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1.
The results of the electron paramagnetic resonance (EPR) analysis of pure tooth enamel and the data on the radionuclide content in bones were used for estimating the radiation load on reindeer that lived on Wrangel Island in the 1970s and early 1980s. Based on the measurements of the lower jaws, some biological parameters of the Wrangel reindeer population were estimated and compared with those in the Novaya Zemlya and Taimyr populations. Changes in only two of these parameters—the degree of root cementum resorption and animal life span–might be attributed to the effect of the radiation load.  相似文献   

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The objective of this study was to assess and analyze the human bioclimatic conditions of Crete Island, by applying two human thermal indices: physiological equivalent temperature (PET), derived from the Munich Energy-balance Model for Individuals human energy balance model, and Universal Thermal Climate Index (UTCI), based on the Fiala multi-node model of human thermoregulation. Human bioclimatic studies provide a framework for considering the effects of climatic conditions on human beings and highlighting the social/economic factors that mitigate or amplify the consequences of environmental changes. In order to estimate the thermal effect of the environment on the human body, it has been considered that the total effects of all thermal components, not only of individual parameters, should be taken into account. The climatic data (air temperature, relative humidity, cloudiness, wind speed) used in this study were acquired from the archives of the Hellenic National Meteorological Service, regarding ten meteorological stations in Crete Island. These data, covering the 30-year period 1975–2004, were used for the calculation of PET and UTCI in order to assess thermo-physiological stress levels. The findings of this analysis, such as bioclimatic diagrams, temporal and spatial distributions of PET and UTCI as well as trends and variability, will help stake holders to understand and interpret the island’s current bioclimate, in order to make any necessary adaptations and become more resilient to the foreseen climate change.  相似文献   

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The (137)Cs method was employed to investigate the recent historical rate of sediment deposition on a lowland alluvial floodplain in the Falefa River basin, Upolu Island, Samoa. Caesium stratigraphy in the floodplain sediment profile was clearly defined, with a broad peak at 145-175 cm depth. The measured rate of vertical accretion over the last 40 years is 4.0+/-0.4 cm per year. This rate exceeds observations in humid environments elsewhere, but is similar to that recorded on other tropical Pacific Islands. Available flow data for the Vaisigano River in Samoa give a 'near-catastrophic' index value of 0.6 for flood variability. This is associated with the occurrence of tropical cyclones and storms in the Samoa area. Large floods therefore probably contribute to the high rate of floodplain sedimentation on Upolu Island. A small but growing body of evidence suggests that fluvial sedimentation rates on tropical Pacific islands are some of the highest in the world.  相似文献   

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Perfluorinated compounds (PFCs) have been frequently detected in both the environment and biota, and have become a growing concern. However, information is limited on the potential sources and human health implications of such exposure. We evaluated the exposure levels of 13 major PFCs among a population (n = 633, > 12 years of age) in a mid-sized city of Korea, and investigated for their potential dietary sources and the impact on thyroid hormone concentrations. For this purpose, we collected blood samples from a general population in Siheung, Korea and measured for 13 PFCs, total thyroxine (T4), and thyroid stimulating hormone (TSH). In addition, a questionnaire survey on diet was conducted. Perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), perfluorohexane sulfonic acid (PFHxS), and perfluorononanoic acid (PFNA) were detected in relatively greater concentrations than the other 9 PFCs in the blood serum. Males tend to have greater concentrations than females for most PFCs, and the concentrations were elevated as age increased up to 50s. Body mass index (BMI) was also shown to influence the serum concentrations of several PFCs. After adjustment for age, sex, and BMI, the consumption of vegetable, potato, fish/shellfish, and popcorn was identified to be significantly related with concentrations of major PFCs in blood. Among the studied PFCs, the concentrations of perfluorotridecanoic acid (PFTrDA) were negatively correlated with total T4, and positively with TSH levels, especially among females. The result of this study will provide information useful for developing public health and safety management measures for PFCs.  相似文献   

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The intensity of geese migration has increased since 2005, and its routes have shifted eastward. The main migration route of the geese previously passed over the northwestern Sea of Okhotsk, far from the coast; since 2005, however, a major migration flow has been recorded over northern Sakhalin and the mainland part of Tatar Strait. A probable factor accounting for this shift is a change in weather conditions and, in particular, in the circulation of air masses over the northwestern Sea of Okhotsk.  相似文献   

