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排序方式: 共有167条查询结果,搜索用时 31 毫秒
161.
Manfred Lenzen Roberto Schaeffer Jonas Karstensen Glen P. Peters 《Climatic change》2013,121(4):815-824
Brazil’s economic development has been underpinned by a diverse and – in a global comparison – unusual set of energy carriers, notably hydroelectricity and ethanol from sugar cane. Its energy mix makes Brazil one of the least energy-related carbon-intensive economies worldwide. Given that the country is fast becoming one of the world’s economic powerhouses, decision-makers need to understand the drivers underlying past and current carbon dioxide emissions trends. We therefore investigate a) which key long-term drivers have led to Brazil’s unique emissions profile, and b) the implications of these drivers for Brazil’s national policies. We show that Brazil’s emissions are growing mainly due to increasing individual standards of living, exports and population size, and that this growth is so far unchallenged by technological and structural improvements toward lower emissions intensities and more efficient production structures. As these trends are likely to continue amidst growing international pressure on key economies to reduce their carbon emissions, a decoupling of drivers from emissions is needed to simultaneously meet development and environmental goals. 相似文献
162.
The mountain belts of the Dzungarian Alatau (SE Kazakhstan) and the Tien Shan are part of the actively deforming India–Asia collision zone but how the strain is partitioned on individual faults remains poorly known. Here we use terrace mapping, topographic profiling, and 10Be exposure dating to constrain the slip rate of the 160-km-long Usek thrust fault, which defines the southern front of the Dzungarian Alatau. In the eastern part of the fault, where the Usek River has formed five terraces (T1–T5), the Usek thrust fault has vertically displaced terrace T4 by 132 ± 10 m. At two sites on T4, exposure dating of boulders, amalgamated quartz pebbles, and sand from a depth profile yielded 10Be ages of 366 ± 60 ka and 360 + 77/− 48 ka (both calculated for an erosion rate of 0.5 mm/ka). Combined with the vertical offset and a 45–70° dip of the Usek fault, these age constraints result in vertical and horizontal slip rates of ~ 0.4 and ~ 0.25 mm/a, respectively. These rates are below the current resolution of GPS measurements and highlight the importance of determining slip rates for individual faults by dating deformed landforms to resolve the pattern of strain distribution across intracontinental mountain belts. 相似文献
163.
During Typhoon Morakot which hit Taiwan from 6 to 9 August, 2009, Kaohsiung City was highly affected by devastating debris-flows and flooding. Recorded casualties were 699 deaths and 1,766 damaged homes, mostly in the mountainous areas of Kaohsiung City. Due to a largely malfunctioning or absent early-warning system, residents in those mountainous villages were required to rely on individual- and/or community-based capacities to evacuate and respond to debris-flow-related disasters. Hence, this study investigates the response behaviour of selected debris-flow-affected communities in Kaohsiung City, based on a preparedness awareness action and affect model. Key results from the survey highlight that only 13.8 % of the households received formal (institutional) early warning, whereas 86.2 % households had to rely on their intrinsic senses and indigenous knowledge to recognise the onset of debris-flows in their villages during Typhoon Morakot. Among those households who did not receive formal early warning, 10 % of the households received previous disaster education, 17 % had previous disaster experience, and 73 % did have neither disaster education nor disaster experience. Furthermore, households with disaster education were among those who were best prepared and knew best how to evacuate and respond to debris-flow-related disasters followed by households with disaster experiences. Finally, findings from the survey and selected key informants’ interviews identified that the response behaviour of communities ought to be enhanced through the following measures: conduction of hydro-meteorological-related disaster education, improved participatory risk communication and enhanced recognition of communities as vital actors during a disaster to provide local knowledge and support to relief operations. 相似文献
164.
Robert Mokrik Vytautas Juodkazis Anicetas Štuopis Jonas Mažeika 《Hydrogeology Journal》2014,22(4):925-941
A steady-state groundwater flow model of three Quaternary intertill aquifers in the eastern part of Lithuania has been compiled. The distinction of separate modelled layers is based on hydraulic and isotope-hydrochemistry data criteria. 3H data were used to estimate the corrected groundwater age and were coupled with a groundwater-flow-dynamics model of the Quaternary aquifer system along a cross-section flow pathway from the Baltic Upland recharge area in eastern Lithuania towards the discharge area in the lowlands near the city of Kaunas in central Lithuania. The bicarbonate content in groundwater (214–462 mg/l) increases downgradient towards the lowland area. The other major constituents and total dissolved solids (TDS) have a trend analogous to the bicarbonate. The 14C activity of dissolved inorganic carbon (DIC) in the groundwater ranges from 41.4 to 85.7 pMC. With aquifer-system depth, active precipitation of aqueous solution takes place by dissolving minerals of calcite and dolomite and leakage of “old” groundwater from lower aquifers; the process is also traced by lower 14C and 3H activities and by more positive δ18O values in lowland areas. 相似文献
165.
