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961.
Application and verification of fuzzy algebraic operators to landslide susceptibility mapping 总被引:4,自引:2,他引:4
Saro Lee 《Environmental Geology》2007,52(4):615-623
The aim of this study was to apply and to verify the use of fuzzy logic to landslide susceptibility mapping in the Gangneung
area, Korea, using a geographic information system (GIS). For this aim, in the study, a data-derived model (frequency ratio)
and a knowledge-derived model (fuzzy operator) were combined. Landslide locations were identified by changing the detection
technique of KOMPSAT-1 images and checked by field studies. For landslide susceptibility mapping, maps of the topography,
lineaments, soil, forest, and land cover were extracted from the spatial data sets, and the eight factors influencing landslide
occurrence were obtained from the database. Using the factors and the identified landslide, the fuzzy membership values were
calculated. Then fuzzy algebraic operators were applied to the fuzzy membership values for landslide susceptibility mapping.
Finally, the produced map was verified by comparing with existing landslide locations for calculating prediction accuracy.
Among the fuzzy operators, in the case in which the gamma operator (λ = 0.975) showed the best accuracy (84.68%) while the
case in which the fuzzy or operator was applied showed the worst accuracy (66.50%). 相似文献
962.
This review describes developments major and in trace element determination using atomic absorption spectroscopy (AAS), inductively coupled plasma-atomic emission spectrometry (ICP-AES), instrumental neutron activation analysis (INAA), and X-ray fluorescence (XRF) spectrometry that were reported in 2008 and 2009. Publication levels were comparable to those of previous years, except for XRF which showed an increase in the number of articles published in the past 2 years. In terms of number of publications and impact, the most active field was AAS, while INAA was the least active. As expected for well-established and mature methods, novel developments for all four analytical techniques were relatively sparse. For AAS, the most notable publications concerned developments in sample introduction, particularly focussing on solid samples, increasing analyte sensitivity, and higher sample throughput. For ICP-AES, publication of developments in sample introduction, remediation of matrix effects and calibration continues. Compared with past years, there was a clear focus on sample preconcentration methods, but very few publications reporting new hyphenated speciation methods. For INAA, there were several publications exploring the accuracy and robustness of the method, as well as the requirements for INAA to meet criteria for a primary method of measurement. Two other related techniques, delayed neutron activation analysis, and prompt gamma activation analysis, were also described. Hyphenated XRF techniques showed interesting developments in enabling XRF and XRD analysis on the same spot, and further work characterising and calibrating three-dimensional micro-XRF shows promising results for investigating sample heterogeneity. 相似文献
963.
Aina G. Gómez Bárbara Ondiviela María Fernández José A. Juanes 《Marine pollution bulletin》2017,114(1):239-246
An atlas of susceptibility to pollution of 320 Spanish marinas is provided. Susceptibility is assessed through a simple, fast and low cost empirical method estimating the flushing capacity of marinas. The Complexity Tidal Range Index (CTRI) was selected among eleven empirical methods. The CTRI method was selected by means of statistical analyses because: it contributes to explain the system's variance; it is highly correlated to numerical model results; and, it is sensitive to marinas' location and typology. The process of implementation to the Spanish coast confirmed its usefulness, versatility and adaptability as a tool for the environmental management of marinas worldwide. The atlas of susceptibility, assessed through CTRI values, is an appropriate instrument to prioritize environmental and planning strategies at a regional scale. 相似文献
964.
Several horizons of a unique lithotype called “chertbreccia” are interbedded within the Proterozoic platform sediments of
the Peninsular India. These cherty rocks with brecciated texture appearing as blocky masses were earlier diversely interpreted
as being products of disparate processes such as fault-zone breccias, collapse breccias, and so on. Two of these horizons,
one from the Kaladgi Basin (Dharwar Craton) and the other from the Dhar Forest Inlier of the Vindhyanchal Basin (Bundelkhand
— Aravalli Craton) are compared in context of their geological setting, field relations and petrological constitution. A model
of the mode of development of these peculiar rocks is reconstructed, taking into account their characters and limitations
of previous interpretations. They are interpreted as transported debris deposits of syntectonogenic material released during
the episodic activity of the growth faults of the Kaladgi and Vindhyanchal Basins that was diagenetically silicified. 相似文献
965.
Márcio Poletti Laurini 《Journal of Geographical Systems》2017,19(4):371-398
We propose a spatial error model with continuous random effects based on Matérn covariance functions and apply this model for the analysis of income convergence processes (\(\beta \)-convergence). The use of a model with continuous random effects permits a clearer visualization and interpretation of the spatial dependency patterns, avoids the problems of defining neighborhoods in spatial econometrics models, and allows projecting the spatial effects for every possible location in the continuous space, circumventing the existing aggregations in discrete lattice representations. We apply this model approach to analyze the economic growth of Brazilian municipalities between 1991 and 2010 using unconditional and conditional formulations and a spatiotemporal model of convergence. The results indicate that the estimated spatial random effects are consistent with the existence of income convergence clubs for Brazilian municipalities in this period. 相似文献
966.
Igri P. Moudi Tanessong Roméo S. Vondou D. A. Panda Jagabandhu Garba Adamou Mkankam F. Kamga Kamga A. 《Natural Hazards》2018,93(3):1565-1587
Natural Hazards - For numerical weather prediction over a particular region, it is important to know the best combination of physical parameterizations available in the considered modelling frame... 相似文献
967.
