Assessing optical earth observation systems for mapping and monitoring temporary ponds in arid areas     

Valrie Soti  Annelise Tran  Jean-Stphane Bailly  Christian Puech  Danny Lo Seen  Agnes Bgu 《International Journal of Applied Earth Observation and Geoinformation》2009,11(5):344-351

Remote sensing methods for locating and monitoring temporary ponds over large areas in arid lands were tested on a study site in Northern Senegal. Three main results are presented, validated with field data and intended to highlight different spectral, spatial and temporal characteristics of the methods: (1) Among several water indices tested, two Middle Infrared-based indices (MNDWI—Modified Normalized Difference Water Index and NDWI₁—Normalized Difference Water Index) are found to be most efficient; (2) an objective method is given prescribing the necessary sensor spatial resolution in terms of minimal detected pond area; and (3) the potential of multi-temporal MODIS imagery for tracking the filling phases of small ponds is illustrated. These results should assist in epidemiological studies of vector-borne diseases that develop around these ponds, but also more generally for land and water management and preservation of threatened ecosystems in arid areas.  相似文献   

Two-dimensional Hurst Index of Joint Surfaces   总被引：2，自引：1，他引：2  

Z. Y. Yang  C. C. Di  S. C. Lo 《Rock Mechanics and Rock Engineering》2001,34(4):323-345

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湖南省地层结构与盆地格架     

罗海晏 《湖南地质》1993,12(4):217-220

本文以湖南省岩石地层展布特点为前提,以北西-南东向横切地层剖面为基础。探讨了我省地层结构与盆地格架。笔者通过地层结构分析。对地层分区界线、物源区、主导构造作用特点等进行了讨论,从而建立了沉积盆地格架。指出我省盆地是在陆壳基底上,受扬子陆块与华夏陆块的双重控制。沉积范围不断缩小的沉积盆地。这种认识的确立,对各盆地期沉积层的变形、岩浆岩的分带与侵位方式、隐伏矿床的探索等都将产生新的联系。  相似文献   

On the P-wave velocity and plate-tectonics implications for the Tyrrhenian deep-earthquake zone     

A. Bottari  E.Lo Giudice   《Tectonophysics》1975,25(3-4)

P-wave velocities in the Tyrrhenian mantle have been determined for the 230–480 km depth range. Analysis of P-wave travel times for a set of Tyrrhenian deep earthquakes gives a velocity-distribution law which shows different behaviours in the 230–300 km and 300–480 km depth intervals. For the first interval the velocity gradient is 0.64 · 10⁻² sec⁻¹ and for the second one it is 0.59 · 10⁻² sec⁻¹. At a depth of 300 km the velocity decreases rapidly from 8.75 to 8.43 km/sec.The results have been analyzed in the framework of a Tyrrhenian structural model characterized by a lithospheric slab dipping 55–60° in the WNW direction.It is also pointed out that the analysis of some geodynamic features of the slabs of Pacific island arcs carried out by Oliver et al. (1973) and Sleep (1973) can be applied to the Tyrrhenian mantle geodynamic features.  相似文献   

The 1974 etna eruption: Multispectral analysis of skylab images reveals the vegetation canopy as a likely transducer of pre-eruptive volcanic emissions     

C. de Carolis  E. Lo Giudice  A. M. Tonelli 《Bulletin of Volcanology》1975,39(3):371-384

On the Skylab images taken over Mt. Etna in September, 1973, an area with a reduced near-infrared reflectivity was observed in the zone where five months later the lateral eruption of February 1974 took place. This fact suggested to the authors the working hypothesis that the vegetation was influenced by latent volcanic phenomena. Moreover the intensification of linear features across the same area led to the development of a new point of view in which the vegetation is perceived as a volcanologic transducer. Ground investigations and thermal-infrared and multispectral surveys performed in July 1974 neither confirmed nor contradicted the first part of the assumption because subsequent paroxysmal phenomena modified the area investigated. The multispectral analysis on the other hand gave a greater emphasis to the correlation between the linear features and the distribution of plants. A more detailed study of this relationship is suggested.  相似文献   

Microtremors and volcanic explosions at Stromboli — Part 2     

E. Del Pezzo  I. Guerra  A. Lo Bascio  G. Luongo  G. Nappi  R. Scarpa 《Bulletin of Volcanology》1974,38(3):1023-1036

A seismic survey was carried out at Stromboli volcano during August 1973. Statistical and spectral analyses of volcanic tremor and explosion quakes were performed. The statistical analysis has shown that the value of them coefficient in Ishimoto & Iida’s relation is high and that the hourly frequencies of events are fairly constant. The spectral analysis has shown a similarity in shape between tremors and explosion quakes. These events have the dominant frequency of 5 Hz at the craters area.  相似文献   

Strahlungsmessungen als Hilfsmittel zur Diagnose atmosphärischer Zustände und Vorgänge     

