Indirect and direct recharges in a tropical forested watershed: Mule Hole,India     

Jean-Christophe Maréchal  Murari R.R. Varma  Jean Riotte  Jean-Michel Vouillamoz  M.S. Mohan Kumar  Laurent Ruiz  M. Sekhar  Jean-Jacques Braun 《Journal of Hydrology》2009,364(3-4):272-284

  相似文献   

Comparative analysis of the response of various land covers to an exceptional rainfall event in the central Spanish Pyrenees,October 2012          下载免费PDF全文

N. Lana‐Renault  E. Nadal‐Romero  M. P. Serrano‐Muela  B. Alvera  P. Sánchez‐Navarrete  Y. Sanjuan  J. M. García‐Ruiz 《地球表面变化过程与地形》2014,39(5):581-592

The hydrological and geomorphological effects of an exceptional rainstorm event that occurred in the central Spanish Pyrenees during 19–21 October 2012 were studied in five experimental catchments under various land covers: (i) subhumid badlands; (ii) dense forest; (iii) an abandoned farmland area recolonized by shrubs and forest patches; and (iv) subalpine grasslands. Hydrographs and sedigraphs demonstrated that vegetation cover is a major factor affecting the control of floods even during exceptional rainstorms, at least at the spatial scale at which the phenomenon was studied (catchment sizes: 0.3–2.8 km2) and under dry catchment conditions. The combined precipitation over the two days (c. 250 mm) was the greatest for any two‐day event recorded since 1950 in the central‐western Pyrenees for all but one of the stations in the study. Five pulses of most intense rainfall were recorded. The forested catchment did not react to the two most intense rainfall pulses, because of the very low antecedent level of the water table. The main peak flow occurred only when at least a part of the catchment was saturated. The abandoned farmland catchment had two small peak discharges at the beginning of the event, which were produced by infiltration excess overland flow from eroded areas close to the main stream. During the third most intense rainfall period a large part of this catchment contributed to runoff and a relatively high peak discharge was produced. The badland catchment reacted immediately from the beginning of the rainstorm, yielding very high discharges accompanied by high suspended sediment concentrations. The subalpine catchment showed a hydrograph mirroring the hyetograph, with brief but intense hydrological responses to increased precipitation, because of the marked gradients and the presence of bare rock in the headwaters. A high volume of bedload was carried during the peak discharge. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

X-ray Computed Tomography study of the influence of consolidants on the hydric properties of sandstones for stone conservation studies     

Vicente G. Ruiz de Argandoa  Lope Calleja  ngel Rodríguez-Rey  Luis Miguel Surez del Río  Carmen Celorio 《Engineering Geology》2009,103(3-4):69-75

X-ray Computed Tomography (X-ray CT) has been used to study the petrophysical characteristics of a Jurassic sandstone from Asturias (Northern Spain) used as building stone in several monuments in the region. CT monitoring of water capillarity tests has made it possible to visualize the movement of water inside the samples, to relate this movement with texture characteristics, and to measure the height reached in successive images, thereby determining the capillary penetration coefficient; based on this coefficient, the effective capillary pore radius has also been estimated. An advantage of the use of CT is that, as the information comes from the sample interior, border effects that can be generated in the external faces can be avoided.The CT was also used to visualize how a commercial organosilicon consolidant penetrates inside the rock by means of capillarity, a usual way of consolidant application in stone restoration processes. The coefficient of capillary penetration of the product, determined on the basis of the measurements made on the tomographic images, is 53% less than that of water. The influence of rock texture characteristics on the capillarity both of the consolidant and the water was also observed.The samples underwent CT water capillarity studies before and after the consolidant application, proving that the treatment improves the rock's hydric properties. The coefficient of capillary penetration decreased by 24% following the application of the consolidant, whereas the effective pore radius decreased by more than 40%.  相似文献   

Finite element methodology for the evaluation of soil damping in LNG tanks supported on homogeneous elastic halfspace     

Diego Peña Ruiz  Santiago Guzmán Gutiérrez 《Bulletin of Earthquake Engineering》2015,13(3):755-775

  相似文献   

Geoarchaeological study of the Phoenician cemetery of Tyre‐Al Bass (Lebanon) and geomorphological evolution of a tombolo     

Pilar Carmona  Jos Miguel Ruiz 《Geoarchaeology》2008,23(3):334-350

The geoarchaeological record of the Phoenician necropolis of Al Bass (Lebanon) provides information concerning the geomorphological evolution of a late Holocene tombolo. Physical and chemical analysis of sediments indicates that the cemetery (9th century B.C.) was located near a littoral lagoon, between the dunes of a cuspate spit pointing toward the island of Tyre. From the sea apex of this spit, the moles mentioned in historical chronicles were constructed. Once mainland and island were connected, at the northern coast (where the port of Sidon was located), a sediment trap was formed, which quickly filled with silt. Afterwards, an extensive field of sand dunes buried all the archaeological remains from Phoenician to Roman times. © 2008 Wiley Periodicals, Inc.  相似文献   

Degassing patterns of Tungurahua volcano (Ecuador) during the 1999–2006 eruptive period,inferred from remote spectroscopic measurements of SO₂ emissions     

S.R. Arellano  M. Hall  P. Samaniego  J.-L. Le Pennec  A. Ruiz  I. Molina  H. Yepes 《Journal of Volcanology and Geothermal Research》2008

