Presence and origin of polycyclic aromatic hydrocarbon in sediments of nine coastal lagoons in central Vietnam     

Giuliani S  Sprovieri M  Frignani M  Cu NH  Mugnai C  Bellucci LG  Albertazzi S  Romano S  Feo ML  Marsella E  Nhon DH 《Marine pollution bulletin》2008,56(8):1504-1512

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The dual-beam mini-DOAS technique—measurements of volcanic gas emission,plume height and plume speed with a single instrument   总被引：2，自引：0，他引：2  

Mattias Johansson  Bo Galle  Yan Zhang  Claudia Rivera  Deliang Chen  Klaus Wyser 《Bulletin of Volcanology》2009,71(7):747-751

The largest error in determining volcanic gas fluxes using ground based optical remote sensing instruments is typically the determination of the plume speed, and in the case of fixed scanning instruments also the plume height. We here present a newly developed technique capable of measuring plume height, plume speed and gas flux using one single instrument by simultaneously collecting scattered sunlight in two directions. The angle between the two measurement directions is fixed, removing the need for time consuming in-field calibrations. The plume height and gas flux is measured by traversing the plume and the plume speed is measured by performing a stationary measurement underneath the plume. The instrument was tested in a field campaign in May 2005 at Mt. Etna, Italy, where the measured results are compared to wind fields derived from a meso-scale meteorological model (MM5). The test and comparison show that the instrument is functioning and capable of estimating wind speed at the plume height.  相似文献   

Tomographic reconstruction of gas plumes using scanning DOAS     

Mattias Johansson  Bo Galle  Claudia Rivera  Yan Zhang 《Bulletin of Volcanology》2009,71(10):1169-1178

This paper presents a method to reconstruct the gas distribution inside a vertical cross section of a gas plume by combining data from two or more scanning DOAS instruments using a tomographic algorithm. The method can be applied to gas plumes from any single, elevated point source, such as a volcano or industrial chimney. Such two-dimensional concentration distributions may prove to be useful for example in plume chemistry, dispersion and environmental impact studies. Here we show the case with one scanning DOAS instrument located on each side of the plume, which is the easiest and most economic setup as well as the most useful in routine monitoring of e.g. volcanic gas emissions. The paper investigates the conditions under which tomographic reconstructions can be performed and discusses limitations of this setup. The proposed method has been studied theoretically by numerical simulations and has been experimentally tested during two field campaigns, with measurements of SO₂ emissions from a volcano and a power plant. The simulations show that, under good measurement conditions, the algorithm presented performs well, which is further confirmed by the experimental results.  相似文献   

Topographic effects observed at Amatrice hill during the 2016-2017 Central Italy seismic sequence     

Gerardo Grelle  Laura Bonito  Maresca Rosalba  Silvia Iacurto  Claudia Madiai  Paola Revellino  Giuseppe Sappa 《地震工程与工程振动(英文版)》2021,20(1):63-78

The estimate of seismic site effects by experimental approaches is based on different assumptions aimed at simplifying the complex actual site conditions and related uncertainties.However,the reliability of the results can increase if the experimental data is focused on quite strong seismic sequences and the on-site acquisition of a large number of signals is deemed strategic for the assessment of the expected phenomena.Based on these considerations,the ground motion at the Red Zone sector of Amatrice hill,violently struck by the 2016-2017 Central Italy seismic sequence,was analyzed via an observational approach.A large set of weak motions(moment magnitude Mw 2.5-3.9)was analyzed in this study by means of standard(SSR)and horizontal to vertical(HVSR)spectral ratio techniques.The results from the experimental analysis of the site effects by using weak motion and noise signals show a significant amplification at the top of Amatrice hill with a remarkable polarization of the motion and changes in spectral shapes according to the topographic setting of the relief.  相似文献   

Behavioural adaptations in talitrids from two Atlantic beaches     

Claudia Rossano  Simone Gambineri  Lucia Fanini  Virginie Durier  Colette Rivault  Felicita Scapini 《Estuarine, Coastal and Shelf Science》2009

