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91.
92.
黄连山自然保护区的土壤及其地理分布规律 总被引:1,自引:1,他引:1
本文根据野外调查,土样室内理化分析及对前人工作成果的系统分析结果表明,黄连山自然保护区的土壤及其地理分布规律是;海拔800m以下为砖红壤;海拔800-1100m为砖红壤性红壤;海拔1100—1600m为山地红壤;海拔1600—1900m为山地黄壤;海拔1900m以上为山地黄棕壤。 相似文献
93.
Efficient conceptual model for simulating the effect of aquifer heterogeneity on natural groundwater discharge to rivers 总被引:1,自引:0,他引:1
David Pulido-Velazquez Carlos Llopis-Albert Salvador Peña-Haro Manuel Pulido-Velazquez 《Advances in water resources》2011,34(11):1377-1389
When linearity can be assumed (linear response of heads to stresses), stream–aquifer flow exchange can be simulated as the drainage of a number of independent linear reservoirs. This conceptual model, which can be mathematically deduced in a univocal way from an eigenvalue solution of the linear groundwater flow problem, facilitates the understanding of the physical phenomenon and the analysis of influencing factors. The number of reservoirs required to simulate stream depletion in some ideal homogeneous cases of stream–aquifer connection was analyzed in detail in a previous investigation using analytical eigenvalue solutions [16]. However, most aquifers are heterogeneous in nature and numerical solutions must be employed to analyze whether they could also be simulated using few reservoirs. This paper presents a stochastic analysis of the influence of heterogeneity on the simulation of natural groundwater discharges in aquifers connected to rivers, as a series of linear reservoirs. A Monte-Carlo approach was employed to perform this study. The results show that, on a monthly time scale, many cases (even heterogeneous aquifers) can be simulated using just a few reservoirs with sufficient accuracy and at minimum computational cost. Therefore, this modeling technique can be useful to efficiently simulate the integrated management of complex water resources systems at the basin scale (with many aquifers, reservoirs, demands, etc.) that need to simultaneously consider surface and groundwater flow and stream–aquifer interaction. 相似文献
94.
The organic matter of the surface horizons of soils developed below scrub vegetation in a Mediterranean semi-arid area of great environmental interest (Cabo de Gata-Níjar Natural Park, SE Spain) has been studied. The study mainly concentrates on examining the influence of two vegetation types, one evolved (according to its successional stage), and the other clearly degraded as a result of prior removal of vegetation. In spite of the homogeneity in the results obtained from the analysis of the organic matter from the soils studied, a relationship may be established between vegetation biotype and characteristics and evolution of the soil organic matter. The evolved vegetation results in the presence in the soil of a somewhat more evolved and stable organic matter (demonstrated by certain chemical and microbiological aspects), resulting in a greater degree of humification, thus favouring the protection of the soil and the ecosystem as a whole. Hence, the presence of degraded vegetation might lead to soil degradation, something that is unsustainable in semi-arid areas that are particularly fragile in nature. 相似文献
95.
国家自然科学基金人文地理学项目研究特征简析 总被引:3,自引:0,他引:3
以2007-2011 年国家自然科学基金人文地理学代码(D0102) 的申请书作为样本,对申请代码、重点研究领域以及研究内容进行梳理,分析中国人文地理学近期发展特征。分析认为,科学问题综合与学科间交叉研究的增加使人文地理学学科边界呈现模糊化的趋势;研究方向体现了时代特点且各研究方向之间申请数量比较均衡;研究关键词大量涌现但共识性表述相对较少;选题颇具本土应用特点但学科体系建设意识逐步增强。 相似文献
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97.
