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21.
Bianca Mitrică Istvan Bogardi Eugen Mitrică Irena Mocanu Marin Minciună 《Norsk geografisk tidsskrift. Norwegian journal of geography》2017,71(1):12-29
The article examines the risk of water shortages due to the climate change on Leu-Rotunda Plain, which is part of Oltenia Plain in Romania. The region has been exposed to several extreme climatic phenomena, mostly droughts, which has created several problems related to water quality and quantity. The authors defined climate change scenarios using two regional climate models. Water resources under climate change were estimated by a regional numerical groundwater model covering a deep aquifer. The water demand components were estimated for households, industries, services, and livestock, based on specific socio-economic assumptions. A non-probabilistic risk assessment, using simplified fuzzy sets mathematics, was used to estimate water supply, water demand, and the consequences of water shortages. The results of the study revealed significant vulnerability in the water supply, a limited territorial expansion of sewerage networks, an expected increase in households’ demand, an expected increase in industrial and services water demand, a relatively stable demand for water for livestock farming, and an important water shortage in the study area. The authors conclude by highlighting a set of actions to mitigate the risk of the potential crisis. 相似文献
22.
Abstract— The 65 Ma old Chicxulub impact structure with a diameter of about 180 km is again in the focus of the geosciences because of the recently commenced drilling of the scientific well Yaxcopoil‐ 1. Chicxulub is buried beneath thick post‐impact sediments, yet samples of basement lithologies in the drill cores provide a unique insight into age and composition of the crust beneath Yucatàn. This study presents major element, Sr, and Nd isotope data for Chicxulub impact melt lithologies and clasts of basement lithologies in impact breccias from the PEMEX drill cores C‐1 and Y‐6, as well as data for ejecta material from the K/T boundaries at La Lajilla, Mexico, and Furlo, Italy. The impact melt lithologies have an andesitic composition with significantly varying contents of Al, Ca, and alkali elements. Their present day 87Sr/86Sr ratios cluster at about 0.7085, and 143Nd/144Nd ratios range from 0.5123 to 0.5125. Compared to the melt lithologies that stayed inside the crater, data for ejecta material show larger variations. The 87Sr/86Sr ratios range from 0.7081 for chloritized spherules from La Lajilla to 0.7151 for sanidine spherules from Furlo. The 143Nd/144Nd ratio is 0.5126 for La Lajilla and 0.5120 for the Furlo spherules. In an εtCHUR(Nd)‐εtUR(Sr) diagram, the melt lithologies plot in a field delimited by Cretaceous platform sediments, various felsic lithic clasts and a newly found mafic fragment from a suevite. Granite, gneiss, and amphibolite have been identified among the fragments from crystalline basement gneiss. Their 87Sr/86Sr ratios range from 0.7084 to 0.7141, and their 143Nd/144Nd ratios range from 0.5121 to 0.5126. The TNdDM model ages vary from 0.7 to 1.4 Ga, pointing to different source terranes for these rocks. This leads us to believe that the geological evolution and the lithological composition of the Yucatàn basement is probably more complex than generally assumed, and Gondwanan as well as Laurentian crust may be present in the Yucatàn basement. 相似文献
23.
Gabriella De Lucia Bianca M. Poggianti Alfonso Aragón-Salamanca Simon D. M. White Dennis Zaritsky Douglas Clowe Claire Halliday Pascale Jablonka Anja von der Linden Bo Milvang-Jensen Roser Pelló Gregory Rudnick Roberto P. Saglia Luc Simard 《Monthly notices of the Royal Astronomical Society》2007,374(3):809-822
24.
Michel Michaelovitch de Mahiques Samara Cazzoli y Goya Maria Carolina da Silva Nogueira de Matos Rodrigo Augusto Udenal de Oliveira Bianca Sung Mi Kim Paulo Alves de Lima Ferreira Rubens Cesar Lopes Figueira Marcia Caruso Bícego 《国际泥沙研究》2021,36(2):317-327
The current study aims to do a comparative analysis of the results obtained with two End-Member(EM)grain-size modeling techniques(AnalySize and BasEMMA)and the Environmental Sensitive Grain-Size(ESGS)modeling for sediment samples collected in the mudbelts of the southern Brazilian shelf.The methods were compared using grain-size data from the south Brazilian shelf,and the results are discussed here.It is the first time that the concept of ESGS,in its present form,is utilized outside China.The results show that despite its relative ease of use,the ESGS is not fully comparable to the EM analyses,and only two grain-size ESGS classes were recognized as analogous to EMs.The comparison of the AnalySize and BasEMMA procedures also revealed significant differences between the techniques.A comparative analysis between the two EM techniques revealed advantages in the BasEMMA,especially in the better correlation of the end-members with the original grain size distribution.The analysis of the geographical distribution of the EM abundances allowed point sources of sandy populations to be recognized as well as the contribution of the Rio de la Plata as a source of silty sediments to be inferred. 相似文献
25.
