Impact of urbanization on suspended sediment and organic matter fluxes from small catchments in Tahiti     

G. Wotling  Ch. Bouvier 《水文研究》2002,16(9):1745-1756

This study provides an initial characterization of pollution associated with storm runoff in Tahiti. A thousand floodwater samples were collected from three representative catchments and subsequently analysed. The main pollution parameters chosen were total suspended sediment (TSS), chemical oxygen demand (COD), biochemical oxygen demand (BOD5), total nitrogen (TN) and Total Phosphorus (TP). First, organic pollution appeared to be related closely to sediment, thus TSS could be used as a global indicator. Next, regression models between an event's TSS load and its hydrological characteristics were used to obtain annual load estimates. Great interannual variability was found to be strongly influenced by the few major floods that occur during the rainy season. Our results also emphasize the importance of the impact of urbanization on solid catchment exportation: from 60 TSS t/km²/year in a natural forested catchment, fluxes reached more than 700 TSS t/km²/year during preparatory urbanization earthworks before stabilizing at 140 TSS t/km²/year in a consolidated urbanized area. Clearly, runoff effects need to be taken into consideration for effective urban planning and for the preservation of the coastal environment in Tahiti. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献   

The dynamical evolution of Taurus–Auriga-type aggregates     

Pavel Kroupa †  Jerome Bouvier 《Monthly notices of the Royal Astronomical Society》2003,346(2):343-353

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147Sm‐143Nd and 176Lu‐176Hf systematics of eucrite and angrite meteorites          下载免费PDF全文

Audrey Bouvier  Janne Blichert‐Toft  Maud Boyet  Francis Albarède 《Meteoritics & planetary science》2015,50(11):1896-1911

Comparative planetary geochemistry provides insight into the origin and evolutionary paths of planetary bodies in the inner solar system. The eucrite and angrite achondrite groups are particularly interesting because they show evidence of early planetary differentiation. We present ¹⁴⁷Sm‐¹⁴³Nd and ¹⁷⁶Lu‐¹⁷⁶Hf analyses of eight noncumulate (basaltic) eucrites, two cumulate eucrites, and three angrites, which together place new constraints on the evolution and differentiation histories of the crusts of the eucrite and angrite parent bodies and their mantle mineralogies. The chemical compositions of both eucrites and angrites indicate similar evolutionary paths and petrogenetic models with formation and isolation of differentiated crustal reservoirs associated with segregation of ilmenite. We report a ¹⁴⁷Sm‐¹⁴³Nd mineral isochron age for the Moama cumulate eucrite of 4519 ± 34 Ma (MSWD = 1.3). This age indicates protracted magmatism within deep crustal layers of the eucrite parent body lasting up to about 50 Ma after the formation of the solar system. We further demonstrate that the isotopic compositions of constituent minerals are compromised by secondary processes hindering precise determination of mineral isochron ages of basaltic eucrites and angrites. We interpret the changes in geochemistry and, consequently, the erroneous ¹⁴⁷Sm‐¹⁴³Nd and ¹⁷⁶Lu‐¹⁷⁶Hf internal mineral isochron ages of basaltic eucrites and angrites as the result of metamorphic events such as impacts (effects from pressure, temperature, and peak shock duration) on the surfaces of the eucrite and angrite parent bodies.  相似文献   

Brown Dwarfs and Very Low Mass Stars: Towards a New Age Scale for Young Open Clusters     

D. Barrado Y Navascués  J.R. Stauffer  J. Bouvier 《Astrophysics and Space Science》1998,263(1-4):239-242

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The Monitor project: rotation periods of low-mass stars in M50     

Jonathan Irwin  Suzanne Aigrain  Jerome Bouvier  Leslie Hebb  Simon Hodgkin  Mike Irwin  Estelle Moraux 《Monthly notices of the Royal Astronomical Society》2009,392(4):1456-1466

We report on the results of a time-series photometric survey of M50 (NGC 2323), a  ∼130 Myr  open cluster, carried out using the Cerro Tololo Inter-American Observatory (CTIO) 4-m Blanco telescope and Mosaic-II detector as part of the Monitor project. Rotation periods were derived for 812 candidate cluster members over the mass range  0.2 ≲ M /M_⊙≲ 1.1  . The rotation period distributions show a clear mass-dependent morphology, statistically indistinguishable from those in NGC 2516 and M35 taken from the literature. Due to the availability of data from three observing runs separated by ∼10 and 1 month time-scales, we are able to demonstrate clear evidence for evolution of the photometric amplitudes, and hence spot patterns, over the 10 month gap. We are not able to constrain the time-scales for these effects in detail due to limitations imposed by the large gaps in our sampling, which also prevent the use of the phase information.  相似文献   

Influence of rainfall spatial variability on flood prediction   总被引：9，自引：0，他引：9  

Patrick Arnaud  Christophe Bouvier  Leonardo Cisneros  Ramon Dominguez 《Journal of Hydrology》2002,260(1-4):216-230

