Suchergebnisse

Abstract. This study investigates precipitation variability in five regions of Southern Italy (Campania, Apulia, Basilicata, Calabria and Sicily) using a homogeneous database of about 70 rain gauges with more than 50 years of observation. First, a statistical analysis was performed through the Mann-Kendall non-parametric test in order to determine rainfall the trend on both yearly and seasonal scales. Then, the relationship between the rainfall and some teleconnection pattern indexes was investigated using Spearman's test. The results show remarkable statistically significant negative trends for annual and winter aggregations in most part of the series. Moreover, a strong correlation has emerged between the teleconnection patterns and precipitation in Southern Italy, particularly in winter and on the Tyrrhenian side of the study area.

Abstract. In recent years, the interest in the prediction and prevention of natural hazards related to hydrometeorological events has grown due to the increased frequency of extreme rainstorms. Several research projects have been developed to test hydrometeorological models for real-time flood forecasting. However, flood forecasting systems are still not widespread in operational context. Real-world examples are mainly dedicated to the use of flood routing model, best suited for large river basins. For small basins, it is necessary to take advantage of the lag time between the onset of a rainstorm and the beginning of the hydrograph rise, with the use of rainfall-runoff transformation models. Nevertheless, when the lag time is very short, a rainfall predictor is required, as a result, meteorological models are often coupled with hydrological simulation. While this chaining allows floods to be forecasted on small catchments with response times ranging from 6 to 12 h it, however, causes new problems for the reliability of Quantitative Precipitation Forecasts (QPF) and also creates additional accuracy problems for space and time scales. The aim of this work is to evaluate the degree to which uncertain QPF affects the reliability of the whole hydro-meteorological alert system for small catchments. For this purpose, a distributed hydrological model (FEST-WB) was developed and analysed in operational setting experiments, i.e. the hydrological model was forced with rain observation until the time of forecast and with the QPF for the successive period, as is usual in real-time procedures. Analysis focuses on the AMPHORE case studies in Piemonte in November 2002.

Arizona Department of Transportation, Phoenix ; Mode of access: Internet. ; Author corporate affiliation: DMJM-Harris, Phoenix, Ariz. ; ""May 2003." ; Includes bibliographical references ; Final report; July 2002-June 2003 ; In cooperation with the U.S. Department of Transportation, Federal Highway Administration ; Subject code: EJV ; Subject code: HBEF ; Subject code: CDNC ; Subject code: SFB ; Subject code: VI ; Subject code: LCC ; Subject code: FGD ; Subject code: KN

Urban lakes are environments with structural and functional features quite different from common lakes. This study aims to present the main results related to the environmental status of Villa Dalcar lake (33°06'25"S, 64°22'31"W, 7 ha), located in the city of Río Cuarto (Córdoba). In this lake, diverse activities as swimming, boating (including motorboat competitions), recreational and for human consumption fishing, removal of bait fish, research and teaching are usually performed. The lake also provides habitat for at least 16 fish species and other communities. However, there has been a significant conflict about the use of water, landscape contamination, fish mortality and different expressions of the trophic state, which was manifested by periods of clear and turbid waters. Different management measures were implemented to control aquatic macrophytes, such as mechanical removal, biomanipulation with fish using Ctenopharyngodon idella and dredging. The results have been variable depending on: the abundance of cyprinids, the activities developed in the basin and the fluctuations in water volume. The lake is a challenge as far as handling is concerned and the latter depends on a number of environmental, social and even political factors. ; Instituto de Limnología "Raúl A. Ringuelet"

Abstract. In recent years the interest in the forecast and prevention of natural hazards related to hydro-meteorological events has increased the challenge for numerical weather modelling, in particular for limited area models, to improve the quantitative precipitation forecasts (QPF) for hydrological purposes. After the encouraging results obtained in the MAP D-PHASE Project, we decided to devote further analyses to show recent improvements in the operational use of hydro-meteorological chains, and above all to better investigate the key role played by temperature during snowy precipitation. In this study we present a reanalysis simulation of one meteorological event, which occurred in November 2008 in the Piedmont Region. The attention is focused on the key role of air temperature, which is a crucial feature in determining the partitioning of precipitation in solid and liquid phase, influencing the quantitative discharge forecast (QDF) into the Alpine region. This is linked to the basin ipsographic curve and therefore by the total contributing area related to the snow line of the event. In order to assess hydrological predictions affected by meteorological forcing, a sensitivity analysis of the model output was carried out to evaluate different simulation scenarios, considering the forecast effects which can radically modify the discharge forecast. Results show how in real-time systems hydrological forecasters have to consider also the temperature uncertainty in forecasts in order to better understand the snow dynamics and its effect on runoff during a meteorological warning with a crucial snow line over the basin. The hydrological ensemble forecasts are based on the 16 members of the meteorological ensemble system COSMO-LEPS (developed by ARPA-SIMC) based on the non-hydrostatic model COSMO, while the hydrological model used to generate the runoff simulations is the rainfall–runoff distributed FEST-WB model, developed at Politecnico di Milano.

<i>Background:</i> The Italian external quality assessment scheme in classical cytogenetics was started in 2001 as an activity funded by the National Health System and coordinated by the Italian Public Institute of Health. <i>Objectives:</i> The aim of our work is to present data from the first 4 years of activity, 2001–2004. <i>Methods:</i> Italian cytogenetics public laboratories were enrolled on a voluntary basis, and this nationwide program covered prenatal, postnatal and oncological diagnosis. The scheme is annual and retrospective; a panel of experts reviewed the quality of images and reports in order to assess technical, analytical and interpretative performance. <i>Results:</i> Over the 4-year period, the number of participating laboratories increased: from 36 in 2001, 46 in 2002, 49 in 2003 to 51 in 2004. The overall technical performance was satisfactory. Inadequacy or lack of information in reporting was the most frequent analytical inaccuracy identified in all parts of the scheme. However, the percentage of complete reports increased significantly during the period: by 36% in postnatal diagnosis between 2001 and 2004 (p < 0.001) and by 42% in oncological diagnosis between 2002 and 2004 (p = 0.003). <i>Conclusions:</i> Our experience reveals that participation in external quality assessment programs has significant advantages, helping to standardize and to assure quality in cytogenetic testing.