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大河入海河口由于巨量泥沙堆积以及潮汐作用,往往发育着河口沙岛。崇明岛是世界上典型的河口沙岛,近年来,随着长江流域泥沙来源锐减以及河口大型水利工程建设等,给崇明岛周边岸滩沉积环境带来深刻影响。研究依据2015年9月~2018年4月对崇明岛周边14个岸滩断面的表层沉积物采样数据和定点水文观测资料,分析崇明岛周边岸滩沉积环境特征和区域性差异,探讨不同岸滩断面沉积过程和作用机制。结果表明:崇明岛岸滩沉积物以砂质粉砂和粉砂质砂为主,沉积物中值粒径总体表现为南岸北岸东滩,平均为48μm。南、北岸岸滩总体表现为坡陡、滩窄,沉积物自西向东逐渐变细的特征,北岸岸滩坡度略缓,南岸崇头至庙镇之间存在局部细颗粒物质沉积区;东部岸滩滩宽、坡缓,整体表现为"北细南粗"的沉积特征。岸滩沉积断面上,上细下粗,高潮滩处粘土组分含量相对较高,水下斜坡和河槽底部粉砂含量较高。南、北支河势演变形成了崇明岛"南坍北涨"沉积环境的分布格局;径、潮流作用对岸滩断面沉积物分布特征影响明显;风浪对崇明东滩浅滩沉积物具有强烈的分选作用;潮滩植被主要影响细颗粒沉积物在潮间带的分布;流域来沙减少对崇明东滩前沿沉积环境趋势影响显著。  相似文献   

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Zou  Ye-Ai  Tang  Yue  Xie  Yong-Hong  Zhao  Qi-Hong  Zhang  Hong 《Regional Environmental Change》2017,17(3):879-888
Regional Environmental Change - The majority of Eastern China’s herbivorous geese overwinter in the East Dongting Lake, China, and there is growing concern about how changes in their habitats...  相似文献   

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水体和植被组成的蓝绿空间能够有效减缓城市热岛效应,探究其时空变化特征和影响因素对于改善城市环境和促进区域绿色低碳发展具有重要意义.以2004、2010和2014年三期Landsat遥感影像为数据源反演地表温度表征热环境,构建冷岛效应强度和冷岛指数定量分析苏州市蓝绿空间降温作用的时空变化特征,利用分类统计、剖面趋势法和线性拟合等方法分析蓝绿空间面积、土地利用变化和其它社会经济因素对冷岛效应的时空影响,结论如下:(1)2004~2014年苏州市冷岛效应面积不断减小,减少比例高达24.04%;空间上看,苏州北部和东部冷岛区域减少尤为明显,南部湖泊为主的地区变化相对较小.(2)从冷岛强度数值大小看,蓝绿空间的降温能力不断增强,2004、2010和2014年的冷岛强度分别为6.3℃、7.1℃和9.6℃;但考虑到其面积变化,苏州市蓝绿空间冷岛效应对于热环境的调节作用呈现出减弱趋势.(3)水体构成的蓝色空间降温能力(10.5℃)远大于植被绿色空间的冷岛强度(4.8℃);流动河渠的冷岛强度要明显高于静止的湖泊.(4)土地利用变化:尤其城市扩张侵占大量水田为影响苏州市冷岛效应时空变化的重要驱动因素,反观苏州市湖泊总面积在研究时间范围内有小幅增长,推断出政府决策者对于蓝绿空间类型的优先保护程度.  相似文献   

11.
As part of an extensive air chemistry programme, during summer 1980, on board the Swedish ice-breaker ‘Ymer’, levels of 222Rn (radon) and its long-lived daughters 210Pb and 210Po were measured. The radon was trapped on charcoal and the long-lived daugther products sampled on filters on a daily basis. In addition, short-lived progenies were followed continuously on the filters in order to achieve a time resolution of about one hour. The concentrations of radon and 210Pb in the Arctic summer air north of latitude 75° N averaged 75 ± 21 (1 sd) and 0·075 ± 0·028 mBqm−3, r respectively. During a two week period of persistent polar winds, the mean radon concentration was 19 ±5 mBq m−3. During such ‘Arctic background’ conditions, radon exhalation from the sea may contribute significantly to the measured radon-in-air concentration. It is shown that steady-state equilibrium models, applied to an air mass over the sea, overstimate the aerosol residence-time calculated from activity ratios. Time-dependent calculations indicate a mean aerosol residence time of 4 to 7 d in Arctic air. Good agreement is observed between radon levels and the time since the air mass left larger areas. Both the 222Rn and the long-lived daughter measurements are insensitive to contamination from ship and local settlement.  相似文献   

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Studies on the fate of organohalogen contaminants (OHCs) in wild top predator mammals in the Arctic have often been a challenge due to important knowledge deficiencies in the life history of the sampled animals. The present study investigated the influence of age, dietary and trans-generational factors on the fate of major lipophilic chlorinated and brominated OHCs in adipose tissue of a potential surrogate captive species for the polar bear (Ursus maritimus), the sledge dog (Canis familiaris) in West Greenland. Adult female sledge dogs (P) and their sexually-mature (F1) and/or pre-weaning pups (F1-MLK) were divided into an exposed group (EXP) fed blubber from a Greenland minke whale (Balaenoptera acutorostrata) and a control group (CON) given commercially available pork fat. Large dietary treatment-related differences in summed and individual congener/compound adipose tissue concentrations of polybrominated diphenyl ethers (PBDEs), hexachlorobenzene (HCB), chlordanes (CHLs) and polychlorinated biphenyls (PCBs) were found between the EXP and CON groups for all the sledge dog cohorts. However, among the F1-MLK, F1 and P dogs in both of the EXP and CON groups, little or no difference existed in PBDE, HCB, CHL and PCB concentrations, suggesting higher state of equilibrium in adipose tissue concentrations from a very early stage of life. In contrast, the distribution pattern (proportions to the summed concentrations) of OHC classes, and the major congeners/compounds constituting those classes, varied on a dietary group- and/or cohort-dependent manner. The present captive sledge dog study demonstrated the importance of the confounding effects of diet composition, mother-pup association (maternal transfer), reproductive status (nursing), and to a lesser extent age in the fate of OHCs in adipose tissue of a large top carnivore mammal.  相似文献   