This paper presents the results of 7 years (Aug. 1999–Oct. 2006) of SO₂ gas measurements during the ongoing eruption of Tungurahua volcano, Ecuador. From 2004 onwards, the operation of scanning spectrometers has furnished high temporal resolution measurements of SO₂ flux, enabling this dataset to be correlated with other datasets, including seismicity. The emission rate of SO₂ during this period ranges from less than 100 to 35,000 tonnes/day (t d^− 1) with a mean daily emission rate of 1458 t d^− 1 and a standard deviation of ± 2026 t d^− 1. Average daily emissions during inferred explosive phases are about 1.75 times greater than during passive degassing intervals. The total amount of sulfur emitted since 1999 is estimated as at least 1.91 Mt, mostly injected into the troposphere and carried westwards from the volcano. Our observations suggest that the rate of passive degassing at Tungurahua requires SO₂ exsolution of an andesitic magma volume that is two orders of magnitude larger than expected for the amount of erupted magma. Two possible, and not mutually exclusive, mechanisms are considered here to explain this excess degassing: gas flow through a permeable stagnant-magma-filled conduit and gas escape from convective magma overturning in the conduit. We have found that real-time gas monitoring contributes significantly to better eruption forecasting at Tungurahua, because it has provided improved understanding of underlying physical mechanisms of magma ascent and eruption.  相似文献   

Assessment of Geogenic and Anthropogenic Pollution Sources Using an Aquatic Plant Along the Sonora River Basin: Insights from Elemental Concentrations and Pb Isotope Signatures     

Romo-Morales  Diana  Moreno-Rodríguez  Verónica  Molina-Freaner  Francisco  Valencia-Moreno  Martín  Ruiz  Joaquín  Minjárez-Osorio  Christian  Hernández-Mendiola  Ernesto  del Rio-Salas  Rafael 《Natural Resources Research》2020,29(4):2773-2786

Natural Resources Research - Mining is an important activity in Mexico; however, despite its economic benefits, it carries potential environmental risks, including mine spills. On August 6,...  相似文献   

A reappraisal of the chemical composition of the Orion nebula based on Very Large Telescope echelle spectrophotometry     

C. Esteban  M. Peimbert  J. García-Rojas  M. T. Ruiz  A. Peimbert  M. Rodríguez 《Monthly notices of the Royal Astronomical Society》2004,355(1):229-247

  相似文献   

Stratigraphic sequence, elemental concentrations and heavy metal pollution in Holocene sediments from the Tinto-Odiel Estuary, southwestern Spain   总被引：1，自引：0，他引：1  

F. Ruiz  M. L. González-Regalado  J. Borrego  J. A. Morales  J. G. Pendón  J. M. Muñoz 《Environmental Geology》1998,34(4):270-278

 The Holocene filling of the Tinto-Odiel Estuary comprises seven lithofacies over a Mio-Pliocene substrate. The sequence includes three system tracts: lowstand system (10 000 to 8700 years BP), transgressive system (8700 to 7000 years BP), and regressive system (7000 to Recent). Twenty sediment samples from the 50-m borehole were analyzed for their major components and minor element concentrations. Two multivariate analysis methods, principal component analysis and cluster analysis, were performed in the analytical data set to help visualize the sample clusters and the element associations. Samples corresponding to unpolluted, pre-mining sediments are clearly separated by cluster analysis, mainly as a result of the low content in sulphide-associated heavy metals such as Cu, Zn, As, Ag, and Pb. So, these sediments may be utilized as a background for geochemical analysis (bulk sample) in other adjacent estuaries, both in sandy and silty-clayey sediments. As a consequence of large-scale mining and smelting operations occurred since prehistoric times on the river banks, a rapid rise in the metal pollution was found in the upper 2.5 m of the natural filling, with values exceeding up to ten times the natural background levels. In addition, since the mid-1960s, large amounts of waste and pollutant effluents have been discharged from industries located around the estuary, increasing the heavy metal content in the last 0.3 m of the natural sedimentation. Received: 18 August 1997 · Accepted: 19 January 1998  相似文献   

The garnets of the eastern area of the Sierra de Guadarrama,Sistema Central,Spain     

J. Lopez Ruiz  L.A. Garcia Cacho 《Chemical Geology》1974,13(4):269-283

Electron-probe microanalysis of a series of garnets in metapelitic rocks of the chloritoid staurolite, kyanite and sillimanite metamorphic zones, eastern area of the Sierra de Guadarrama, Sistema Central, Spain, manifest the well-known cryptozonation commonly observed in these minerals, with MgO and FeO increasing and MnO and CaO decreasing from the center to the outer rim of the crystals.The differences in composition of the garnets, from one metamorphic zone to another, is mainly a result of small differences in composition of the host-rock, since: (1) the amounts of MnO in the garnet are controlled by the amounts of SiO₂, Al₂O₃ and FeO present in the host-rock; and (2) the percentages of MnO and MgO of the parent-rock influence in some way the concentration of CaO in the garnet, and those of MnO, Al₂O₃ and CaO influence the concentration of FeO. Nevertheless, the amount of FeO in the garnet is finally controlled, due to the diadochy, by the concentration of MnO + CaO in this mineral.  相似文献