Riviste Online SApienza - R.O.SA - 2 (Sapienza University of Rome)
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Gis-based permanent displacement maps for urban planning of unstable seismic territories: a case study in Daunia Apennine (Apulia, Italy)
Get PDFEarthquake induced landslides (EIL) represent coseismic effects that heavily affect seismic territories worldwide and must be taken into account in urban planning according to national laws and technical provisions. Inventories of earthquake-triggered landslides and and geotechnical characterization of soils involved into mass movements are commonly prescribed to predict EIL with increasing details as the scale of the study increases. EIL hazard is assessed through several different methods. At urban scale, the deterministic approach of the Newmark’s sliding rigid block method is commonly employed to draw EIL hazard maps by calculating permanent displacements triggered by seismic events. Thematic maps built within ArcGis environment have been combined to draw hazard maps through the raster calculator tool (ARCMAPTM 2010). In this paper the Newmark’s method is applied to the case study of Deliceto town, located in Daunia Apennine (Apulia, Southern Italy). This territory is characterized by frequent and widespread landslide phenomena triggered by seasonal rainfalls and strong earthquakes, such as the 23rd November 1980 Irpinia earthquake. In particular, Deliceto is affected by the highest seismic level within Daunia territory corresponding to the expected peak ground acceleration (PGA) equal to 0.20 g. The outcomes of the present study suggest that the highest permanent displacements are expected along steep slopes made up of an alternation of limestones and marly clays belonging to the Flysch Faeto Fm
Criteria, objectives and methodologies for water network partitioning
Get PDFWater distribution networks are complex infrastructures characterized by very large dimensions (meshed networks with thousands of nodes) and reduced accessibility (generally they are buried underground). These peculiarities make it particularly difficult to manage and show numerous criticalities; at the same time, water distribution networks represent one of the main subsystems of smart cities. The paradigm “divide et impera” is a valid technique to improve the management and facilitate the maintenance, the water balance estimation, the water leakage detection and the pressures control. On this side, Water network District Metering (WDM), a method developed in England, and already implemented in many countries, represents a modern technique to organize urban water systems, offering new perspectives for design, management and maintenance. The WDM is recommended as one of the best practice to limit the huge amount of dispersed water in urban networks, simplifying water leakage detection, carrying out pressure management, improving water system management and monitoring of district hydraulic data. On this subject, the authors developed a specific software (SWANP 3.0) for water network partitioning that integrates the main optimization algorithms. This paper shows the main aspects of water network partitioning summarizing the principal recently proposed techniques in the literature aimed to find the best partitioning layout from an economic and performance point of view
New aquatic species of Megaselia Rondani from Bolivia (Diptera: Phoridae)
Get PDFTen aquatic species of Megaselia Rondani (1856) are reported from the internodes of the large bamboo Guadua angustifolia var. chacoensis in Bolivia. Megaselia aquatica sp. n., and M. imitatrix Borgmeier (1969) are named and seven species given code letters as their males remain unknown. Five of these species closely resemble the distinctive M. imitatrix. The eggs of species C, in addition to a subterminal plastron, uniquely have the rest of the egg covered in fine hairs. Three additional Megaselia species reported from bamboo or other phytotelms in the Americas, Megaselia hansonix Disney (2009), M. rufipes (Meigen) (1804) and M. scalaris (Loew) (1866) are illustrated. A key for Megaselia from the Americas reported from aquatic situations is presented
Amphoraceras rothschildi and A. jordani sp. n.: two sibling species (Lepidoptera: Erebidae)
Get PDFOne new species of Amphoraceras which has so far remained unrecognised and intermingled within A. rothschildi is described as A. jordani sp. n. Both species are endemic to New Guinea, where they even happen to locally coexist and overlap phenologically. Main diagnostic features between the two taxa occur in the development of the unusual amphora-shaped structure present on male antenna, which is herewith detailed morphologically, aspects of the habitus and features of the genitalia
New data on the Australasian Xantholinini. 12. New species from New Caledonia (Coleoptera: Staphylinidae)
Get PDFIn this short contribution some specimens from New Caledonia, colletcted by Dr. Geoff Monteith of the Queensland Museum of Brisbane, are studied and four new species are described and illustrated (Pachycorynus monteithi sp. n., P. flavus sp. n., P. insularis sp. n., and Zeteotomus insularis sp. n.). The known New Caledonian Xantholinini are now represented by 17 species
On the danger of rupture on the interface between fresh and salt water for penetrating wells in karts geohydrolical stratum
Get PDFThe necessary conditions are found in which in a stratum of uniform thickness under pressure, resting on salt water with horizontal interface in state of equilibrium, it is possible know the danger of rupture of this interface with intrusion of salt in the well
Recent impovements for estimation of longshore transport
Get PDFIn the present study, the accuracy of the GLT model (Tomasicchio et alii, 2013) has been verified for the estimation of the Longshore Transport (LT) at shingle and mixed beaches. In order to verify the suitability of the GLT model in determining LT estimates at shingle beaches, without any further calibration, the comparison between the LT predictions and observations from two field data sets (Chadwick, 1989; Nicholls & Wright, 1991) has been considered. The comparison showed that the GLT predicted LT rates within a factor of 2 of the observed values. The predictive capability of the GLT has been also verified against an alternative general formula for the LT estimation at shingle beaches (Van Rijn, 2014). In addition, the suitability of the GLT model, even for the mixed beach case, has been assessed by means of the comparison between the LT prediction and the observation from a field experiment on a mixed sand and gravel beach at Hawke’s Bay, on the east coast of New Zealand (Komar, 2010)
First record of Chaeteessa nigromarginata from Peru (Mantodea: Chaeteessidae)
Get PDFThe second Peruvian record of the genus Chaeteessa Burmeister and the first of the species Chaeteessa nigromarginata Salazar 2004 are reported
Analysis of siltation temporal variability in Foum Elgherza dam, province of Biskra (Algeria)
Get PDFThe majority of dams in Algeria have some thirty years lifetime, when it comes to tanks intended for drinking water supply or irrigation whose socioeconomic interests justify an unlimited service guarantee. It matters to predict the water retention filling rate and protect these dams from siltation that seems very acute. This paper deals with the problem of siltation in Foum Lgherza dam, in the East Algeria. We attempt to identify siltation behavior according to a detailed analysis based on the comparative approach between results obtained by a projected relationship for the study area, and the measuring results obtained by bathymetric surveys, both of results are very close and determine the aggressiveness of erosive balance and accelerated siltation
Water hammer in water distribution system
Get PDFThe hypothesis of Allievi about the uniform valve closure in the first part of an urban water distribution network in order to minimize water hammer, has proved to be unacceptable in view of the theoretical and experimental results that are shown in this paper. Further considerations are made about the unsteady flow in pump rising pipeline systems according to the most recent developments, to mitigate water hammer damages. Furthermore, it is noted that water hammer studies mainly concerned pipeline systems in hydroelectric power plants while less attention was paid to water supply pipeline systems considered in this work