Search results for "rainfall"
showing 10 items of 233 documents
Landslide susceptibility modelling for extreme rainfall-triggered multiple landslides: a key study from the 2009 event in the Giampilieri Area(Sicily…
2013
Regional frequency analysis of extreme rainfall in Sicily (Italy)
2018
Extreme rainfall events have large impacts on society and are likely to increase in intensity under climate change. For design and management decisions, particularly regarding hydraulic works, accurate estimates of precipitation magnitudes are needed at different durations. In this article, an objective approach of the regional frequency analysis (RFA) has been applied to precipitation data for the island of Sicily, Italy. Annual maximum series for rainfall with durations of 1, 3, 6, 12, and 24 h from about 130 rain gauges were used. The RFA has been implemented using principal component analysis (PCA) followed by a clustering analysis, through the k-means algorithm, to identify statistical…
Theoretical prediction of rainfall intensity for a small rainfall simulator
2022
In this contribution, a theoretical approach was developed for predicting rainfall intensity for a small rainfall simulator. The developed equation was tested for two different devices and different pressure head and water temperature values. The proposed relationship was found to have a good predictive ability of rainfall intensity. The proposed theoretical approach could be usable with other devices that operate on the same principles of the simulator considered in this investigation.
A method for evaluating rainfall kinetic power by a characteristic drop diameter
2019
Abstract Empirical relationships linking kinetic energy to rainfall intensity are commonly used to estimate rainfall erosivity. In this paper, using the drop-size distribution (DSD) proposed by Marshall and Palmer, a relationship for calculating the rainfall kinetic power was firstly deduced. This equation requires the simultaneous measurement of both the median volume diameter and the rainfall intensity and its application also reveals the drawback of needing the measurement of the whole DSD by an expensive disdrometric technique. Then, using a fictitious precipitation, which is both constituted by droplets having the same diameter (mean volume diameter) and having the same volume of the a…
Reliability of rainfall kinetic power-intensity relationships
2017
The rainfall erosivity plays a fundamental role in water soil erosion processes and it can be expressed by its kinetic power. At first in this paper the raindrop size distributions measured, in the period June 2006- March 2014, by an optical disdrometer installed at the Department of Agricultural and Forestry Sciences of University of Palermo are aggregated into rainfall intensity classes, having different ranges, and the measured kinetic power values are determined. Measured kinetic power values are initially used for testing the applicability of the kinetic power-rainfall intensity relationships proposed by Wischmeier and Smith (1978), used in Universal Soil Loss Equation (USLE), Brown an…
Residence Time Analysis in the Albufera of Valencia, a Mediterranean Coastal Lagoon, Spain
2021
The Albufera of Valencia is a coastal lagoon located in the western area of the Mediterranean Sea, in the Iberian Peninsula. It has an area of 23.1 km2 and an average depth of only 1 m, with a maximum depth of 1.6 m. This lagoon is the remnants of an original and more extensive wetland of about 220 km2 which is now mostly dedicated to rice cultivation. Surface water is supplied through several main and many secondary canals for a total of 64 water entry points and three exit points to the sea. It is difficult to evaluate the residence time due to the lack of reliable measurements of the inflow or outflow, as well as continuous measurements. Between 1988 and 2018, several procedures were use…
Sensitivity of extreme rainfall to temperature in semi-arid Mediterranean regions
2019
Abstract Warmer air has the potential to hold more water vapour and, therefore, to provide more water to rainfall events. Studying the relationship between rainfall and temperature represents an emerging issue in hydrology and meteorology, since it can be considered fundamental for evaluating the effects of global warming on future precipitation. Various approaches have been tested across different parts of the world, in many cases observing an intensification of extreme precipitation at higher temperatures consistent with the well-known thermodynamic Clausius-Clapeyron relation (CC-scaling rate of 6–7%°C−1). However, at different locations for hourly time-scales, the temperature-extreme ra…
Statistical analysis of inter-arrival times of rainfall events for Italian Sub-Alpine and Mediterranean areas
2012
Abstract. In this work a set of time-series of inter-arrival times of rainfall events, at daily scale, was analysed, with the aim to verify the issue of increasing duration of dry periods. The set consists of 12 time-series recorded at rain gauges in 1926–2005, six of them belong to an Italian Sub-Alpine area (Piedmont) and six to a Mediterranean one (Sicily). In order to overcome the problem related to limited sample size for high values of inter-arrival times, the discrete probability polylog-series distribution was used to fit the empirical data from partial (20 yr) time-series. Moreover, a simple qualitative trend analysis was applied to some high quantiles of inter-arrival times as wel…
Rainfall simulation and Structure-from-Motion photogrammetry for the analysis of soil water erosion in Mediterranean vineyards
2016
[EN] Soil water erosion is a serious problem, especially in agricultural lands.Among these, vineyards deserve attention, because they constitute for the Mediterranean areas a type of land use affected by high soil losses. A significant problem related to the study of soil water erosion in these areas consists in the lack of a standardized procedure of collecting data and reporting results, mainly due to a variability among the measurement methods applied. Given this issue and the seriousness of soil water erosion in Mediterranean vineyards, this works aims to quantify the soil losses caused by simulated rainstorms, and compare them with each other depending on two different methodologies: (…
Co-evolution of hydrological components under climate change scenarios in the Mediterranean area
2015
ABSTRACT The Mediterranean area is historically characterized by high human pressure on water resources. Today, while climate is projected to be modified in the future, through precipitation decrease and temperature increase, that jointly and non-linearly may affect runoff, concerns about water availability are increasing. For these reasons, quantitative assessment of future modifications in the mean annual water availability are important; likewise, the description of the future interannual variability of some hydrological components such as runoff and evapotranspiration are highly wished for water management and ecosystems dynamics analyses. This study investigates at basin spatial scale …