Marco Mucciarelli Marcello Bianca Rocco Ditommaso Marco Vona Maria Rosaria Gallipoli Alessandro Giocoli Sabatino Piscitelli Enzo Rizzo Matteo Picozzi 《Bulletin of Earthquake Engineering》2011,9(3):825-840
In San Gregorio (L’Aquila, Italy) a three-story, reinforced concrete (RC) building had the first floor collapsed following
the earthquake of April 6, 2009. The remaining two stories fell with a displacement in the horizontal projection of about
70 cm. This unusual behaviour is made more puzzling by the fact that buildings located at a short distance and with similar
features had little or no damage reported. To understand the causes of the collapse we performed strong motion recordings,
microtremor measurements, a detailed geological survey, a high-resolution geo-electrical tomography, a borehole with a down-hole
test. On the building we performed a geometrical survey and laboratory tests on concrete cores. The acceleration and noise
recordings have shown a high amplification with uphill-downhill direction. The geological survey has revealed the presence
of co-seismic fractures on stiff soils. Geo-electrical tomography has shown an unexpected, strong discontinuity just below
the building. Taking advantage of excavations in adjacent lots, we have highlighted rare cataclastic decimetric bands with
a very low resistance material incorporated in well-stratified calcarenites. The same soft material has been founded in the
borehole down to 17 m from ground level, showing a shear wave velocity that starts at 250 m/s, increases with depth and has
an abrupt transition in calcarenites at 1,150 m/s. The surface geophysical measurements in the vicinity of the site have not
shown similar situations, with flat HVSR curves as expected for a rock outcrop, except for a lateral extension of the soft
zone. The analysis on the quality of the building materials has yielded values higher than average for the age and type of
construction, and no special design or construction deficiencies have been observed. A strong, peculiar site effect thus appears
to be the most likely cause of the damage observed. 相似文献
26.
M. Mucciarelli M. Bianca R. Ditommaso M. R. Gallipoli A. Masi C. Milkereit S. Parolai M. Picozzi M. Vona 《Bulletin of Earthquake Engineering》2011,9(1):263-283
After the recent Central Italy Earthquake of the 6th April 2009 (Mw = 6.3), the Italian and German engineer and geophysicist
Task Force carried out a wide characterization of sites, buildings and damages. In Navelli, a town about 35 km far from epicentre,
heavy damage occurred on a reinforced concrete (RC) building that represent an anomalous case of damage, when compared with
those occurred in the neighbouring area. In this paper, characterization of the site and damage of the Navelli RC Building
is reported and discussed. We performed ambient noise and strong motion measurements, installing one three-directional accelerometer
on each floor of the structure and two in free-field, and we have carried out repeated measurements using a couple of three-directional
tromometers. In the mean time, a geological survey was carried out and the site response was investigated, with the aid of
down-hole measurements. It was thus possible to investigate the structural response and damage taking into account site condition.
One of the main results of this work is that repeating analyses using ambient noise measurements show that the main structural
frequencies reached after the first damaging shock are constant over time, and then the structural behaviour appears stationary
at long term. On the other hand, the strong motion recordings show that the building exhibits a transient non-stationary behaviour
as the fundamental frequency changes during each aftershock, then returning to the starting value after each event. 相似文献
27.
Over complex terrain, convection and thermally-driven circulations simultaneously occur under fair weather conditions during the day. To investigate these processes on the basis of observations, simultaneous measurements on different scales are necessary. Comprehensive measurements with the mobile observation platform KITcube were performed on the mountainous island of Corsica during the HYdrological cycle in Mediterranean EXperiment (HyMeX) field campaign in late summer and autumn 2012. Using a case study, the benefit of integrated measurement systems and coordinated scan strategies was demonstrated, and experimental evidence of, and new insights into, convective and advective transport processes in a valley were obtained. Convection, thermally-driven circulations and topographic and advective venting led to the diurnal cycle of temperature, humidity and wind over complex terrain in the mountain atmospheric boundary layer (mountain ABL), which was deeper than an ABL over homogeneous terrain under equal surface forcing. Due to the combined transport processes on different scales, the mountain ABL in a valley also extended beyond the convection layer, which was characterized by surface-based, buoyancy-driven turbulent mixing. Strong subsidence, with a vertical velocity of about 1 m s \(^{-1}\) , was present within the mountain ABL for several hours around noon and suppressed the convection-layer growth. Above the layer with subsidence, elevated vertical motions, consisting of alternating updrafts and downdrafts, occurred. Once the convection layer grew to the bottom of the layer with elevated vertical motions, surface-based convective cells occasionally coupled to the elevated updrafts, as a result of which the convection layer rapidly deepened. 相似文献
28.