Adriano Petry André Grahl Pereira Jonas Rodrigues de Souza 《Earth Science Informatics》2017,10(2):183-196
We propose a new algorithm for the problem of approximate nearest neighbors (ANN) search in a regularly spaced low-dimensional grid for interpolation applications. It associates every sampled point to its nearest interpolation location, and then expands its influence to neighborhood locations in the grid, until the desired number of sampled points is achieved on every grid location. Our approach makes use of knowledge on the regular grid spacing to avoid measuring the distance between sampled points and grid locations. We compared our approach with four different state-of-the-art ANN algorithms in a large set of computational experiments. In general, our approach requires low computational effort, especially for cases with high density of sampled points, while the observed error is not significantly different. At the end, a case study is shown, where the ionosphere dynamics is predicted daily using samples from a mathematical model, which runs in parallel at 56 different longitude coordinates, providing sampled points not well distributed that follow Earth’s magnetic field-lines. Our approach overcomes the comparative algorithms when the ratio between the number of sampled points and grid locations is over 2849:1. 相似文献
166.
Consistency of observed near surface temperature trends with climate change projections over the Mediterranean region 总被引:1,自引:0,他引:1
We examine the possibility that anthropogenic forcing (Greenhouse gases and Sulfate aerosols, GS) is a plausible explanation for the observed near-surface temperature trends over the Mediterranean area. For this purpose, we compare annual and seasonal observed trends in near-surface temperature over the period from 1980 to 2009 with the response to GS forcing estimated from 23 models derived from CMIP3 database. We find that there is less than a 5% chance that natural (internal) variability is responsible for the observed annual and seasonal area-mean warming except in winter. Using additionally two pattern similarity statistics, pattern correlation and regression, we find that the large-scale component (spatial-mean) of the GS signal is detectable (at 2.5% level) in all seasons except in winter. In contrast, we fail to detect the small-scale component (spatial anomalies about the mean) of GS signal in observed trend patterns. Further, we find that the recent trends are significantly (at 2.5% level) consistent with all the 23 GS patterns, except in summer and spring, when 9 and 5 models respectively underestimate the observed warming. Thus, we conclude that GS forcing is a plausible explanation for the observed warming in the Mediterranean region. Consistency of observed trends with climate change projections indicates that present trends may be understood of what will come more so in the future, allowing for a better communication of the societal challenges to meet in the future. 相似文献
167.
Norbert Kasch Marco Naujoks Jonas Kley Thomas Jahr 《International Journal of Earth Sciences》2013,102(5):1257-1270
Geodynamic observatories around the globe continuously monitor signals like gravity, tilt and strain as a function of time. However, global signals are often masked by local effects, caused by the direct surroundings of the station, including the local geological setting. This link is well established for superconducting gravimeters (SG) that observe the gravity field variations at very high resolution. An enhancement of the SG time series by the application of local correction is exemplarily shown here in a very practicable procedure for the Geodynamic Observatory Moxa, Germany. We show how the combination of geological and gravimetrical mapping and modelling around Moxa results in a significant correction of the original gravity data, as can be proven by comparison with the satellite-derived gravity field. Detailed geological mapping of the observatory surroundings, including measurements of fold axes, foliations and joints, was the basis of the present study. The fold structure in the area of interest was interpreted by geometrical 3D modelling. The complete representation of different rock types in space also provides a better understanding of the local hydro-geological situation. Using a combination of the 3D geological model with the high-resolution Bouguer map of the observatory surroundings, we developed a 3D density model. This model enables the correction of small gravity effects caused by mass variations close to the SG, in particular local hydro-geological mass changes. Thus, the procedure presented here, based on a close connection of geology and gravimetry, is a powerful tool for the reduction of local gravity effects on SG recordings. It should be applicable to SG stations worldwide, where similar hydrologically driven mass changes can be assumed. 相似文献