Particle composition and size distributions in and around a deep-pit swine operation,Ames, IA 总被引:1,自引:0,他引:1
Randal S. Martin Philip J. Silva Kori Moore Mark Erupe Vishal S. Doshi 《Journal of Atmospheric Chemistry》2008,59(2):135-150
The contribution of emissions from agricultural facilities is rapidly becoming a major concern for local and regional air
quality. Characterization of particle properties such as physical size distribution and chemical composition can be valuable
in understanding the processes contributing to emissions and ultimate fate of particulate matter from agricultural facilities.
A measurement campaign was conducted at an Iowa, deep-pit, three-barn swine finishing facility to characterize near-source
ambient particulate matter. Size-specific mass concentrations were determined using minivol samplers, with additional size
distribution information obtain using optical particle counters. Particulate composition was determined via ion chromatographic
analysis of the collected filters. A thermal-CO2 elemental/organic carbon analyzer measured particulate carbon. The chemical composition and size distribution of sub-micron
particles were determined via real-time aerosol mass spectrometry. Primary particulate was not found to be a major emission
from the examined facility, with filter-based impactor samples showing average near-source increases (~15–50 m) in ambient
PM10 of 5.8 ± 2.9 μg m−3 above background levels. PM2.5 also showed contribution attributable to the facility (1.7 ± 1.1 μg m−3). Optical particle counter analysis of the numerical size distributions showed bimodal distributions for both the upwind
and downwind conditions, with maximums around 2.5 μm and below the minimum quantified diameter of 0.3 μm. The distributions
showed increased numbers of coarse particles (PM10) during periods when wind transport came from the barns, but the differences were not statistically significant at the 95%
confidence level. The PM10 aerosols showed statistically increased concentrations of sulfate, nitrate, ammonium, calcium, organic carbon, and elemental
carbon when the samplers were downwind from the pig barns. Organic carbon was the major constituent of the barn-impacted particulate
matter in both sub-micron (54%) and coarse size (20%) ranges. The AMS PM1 chemical speciation showed similar species increases, with the exception of and Ca+2, the latter not quantified by the AMS. 相似文献
968.
Aurore E. Sibois Shailen D. Desai Willy Bertiger Bruce J. Haines 《Journal of Geodesy》2017,91(8):965-983
We present results from the generation of 10-year-long continuous time series of the Earth’s polar motion at 15-min temporal resolution using Global Positioning System ground data. From our results, we infer an overall noise level in our high-rate polar motion time series of 60 \(\upmu \hbox {as}\) (RMS). However, a spectral decomposition of our estimates indicates a noise floor of 4 \(\upmu \hbox {as}\) at periods shorter than 2 days, which enables recovery of diurnal and semidiurnal tidally induced polar motion. We deliberately place no constraints on retrograde diurnal polar motion despite its inherent ambiguity with long-period nutation. With this approach, we are able to resolve damped manifestations of the effects of the diurnal ocean tides on retrograde polar motion. As such, our approach is at least capable of discriminating between a historical background nutation model that excludes the effects of the diurnal ocean tides and modern models that include those effects. To assess the quality of our polar motion solution outside of the retrograde diurnal frequency band, we focus on its capability to recover tidally driven and non-tidal variations manifesting at the ultra-rapid (intra-daily) and rapid (characterized by periods ranging from 2 to 20 days) periods. We find that our best estimates of diurnal and semidiurnal tidally induced polar motion result from an approach that adopts, at the observation level, a reasonable background model of these effects. We also demonstrate that our high-rate polar motion estimates yield similar results to daily-resolved polar motion estimates, and therefore do not compromise the ability to resolve polar motion at periods of 2–20 days. 相似文献
969.
The present experimental investigation focuses on the characteristics of near bed turbulence in a fully rough, uniform open-channel
flow over a gravel-type bed. Due to bed topography small scale heterogeneity, the flow is not uniform locally in the near
bed region and a double averaging methodology is applied over a length scale much larger than the gravel size. The double-averaged
Turbulent Kinetic Energy (TKE) budget derived in the context of the present flow over a gravel bed differs from the TKE budget
written for flow over a vegetation canopy. The non-constant shape of the roughness function measured in our gravel bed leads
to an additional bed-induced production term which is null for vertical roughness elements, such as simplified vegetation
elements.
The experimental estimation of the terms of the TKE budget reveals that the maximum turbulent activity takes place away from
the reference plane, near the roughness crests. However, within the interface sublayer the work of the bed induced velocity
fluctuations against the Reynolds stress is of the same magnitude as the main turbulence production term. Consequently, the
characteristics of the TKE budget have similarities with uniform flows over canopies and strongly differ from uniform flows
over smooth and transitionally rough flows over sedimentlike beds. 相似文献
970.
Tide-induced vertical suspended sediment concentration profiles: phase lag and amplitude attenuation
In tidal environments, the response of suspended sediment concentration (SSC) to the current velocity is not instantaneous,
the SSC lagging behind the velocity (phase lag), and the amplitude of SSC variation decreasing with height above the bed (amplitude
attenuation). In order to quantitatively describe this phenomenon, a one-dimensional vertical advection–diffusion equation
of SSC is derived analytically for uniform unsteady tidal flow by defining a concentration boundary condition using a constant
vertical eddy diffusivity and sediment settling velocity. The solution, in simple and straightforward terms, shows that the
vertical phase lag increases linearly with the height above the bed, while the amplitude of the SSC variation decreases exponentially
with the height. The relationship between the SSC and the normalized current velocity can be represented by an ellipse or
a line, depending on the phase lag. The lag of sediment movement or “diffusion/settling lag” is the mechanism generating the
phase lag effect. Field observations used for validation show that the theoretically predicted and the observed curves of
the vertical SSC phase lag and amplitude attenuation show reasonable agreement. The procedure proposed in this paper substantially
simplifies the modeling of suspended matter transport in tidal flows. 相似文献