IFKIS-Hydro is an information and warning system for hydrological hazards in small- and medium-scale catchments. The system
collects data such as weather forecasts, precipitation measurements, water level gauges, discharge simulations and local observations
of event-specific phenomena. In addition, IFKIS-Hydro incorporates a web-based information platform, which serves as a central
hub for the submission and overview of data. Special emphasis is given to local information. This is accomplished particularly
by human observers. In medium-scale catchments, discharge forecast models have an increasing importance in providing valuable
information. IFKIS-Hydro was developed in several test regions in Switzerland and the first results of its application are
available now. The system is constantly extended to additional regions and may become the standard for warning systems in
smaller catchments in Switzerland. 相似文献
Interpretation of deep 2-D multi-channel seismic data sheds insights into the geological evolution of the West Luzon Basin,
Philippines. This basin is a sediment-filled trough that is located between the island of Luzon and the outer arc high of
the west Luzon subduction zone. High-amplitude, low-frequency reflection bands mark the acoustic basement. The basement, at
about 6 s (TWT), is dissected by normal faults with some of them being inverted in a later phase of deformation. The sedimentary
successions, overlying the basement are stratified with partly chaotic structures and discontinuous reflectors. Five regional
unconformities separate major stratigraphic units. Grid calculations of our seismic data reveal variations in the sedimentation
pattern of the basin with a shift of the deposition centre from east to west and backwards during formation. A distinct bottom-simulating
reflector is commonly observed. Because the northern boundary of the continental fragments to the South of the West Luzon
Basin is unclear we speculate that the basin may be (partly) underlain by continental crust. The continental crust was affected
by rifting prior to and during the opening of the South China Sea and the basin was overprinted at a later stage by a forearc
structural setting when subduction was initiated. 相似文献
In this paper, possibilities and limits of the application of REE3+ luminescence (especially the Nd3+4F3/2 → 4I9/2 emission) as structural probe are evaluated. Important factors controlling the Nd3+ luminescence signal are discussed, including effects of the crystal-field, crystal orientation, structural state, and temperature. Particular attention was paid to the study of the accessory minerals zircon (ZrSiO4), xenotime–(Y) (YPO4), monazite–(Ce) (CePO4) and their synthetic analogues. Based on these examples we review in short that (1) REE3+ luminescence can be used as non-destructive phase identification method, (2) the intensities of certain luminescence bands are strongly influenced by crystal orientation effects, and (3) increased widths of REE3+-related emission bands are a strong indicator for structural disorder. We discuss the potential of luminescence spectroscopy, complementary to Raman spectroscopy, for the quantitative estimation of chemical (and potentially also radiation-induced) disorder. For the latter, emissions of Nd3+-related centres are found to be promising candidates. 相似文献
Safe pipeline transportation of carbon dioxide is a critical issue in the developing field of carbon capture and storage technology. Inadequate fluid thermo- and regimes for on- and offshore transport through high-pressurized pipelines can induce pipe material obsolescence or even pipeline rupture. In such cases, CO2 (Carbon dioxide) will be released and dispersed in the ambient medium. The dispersion is influenced by the total amount of released fluid, jet pressure and direction, the released concentrations, leakage hole size, ambient material properties and is also affected by the dynamical conditions of the environmental medium. The goal of this study is the hydrodynamical characterization of carbon dioxide jet expansion and dispersion in the ambient atmosphere in case of onshore pipeline accidental leaks. Numerical simulations were carried out by means of a 3D turbulent CFD (computational fluid dynamics) code which includes multi-component flow treatment. The influence of the jet release pressure and size of the leakage hole on harmful CO2 concentration distances will be analyzed. 相似文献
The heat of the Earth derives from internal and external sources. A heat balance shows that most of the heat provided by external
sources is re-emitted by long-wavelength heat radiation and that the dominant internal sources are original heat and heat
generated by decay of unstable radioactive isotopes. Understanding of the thermal regime of the Earth requires appreciation
of properties and mechanisms for heat generation, storage, and transport. Both experimental and indirect methods are available
for inferring the corresponding rock properties. Heat conduction is the dominant transport process in the Earth’s crust, except
for settings where appreciable fluid flow provides a mechanism for heat advection. For most crustal and mantle rocks, heat
radiation becomes significant only at temperatures above 1200°C.
