Search results for "rainfall"
showing 10 items of 233 documents
Influence of rating curve uncertainty on daily rainfall–runoff model predictions
2005
River discharge observations are usually affected by uncertainty, which is due to many concurrent causes and strongly affects the response of rainfall-runoff models. The present paper is aimed at studying the influence of imperfect rating curve knowledge on the uncertainty of the response of a daily conceptual linear-nonlinear rainfall-runoff model. To describe the impact of imperfect rating curve knowledge, simulations have been conducted using a conceptual rainfall-runoff model and continuous daily series of rainfall, air temperature and discharges recorded in a Sicilian catchment. The GLUE procedure was used to introduce the uncertainty of the rating curve in a classical rainfall-runoff …
Investigating the changes in extreme rainfall series recorded in an urbanised area
2002
The aim of this study is to investigate and quantify changes in the rainfall regime of the metropolitan area of Palermo characterised by increasingly strong urbanisation. The rainfall data, considered in this study, were collected on a yearly basis from eight rain gauges within and outside the metropolitan area of Palermo, Sicily, Italy. A preliminary analysis made on the annual total rainfall depths showed a global reduction of total annual rainfall, with two different trends: more regular for the series observed in the rain gauges within the urbanised area and more variable for the series observed in the rain gauges outside the area. A further analysis has been performed using the series …
Umbrales de lluvia, daños y niveles de alerta en la Comunidad Valenciana
2016
Ponencia presentada en: X Congreso de la Asociación Española de Climatología celebrado en Alicante entre el 5 y el 8 de octubre de 2016. [ES]En el contexto de los riesgos climáticos, muchas de las alarmas tempranas de precipitaciones extremas se basan en umbrales de lluvia que, a su vez, están relacionados con niveles probables de daños. A pesar de los grandes esfuerzos que se han venido realizando en los últimos años para discriminar bien los umbrales de estas alertas, uno de los principales problemas es la emisión de un número excesivo de avisos, hecho que puede crear alarmismo. El presente trabajo constituye un estudio aplicado que aborda la detección de indicadores de lluvia y la estima…
Evolución de episodios pluviométricos en la Demarcación Hidrográfica del Júcar (1989-2016): del recurso al riesgo
2020
Este trabajo aborda la clasificación y evolución diacrónica de los episodios de lluvia (1989-2016) en ambientes mediterráneos, en la Demarcación Hidrográfica del Júcar. En base a datos del SAIH, y siguiendo criterios hidrológicos, se seleccionan 698 episodios, que se caracterizan con indicadores de precipitación acumulada, intensidad y persistencia. Mediante un análisis cluster se identifican tres tipologías (episodios de recurso limitado, de gran recurso a largo plazo y de riesgo) y se analiza su evolución temporal, estableciendo diferencias entre los episodios de interior y de litoral. Los resultados muestran una tendencia hacia el incremento del riesgo en detrimento del recurso en los tr…
Comparing Beerkan infiltration tests with rainfall simulation experiments for hydraulic characterization of a sandy-loam soil
2017
[EN] Saturated soil hydraulic conductivity, K-s, data collected by ponding infiltrometer methods and usual experimental procedures could be unusable for interpreting field hydrological processes and particularly rainfall infiltration. The K-s values determined by an infiltrometer experiment carried out by applying water at a relatively large distance from the soil surface could however be more appropriate to explain surface runoff generation phenomena during intense rainfall events. In this study, a link between rainfall simulation and ponding infiltrometer experiments was established for a sandy-loam soil. The height of water pouring for the infiltrometer run was chosen, establishing a sim…
Time Series Analysis of Climatic Vegetation Data in the Oreto Watershed in Sicily
2008
Time series analysis of climate and vegetation variables in the Oreto watershed (Sicily, Italy)
2008
Characterizing rainfall erosivity by kinetic power-Median volume diameter relationship
2018
Abstract Kinetic power, i.e. kinetic energy per unit time and area, is the variable widely used to represent the rainfall erosivity which affects soil loss and sediment yield. This paper shows the results of an experimental investigation using the raindrop size distributions (DSDs) measured by an optical disdrometer installed at the Department of Agricultural, Food and Forestry Sciences of University of Palermo in Italy (June 2006–March 2014) and at the El Teularet experimental station in Spain (July 2015–May 2016). At first an analysis of the DSDs aggregated into intensity classes is carried out, then the measured kinetic power values are determined. The aggregated DSDs allowed to establis…
Assessing changes in rainfall erosivity in Sicily during the twentieth century
2007
Changes in rainfall erosivity are an expected consequence of climate change. Long-term series of the single storm erosion index, EI, may be analysed to detect trends in rainfall erosivity. An indirect approach has to be applied for estimating EI, given that long series of rainfall intensities are seldom available. In this paper, a method for estimating EI from the corresponding rainfall amount, he, was developed for Sicily. This method was then applied at 17 Sicilian locations, representative of different climatic zones of the region, to generate a long series (i.e. from 1916 to 1999 in most cases) of EI values. Linear and step (step located at 1970) trends in annual and seasonal erosivity …
Il ruolo delle precipitazioni occulte nella formazione e mantenimento della vegetazione forestale: il caso studio di Pantelleria
2019
Le testimonianze storiche indicano per le isole circumsiciliane la presenza di floridi boschi che sono stati distrutti a seguito dei processi di deforestazione. In alcuni casi, dopo gli interventi di rimboschimento, la vegetazione riesce a ricostituirsi con difficoltà come a Lampedusa mentre in altri casi i processi di recupero sono molto rapidi. Un ruolo non indifferente viene svolto dalla presenza di piante in grado di diffondere propaguli ma anche dalle condizioni climatiche locali determinate sia dalla morfologia delle singole isole come, ad esempio, la presenza di rilievi montuosi, che dal particolare contesto oceanografico. I dati medi riportati dalle stazioni climatiche in termini di…