HydroCube: an entity-relationship hydrogeological data model   总被引：1，自引：1，他引：0  

Piotr Wojda  Serge Brouyère  Johan Derouane  Alain Dassargues 《Hydrogeology Journal》2010,18(8):1953-1962

Managing, handling and accessing hydrogeological information depends heavily on the applied hydrogeological data models, which differ between institutions and countries. The effective dissemination of hydrogeological information requires the convergence of such models to make hydrogeological information accessible to multiple users such as universities, water suppliers, and administration and research organisations. Furthermore, because hydrogeological studies are complex, they require a wide variety of high-quality hydrogeological data with appropriate metadata in clearly designed and coherent structures. A need exists, therefore, to develop and implement hydrogeological data models that cover, as much as possible, the full hydrogeological domain. A new data model, called HydroCube, was developed for the Walloon Region in Belgium in 2005. The HydroCube model presents an innovative holistic project-based approach which covers a full set of hydrogeological concepts and features, allowing for effective hydrogeological project management. The model stores data relating to the project locality, hydrogeological equipment, and related observations and measurements. In particular, it focuses on specialized hydrogeological field experiments such as pumping and tracer tests. This logical data model uses entity-relationship diagrams and it has been implemented in the Microsoft Access environment. It has been enriched with a fully functional user interface.  相似文献   

The Decline and Restoration of a Coastal Lagoon (Lake Veere) in the Dutch Delta     

Sander Wijnhoven  Vincent Escaravage  Eugène Daemen  Herman Hummel 《Estuaries and Coasts》2010,33(6):1261-1278

The former tidal inlet Lake Veere was turned into a stagnant brackish lake in 1961. Ever since, the system has shown a continuous degradation. The current study shows the monitoring results for the macrozoobenthic communities and the abiotic conditions for the period 1990–2008. This includes the first step to remediation, the restoration of the exchange between the tidal marine Eastern Scheldt and Lake Veere in 2004. A continuous decline in water clearance co-occurring with decreasing macrofauna densities and richness was observed till 2004. Water quality (e.g., secchi depth, nutrient levels, and oxygen conditions) improved significantly after the measure at a higher salinity level with less variation. But the macrofauna densities, biomass, and diversity did not improve yet. First indications of changes in the benthic communities by arrival of new and returning species are however observed and show that restoration at macrofauna level follows the improved abiotic conditions with a delay of several years.  相似文献   

Geophysical exploration of an active pockmark field in the Bay of Concarneau,southern Brittany,and implications for resident suspension feeders     

Agnès Baltzer  Axel Ehrhold  Carinne Rigolet  Aurélie Souron  Céline Cordier  Hélène Clouet  Stanislas F. Dubois 《Geo-Marine Letters》2014,34(2-3):215-230

About a decade ago, a large field of pockmarks (individual features up to 30 m in diameter and <2 m deep) was discovered in water depths of 15–40 m in the Bay of Concarneau in southern Brittany along the French Atlantic coast, covering an overall area of 36 km² and characterised by unusually high pockmark densities in places reaching 2,500 per square kilometre. As revealed by geophysical swath and subbottom profile data ground-truthed by sediment cores collected during two campaigns in 2005 and 2009, the confines of the pockmark field show a spectacular spatial association with those of a vast expanse of tube mats formed by a benthic community of the suspension-feeding amphipod Haploops nirae. The present study complements those findings with subbottom chirp profiles, seabed sonar imagery and ultrasonic backscatter data from the water column acquired in April 2011. Results show that pockmark distribution is influenced by the thickness of Holocene deposits covering an Oligocene palaeo-valley system. Two groups of pockmarks were identified: (1) a group of large (>10 m diameter), more widely scattered pockmarks deeply rooted (up to 8 ms two-way travel time, TWTT) in the Holocene palaeo-valley infills, and (2) a group of smaller, more densely spaced pockmarks shallowly rooted (up to 2 ms TWTT) in interfluve deposits. Pockmark pore water analyses revealed high methane concentrations peaking at ca. 400 μl/l at 22 and 30 cm core depth in silty sediments immediately above Haploops-bearing layers. Water column data indicate acoustic plumes above pockmarks, implying ongoing pockmark activity. Pockmark gas and/or fluid expulsion resulting in increased turbidity (resuspension of, amongst others, freshly settled phytoplankton) could at least partly account for the strong spatial association with the phytoplankton-feeding H. nirae in the Bay of Concarneau, exacerbating impacts of anthropogenically induced eutrophication and growing offshore trawling activities. Tidally driven hydraulic pumping in gas-charged pockmarks represents a good candidate as large-scale short-term triggering mechanism of pockmark activation, in addition to episodic regional seismic activity.  相似文献   

Zonal structure and seasonal variability of the Atlantic Equatorial Undercurrent   总被引：1，自引：0，他引：1  

