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201.
Quantifying groundwater–surface water interactions in a proglacial valley,Cordillera Blanca,Peru 下载免费PDF全文
Lauren D. Somers Ryan P. Gordon Jeffrey M. McKenzie Laura K. Lautz Oliver Wigmore AnneMarie Glose Robin Glas Caroline Aubry‐Wake Bryan Mark Michel Baraer Thomas Condom 《水文研究》2016,30(17):2915-2929
A myriad of downstream communities and industries rely on streams fed by both groundwater discharge and glacier meltwater draining the Cordillera Blanca, Northern Peruvian Andes, which contains the highest density of glaciers in the tropics. During the dry season, approximately half the discharge in the region's proglacial streams comes from groundwater. However, because of the remote and difficult access to the region, there are few field methods that are effective at the reach scale to identify the spatial distribution of groundwater discharge. An energy balance model, Rhodamine WT dye tracing, and high‐definition kite‐borne imagery were used to determine gross and net groundwater inputs to a 4‐km reach of the Quilcay River in Huascaran National Park, Peru. The HFLUX computer programme ( http://hydrology.syr.edu/hflux.html ) was used to simulate the Quilcay River's energy balance using stream temperature observations, meteorological measurements, and kite‐borne areal photography. Inference from the model indicates 29% of stream discharge at the reach outlet was contributed by groundwater discharge over the study section. Rhodamine WT dye tracing results, coupled with the energy balance, show that approximately 49% of stream water is exchanged (no net gain) with the subsurface as gross gains and losses. The results suggest that gross gains from groundwater are largest in a moraine subreach but because of large gross losses, net gains are larger in the meadow subreaches. These insights into pathways of groundwater–surface water interaction can be applied to improve hydrological modelling in proglacial catchments throughout South America. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
202.
Didkovskyi Oleksandr Ivanov Vladislav Radice Alessio Papini Monica Longoni Laura Menafoglio Alessandra 《Mathematical Geosciences》2022,54(3):467-506
Mathematical Geosciences - The problem of providing data-driven models for sediment transport in a pre-Alpine stream in Italy is addressed. This study is based on a large set of measurements... 相似文献
203.
Merrifield Mark A. Johnson Mele Guza R. T. Fiedler Julia W. Young Adam P. Henderson Cassandra S. Lange Athina M. Z. O’Reilly William C. Ludka Bonnie C. Okihiro Michele Gallien Timu Pappas Kyle Engeman Laura Behrens James Terrill Eric 《Natural Hazards》2021,108(3):2591-2612
Natural Hazards - Waves overtop berms and seawalls along the shoreline of Imperial Beach (IB), CA when energetic winter swell and high tide coincide. These intermittent, few-hour long events flood... 相似文献
204.
205.
Laura T. Iraci Brent G. Riffel Carly B. Robinson Rebecca R. Michelsen Rachel M. Stephenson 《Journal of Atmospheric Chemistry》2007,58(3):253-266
The aqueous phase acid-catalyzed reaction of methanol (CH3OH) with nitric acid (HNO3) to yield methyl nitrate (CH3ONO2) under atmospheric conditions has been investigated using gas-phase infrared spectroscopy. Reactions were conducted in aqueous
sulfuric acid solutions (50.5–63.6 wt.%) with [CH3OH] = 0.00005–0.005 M and [HNO3] = 0.02–0.21 M, at 278.2–328.6 K. Methyl nitrate production rates increased linearly with CH3OH and HNO3 concentrations and exponentially with sulfuric acid weight percent within the regime studied. Rates increased linearly with
nitronium ion concentration, indicating that the reaction involves as the nitrating agent under these conditions. At 298 K, the rate of methyl nitrate production can be calculated from k
obs
[CH3OH][HNO3], where k
obs
= 2.337 × 10−13(exp(0.3198*wt.% H2SO4)) when the solubility of CH3ONO2 in acidic solution is approximated by H* for pure water. The temperature dependence of the rate coefficient is related to solution composition, with activation energies
of 59 and 49 kJ/mol at 51.1 and 63.6 wt.% H2SO4, respectively, when k is calculated from rate. The temperature dependence has also been parameterized for application to the atmosphere, but the small quantities of present in aerosol particles will result in methyl nitrate production rates too small to be of significance under most atmospheric
conditions.
An erratum to this article can be found at 相似文献
206.
Laura Beth Bugg 《The Australian geographer》2012,43(3):273-289
This article examines land-use development applications for minority religious facilities in two local government areas on the rural–urban fringe of metropolitan Sydney, Australia. Using critical discourse analysis and underpinned by Lefebvre's (1991) conceptual triad of space, the work interrogates the way in which place identity is generated and codified both by land-use planners and local residents through spatial representation. This representation is revealed in discourses around the compatibility of minority religious facilities for particular zones, lack of a sufficient minority population and social disruption. These discourses reveal a construction of peri-urban space that is aligned with particular elite Anglo-Australian activities (horse riding and gentleman farms) and land uses (rural residential, small-scale agriculture and the ‘bush-church’). These case studies illustrate the potential for the creation of exclusionary, abstract space by urban planners but also the ways in which local residents use discoursive strategies to ensure the stability of their position as elites in rapidly changing spatial situations. 相似文献
207.
