Practices in disaster mitigation in the case of the 2015 Typhoon Koppu debris flows in Nueva Ecija,Philippines     

Llanes  Francesca V.  Eco  Rodrigo  Herrero  Tatum Miko  Briones  Jo Brianne Louise  Escape  Carmille Marie  Sulapas  Jolly Joyce  Galang  Jan Albert Macario  Ortiz  Iris Jill  Sabado  Jasmine May  Lagmay  Alfredo Mahar Francisco  Rodolfo  Kelvin 《Natural Hazards》2022,114(1):665-690

Natural Hazards - In October 2015, heavy rains brought by Typhoon Koppu generated landslides and debris flows in the municipalities of Bongabon, Laur, and Gabaldon in Nueva Ecija province....  相似文献   

Laboratory investigation of pressure gradients induced by plunging breakers     

Adrián Pedrozo-Acuña  Amaia Ruiz de Alegría-Arzaburu  Alec Torres-Freyermuth  Edgar Mendoza  Rodolfo Silva 《Coastal Engineering》2011

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Two in one leachate plume in a karstic aquifer     

Roger Gonzalez-Herrera  Rodolfo Gomez-Lopez 《Environmental Earth Sciences》2013,68(7):1945-1953

Some sites formerly used for waste disposal purposes, even if they are closed, continue generating leachate that seeps into the ground and contaminates groundwater in the area where they are located. It is believed that the rainfall being in contact with waste becomes a source of leachate. This fluid seeps into the aquifer and may identify sources of pollution. A modeling work which determined the migration times of solutes in the karstic aquifer of Merida, Yucatan, Mexico, is presented. Both existing and generated information was analyzed; a leachate plume was identified. The methodology used in the study is described, the application of which allowed concluding that this plume was generated from two sources: a waste disposal site and the oxidation lagoons located next to it. The procedure consisted of performing simulations considering the sources that contribute to the development of the pollution plume and forecasting their behavior. With the developed methodology, similar cases can be analyzed to avoid locating catchment zones of drinking water in inappropriate places and/or develop projects to place waste disposal sites that could affect existing catchment areas and to preserve this resource, essential for life.  相似文献   

Astronomical tuning of the Tortonian ⁸⁷Sr/⁸⁶Sr curve in the Mediterranean basin     

Mario Sprovieri  Mario Barbieri  Adriana Bellanca  Rodolfo Neri 《地学学报》2003,15(1):29-35

ABSTRACT This work presents a detailed ⁸⁷Sr/⁸⁶Sr isotope curve for the interval 7.5–9.7 Ma obtained by a high-resolution analysis (sampling spacing of about 40 kyr) of an astronomically calibrated land-based sedimentary sequence exposed in the central Mediterranean area (Gibliscemi section, southern Sicily). The main aim is to verify a synchronous response of the Mediterranean seawater Sr isotope record to the oceanic forcing on the basis of multiple comparisons of the Gibliscemi record with published coeval ⁸⁷Sr/⁸⁶Sr curves. A good correlation with the ⁸⁷Sr/⁸⁶Sr data from the ODP site 926 (equatorial Atlantic ocean), considered to be the Sr chemostratigraphic reference section for the Late Miocene, and from the Pacific DSDP site 590B was registered. Conversely, the comparison of the Gibliscemi Sr isotope data with ⁸⁷Sr/⁸⁶Sr ratios from the coeval segment of the land-based Sardella section (eastern Mediterranean) shows important differences highlighting a local control on the seawater Sr isotope changes in semi-isolated subbasins within the Late Miocene Mediterranean.  相似文献   

Thermal modeling of a Swiss urban aquifer and implications for geothermal heat pump systems     

Perego  Rodolfo  Pera  Sebastian  Boaga  Jacopo  Bulgheroni  Monica  Dalla Santa  Giorgia  Galgaro  Antonio 《Hydrogeology Journal》2021,29(6):2187-2210

The progressive electrification of the building conditioning sector in recent years has greatly contributed to reducing greenhouse gas emissions by using renewable energy sources, particularly shallow geothermal energy. This energy can be exploited through open and closed shallow geothermal systems (SGS), and their performances greatly depend on the ground/groundwater temperature, which can be affected by both natural and anthropogenic phenomena. The present study proposes an approach to characterize aquifers affected by high SGS exploitation (not simulated in this work). Characterization of the potential hydro/thermogeological natural state is necessary to understand the regional flow and heat transport, and to identify local thermal anomalies. Passive microseismic and groundwater monitoring were used to assess the shape and thermal status of the aquifer; numerical modeling in both steady-state and transient conditions allowed understanding of the flow and heat transport patterns. Two significant thermal anomalies were detected in a fluvio-glacial aquifer in southern Switzerland, one created by river water exfiltration and one of anthropogenic nature. A favorable time lag of 110 days between river and groundwater temperature and an urban hot plume produced by underground structures were observed. These thermal anomalies greatly affect the local thermal status of the aquifer and consequently the design and efficiency of current and future SGS. Results show that the correct characterization of the natural thermo-hydrogeological status of an aquifer is a fundamental basis for determining the impact of boundary conditions and to provide initial conditions required to perform reliable local thermal sustainability assessments, especially where high SGS exploitation occurs.