W. E. Johns  P. Brandt  B. Bourlès  A. Tantet  A. Papapostolou  A. Houk 《Climate Dynamics》2014,43(11):3047-3069

  相似文献   

The challenge of dating early pleistocene fossil teeth by the combined uranium series–electron spin resonance method: the Venta Micena palaeontological site (Orce,Spain)     

Mathieu Duval  Christophe Falguères  Jean‐Jacques Bahain  Rainer Grün  Qingfeng Shao  Maxime Aubert  John Hellstrom  Jean‐Michel Dolo  Jordi Agusti  Bienvenido Martínez‐Navarro  Paul Palmqvist  Isidro Toro‐Moyano 《第四纪科学杂志》2011,26(6):603-615

The palaeontological site of Venta Micena (Orce, Andalusia, Spain) lies in the eastern sector of the Guadix–Baza basin, one of the best documented areas in Europe for Plio‐Pleistocene biostratigraphy. The combination of biochronological and palaeomagnetic results, combined with the radiometric data obtained for Atapuerca Sima del Elefante, indicated that the Venta Micena stratum was formed between the Jaramillo and Olduvai palaeomagnetic events, most likely between 1.22 and 1.77 Ma. Five fossil teeth from two outcrops (sites A and B) were selected to assess the potential of combined uranium series–electron spin resonance (US‐ESR) dating of Early Pleistocene sites. Although the US‐ESR results of the first outcrop showed a large scatter between the three teeth, the mean age of 1.37 ± 0.24 Ma can be considered a reasonable age estimate for Venta Micena. The mean ESR age of 0.62 ± 0.03 Ma obtained for site B seems to be a severe underestimation when compared with the independent age control. This underestimation is attributed to a relative recent U‐mobilization event that led to some U‐leaching. The results show that any ESR age calculations of old samples are extremely sensitive to variations in the measured ²³⁰Th/²³⁴U ratios in dental tissues. Although the results demonstrate that ESR can in principle be applied to Early Pleistocene sites, they also reveal the complexity of dating such old teeth. It is necessary to continue research in several directions, such as study of the behaviour of ESR signals in old teeth and understanding recent U‐mobilization processes, to improve the reliability of the combined US‐ESR dating method applied to Early Pleistocene times, a period for which the number of available numerical dating techniques is very limited. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

Factors and processes of permanent gully evolution in a Mediterranean marly environment (Cape Bon,Tunisia)     

A. El Khalili  H. Habaeib  J. M. Lamachère 《水文科学杂志》2013,58(7):1519-1531

Abstract

Gully erosion is considered to be one of the most important soil erosion processes in Mediterranean marly environments, but its actual contribution to total soil loss is still under discussion. The objectives of this paper are: (a) to acquire the distributed value of erosion rate in a permanent gully developed on a marly substratum in a Mediterranean environment; and (b) to quantify the key factors responsible for the spatial and temporal differences in erosion rates observed within the gully. A permanent gully located in Cap Bon (northeastern Tunisia) has been intensively and regularly monitored over a 7-year period with electronic survey equipment (total station) to give five field topographic surveys, as well as hydrological measurements at the gully outlet. The net soil loss for the 7-year period comprised a denudation of 51 m³ of sediment on the gully bank slopes, which corresponds to a mean soil loss of 61 m³ ha^?1 year^?1 or 6.1 mm year^?1. Denudation was observed on bed units with a slope gradient greater than 20%, while the remainder showed deposition. By confirming the factors involved in gully evolution, and by refining the statistical link between factors and erosion rates within the gully, the results provide important information to predict gully erosion rates in Mediterranean marly environments.

Editor Z.W. Kundzewicz; Associate editor G. Mahé

Citation El Khalili, A., Raclot, D., Habaieb, H., and Lamachère, J.M., 2013. Factors and processes of permanent gully evolution in a Mediterranean marly environment (Cape Bon, Tunisia). Hydrological Sciences Journal, 58 (7), 1519–1531.  相似文献   

The variability of ruthenium in chromite from chassignite and olivine‐phyric shergottite meteorites: New insights into the behavior of PGE and sulfur in Martian magmatic systems          下载免费PDF全文

Raphael J. Baumgartner  Marco L. Fiorentini  David Baratoux  Ludovic Ferrière  Marek Locmelis  Andrew Tomkins  Kerim A. Sener 《Meteoritics & planetary science》2017,52(2):333-350