Zircon, monazite and xenotime crystallized over a temperature interval of several hundred degrees at the magmatic to hydrothermal transition of the Sn and W mineralized Mole Granite. Magmatic zircon and monazite, thought to have crystallized from hydrous silicate melt, were dated by conventional U–Pb techniques at an age of 247.6 ± 0.4 and 247.7 ± 0.5 Ma, respectively. Xenotime occurring in hydrothermal quartz is found to be significantly younger at 246.2 ± 0.5 Ma and is interpreted to represent hydrothermal growth. From associated fluid inclusions it is concluded that it precipitated from a hydrothermal brine ≤ 600 °C, which is below the accepted closure temperature for U–Pb in this mineral. These data are compatible with a two-stage crystallization process: precipitation of zircon and monazite as magmatic liquidus phases in deep crustal magma followed by complete crystallization and intimately associated Sn–W mineralization after intrusion of the shallow, sill-like body of the Mole Granite. Later hydrothermal formation of monazite in a biotite–fluorite–topaz reaction rim around a mineralized vein was dated at 244.4 ± 1.4 Ma, which distinctly postdates the Mole Granite and is possibly related to a younger hidden intrusion and its hydrothermal fluid system.
Obtaining precise age data for magmatic and hydrothermal minerals of the Mole Granite is hampered by uncertainties introduced by different corrections required for multiple highly radiogenic minerals crystallising from evolved hydrous granites, including 230Th disequilibrium due to Th/U fractionation during monazite and possibly xenotime crystallization, variable Th/U ratios of the fluids from which xenotime was precipitating, elevated contents of common lead, and post-crystallization lead loss in zircon, enhanced by the fluid-saturated environment. The data imply that monazite can also survive as a liquidus phase in protracted magmatic systems over periods of 106 years. The outlined model is in agreement with prominent chemical core-rim variation of the zircon. 相似文献
We examine the space–time structure of the wind and temperature fields, as well as that of the resulting spatial temperature
gradients and horizontal advection of sensible heat, in the sub-canopy of a forest with a dense overstorey in moderately complex
terrain. Data were collected from a sensor network consisting of ten stations and subject to orthogonal decomposition using
the multiresolution basis set and stochastic analyses including two-point correlations, dimensional structure functions, and
various other bulk measures for space and time variability. Despite some similarities, fundamental differences were found
in the space–time structure of the motions dominating the variability of the sub-canopy wind and temperature fields. The dominating
motions occupy similar spatial, but different temporal, scales. A conceptual space–time diagram was constructed based on the
stochastic analysis that includes the important end members of the spatial and temporal scales of the observed motions of
both variables. Short-lived and small-scale motions govern the variability of the wind, while the diurnal temperature oscillation
driven by the surface radiative transfer is the main determinant of the variability in the temperature signal, which occupies
much larger time scales. This scale mismatch renders Taylor’s hypothesis for sub-canopy flow invalid and aggravates the computation
of meaningful estimates of horizontal advective fluxes without dense spatial information. It may further explain the ambiguous
and inconclusive results reported in numerous energy and mass balance and advection studies evaluating the hypothesis that
accounting for budget components other than the change in storage term and the vertical turbulent flux improves the budget
closure when turbulent diffusion is suppressed in plant canopies. Estimates of spatial temperature gradients and advective
fluxes were sensitive to the network geometry and the spatial interpolation method. The assumption of linear spatial temperature
gradients was not supported by the results, and leads to increased spatial and temporal variability of inferred spatial gradients
and advection estimates. A method is proposed to estimate the appropriate minimum network size of wind and temperature sensors
suitable for an evaluation of energy and mass balances by reducing spatial and temporal variability of the spatially sampled
signals, which was estimated to be on the order of 200 m at the study site. 相似文献