Riviste Online SApienza - R.O.SA - 2 (Sapienza University of Rome)
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Evolution, forecasting and managment of siltation in Algerian dams
No full textThe aim of this study was to improve the sedimentation estimates and to know the evolution of the siltation of 8 Algerian dams according to a semi-quantitative approach which takes into account the comparison of the bathymetric surveys and the calculations carried out by empirical formulas widely used in Algeria (F. Orth). The initial capacity of the 8 considered reservoirs was 906 Mm3, it was reduced to 675.14 Mm3 in 1986 about 524.5 Mm3 in 2010, It is noticed a decrease of 370.5 Mm3 or 58.6% between the initial capacity and the last bathymetric survey in 2010. The average annual siltation is clearly varied according to the following phases:- a weak alluvial phase had started with the impoundment until 1986 and showed less than 0.50 Mm3 of silt;- an average alluvial phase extends between 1986 and 2004 and presents values varying between 0.50 Mm3 and 0.60 Mm3;- a high alluvial phase spread between 2004 and 2010, it gives considerable volumes which annually exceeds 0.60 Mm3.On the other hand, F. Orth model gives results close and comparable to those obtained by bathymetric surveys for most dams, which qualifies the application of this model in similar conditions in the absence of gauging stations
Engineering Geological Factors Affecting Loess Caves Susceptibility Mapping in Gorgan plain, Golestan province, northeastern Iran
No full textLoess cave is one of the geological hazards in the Loess Plateau of northeast Iran, in the Gorgan plain. In total, 697 caves were mapped, and an inventory map was prepared. Due to the importance of geo-environmental and soil properties in the development of loess caves, six independent variables, including joint density, land use, soil type, collapse sensitivity, self-weight collapse coefficient, and surface water distance, were designed for modeling the caves susceptibility in the GIS software. Loess cave susceptibility maps were constructed using Density Area (DA), Information Value (IF), and Frequency Ratio (FR) methods in a GIS environment. Loess cave susceptibility map obtained from three models was compared using Relative Operating Characteristic (ROC) and Area Under Curve (AUC). The area under the curve analysis was used to evaluate model compatibility and predictability. The equal interval classification method classified the study area into five ordinal categories, i.e., very low, low, moderate, high, and very high. AUC of the IF model was 0.727. The values of AUC for DR and the FR models were similar and equal to 0.725. Therefore, the loess cave susceptibility maps of Golestan Province is valuable for decision-maker in loess cave-prone area
Development and evaluation of the drinking water quality index in the Eastern Bank of Nineveh Governorate
No full textGroundwater quality is the result of all the chemical and hydrological reactions and processes that affected on the water. The Water Quality Index (WQI) is a mathematical tool that describes water quality to assess the levels of water usage. This study attempts to develop a new method for the groundwater quality index (GWQI). It is based on the standards of the (WHO, 2006) and the (IQS 417, 2001) to assess the groundwater and validity of wells water for drinking in the eastern bank of Nineveh Governorate. 139 well water samples were taken to measure 12 physical variables (pH, E.C. and T.D.S.) and chemical variables (Ca2+, Mg2+, Na+, K+, SO42, HCO32-, Cl-, NO3-, and T.H.). Nine variables were use to calculate the WQI, excluding non-influential parameters (potassium, pH, and bicarbonate) that fall within the permissible ranges for drinking in WHO and IQS 417, based on the statistical treatments. The study developed and modified equations and classifications were used to reflect an accurate quality of the groundwater in the region. The (GWQI.3) classified depending on (WHO, 2006), 37% of wells were unsuitable, 57% were very poor, 6% were poor, while the (GWQI.6) was classified as follows: 68% are unsuitable, 30% very poor, 2% poor, depending on (IQS 417, 2001). In general, groundwater in the study area is unsuitable for drinking and civil uses
Severe attacks caused by Macrolenes dentipes (Olivier) on Feijoa, Acca sellowiana (O. Berg) Burret (Myrtaceae) in Italy (Coleoptera: Chrysomelidae)