The aim of the present study was to test sun orientation and rhythmic activity of two sandhopper populations from two Atlantic macro-tidal beaches. A population from Le Verger beach (orientated to 346°, Ille et Vilaine, Brittany, France) and a population from Damgan (orientated to 195°, Morbihan, Brittany, France), were tested on the beach under clear sky discriminating for landscape vision. For both populations locomotor activity rhythm was recorded in the laboratory. The two beaches differed for climatic features, tidal range and for human use. Both talitrid populations resulted very well orientated toward the shoreline, and both used solar position and landscape vision to orient. However the multiple regression analysis of orientation with climatic features showed a different use of local cues by the two populations and a slight influence of tidal regime (ebbing and rising tide), in spite of the supralittoral zonation of sandhoppers. In the laboratory they showed a well defined rhythmic behaviour as well as a bimodal rhythmicity, explained as a tidal one. These results are a new brick in the complex picture of orientation and rhythm studies on sandy beach invertebrates.  相似文献   

Scleractinian cold-water corals in the Gulf of Cádiz—First clues about their spatial and temporal distribution     

Claudia Wienberg  Dierk Hebbeln  Hiske G. Fink  Furu Mienis  Boris Dorschel  Agostina Vertino  Matthias Lpez Correa  Andr Freiwald 《Deep Sea Research Part I: Oceanographic Research Papers》2009,56(10):1873-1893

This paper presents the first compilation of information on the spatial distribution of scleractinian cold-water corals in the Gulf of Cádiz based on literature research and own observations (video footage, sediment samples). Scleractinian cold-water corals are widely distributed along the Spanish and Moroccan margins in the Gulf of Cádiz, where they are mainly associated with mud volcanoes, diapiric ridges, steep fault escarpments, and coral mounds. Dendrophyllia cornigera, Dendrophyllia alternata, Eguchipsammia cornucopia, Madrepora oculata and Lophelia pertusa are the most abundant reef-forming species. Today, they are almost solely present as isolated patches of fossil coral and coral rubble. The absence of living scleractinian corals is likely related to a reduced food supply caused by low productivity and diminished tidal effects. In contrast, during the past 48 kyr scleractinian corals were abundant in the Gulf of Cádiz, although their occurrence demonstrates no relationship with main climatic or oceanographic changes. Nevertheless, there exists a conspicuous relationship when the main species are considered separately. Dendrophylliids are associated with periods of relatively stable and warm conditions. The occurrence of L. pertusa mainly clusters within the last glacial when bottom current strength in the Gulf of Cádiz was enhanced and long-term stable conditions existed in terms of temperature. Madrepora oculata shows a higher tolerance to abrupt environmental changes.  相似文献   

Multi-criteria Evaluation of Bran Use to Promote Circularity in the Cereal Production Chain     

Grippo  Valeria  Romano  Severino  Vastola  Antonella 《Natural Resources Research》2019,28(1):125-144

Natural Resources Research - A reliable and realistic subsurface resource spatial modeling is a common and critical task for geosciences projects (mining, petroleum and environmental) because the...  相似文献   

Impacts of Wildlife on Agriculture: A Spatial-Based Analysis and Economic Assessment for Reducing Damage     

Cozzi  Mario  Prete  Carmelina  Viccaro  Mauro  Romano  Severino 《Natural Resources Research》2019,28(1):15-29

Over the last few years, the impacts of wildlife on agriculture have constantly been growing, in particular in areas close to woodland and in hunting ban zones (“refuge effect”). Public administrations have difficulty in meeting the growing requests for crop damage compensation. The development of appropriate measures to control this trend—starting from the understanding of the dynamics concerned—is crucial. The aim of this study was, therefore, to analyze damage at regional scale and define common local actions. In particular, the study involved different steps that define a spatial-based classification of risk levels, integrating statistical methods (principal component analysis and receiver operating characteristic) with multi-criteria evaluation (MCE) in a geographic information system (GIS). It turns out that, in the study area, the very high-risk zones affect 8.83% of used agricultural areas; about 97% of them concentrated in the first 400 m from the most suitable habitats. A selected cluster of 11 test areas within these zones allowed us to assess the cost-effectiveness of integrated prevention and control actions (IPCA) with respect to the compensation of the damage. The analysis shows cost of IPCA to be nearly twice the actual cost incurred by the public administration to compensate partially the damage. The comparison with the estimated damage shows the overall economic convenience of the proposed investment with significant differences depending on the areas. Thus, we suggest reaching an “agro-ecological” balance starting from actions on specific areas; if they produce the desired effects, they could be progressively extended to other areas with gradual investments (adaptive management).