The Martian meteorites comprise mantle‐derived mafic to ultramafic rocks that formed in shallow intrusions and/or lava flows. This study reports the first in situ platinum‐group element data on chromite and ulvöspinel from a series of dunitic chassignites and olivine‐phyric shergottites, determined using laser‐ablation ICP‐MS. As recent studies have shown that Ru has strongly contrasting affinities for coexisting sulfide and spinel phases, the precise in situ analysis of this element in spinel can provide important insights into the sulfide saturation history of Martian mantle‐derived melts. The new data reveal distinctive differences between the two meteorite groups. Chromite from the chassignites Northwest Africa 2737 (NWA 2737) and Chassigny contained detectable concentrations of Ru (up to ~160 ppb Ru) in solid solution, whereas chromite and ulvöspinel from the olivine‐phyric shergottites Yamato‐980459 (Y‐980459), Tissint, and Dhofar 019 displayed Ru concentrations consistently below detection limit (<42 ppb). The relatively elevated Ru signatures of chromite from the chassignites suggest a Ru‐rich (~1–4 ppb) parental melt for this meteorite group, which presumably did not experience segregation of immiscible sulfide liquids over the interval of mantle melting, melt ascent, and chromite crystallization. The relatively Ru‐depleted signature of chromite and ulvöspinel from the olivine‐phyric shergottites may be the consequence of relatively lower Ru contents (<1 ppb) in the parental melts, and/or the presence of sulfides during the crystallization of the spinel phases. The results of this study illustrate the significance of platinum‐group element in situ analysis on spinel phases to decipher the sulfide saturation history of magmatic systems.  相似文献   

Combining shock barometry with numerical modeling: Insights into complex crater formation—The example of the Siljan impact structure (Sweden)          下载免费PDF全文

Sanna Holm‐Alwmark  Auriol S. P. Rae  Ludovic Ferrière  Carl Alwmark  Gareth S. Collins 《Meteoritics & planetary science》2017,52(12):2521-2549

Siljan, central Sweden, is the largest known impact structure in Europe. It was formed at about 380 Ma, in the late Devonian period. The structure has been heavily eroded to a level originally located underneath the crater floor, and to date, important questions about the original size and morphology of Siljan remain unanswered. Here we present the results of a shock barometry study of quartz‐bearing surface and drill core samples combined with numerical modeling using iSALE. The investigated 13 bedrock granitoid samples show that the recorded shock pressure decreases with increasing depth from 15 to 20 GPa near the (present) surface, to 10–15 GPa at 600 m depth. A best‐fit model that is consistent with observational constraints relating to the present size of the structure, the location of the downfaulted sediments, and the observed surface and vertical shock barometry profiles is presented. The best‐fit model results in a final crater (rim‐to‐rim) diameter of ~65 km. According to our simulations, the original Siljan impact structure would have been a peak‐ring crater. Siljan was formed in a mixed target of Paleozoic sedimentary rocks overlaying crystalline basement. Our modeling suggests that, at the time of impact, the sedimentary sequence was approximately 3 km thick. Since then, there has been around 4 km of erosion of the structure.  相似文献   

A 20cm 2 CCD mosaic camera for a dark matter search part II : Electronics,data acquisition and performance     

Arnaud  M.  Aubourg  E.  Bareyre  P.  Br';ehin  S.  Caridroit  R.  de Kat  J.  Dispau  G.  Djidi  K.  Gros  M.  Lachièze-Rey  M.  Laigneau  Y.  Laurent  B.  Lesquoy  E.  Lavocat  Ph.  Magneville  C.  Mazeau  B.  Milsztajn  A.  Moscoso  L.  Pasquaud  J.  Paul  B.  Perrin  P.  Petibon  J.  Piret  Y.  Queinnec  F.  Rich  J.  Spiro  M.  de Trogoff  J.  Vigroux  L.  Zylberajch  S.  Ansari  R.  Cavalier  F.  Moniez  M.  Beaulieu  J. P.  Ferlet  R.  Grison  Ph.  Vidal-Madjar  A.  Adrianzyk  G.  Berger  J. P.  Burnage  R.  Delclite  J. C.  Kohler  D.  Magnan  R.  Richaud  A.  Guibert  J.  Moreau  O.  Tajahmady  F.  Baranne  A.  Maurice  E.  Prévôt  L.  Gry  C. 《Experimental Astronomy》1994,4(3-4):279-296

Conclusion To summarize, the readout and the control system of the CCD mosaic camera are running since December 1991 at the La Silla Observatory (ESO). The overall performance of the camera has been good. About 12000 pictures (data and flat-fields) have been successfully registered up to now. We will report in the near future preliminary scientific results of the EROS experiment.  相似文献   

Surfaces of section in the Miranda-Umbriel 3:1 inclination problem     

Michèle Moons  Jacques Henrard 《Celestial Mechanics and Dynamical Astronomy》1994,59(2):129-148

The recent numerical simulations of Tittemore and Wisdom (1988, 1989, 1990) and Dermottet al. (1988), Malhotra and Dermott (1990) concerning the tidal evolution through resonances of some pairs of Uranian satellites have revealed interesting dynamical phenomena related to the interactions between close-by resonances. These interactions produce chaotic layers and strong secondary resonances. The slow evolution of the satellite orbits in this dynamical landscape is responsible for temporary capture into resonance, enhancement of eccentricity or inclination and subsequent escape from resonance. The present contribution aims at developing analytical tools for predicting the location and size of chaotic layers and secondary resonances. The problem of the 3:1 inclination resonance between Miranda and Umbriel is analysed.  相似文献