caused by overtopping for low probability events with return period higher than the design value, and into the “structural residual risk”, RRS, in case of failure of the protection because of mechanisms other than overtopping, as piping, erosion, structural instability for medium and high probability events. Statistics of levee failure type and breach size on the Po, Piave, Tagliamento and Adige rivers, in Northern Italy, are estimated, as a function of river morphology and, for the Adige river, of flood intensity. A stochastic framework for probabilistic flood mapping is then discussed, taking into account in a Monte Carlo approach the effect of position, size, density of levees failures on the statistics of depth and velocity of inundated areas. An example is shown of the resulting water velocity uncertainty map which contributes to the residual hazard for the 100-year return period flooding map for a 23 km-reach in the middle-lower portion of the Po River. Implications for flood hazard mapping as requested, for instance, by the European Flood Directive 2007/60/EC are briefly discussed.