This paper deals with the sensitivity of distributed hydrological models to different patterns that account for the spatial distribution of rainfall: spatially averaged rainfall or rainfall field. The rainfall data come from a dense network of recording rain gauges that cover approximately 2000 km² around Mexico City. The reference rain sample accounts for the 50 most significant events, whose mean duration is about 10 h and maximal point depth 170 mm. Three models were tested using different runoff production models: storm-runoff coefficient, complete or partial interception. These models were then applied to four fictitious homogeneous basins, whose sizes range from 20 to 1500 km². For each test, the sensitivity of the model is expressed as the relative differences between the empirical distribution of the peak flows (and runoff volumes), calculated according to the two patterns of rainfall input: uniform or non-uniform. Differences in flows range from 10 to 80%, depending on the type of runoff production model used, the size of the basin and the return period of the event. The differences are generally moderate for extreme events. In the local context, this means that uniform design rainfall combining point rainfall distribution and the probabilistic concept of the areal reduction factor could be sufficient to estimate major flood probability. Differences are more significant for more frequent events. This can generate problems in calibrating the hydrological model when spatial rainfall localization is not taken into account: a bias in the estimation of parameters makes their physical interpretation difficult and leads to overestimation of extreme flows.  相似文献   

Monitoring soil water content and deficit using Electrical Resistivity Tomography (ERT) – A case study in the Cevennes area,France     

Pascal Brunet  Rémi Clément  Christophe Bouvier 《Journal of Hydrology》2010,380(1-2):146-153

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The Meteoritical Bulletin,No. 106     

Jrme Gattacceca  Audrey Bouvier  Jeffrey Grossman  Knut Metzler  Minoru Uehara 《Meteoritics & planetary science》2019,54(2):469-471

Meteoritical Bulletin 106 contains 1868 meteorites including 10 falls (Aiquile, Broek in Waterland, Degtevo, Dingle Dell, Dishchii'bikoh, Hradec Králové, Kheneg Ljouâd, Oudiyat Sbaa, Serra Pelada, Tres Irmaos), with 1386 ordinary chondrites, 166 carbonaceous chondrites, 119 HED achondrites, 48 Lunar meteorites, 37 iron meteorites, 36 ureilites, 19 Martian meteorites, 13 enstatite chondrites, 12 Rumuruti chondrites, 9 primitive achondrites, 8 mesosiderites, 5 enstatite achondrites, 4 ungrouped achondrites, 4 pallasites, and 1 relict meteorite. A total of 958 meteorites are from Africa, 405 from Antarctica, 245 from Asia, 228 from South America, 12 from North America, 8 from Europe, 5 from Mars, 4 from Oceania, and 1 from an unknown location.  相似文献   

The Meteoritical Bulletin,No. 104          下载免费PDF全文

Audrey Bouvier  Jérôme Gattacceca  Carl Agee  Jeffrey Grossman  Knut Metzler 《Meteoritics & planetary science》2017,52(10):2284-2284

Meteoritical Bulletin 104 contains 2279 meteorites including 12 falls (Annama, Cartersville, Creston, Diepenveen, Famenin, Izarzar, Nkayi, Porangaba, San Juan de Ocotán, Trâpe?ng Rôno?s, Xinglongquan, ?d’ár nad Sázavou), with 1847 ordinary chondrites, 138 carbonaceous chondrites, 128 HED achondrites, 38 lunar meteorites, 24 ureilites, 22 Martian meteorites, 19 iron meteorites, 17 primitive achondrites, 14 enstatite chondrites, 10 mesosiderites, 9 Rumuruti chondrites, 5 pallasites, 4 ungrouped achondrites, 2 enstatite achondrites, 1 ungrouped chondrite, and 1 Kakangari chondrite, and with 996 from Antarctica, 790 from Africa, 337 from Asia, 111 from South America, 30 from North America, 11 from Oceania, and 4 from Europe. Note: 1 meteorite from Russia was counted as European.  相似文献   

Virioplankton distribution and activity in a tropical eutrophicated bay     

Yvan Bettarel  Robert Arfi  Thierry Bouvier  Marc Bouvy  Enora Briand  Jonathan Colombet  Daniel Corbin  Télesphore Sime-Ngando 《Estuarine, Coastal and Shelf Science》2008

The study of lysogeny in aquatic systems is an often overlooked aspect of microbial ecology, especially in tropical environments. Herein, the fraction of lysogenized cells (FLC) was detected in the surface waters of 20 coastal stations distributed from the eutrophicated shoreline to seaward waters of Hann Bay (Senegal). Concurrently, viral lytic infection rates were extrapolated from the frequency of visibly infected bacterial cells (FVIC), as determined from transmission electron microscopy observations. The experimental induction of prophage was observed in less than 3% of indigenous marine bacteria, suggesting that lysogenic stages of infection are rare in Hann Bay. Similarly, only 0.5–4.7% of bacteria showed visible signs of lytic infection. However, the positive correlation between the fraction of lysogenic and lytic cells (r = 0.67, p < 0.05, n = 20) may actually indicate that the coexistence of both lifestyles may be due to the massive and rapid induction of lysogens, potentially from the high levels of local UV radiation. Overall, we suggest that the determination of FVIC and FLC to examine the predominance of one type of cycle versus the other may be a source of misinterpretation in some particular aquatic environments.  相似文献