Search results for "rainfall"

About time of occurrence of rainy days for Mediterranean and (sub)-Alpine areas

2012

A spatially distributed and physically based tool to modelling rainfall-triggered landslides

2009

Landslides are a serious threat to lives and property throughout the world. Over the last few years the need to provide consistent tools and support to decision-makers and land managers have led to significant progress in the analysis and understanding of the occurrence of landslides. The causes of landslides are varied. Multiple dynamic processes are involved in driving slope failures. One of these causes is prolonged rainfall, which affect slope stability in different ways. Water entering the ground beneath a slope always causes a rise of the piezometric surface, which in turn involves an increase of the pore-water pressure and a decrease of the soil shear resistance. For this reason, kno…

Calibration of the SARI portable rainfall simulator for field and laboratory experiments

2019

The Simulator of Artificial RaInfall (SARI) rainfall simulator (RS) is a newly designed, constructed and calibrated, portable, two-nozzle RS with low water consumption, accurate measurement, easy m...

Design and operation of a small and portable rainfall simulator for rugged terrain

1997

A rainfall simulator designed to perform experiments in rugged terrain is presented. The portability of the apparatus allows the researcher to work in remote areas and on steep slopes. Rainfall intensity and distribution within the plot (0.24 m2) and drop-size were measured under different water pressure. For the best simulated rainfall distribution (1.55 kg cm2 of water pressure and 55 mm h−1 of rain intensity) the drop velocity and the kinetic energy were measured.

Regional models based on Multi-Gene Genetic Programming for the simulation of monthly runoff series

2022

Accurate estimates of runoff in river basins are useful for several applications. The use of data-driven procedures for simulating the complex runoff generation process is a promising frontier that could allow for overcoming some typical problems related to more complex traditional approaches. This study explores soft computing based regional models for the reconstruction of monthly runoff in river basins. The region under analysis is the Sicily (Italy), where a regressive rainfall-runoff model, here used as benchmark model, was previously built using data from almost a hundred gauged watersheds across the region. This previous model predicts monthly river runoff based on a unique regional,…

Laboratory testing of Beerkan infiltration experiments for assessing the role of soil sealing on water infiltration

2018

Abstract Soil surface sealing is a major cause of decreased infiltration rates and increased surface runoff and erosion during a rainstorm. The objective of this paper is to quantify the effect of surface sealing on infiltration for 3 layered soils with different textures for the upper layer and investigate the capability of BEST procedure to catch the formation of the seal and related consequences on water infiltration. Rainfall experiments were carried out to induce the formation of the seal. Meanwhile, Beerkan infiltration runs were carried out pouring water at different distances from the soil surface (BEST-H versus BEST-L runs, with a High and Low water pouring heights, respectively) f…

Multivariate nonparametric estimation of the Pickands dependence function using Bernstein polynomials

2017

Abstract Many applications in risk analysis require the estimation of the dependence among multivariate maxima, especially in environmental sciences. Such dependence can be described by the Pickands dependence function of the underlying extreme-value copula. Here, a nonparametric estimator is constructed as the sample equivalent of a multivariate extension of the madogram. Shape constraints on the family of Pickands dependence functions are taken into account by means of a representation in terms of Bernstein polynomials. The large-sample theory of the estimator is developed and its finite-sample performance is evaluated with a simulation study. The approach is illustrated with a dataset of…

Bioclimatic atlas of the terrestrial Arctic

2023

AbstractThe Arctic is the region on Earth that is warming at the fastest rate. In addition to rising means of temperature-related variables, Arctic ecosystems are affected by increasingly frequent extreme weather events causing disturbance to Arctic ecosystems. Here, we introduce a new dataset of bioclimatic indices relevant for investigating the changes of Arctic terrestrial ecosystems. The dataset, called ARCLIM, consists of several climate and event-type indices for the northern high-latitude land areas > 45°N. The indices are calculated from the hourly ERA5-Land reanalysis data for 1950–2021 in a spatial grid of 0.1 degree (~9 km) resolution. The indices are provided in three subsets…

A non-homogeneous Poisson based model for daily rainfall data

2007

In this paper we report some results of the application of a new stochastic model applied to rainfall daily data. The Poisson models, characterized only by the expected rate of events (impulse occurrences, that is the mean number of impulses per unit time) and the assigned probability distribution of the phenomenon magnitude, do not take into consideration the datum regarding the duration of the occurrences, that is fundamental from a hydrological point of view. In order to describe the phenomenon in a way more adherent to its physical nature, we propose a new model simple and manageable. This model takes into account another random variable, representing the duration of the rainfall due to…

A paradigm of extreme rainfall pluvial floods in complex urban areas: the flood event of 15 July 2020 in Palermo (Italy)

2021

Abstract. In the last few years, some regions of the Mediterranean area have witnessed a progressive increase in extreme events, such as urban and flash floods, as a response to the increasingly frequent and severe extreme rainfall events, which are often exacerbated by the ever-growing urbanization. In such a context, the urban drainage systems may not be sufficient to convey the rainwater, thus increasing the risk deriving from the occurrence of such events. This study focuses on a particularly intense urban flood that occurred in Palermo (Italy) on 15 July 2020; it represents a typical pluvial flood due to extreme rainfall on a complex urban area that many cities have experienced in rece…