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101.
Emö Márton Balázs Bradák Marta Rauch-Włodarska Antek K. Tokarski 《Studia Geophysica et Geodaetica》2010,54(1):121-134
AMS studies earlier carried out on the flysch sediments from the Outer Western Carpathians focused on the sandstone members
deposited from turbidity currents. The main conclusion of these studies was that the dominant features of the AMS fabric developed
during sedimentation and the tectonic overprint was weak. In recent years a large number of claystone (deposited also from
turbidity currents, but in calm water) localities were sampled from the Krosno beds of the Silesian nappe, primarily for paleomagnetic
study. Nevertheless, the AMS of the samples was also measured. The magnetic fabrics of the claystones were dominated by foliation,
but lineations were also expressed and attributed to deformation. The question arose how different are the reactions of the
claystone and the siltstone beds to deformation. 相似文献
102.
This research integrates data procedures for the delineation of regional ground water flow systems in arid karstic basins with sparse hydrogeologic data using surface topography data, geologic mapping, permeability data, chloride concentrations of ground water and precipitation, and measured discharge data. This integrative data analysis framework can be applied to evaluate arid karstic aquifer systems globally. The accurate delineation of ground water recharge areas in developing aquifer systems with sparse hydrogeologic data is essential for their effective long-term development and management. We illustrate the use of this approach in the Cuatrociénegas Basin (CCB) of Mexico. Aquifers are characterized using geographic information systems for ground water catchment delineation, an analytical model for interbasin flow evaluation, a chloride balance approach for recharge estimation, and a water budget for mapping contributing catchments over a large region. The test study area includes the CCB of Coahuila, Mexico, a UNESCO World Biosphere Reserve containing more than 500 springs that support ground water-dependent ecosystems with more than 70 endemic organisms and irrigated agriculture. We define recharge areas that contribute local and regional ground water discharge to springs and the regional flow system. Results show that the regional aquifer system follows a topographic gradient that during past pluvial periods may have linked the Río Nazas and the Río Aguanaval of the Sierra Madre Occidental to the Río Grande via the CCB and other large, currently dry, upgradient lakes. 相似文献
103.
Adebayo O. Eludoyin Bruce Griffith Robert J. Orr Roland Bol Timothy A. Quine Richard E. Brazier 《水文科学杂志》2017,62(8):1243-1254
This study examined the hysteresis exhibited in concentration–discharge (C–Q) relationships in the runoff from four hydrologically separated fields (catchments) at an intensively managed grassland. The objectives were to examine C–Q relationships constructed from high-resolution time series of flow, temperature, pH, conductivity, nitrate and turbidity, and their implications for hydrological processes. High-resolution datasets from the quality assured records of the Rothamsted Research North Wyke Farm Platform in the UK were examined using a graphical method and cross-correlation statistics. The study found that storm events based C–Q hysteresis reflects the cross-correlation that is generally hidden in time series analysis of large datasets, and that although Q and water quality variables can be effectively influenced by catchment size, the C–Q relationship is less significantly influenced. The dominant C–Q relationships of the water variables in the study area reflect that saturated overland flow was prevalent during the study period in the catchments, while the CCF results indicate coupled transfer of sediments and solute in the area at lag ≥ 0.
EDITOR D. KoutsoyiannisASSOCIATE EDITOR M. D. Fidelibus 相似文献
104.
SUPERCOMPUTING AND SPATIAL STATISTICS: A RECONNAISSANCE* 总被引：1，自引：0，他引：1
Daniel A. Griffith 《The Professional geographer》1990,42(4):481-492
105.
Brad M. S. Hansen & Sterl Phinney 《Monthly notices of the Royal Astronomical Society》1998,294(4):557-568
The presence of low-mass, degenerate secondaries in millisecond pulsar binaries offers the opportunity to determine an age for the binary system independently of the rotational properties of the pulsar. To this end, we present here a detailed calculation of the evolution of a grid of low-mass (< 0.05 M⊙) helium core white dwarfs. We investigate the effects of different hydrogen layer masses and provide results for well-known optical bandpasses. We supplement the OPAL opacity calculations with our own calculations for low effective temperatures ( T eff < 6000 K) and also provide fitting formulae for the gravity as a function of mass and effective temperature. In Paper II we apply these results to individual cases. 相似文献
106.