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Fast Mid-IR Flashes Detected During Small Solar X-Ray Bursts     

Marta M. Cassiano  Pierre Kaufmann  Rogério Marcon  Amauri S. Kudaka  Adolfo Marun  Rodolfo Godoy  Pablo Pereyra  Arline M. Melo  Hugo Levato 《Solar physics》2010,264(1):71-79

Solar observations in the mid-infrared 8 – 14 μm band continuum were carried out with cadence of 5 frames per second, in December 2007. Rapid small heated sources, with a typical duration of the order of seconds, were found on the bright plage-like areas around sunspots, in association with relatively weak GOES soft X-ray bursts. This work presents the analysis of fast mid-infrared flashes detected during a GOES B2.0-class event on 10 December 2007, beginning at about 10:40 UT. Rapid brightness temperature enhancements of 0.5 to 2.0 K were detected at the Earth by a microbolometer array, using a telescope with 10.5 cm diameter aperture producing a diffraction-limited photometric beam of 25 arc sec. The minimum detectable temperature change was of 0.1 K. The corresponding fluxes are 30 – 130 solar flux units. At the solar surface the estimated rapid brightenings represented a temperature enhancement of 50 – 150 K.  相似文献   

The symbiotic system AG Draconis: Soft X-ray bremsstrahlung from the nebulae     

Marcella Contini  Rodolfo Angeloni 《New Astronomy》2011,16(3):199-208

The modeling of UV and optical spectra emitted from the symbiotic system AG Dra, adopting collision of the winds, predicts soft X-ray bremsstrahlung from nebulae downstream of the reverse shock with velocities > 150 km s^?1 and intensities comparable to those of the WD black body flux. At outbursts, the envelop of debris, which corresponds to the nebula downstream of the high velocity shocks (700–1000 km s^?1) accompanying the blast wave, absorbs the black body soft X-ray flux from the WD, explains the broad component of the H and He lines, and leads to low optical-UV–X-ray continuum fluxes. The high optical-UV flux observed at the outbursts is explained by bremsstrahlung downstream of the reverse shock between the stars. The depletion of C, N, O, and Mg relative to H indicates that they are trapped into dust grains and/or into diatomic molecules, suggesting that the collision of the wind from the WD with the dusty shells, ejected from the RG with a ～1 year periodicity, leads to the U-band fluctuations during the major bursts.  相似文献   

Long-term fluctuations in volcanic activity: implications for future environmental impact     

Hazel Rymer  Corinne A. Locke  rea Borgia  Maria Martinez  Jorge Brenes  Rodolfo Van der Laat  Glyn Williams-Jones 《地学学报》2009,21(4):304-309

Acidic crater lakes at persistently active volcanoes act as both an index and a moderator of volcanic processes. A catastrophic drop in lake level can therefore lead to serious local environmental damage. In the early 1990s, the crater lake at Poás volcano, Costa Rica diminished, and acid aerosols erupted with devastating consequences for local health, environment and economy. The first indications of this event can be  retrospectively identified to have started from 1985, on the basis of our unique 20-year data time series, which provides evidence for the shallow intrusion of magma. New data presented in this article show similar trends and we conclude that Poás has now entered another active period with renewed intrusion. Severe environmental damage in this region is expected within the next few years if the current trend continues.  相似文献   

Quantitative Benthic Community Structure in Blanca Bay and Its Relationship With Organic Enrichment*     

Rodolfo Elias 《Marine Ecology》1992,13(3):189-201

Abstract. A two year benthic sampling program of a 2000 km² area, covering 22 stations, showed a dominance of deposit-feeding polychaetes. The quantitative structure of the three infaunal assemblages was related to a salinity gradient: the inner and outer regions were inhabited by, respectively, mixohaline and euhaline associations, both quantitatively related to granulometric facies of sediment. Species diversity was very low in the inner region, although abundance of opportunistic species was high. In the outer region, abundance and diversity were more stable, with an increasing number of species. A comparison of species number and abundance with Species-Abundance-Biomass curves from enriched environments showed that the inner region of Bianca Bay may be considered as an organically enriched environment. Scoloplos, a species associated with organic enrichment, and dense terebellid belts were present in great abundances in front of sewage outflows. The spatial distribution of heterotrophic bacteria and the bivalves Corbula and Nucula also followed this pattern.  相似文献   

Anomalous Diffuse CO2 Emission prior to the January 2002 Short-term Unrest at San Miguel Volcano, El Salvador, Central America     

Nemesio M. Pérez  Pedro A. Hernández  Eleazar Padrón  Rafael Cartagena  Rodolfo Olmos  Francisco Barahona  Gladys Melián  Pedro Salazar  Dina L. López 《Pure and Applied Geophysics》2006,163(4):883-896

On January 16, 2002, short-term unrest occurred at San Miguel volcano. A gas-and-steamash plume rose a few hundred meters above the summit crater. An anomalous microseismicity pattern, about 75 events between 7:30 and 10:30 hours, was also observed. Continuous monitoring of CO₂ efflux on the volcano started on November 24, 2001, in the attempt to provide a multidisciplinary approach for its volcanic surveillance. The background mean of the diffuse CO₂ emission is about 16 g m^-2 d^-1, but a 17- fold increase, up to 270 g m^-2 d^-1, was detected on January 7, nine days before the January 2002 short-term unrest at San Miguel volcano. These observed anomalous changes on diffuse CO₂ degassing could be related to either a sharp increase of CO₂ pressure within the volcanic-hydrothermal system or degassing from an uprising fresh gas-rich magma within the shallow plumbing system of the volcano since meteorological fluctuations cannot explain this observed increase of diffuse CO₂ emission.  相似文献