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841.
高华中 《地球与环境》2016,44(6):595-599
地球化学元素比值的变化不仅可以指示气候变化和环境特征,也可以揭示气候异常和突变性气候事件。本文通过对沂沭河流域沭埠岭剖面沉积物淋溶系数、残积系数、CaO/MgO、硅铝率、硅铝铁率等气候代用指标的分析,发现研究区7 470~2550 a BP期间的气候变化经历了五个阶段:(1)7 472~6 043 a BP,气候趋向温暖湿润;(2)6 043~4 801 a BP,稳定的暖湿时期;(3)4 801~3 986 a BP,气候向冷干转变;(4)3 986~3 512 a BP,不稳定时期;(5)3 512~2 552 a BP,气候不稳定的波动时期。  相似文献   
842.
运用相关分析、因子分析、富集因子和HYSPLIT模型对石羊河流域从2013年7月到2014年7月连续收集降水样品的主要离子浓度特征及来源进行了探讨分析,结果表明,Ca~(2+)和Na~+是主要的阳离子,SO_4~(2-)和NO_3~-是主要的阴离子,石羊河流域的主要降水类型为SO_4~(2-)-NO_3~--Ca~(2+);石羊河流域的总离子浓度的季节大小变化顺序为冬季春季秋季夏季,石羊河流域的降水水化学主要受地壳源和人为源的影响;石羊河流域的降水类型分为季风降水、西风降水和混合降水,而混合降水是石羊河流域的主要降水类型,其次为西风降水,最后为季风降水。  相似文献   
843.
Carbon labels are innovative medium and tools for climate change communication and low-carbon marketing. This study aims at examining how college students are aware of low-carbon and carbon labels, whether they are more willing to communicate low-carbon ideas, and also the determinants affecting their interpersonal communication of carbon labels. The multiple regression analysis shows that Chinese college students’ willingness of interpersonal communication of carbon labels are significantly influenced by their awareness of climate change crisis, the perceived value of carbon labels, the consideration of product environmental attributes, the preferences of carbon labels, the household background, and their educational background. In response to these factors, this paper proposes, in a public perspective, the strategies to enhance the dissemination of carbon labels.  相似文献   
844.
Abstract: Populations at the margin of geographic ranges of distribution have been considered more vulnerable than central ones, but recent reviews have caste doubt on this generalization. We examined the reproductive and demographic performance of a rare Euroasiatic orchid (Cypripedium calceolus) at its southwesterly range limit and compared our findings with those of previous studies of nine central populations at the center of the orchid's range. We sought to test the central‐marginal model and to evaluate factors involved in long‐term performance of forest Eurosiberian species with peripheral populations in southern European mountains. We characterized (structure, temporal fluctuations, herbivory, reproductive success, and recruitment at different habitats) four Pyrenean populations of C. calceolus of different sizes (5–3500 ramets) and monitored three of them for up to 13 years. Two quantitative stochastic models (count data and matrix models) were used to assess population trends and viability and the effect of herbivory. Contrary to expectations, and despite the negative effect of sporadic events of herbivory, the peripheral populations we studied (except the smallest one) performed similarly or better than populations occurring in central part of the species’ range in terms of reproductive success and population growth rates. Landscape changes over the last 50 years suggest that natural reforestation could be involved in the success of this plant at its southern limit. Forest expansion in the mountain regions of southern Europe may provide new opportunities for plants with geographic distributions centered mainly at higher latitudes and give some hope for their recovery in future scenarios dominated by biodiversity loss.  相似文献   
845.
Parks, waterways, and vegetation enhance the well-being of urbanites and thus warrant consideration in planning and policy-making. It is, however, difficult to assess how land-use change may impact these features and how this in turn may impact well-being. I use a case-study approach to present a framework that combines geospatial and economic valuation techniques to generate indicators of the effects of land-use policies that alter these amenities on community well-being. This framework quantifies the impacts of land-use change on urban environmental amenities in a way that could help communities plan land use so as to maintain well-being as they urbanise.  相似文献   
846.