Modeling spatial autocorrelation in spatial interaction data: empirical evidence from 2002 Germany journey-to-work flows 总被引：3，自引：3，他引：0
Daniel A. Griffith 《Journal of Geographical Systems》2009,11(2):117-140
Since before the inception of work by Okabe, the intermingling of spatial autocorrelation (i.e., local distance and configuration)
and distance decay (i.e., global distance) effects has been suspected in spatial interaction data. This convolution was first
treated conceptually because technology and methodology did not exist at the time to easily or fully address spatial autocorrelation
effects within spatial interaction model specifications. Today, however, sufficient computer power coupled with eigenfunction-based
spatial filtering offers a means for accommodating spatial autocorrelation effects within a spatial interaction model for
modest-sized problems. In keeping with Okabe’s more recent efforts to dissemination spatial analysis tools, this paper summarizes
how to implement the methodology utilized to analyze a particular empirical flows dataset.
相似文献
| Daniel A. GriffithEmail: |
107.
108.
109.
Sprawl measures have largely been neglected in land‐use forecasting models. The current approach for land‐use allocation using optimization mostly utilizes objective functions and constraints that are non‐spatial in nature. Application of spatial constraints could take care of the contiguity and compactness of land uses and can be utilized to address urban sprawl. Because a land‐use model is used as an input to transportation modeling, a better spatial allocation strategy for more compact land‐use projections will promote better transportation planning and sustainable development. This study formulates a scenario‐based approach to normative modeling of urban sprawl. In doing so, it seeks to improve the land‐use projections by employing a spatial optimization model with contiguity and compactness consideration. This study incorporates urban sprawl measures based on smart growth principles together with a mixed‐use factor, and adjacency consideration of nearby land uses. The objective function used in the study maximizes net suitability based on imposed constraints. These constraints are based on smart growth principles that enhance walkability in neighborhoods, promote better health for residents, and encourage mixed‐use development. The formulated model has been applied to Collin County, TX, a fast‐developing suburban county located to the north of the Dallas–Fort Worth metroplex. The suitability of land cells indicates the probability of conversion, which is calculated using spatial discrete choice analysis with Moran eigenvector spatial filtering for vacant cells at a resolution of 150 × 150 m employing factors of the built environment, and socioeconomic and demographic characteristics. This study demonstrates how spatial proximity between land uses, which has been ignored to date, can be used to control sprawl, resulting in better mixing of different land uses based on constraints imposed in a spatial optimization problem. 相似文献
110.
Abstract The hydrography and circulation of Conception Bay (Newfoundland) are described based on hydrographic, current‐meter and drifter data collected over four years (1988–1991). The seasonal cycles of temperature (‐1.6 to 13–17°C) and salinity (31–32.5) in the bay closely follow those on the adjacent shelf. Exchange of bottom water was observed in April 1989. Deepwater exchange was observed from late fall to early winter of 1989–90. Tidal currents are weak, 1–2 cm s‐1 for the M2 and K1 constituents. Observed Eulerian mean currents (<3 cm s‐1) are smaller than the standard deviation (1–11 cm s‐1); however, there is a persistent outflowing current of 10 to 20 cm s‐1 within 2 km of the shoreline on the eastern side of the outer bay. The Lagrangian correlation length scale is from 4 to 10 km, in agreement with the weak coherence squared (≤0.4) found between the fixed current‐meter sites separated by greater than 4–5 km. The variable currents (up to 20 cm s‐1) tend to be cyclonic. Cyclonic eddies were observed near the mouth on the eastern side of the bay, adjacent to the outflow. A simplified fractal dispersion model gives residence times of 42 d similar to those obtained from a scaling analysis (30–40 d) and a diagnostic numerical model (30 d). 相似文献