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121.
122.
We review recent psychological research that pertains to remote sensing, with a focus on two major problem areas: The problem of eliciting and characterizing the knowledge of expert interpreters of remotely‐sensed data, and the problem of how to best utilize color in remote sensing displays. This research has immediate relevance to many remote sensing activities, but it also has broader implications. One general implication is that experimental psychology offers concepts and research methods that can be of benefit to the field of remote sensing. It is possible to discover the principles involved in the design of “good”; remote sensing displays, and the design of methods for teaching novices how to interpret remote sensing displays. A second broad implication of the psychological research is that remote sensing, as traditionally conceived, is actually just one part of a larger process of “remote perceiving.”; This idea is pursued in a second article (Hoffman, 1990), in which an attempt is made to characterize remote sensing as a unified science. 相似文献
123.
Timothy D. Jones Ian T. Lawson Jane M. Reed Graham P. Wilson Melanie J. Leng Merle Gierga Stefano M. Bernasconi Rienk H. Smittenberg Irka Hajdas Charlotte L. Bryant P. C. Tzedakis 《Journal of Paleolimnology》2013,49(2):185-204
The character and impact of climate change since the last glacial maximum (LGM) in the eastern Mediterranean region remain poorly understood. Here, two new diatom records from the Ioannina basin in northwest Greece are presented alongside a pre-existing record and used to infer past changes in lake level, a proxy for the balance between precipitation and evaporation. Comparison of the three records indicates that lake-level fluctuations were the dominant driver of diatom assemblage composition change, whereas productivity variations had a secondary role. The reconstruction indicates low lake levels during the LGM. Late glacial lake deepening was underway by 15.0 cal kyr BP, implying that the climate was becoming wetter. During the Younger Dryas stadial, a lake-level decline is recorded, indicating arid climatic conditions. Lake Ioannina deepened rapidly in the early Holocene, but long-term lake-level decline commenced around 7.0 cal kyr BP. The pattern of lake-level change is broadly consistent with an existing lake-level reconstruction at Lake Xinias, central Greece. The timing of the apparent change, however, is different, with delayed early Holocene deepening at Xinias. This offset is attributed to uncertainties in the age models, and the position of Xinias in the rain shadow of the Pindus Mountains. 相似文献
124.
Rosa M. Carrasco Javier Pedraza David Domínguez‐Villar Jane K. Willenbring Javier Villa 《Geografiska Annaler: Series A, Physical Geography》2013,95(3):211-226
During the deglaciation stages of the last glacial period a rock avalanche took place on the glacier that occupied the upper sector of the Cuerpo de Hombre Valley (Sierra de Béjar). The material displaced during the avalanche fell onto the ice, was transported by the glacier and later deposited as supraglacial ablation till. The cause of the avalanche was the decompression of the valley slopes after they were freed from the glacier ice (stress relaxation). Reconstruction of the ice masses has been carried out to quantify the stress relaxation that produced the collapse. The rock avalanche took place on a lithologically homogeneous slope with a dense fracture network. The avalanche left a 0.4 ha scar on the slope with a volume of displaced material of 623 ± 15 × 103 m3. The deposit is an accumulation of large, angular, heterometric boulders (1–100 m3 in volume) with a coarse pebble‐size matrix. The avalanche can be explained as a relaxation process. This implies rock decompression once the glacier retreat left the wall ice free (debuttressing). Calculations show that the avalanche took place where the decompression stresses were highest (130–170 kPa). In the Spanish Central System paleoglaciers the largest accumulation of morainic deposits occurred after the glacial maximum and the earliest stages of the ice retreat. The process described here is used as an example to formulate a hypothesis that the largest accumulations of tills were formed in relation to enhanced slope dynamics once some glacier retreat had occurred. 相似文献
125.
Alexandros A. Taflanidis Gaofeng Jia Andrew B. Kennedy Jane M. Smith 《Natural Hazards》2013,66(2):955-983
One of the important recent advances in the field of hurricane/storm modelling has been the development of high-fidelity numerical simulation models for reliable and accurate prediction of wave and surge responses. The computational cost associated with these models has simultaneously created an incentive for researchers to investigate surrogate modelling (i.e. metamodeling) and interpolation/regression methodologies to efficiently approximate hurricane/storm responses exploiting existing databases of high-fidelity simulations. Moving least squares (MLS) response surfaces were recently proposed as such an approximation methodology, providing the ability to efficiently describe different responses of interest (such as surge and wave heights) in a large coastal region that may involve thousands of points for which the hurricane impact needs to be estimated. This paper discusses further implementation details and focuses on optimization characteristics of this surrogate modelling approach. The approximation of different response characteristics is considered, and special attention is given to predicting the storm surge for inland locations, for which the possibility of the location remaining dry needs to be additionally addressed. The optimal selection of the basis functions for the response surface and of the parameters of the MLS character of the approximation is discussed in detail, and the impact of the number of high-fidelity simulations informing the surrogate model is also investigated. Different normalizations of the response as well as choices for the objective function for the optimization problem are considered, and their impact on the accuracy of the resultant (under these choices) surrogate model is examined. Details for implementation of the methodology for efficient coastal risk assessment are reviewed, and the influence in the analysis of the model prediction error introduced through the surrogate modelling is discussed. A case study is provided, utilizing a recently developed database of high-fidelity simulations for the Hawaiian Islands. 相似文献
126.