H. Loßnitzer 《Theoretical and Applied Climatology》1954,6(1-2):91-112

Zusammenfassung An einem umfangreichen Beobachtungsmaterial besonders der zenitalen Himmelsstrahlung wird die Brauchbarkeit von Strahlungsmessungen mit verschiedenen Empfängern für die Überwachung atmosphärischer Trübungsverhältnisse und der Struktur der Trübung erprobt. Der Einfluß der selektiven Eigenschaften der einzelnen Empfängertypen auf die Meßvorgänge wird eingehend erörtert. Es wird gezeigt, daß Polarisations-und Farbwerte der zenitalen Himmelsstrahlung, die mit verhältnismäßig einfachen Mitteln (Selen-Photoelementen) gewonnen werden können, schon wesentliche Einblicke in den Trübungscharakter der Atmosphäre ermöglichen. Eine Verfeinerung der Analyse ist durch Intensitäts- und Polarisationsmessungen in engen Spektralbereichen, wie sie durch Verwendung von Interferenzfiltern in Verbindung mit Photomultipliern möglich sind, zu erreichen. Im Hinblick auf die noch unbefriedigende Bestimmung des Gesamtwasserdampfgehalts aus den atmosphärischen Absorptionsbanden bei durchgehender Strahlung wird auf die Möglichkeit, sie durch Messung der langwelligen Ausstrahlung zu kontrollieren und zu verbessern, hingewiesen.

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Summary On the basis of an extensive material of observations, in particular of zentithal sky radiation, the applicability of radiation measurements with different receivers for the control of atmospheric turbidity conditions and the structure of turbidity is investigated. The influence of the selective prpperties of the different receiver types on the measuring processes is discussed in detail. It is shown that polarisation and colour values of zenithal sky radiation obtainable by relatively simple means (selenium rectifier cells) give considerable insight into the character of atmospheric turbidity. An improvement of the analysis can be reached by measurements of intensity and polarisation within small spectral ranges such as are possible by applygin interference filters in combination with photomultipliers. With regard to the yet unsatisfactory determination of total water vapour contents from the atmospheric absorption bands of transmitted radiation the possibility is emphasized to control and improve it by measuring the outgoing long-wave radiation.

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Résumé Au moyen d'un riche matériel d'observations concernant surtout le rayonnement du ciel zénital on étudie la valeur de différents récepteurs en vue du contrôle du trouble atmosphérique et notamment de sa structure. On discute l'effet des propriétés sélectives des récepteurs sur lesprocédés des mesures. On montre que la polarisation et la couleur du rayonnement du ciel zénital mesurées par des moyens relativement simples (cellules au sélénium) fournissent déjà d'utiles renseignements sur le caractère du trouble atmosphérique. On arrive à améliorer les résultats par des mesures d'intensité et de polarisation à l'intérieur de régions spectrales étroites, ainsi que par l'emploi de filtres à interférences combinés avec des photomultiplicateurs. Considérant que la teneur totale en vapeur d'eau de l'atmosphère ne se détermine qu'imparfaitement par la transmission dans les bandes d'absorption, l'auteur évoque la possibilité de la déterminer par la mesure du rayonnement effectif à grande longueur d'onde.

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Mit 12 Textabbildungen.  相似文献   

Diesel oil and PCB-degrading psychrotrophic bacteria isolated from Antarctic seawaters (Terra Nova Bay, Ross Sea)   总被引：2，自引：0，他引：2  

Maria De  Domenico  Angelina Lo Giudice  Luigi Michaud  Marcello Saitta  Vivia Bruni 《Polar research》2004,23(2):141-146

Fifty-seven Antarctic marine bacteria were examined for their ability to degrade commercial diesel oil as the sole organic substrate at both 4 °C and 20 °C. Based on the preliminary screening, two isolates (B11 and B15) with high capacity to degrade diesel oil were selected and their biodegradation efficiency was quantified by gas chromatographic analysis. As expected for psychrotrophs, diesel oil biodegradation was slower at 4 °C than at 20 °C. The two strains also mineralized the C₂₈ n-paraffin octacosane at 20 °C and polychlorinated biphenyls (PCBs) at 4 °C and 20 °C.  相似文献   

Comment on “The persistence of the water budget myth and its relationship to sustainability” by J.F. Devlin and M. Sophocleous, Hydrogeology Journal (2005) 13:549–554     

Hugo A. Loáiciga 《Hydrogeology Journal》2006,14(7):1383-1385

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Building stone employed in the historical monuments of Eastern Sicily (Italy). An example: the ancient city centre of Catania     

Rosalda Punturo  Laura G. Russo  Antonino Lo Giudice  Paolo Mazzoleni  Antonino Pezzino 《Environmental Geology》2006,50(2):156-169

An archaeometric study of the stone materials employed in the Late Baroque historical monuments of the ancient city centre of Catania was carried out. Lithological maps of a selection of monuments, transferred to a digital format, revealed that the stone materials are both magmatic and sedimentary rocks, the colours of which are matched in a peculiar type of bichromy. Particular attention focused on sedimentary rocks, which consist of various types of limestone quarried near the city of Syracuse (Hyblean Plateau, south-eastern Sicily). Carbonate rocks were characterised in terms of mineralogy, petrography and geochemistry, by studying rock samples from both monuments and historical extraction sites. Results showed that, although only one name was historically attributed to the above lithotypes (i.e. “Pietra di Siracusa‘’), they were quarried from many locations and, as they belong to various geological formations, they therefore exhibit great variety. In order to examine the durability of Hyblean limestones employed in works of cultural heritage interest, salt crystallisation tests were carried out according to standard procedure norms (UNI EN 12370 (1999) Determination of resistance to crystallisation of salts, 6p). Results are consistent with the forms of deterioration observed in the monuments, and highlight the close relationship between textural characteristics and damage. Our purpose is to provide a basic tool, which may be useful both for conserving monuments of cultural heritage and for their restoration.  相似文献