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Evaluation of the geometric stability and the accuracy potential of digital cameras — Comparing mechanical stabilisation versus parameterisation     

D. Rieke-Zapp  W. Tecklenburg  J. Peipe  H. Hastedt  Claudia Haig 《ISPRS Journal of Photogrammetry and Remote Sensing》2009,64(3):248-258

Recent tests on the geometric stability of several digital cameras that were not designed for photogrammetric applications have shown that the accomplished accuracies in object space are either limited or that the accuracy potential is not exploited to the fullest extent. A total of 72 calibrations were calculated with four different software products for eleven digital camera models with different hardware setups, some with mechanical fixation of one or more parts. The calibration procedure was chosen in accord to a German guideline for evaluation of optical 3D measuring systems [VDI/VDE, VDI/VDE 2634 Part 1, 2002. Optical 3D Measuring Systems–Imaging Systems with Point-by-point Probing. Beuth Verlag, Berlin]. All images were taken with ringflashes which was considered a standard method for close-range photogrammetry. In cases where the flash was mounted to the lens, the force exerted on the lens tube and the camera mount greatly reduced the accomplished accuracy. Mounting the ringflash to the camera instead resulted in a large improvement of accuracy in object space. For standard calibration best accuracies in object space were accomplished with a Canon EOS 5D and a 35 mm Canon lens where the focusing tube was fixed with epoxy (47  μm maximum absolute length measurement error in object space). The fixation of the Canon lens was fairly easy and inexpensive resulting in a sevenfold increase in accuracy compared with the same lens type without modification. A similar accuracy was accomplished with a Nikon D3 when mounting the ringflash to the camera instead of the lens (52  μm maximum absolute length measurement error in object space). Parameterisation of geometric instabilities by introduction of an image variant interior orientation in the calibration process improved results for most cameras. In this case, a modified Alpa 12 WA yielded the best results (29  μm maximum absolute length measurement error in object space). Extending the parameter model with FiBun software to model not only an image variant interior orientation, but also deformations in the sensor domain of the cameras, showed significant improvements only for a small group of cameras. The Nikon D3 camera yielded the best overall accuracy (25  μm maximum absolute length measurement error in object space) with this calibration procedure indicating at the same time the presence of image invariant error in the sensor domain. Overall, calibration results showed that digital cameras can be applied for an accurate photogrammetric survey and that only a little effort was sufficient to greatly improve the accuracy potential of digital cameras.  相似文献   

The impact of overfishing and El Niño on the condition factor and reproductive success of Peruvian hake, Merluccius gayi peruanus   总被引：1，自引：1，他引：0  

Michael Balln  Claudia Wosnitza-Mendo  Renato Guevara-Carrasco  Arnaud Bertrand 《Progress in Oceanography》2008,79(2-4):300

In this study we examine physiological responses of Peruvian hake (Merluccius gayi peruanus) to changes in their population structure and physical environment during the period 1971–2004. In particular, we assess the relative investment of energy in growth and/or reproduction of small (20–35 cm) and large (35–50 cm) hake. We calculated the (i) condition (Fulton’s K), (ii) gonad and (iii) gut fullness indices for 42,761 female hakes sampled from commercial landings; these indices indicate fish somatic, reproductive and feeding condition, respectively. Using Generalized Additive Models we then examined potential relationships between these indices and sea surface temperature anomalies and date. Drastic energy exhaustion and a decrease in female hake fecundity were observed during El Niño events. The long-term trend showed a general increase in condition factor and a decrease in gonad index for large hake between 1971 and 2004. Small hake exhibited a different trend with an increase in reproductive activity, which was accompanied by an earlier maturation. We hypothesise that the observed low investment of energy in reproduction by large female hake might be related to the lack of large males, due to a sex-selective fishery and the impact of El Niño. We suggest that fishing diminished hake reproductive capacity, modified the sex ratio in favour of females and increased population vulnerability to environmental stress, in particular to the El Niño. The impact of multidecadal variability and predators like the squid, Dosidicus gigas, remain unresolved until longer time series become available.  相似文献