A Bayesian procedure for Probabilistic Tsunami Hazard Assessment 总被引:1,自引:1,他引:0
In this paper, a Bayesian procedure is implemented for the Probability Tsunami Hazard Assessment (PTHA). The approach is general
and modular incorporating all significant information relevant for the hazard assessment, such as theoretical and empirical
background, analytical or numerical models, instrumental and historical data. The procedure provides the posterior probability distribution that integrates the prior probability distribution based on the physical knowledge of the process
and the likelihood based on the historical data. Also, the method deals with aleatory and epistemic uncertainties incorporating
in a formal way all sources of relevant uncertainty, from the tsunami generation process to the wave propagation and impact
on the coasts. The modular structure of the procedure is flexible and easy to modify and/or update as long as new models and/or
information are available. Finally, the procedure is applied to an hypothetical region, Neverland, to clarify the PTHA evaluation in a realistic case. 相似文献
208.
Florencia Bechis Laura Giambiagi Víctor García Silvia Lanés Ernesto Cristallini Maisa Tunik 《Journal of Structural Geology》2010,32(7):886-899
The Atuel depocenter of the Neuquén basin originated as an Upper Triassic to Lower Jurassic rift system, later inverted during the Andean contractional deformation. In order to study the extensional architecture and the kinematic evolution of this depocenter, we collected a large amount of field and sub-surface data, consisting of slip data from outcrop-scale normal faults, thickness and facies distribution within the synrift deposits, and structural data from angular and progressive unconformities. The Atuel depocenter has a NNW trend, showing a bimodal distribution of NNW and WNW major faults (first and second order faults). On the other hand, from kinematic indicators measured on outcrop-scale faults (third and fourth order faults), we found a mean NE internal extension direction, which is oblique to the general trend of the sub-basin. Taking these particular characteristics into account, we interpreted the Atuel depocenter as an oblique rift system. We evaluated two mechanisms in order to explain the development of this transtensional system: 1) reactivation of upper-crustal NNW-oriented Paleozoic shear zones, and 2) oblique stretching of a previous NNW-oriented lithospheric weakness zone. 相似文献
209.
The role of water ice clouds in the martian water cycle and climate depends on cloud properties such as particle size and number distribution. These properties, in turn, depend on heterogeneous nucleation parameters which are poorly understood. Here we report laboratory experiments performed under martian temperature and water partial pressure conditions (158–185 K, 9 × 10−7–1 × 10−4 Torr H2O) to determine the critical saturation ratio for ice onset, Scrit, as a function of temperature and dust composition. Using infrared spectroscopy to monitor ice nucleation and growth, we find a significant barrier to ice formation, with a pronounced temperature dependence. Even on clay minerals which show uptake of non-crystalline water before ice nucleation, we find a saturation ratio of 2.5 or more (RHice > 250%) is needed to begin ice growth at temperatures near 160 K. These results could lead to changes of four orders of magnitude in the nucleation rate relative to the presumptions used currently in Mars microphysical models, which commonly set the contact parameter, m, to a single value of 0.95. Our results range from m = 0.84 to m = 0.98. For ice nucleation on Arizona Test Dust, the temperature dependence is described by m = 0.0046 * Tnucl + 0.1085, while m = 0.0055 * Tnucl + 0.0003 on a smectite-rich clay sample. Our findings suggest that cloud formation will be more difficult than previously thought, potentially leading to areas of increased near-surface humidity but generally drier conditions in the atmosphere of Mars, overall. 相似文献
210.
Curtis M. Oldenburg Jennifer L. Lewicki Lehua Pan Laura Dobeck Lee Spangler 《Environmental Earth Sciences》2010,60(2):241-250
A numerical experiment was carried out to test whether the patchy CO2 emission patterns observed at the Zero Emissions Research and Technology release facility are caused by the presence of packers
that divide the horizontal injection well into six CO2-injection zones. A three-dimensional model of the horizontal well and cobble–soil system was developed and simulations using
TOUGH2/EOS7CA were carried out. Simulation results show patchy emissions for the seven-packer (six-injection-zone) configuration
of the field test. Numerical experiments were then conducted for the cases of 24 packers (23 injection zones) and an effectively
infinite number of packers. The time to surface breakthrough and the number of patches increased as the number of packers
increased suggesting that packers and associated along-pipe flow are the origin of the patchy emissions. In addition, it was
observed that early breakthrough occurs at locations where the horizontal well pipe is shallow and installed mostly in soil
rather than the deeper cobble. In the cases where the pipe is installed at shallow depths and directly in the soil, higher
pipe gas saturations occur than where the pipe is installed slightly deeper in the cobble. It is believed this is an effect
mostly relevant to the model rather than the field system and arises through the influence of capillarity, permeability, and
pipe elevation of the soil compared to the cobble adjacent to the pipe. 相似文献