RaMCo is a prototype version of a decision-support system for coastal-zone management. The model is based on the findings of a multidisiciplinary research program, conducted in Southwest Sulawesi, Indonesia. Different management strategies can be compared on the basis of the short- and long-term consequences. Land-use change has been included in RaMCo in view of the impacts of land-based human activities on the marine environment. The key aspect of the model is a combination of the temporal dynamics of land-use change on the regional (macro-level) scale and spatial dynamics on the local (micro-level) scale. Constrained cellular automata are used to integrate both scale levels. The state changes of the cells depend on the consistency with the macro-scale model, local geographical conditions, and interaction with neighboring cells. In this paper, we discuss the underlying theoretical assumptions of the macro-scale and micro-scale models, some characteristic results for land-use change in the study area, and the validation problem.  相似文献   
847.
Stedinger, Jery R. and Veronica W. Griffis, 2011. Getting From Here to Where? Flood Frequency Analysis and Climate. Journal of the American Water Resources Association (JAWRA) 47(3):506‐513. DOI: 10.1111/j.1752‐1688.2011.00545.x Abstract: Modeling variations in flood risk due to climate change and climate variability are a challenge to our profession. Flood‐risk computations by United States (U.S.) federal agencies follow guidelines in Bulletin 17 for which the latest update 17B was published in 1982. Efforts are underway to update that remarkable document. Additional guidance in the Bulletin as to how to address variation in flood risk over time would be welcome. Extensions of the log‐Pearson type 3 model to include changes in flood risk over time would be relatively easy mathematically. Here an example of the use of a sea surface temperature anomaly to anticipate changes in flood risk from year to year in the U.S. illustrates this opportunity. Efforts to project the trend in the Mississippi River flood series beg the question as to whether an observed trend will continue unabated, has reached its maximum, or is really nothing other than climate variability. We are challenged with the question raised by Milly and others: Is stationarity dead? Overall, we do not know the present flood risk at a site because of limited flood records. If we allow for historical climate variability and climate change, we know even less. But the issue is not whether stationarity is dead – the issue is how to use all the information available to reliably forecast flood risk in the future: “Where do we go from here?”  相似文献   
848.
ABSTRACT

This study investigates the structural linkages of product quality, corporate image, store image, and price on customer satisfaction and loyalty towards green products usage in Malaysia. The research used structural equation modelling technique via AMOS 21.0 computer program for data analysis across a sample of 200 university students who applies a green lifestyle, such as purchasing green products which are referring to only retail goods, using recyclable products, and ozone-free products. Empirical analysis divulged that product quality followed by corporate image, store image, and product price jointly affected customer satisfaction in using green products. They are highly concerned that the green store provides a variety of good quality products with good value for money. Marketers should aggressively promote the identification of green products and overcome the problem of just noticeable difference between green product and non-green product among consumers for business sustainability. Empirical findings provide valuable insights to put forth in outlining effective marketing strategies that widen the marketers’ understanding of consumer behaviour in using green products with regard to their satisfaction and loyalty levels from the perspective of product quality, corporate image, store image, and product prices in Malaysia markets.  相似文献   
849.
Methane oxidation capacity of soil from an experimentalsite in Northwest England was strongly dependent on temperatureand percentage water holding capacity. The soil had a distincttemperature optimum of 25 °C, with capacity for net methaneoxidation being completely lost below 5 and greater than37 °C. Optimum percentage water holding capacity for methaneoxidation was in the range 30–60%, with significant reductions inmethane oxidation rates in soils outside this range. Organic andmineral layers within the soil showed differences in potentialmethane oxidation rate, with methane oxidation being most rapid inthe buried organic layer and least rapid in the surface organiclayer. The importance of soil structure and gas diffusionlimitation is underlined, as is the strong temperature dependenceof methane oxidation when such diffusion limitation is removed.  相似文献   
850.
应用遥感技术,利用长时间序列的SPOT VEGETATION NDVI数据集,结合改进的像元二分模型,对豫西山区1998年、2003年和2008年的植被覆盖度进行计算。结果表明,豫西山区植被覆盖总体上略有上升,局部地区植被覆盖度有所下降。高海拔区域植被覆盖相对稳定,退化概率较低;低海拔区域植被退化和恢复的概率都相对较高;坡度小的区域植被退化和修复的概率都较高;坡度较大的区域植被轻微退化概率增大,坡度越大,植被覆盖修复的概率越低;南坡和北坡植被覆盖度相对较高,东坡和西坡植被覆盖度较低;西南坡向的植被退化相对严重,东南坡向植被退化概率相对较低。  相似文献   
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