Bianca Alves de Souza Igor da Silva Rocha Paz Abdellah Ichiba Bernard Willinger Auguste Gires Jose Carlos Cesar Amorim 《水文科学杂志》2013,58(11):1619-1635
ABSTRACTThe spread of impervious surfaces in urban areas combined with the rise in the intensity of rainfall events as a result of climate change has led to dangerous increases in storm water flows. This paper discusses a new implementation of the fully distributed hydrological model Multi-Hydro (developed at École des Ponts ParisTech), when operating storage basins, and its ability to deal with high-resolution radar rainfall data. The peri-urban area of Massy (south of Paris, France) was selected as a case study for having six of these drainage facilities, used extensively in flood control. Two radar rainfall datasets with different spatiotemporal resolutions were used: Météo-France’s PANTHER rainfall product (C-band) and ENPC’s X-band DPSRI. The rainfall spatiotemporal variability was analysed statistically using Universal Multifractals (UM). Finally, to validate the application, the water level simulations were compared with local measurements in the Cora storage basin located next to the catchment’s single outlet. 相似文献
29.
Bianca B. Perren N. John Anderson Marianne S. V. Douglas Sherilyn C. Fritz 《Journal of Paleolimnology》2012,48(1):223-239
Holocene paleolimnological records (diatoms, organic content, spectrally inferred sediment chlorophyll-a) from three West Greenland lakes (~67°N) situated along a transect from the outer coast to a nunatak at the periphery of the Greenland Ice Sheet are used to explore the nature of regional postglacial lake development and its relationship to Holocene climate evolution. The lakes were deglaciated asynchronously by approximately 4?ka (earliest on the coast) and thus their sediment records document different starting points of Holocene ontogeny, both temporally and paleoclimatically. Despite similar time-transgressive characteristics of the diatom stratigraphies, overarching climatic factors, principally effective moisture, and eolian inputs, govern individual lake development. The transition to Neoglaciation between 5.6 and 4?ka BP marks a shift toward a cooler, moister, windier climate from the aridity and higher temperatures of the mid-Holocene (8?C6?ka BP). A shift toward increased aridity, windiness, and eolian activity is documented in the interior lakes over the last 500?years. These lake records demonstrate the sensitivity of freshwater lakes in arid regions to changes in effective moisture and highlight the role of wind and eolian activity in Arctic lake environments. 相似文献
30.
Maria Bianca Cita Colette Vergnaud-Grazzini Christian Robert Hervé Chamley Neri Ciaranfi Sara d&#x;Onofrio 《Quaternary Research》1977,8(2):205-235
A deep-sea core over 16 m long from the crestal area of the Mediterranean Ridge has been investigated with different techniques, including quantitative micropaleontology, stable isotopes (measured on the epipelagic species Globigerinoides ruber and on the mesopelagic species Globorotalia inflata), and clay mineralogy. The resulting record of climatic fluctuations can be cross correlated to other Mediterranean cores by means of isochronous lithologies (tephra layers and sapropels). The climatic record of the Mediterranean is similar in character, phase, and chronology to the records investigated in the equatorial Pacific and in the Caribbean. Isotope stages 1 to 17 have been recognized. Cyclically repeated stagnant cycles resulting in sapropel deposition complicate both the isotopic and the faunal signal. The isotopic investigations reveal that the temperature change in the surface layers of the eastern Mediterranean was no greater than 8°C in the late “glacial” Pleistocene. The chronostratigraphic and biostratigraphic interpretation of Core KS09 indicate that the mean sedimentation rate was 2.4 cm/1000 years, a value very close to the 2.5 cm/1000 years calculated for the entire Quaternary section at DSDP Site 125, also located in the crestal area of the Mediterranean Ridge in the Ionian Basin. The base of KS09 is likely to be very close to the Brunhes/Matuyama boundary dated at 0.7 my. 相似文献