F. Valera C. Díaz-Paniagua J.A. Garrido-García J. Manrique J.M. Pleguezuelos F. Suárez 《Journal of Arid Environments》2011,75(12):1342-1351
Southern Spain’s semi-arid habitats are a Mediterranean ecosystem modelled mainly by historic factors which make them unique in comparison with North African deserts. Southern Spanish vertebrates have adapted to the recent emergence of semi-arid habitats in varying degrees of success. This paper reviews the current status of these terrestrial vertebrates (amphibians, reptiles, birds and mammals), their origins and their main features in relation to this biogeographic area. The vertebrate fauna of the semi-arid southeast of the Iberian peninsula differs widely from the one in the semi-arid Maghreb mainly because the former is composed by generalist vertebrates and much less so by species adapted to arid conditions. Moreover, a large fraction of the vertebrates in the semi-arid Iberia does not exploit the semi-arid areas but depends on riparian and human-managed habitats. The species diversity is rather low since only a small fraction of Palaearctic, European or Mediterranean species can adapt to the ecological limitations imposed by aridity and dwell in these semi-arid habitats. Such adaptations comprehend features like trophic plasticity, low morphological specialization, high dispersal ability, shortened life cycles and behavioural mechanisms to exploit the limited resources available. This paper identifies major conservation issues and proposes specific courses of action. 相似文献
98.
天然气水合物是一种具有巨大潜能的新型能源,研究冻土区天然气水合物的地震响应特征,对我国陆域天然气水合物的勘探和开发具有重要意义。本文运用Kelvin粘弹性介质模型,基于祁连山冻土区的实际地质地层条件,建立理论地质-地球物理模型;采用交错网格有限差分法进行正演数值模拟,并对自激自收地震记录进行波场特征分析和提取瞬时地震属性。研究结果表明:地震波通过天然气水合物地层时,反射振幅能量较弱;在瞬时频率属性剖面可分辨层厚的范围内,瞬时频率随着层厚增加,频率在小幅度衰减;地震波通过含天然气地层时,反射波表现为强反射特征,瞬时频率能量明显增大;瞬时地震属性对波阻抗界面有更好的分辨能力,特别是瞬时相位属性剖面,作用明显。因此,综合分析波场特征与瞬时属性特征可以为陆域天然气水合物的识别、预测提供依据。
相似文献99.
Anke Fischer Vera PetersJan Vávra Mirjam NeebeBoldizsár Megyesi 《Global Environmental Change》2011,21(3):1025-1034
Citizens’ support for policies that aim to curb carbon emissions and energy use is often seen as informed by their values, attitudes and perceptions of the environmental problem in question. We argue that we also need to understand how people conceptualise policies and the governance approaches underpinning them to be able to judge the likely acceptance of policy change.In this study, we draw on qualitative interviews (n = 202) from five European countries to explore citizens’ views on governance approaches to stimulate behavioural change in the field of resource use, including regulations, price changes, collective action, technological change and education.We found that many of our interviewees referred to generalised characteristics of humankind and contemporary society to back up their arguments for or against specific governance approaches. In particular, many interviewees concurred that people in general were so self-centred, driven by habit and money- and consumption-oriented that only strict regulations, drastic price changes and technological innovation could possibly achieve widespread behavioural change. As a consequence, such ‘folk psychologies’ can have substantial impact not only on public acceptance, but also on the success of policy measures that aim to reduce citizens’ resource use. 相似文献
100.
An increasing number of publications focus on social vulnerability, resilience, and adaptation (SVRA) towards natural hazards and climate change. Despite this proliferation of research, a systematic understanding of how these studies are theoretically grounded is lacking. Here, we systematically reviewed 4432 articles that address SVRA in various disciplinary fields (e.g. psychology, sociology, geography, mathematics) for various hazards, including floods, droughts, landslides, storm surges, wildfires, tsunamis, earthquakes, and volcano eruptions. We focus on the extent to which these studies explicate the frameworks, theoretical constructs or theories they rely on. Surprisingly, we found that about 90% of the reviewed studies do not explicitly refer to a theoretical underpinning. Overall, theories focusing on individuals’ SVRA were more frequently used than those focusing on systems, society, groups, and networks. Moreover, the uptake of theories varied according to the hazard investigated and field of knowledge, being more frequent in wildfire and flood studies and articles published in social science journals. Based on our analysis, we propose a reflexive handling of theories to foster more transparent, comparable, and robust empirical research on SVRA. 相似文献