The resiliency of coastal communities is imperative because these areas experience risk of damage from coastal storms as well as increasing population pressures and development. The severity of this hazard is compounded by sea level rise and a potential increase in storm intensities due to climate change. The ability of coastal communities to plan for, resist, and quickly and completely recover from severe coastal storm events and flooding is of critical importance. There is a growing interest in applying complementary and redundant approaches to reduce the flood risk of these vulnerable communities, such as incorporating natural and nature‐based features into the project planning process. However, accounting for the benefits of these nature‐based features in coastal design is still challenging. One of the natural features generally acknowledged to offer coastal protection benefits is wetlands. Using laboratory experiments of artificial vegetation as a foundation, the bounds of wave dissipation by vegetation are explored analytically and the effectiveness of wave dissipation by vegetation over large scales is investigated using the spectral wave model STWAVE. Wave heights modeled using a vegetation dissipation formulation are compared to those modeled with the current practice of representing vegetation using bottom friction, particularly the Manning formulation. The vegetation dissipation formulation reduced more wave energy than the Manning bottom friction formulation for submerged wetlands. Because the Manning formulation does not integrate vegetation properties, to achieve consistent results would require varying the Manning n coefficient to account for the spatial and temporal variation in form drag induced by the plants due to changes in plant density, diameter, and degree of plant submergence. Thus, a re‐evaluation of existing methods for assessing wave dissipation by vegetation is recommended for wider application of vegetation dissipation formulations in numerical models. Such models are critical for evaluating coastal resiliency of communities protected by wetland features. Published 2016. This article is a U.S. Government work and is in the public domain in the USA. 相似文献
127.
Trace fossils are recorded from eight localities within Upper Cambrian (Ffestiniog Stage) strata in North Wales. Trilobite furrows (Cruziana), resting impressions (Rusophycus), walking and striding tracks (Diplichnites), sideways grazing tracks (Dimorphichnus) and swimming grazing marks (Monomorphichnus, gen. nov.) are described, largely on the basis of over 500 collected specimens, and are figured together with examples of other trace fossil genera including Rouaultia, Phycodes and Monocraterion. The trilobite traces are used to investigate the varied methods of locomotion of the animais. They also indicate the morphology of some of the trilobite hard and soft parts from which it is inferred that most of these traces were probably made by a population consisting of a small number of closely allied species of trilobites belonging to the Olenid family. 相似文献
128.
Climate change adaptation in Australian mining communities: comparing mining company and local government views and activities 总被引:1,自引:0,他引:1
Effective climate change adaptation in mining communities is reliant on action by both local authorities and mining operations. This article reports the findings of two surveys conducted in late 2010, with Australian mining companies and local government authorities respectively, investigating their perceptions and activities related to climate change adaptation. The research identified the main types of weather and climate-related impacts experienced in the past and expected under future climate conditions for the two groups. There were significantly differing levels of concern about weather and climate-related impacts between the two types of organisations. Mining company respondents reported lower levels of severity of impact from both past and (expected) future weather events, as well as lower levels of belief in climate change and of adaptation activities to prepare for it. Interestingly, mining companies generally reported less concern about future impacts than those experienced in the past, suggesting discounting of risks due to climate change scepticism. The article reports on a range of factors relevant to adaptation in mining communities, including perceived barriers, collaboration and further information needs. The research findings are discussed in the context of other recent research on climate change adaptation by Australian organisations and studies of mining industry adaptation in other countries. 相似文献
129.
Eduardo Teixeira Mansur Sarah‐Jane Barnes Dany Savard Peter C. Webb 《Geostandards and Geoanalytical Research》2020,44(1):147-167
The study of Te, As, Bi, Sb and Se (TABS) has increased over the past years due to their use in the development of low‐carbon energy technologies. However, there is a scarcity of mass fraction values of TABS in geological reference materials. This underlines the difficulty in undertaking routine determinations of these elements. The mass fractions of TABS were determined in geological reference materials using hydride generation‐atomic fluorescence spectrometry (HG‐AFS), calibrated with standard solutions. Comparisons with literature values were used to validate the method. Samples from the GeoPT proficiency test were also analysed. For most elements, there are no assigned or even provisional values for many of the GeoPT and reference materials because of the wide range of results reported. For mass fractions above the quantification limit of the method, our results are in good agreement with the median of GeoPT results. Thus, we propose GeoPT median values as informational values for these elements. In contrast, at mass fractions < 0.5 µg g?1 median values of Se from GeoPT are systematically higher than our results. Our Se results are in agreement with the reference materials down to 0.02 µg g?1, which suggest that many of the results for Se reported in GeoPT testing are too high. 相似文献
130.
Anne E. Giblin Nathaniel B. Weston Gary T. Banta Jane Tucker Charles S. Hopkinson 《Estuaries and Coasts》2010,33(5):1054-1068
Benthic respiration, sediment–water nutrient fluxes, denitrification and dissimilatory nitrate reduction to ammonium (DNRA)
were measured in the upper section of the Parker River Estuary from 1993 to 2006. This site experiences large changes in salinity
over both short and long time scales. Sediment respiration ranged from 6 to 52 mmol m−2 day−1 and was largely controlled by temperature. Nutrient fluxes were dominated by ammonium fluxes, which ranged from a small uptake
of −0.3 to an efflux of over 8.2 mmol N m−2 day−1. Ammonium fluxes were most highly correlated with salinity and laboratory experiments demonstrated that ammonium fluxes increased
when salinity increased. The seasonal pattern of DNRA closely followed salinity. DNRA rates were extremely low in March, less
than 0.1 mmol m−2 day−1, but increased to 2.0 mmol m−2 day−1 in August. In contrast, denitrification rates were inversely related to salinity, ranging from 1 mmol m−2 day−1 during the spring and fall to less than 0.2 mmol m−2 day−1 in late summer. Salinity appears to exert a major control on the nitrogen cycle at this site, and partially decouples sediment
ammonium fluxes from organic matter decomposition. 相似文献