Get PDFDuring recent surveys of tropical fruit plants in Southern Italy, severe infestations were observed on young vegetation of Feijoa, Acca sellowiana (O. Berg) Burret inflicted by the leaf beetle Macrolenes dentipes (Olivier, 1808) (Coleoptera, Chrysomelidae, Cryptocephalinae) which occurs in the Mediterranean area. Feijoa is a species that belongs to the Myrtaceae family and bears an edible interesting fruit. From 2016 we observed adults of M. dentipes feeding on Acca sellowiana leaves in orchards located in the Calabria and Sicily regions. We identified the phenological stages of Feijoa leaves in 12 trees according to the Biologische Bundesanstalt, Bundessortenamt und Chemische Industrie (BBCH) scale. M. dentipes feeds on young leaves (BBCH scale: principal stage 1, substages 10-17). Its adult life cycle on feijoa trees lasts from early June until the end of flowering in late June (BBCH scale: principal growth 7, substage 65) and when the fruits begin to develop (BBCH scale: principal stage 7, substage 70). Details on the current distribution, host plants, biologicaltraits, and natural enemies are given for M. dentipes
Rhizotrogus tedeschii, a new species from the alpine zone of the Pollino Massif, southern Italy (Coleoptera: Scarabaeidae, Melolonthinae)
Get PDFA new species of Rhizotrogus from southern Italy (Calabria, Pollino Massif) is described and illustrated. Rhizotrogus tedeschii n. sp. is a high-altitude, day-active species, very similar to R. cicatricosus, from which differs by characters of external morphology and genitalia. Images of its environment, and natural history observations are also provided. The intraspecific variation of R. cicatricosus is also briefly addressed
First Italian records of the rare minute tree-fungus beetle Cisarthron laevicolle (Coleoptera: Ciidae)
No full textThe rare South-European beetle Cisarthron laevicolle Reitter, 1885 is here reported for the first time from Italy. The currently known distribution, ecology and phenology of this species are briefly discussed
Managing cash-in risk embedded in Portfolio Insurance strategies: a review
No full textA portfolio insurance strategy is a dynamic hedging process aiming to limit downside risk during a market downturn and allow the investor to obtain an equity market participation in the upside market. The biggest potential risk of implementing a portfolio insurance strategy is the so-called cash-in risk, i.e., the risk that the underlying asset registers huge drops before the portfolio can be rebalanced. In such cases, the value of the insured portfolio would fall below the floor (the insured capital), and the consequence is that the portfolio is fully monetized, not allowing the investor to recover the capital initiallyinvested. First, this paper reviews the main properties of the most important allocation algorithm, the so called Constant Proportion Portfolio Insurance(CPPI), and how the cash-in risk embedded with this allocation strategy can be modeled and hedged. Secondly, it describes the main extensions of CPPIproposed in the literature to improve its capability to reduce cash-in risk
Le Komintern et les paysans
Get PDFLo scopo del presente saggio è di mostrare la storia del “comunismo rurale” e della sua relazione con il Comintern (Internazionale Comunista) nel corsodel periodo inter-bellico. Concentrandosi in particolare sulla creazione di un ramo specifico, il Krestintern o Centro Contadino Internazionale, il contributo cerca di analizzare e comprendere la relazione che intercorre tra le istanze del Comintern e le risposte che vengono fornite a livello locale. L’idea di una riforma agraria era infatti in grado di incontrarsi con le proposte portate avanti da molteplici movimenti d’emancipazione in differenti paesi
Seawater intrusion vulnerability assessment by Galdit method in the Metaponto coastal aquifer (Basilicata, Italy)
No full textThe groundwater vulnerability assessment to seawater intrusion (SWI), applying the GIS-based overlay-index GALDIT method, is provided for the Metaponto coastal aquifer (Basilicata region, southern Italy). The method is based on six conditioning parameters: groundwater occurrence (G), aquifer hydraulic conductivity (A), groundwater level (L), distance from the shore (D), impact of the existing status of SWI (I), and aquifer thickness (T). Three vulnerability classes were detected: low, moderate, and high, covering 70.40%, 22.65%, and 6.95% of the study area, respectively. The highest class is located close to the coastal sector due to the proximity to the sea, the greater thickness of the aquifer, and the shallow freshwater-seawater interface. To evaluate the sensitivity of the method on the predictive analysis and the influence of the single parameter and weight on the final vulnerability, the sensitivity analysis was carried out. The single-parameter analysis indicated that the factors such as groundwater table above sea level (a.s.l.), aquifer type, and impact of SWI have the greatest influence on the vulnerability. The application leads to the vulnerability mapping to SWI in the coastal plain that results to be a promising tool for decision-making finalized to properly manage groundwater