13.
Regional Environmental Change - Existing climate data for Bolivian Amazonia rely on observations from a few sparse weather stations, interpolated on coarse-resolution grids. At the same time, the...  相似文献   

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Environment, Development and Sustainability - This study analyzes the evolution of the land use structure, demographic reconstruction, and social reconstruction of Dachangshan Island, Changhai...  相似文献   

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Present trends of urbanization are accompanied by increasing demographic and economic shrinkage of rural regions. In countries such as Japan, these rural regions trail behind metropolitan counterparts according to GDP, the conventional measure used to guide governmental policies. Yet, past research suggests that these regions may be undervalued. Further, the Inclusive Wealth Index (IWI), largely only used at the national level, may be able to capture aspects previously missed. As such, our study attempts to highlight the wealth of rural regions by comparing the inclusive wealth of Sado Island and Japan between 1990 and 2014. Minor methodological modifications were made according to data availability at the local level and to improve the accuracy of human capital estimations. Results captured the ongoing shrinkage of Sado and demonstrate the distinct potential of the IWI as a stock measure. Sado’s per capita wealth was about 10% lower than the national averages, but its natural capital was about threefold national averages. Supplementary estimations of the natural capital of fisheries and cultivated forests suggest that inclusion of additional factors in the evaluation would further increase the relative valuation of rural regions. We discuss implications of our estimations for wellbeing, and conclude with a critical appraisal of the IWI calculation towards policy implementation of the index.  相似文献   

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Nesting bird communities of individual habitat types in the Arkaim reserve are formed every year under the influence of nonrandom factors. Their qualitative and quantitative composition may gradually shift in a certain direction, but more often it remains relatively stable over several years and then makes an abrupt transition into a different state. The strongest effect on the dynamics of these communities has been exerted by progressive succession following the assignment of special protection status to the Arkaim area. The effects of fires and other elemental factors are also significant.  相似文献   

18.
Whangapoua Estuary, Great Barrier Island, New Zealand, is central to a proposed Marine Reserve, and is currently managed for conservation by the Department of Conservation. This paper describes the sequential impacts of Maori and European people on the process of estuarine vegetation succession in time and space, and the rate of estuarine sedimentation. Multiple cores from one estuary gave confidence in assessing the temporal sequence of vegetation change, but bioturbation and other disturbance factors made it difficult to interpret 14C dates from the estuarine environment. The modern vegetation zonation pattern on the estuary is an active succession, which has been generated by rapid estuary in-filling, probably initiated as a consequence of erosion following Maori burning of the adjacent forest. European forest clearance for agriculture resulted in a further increase in estuarine sedimentation, and may have re-activated earlier sediments trapped in adjacent swamps. The combined effects of two phases of human exploitation have resulted in large-scale loss of nutrients and top-soil from catchments throughout Great Barrier Island. Conservation management of the estuary should take account of the anthropogenic impacts that have driven the plant succession and created the current vegetation zonation pattern. This pattern is neither static nor ‘natural’, but rather an on-going response to the changing human activities in the surrounding catchment.  相似文献   

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In this study, we compare the perception of climate change in two different tourist settings of northeastern Spain: the Catalan Pyrenees and the Catalan Mediterranean coast and the Balearic Islands. We carried out a survey of 906 cases (506 in the coastal areas of Catalonia and the Balearic Islands and 400 in the Catalan Pyrenees) asking residents on those areas to assess the possible effects of climate change on tourist-related activities. While the existence of climate change and of its estimated impacts is widely accepted, we observe statistically significant differences in most of the questions between residents in the coastal areas and residents in the Pyrenees. In general terms, respondents from the Pyrenees display a much higher concern regarding the economic impacts of climate change on tourism. On the other hand, the results also show that some demographic groups, such as women, members of large households, or unemployed, tend to present higher levels of concern. This study may give new hints on which tourist modalities and which groups are more concerned for the impacts of climate change in Mediterranean tourist environments and could translate into more targeted adaptive and mitigation practices.  相似文献   

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Regional Environmental Change - Land degradation in many Pacific Island Countries (PICs) has become an emerging concern in recent years. The causes of land degradation in PICs include:...  相似文献   

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