双壳类壳体时间序列的建立方法及存在的问题

利用双壳类壳体提取古气候古环境信息是生物碳酸盐研究的热点,而壳体定年一直是研究中的难点。相关研究主要观点是先找到一些时间控制点,再按照线性内插法来确定壳体的时间序列。本文综述了国内外目前双壳类壳体定年的常用方法,根据时间控制点的获得将这些方法归为以下几类:壳体日生长层法、壳体氧同位素法、数字图像技术法和微量元素法,介绍并讨论了每种方法的应用和存在的不足。研究者应该根据具体研究的生物和环境选择适合的方法。     

A~2/O工艺中好氧污泥絮体的分形结构与理化特征分析

采用图像法和沉降柱法分别研究了A2/O工艺中好氧污泥絮体的形貌、粒度分布、低维分形维数和沉降速率、有效密度、空隙率以及质量分形维数,并尝试探讨了上述相关性质与这些污泥宏观操作性质(沉降、压缩、脱水和稳定性)相关的各种理化指标以及胞外高分子物质(EPS)的含量之间的变化关系.结果表明,污泥絮体呈现不规则的形貌,表面具有空隙.其有效密度一般随着其粒径的增加而降低,而空隙率和沉降速率却呈现与有效密度相反的变化趋势,这些均表明了污泥絮体的分形结构的存在.2次所采集的污泥絮体的中位直径分别为248.81、332.86μm,有效密度的平均值分别为0.0040、0.0072g·cm-3,自由沉降速率的平均值分别为2.67、4.79mm·s-1,空隙率的平均值分别为0.94、0.89,一维分形维数分别为1.03、1.19,二维分形维数分别为1.64、1.84,采用基于Logan经验公式的有效密度-最大直径的双对数关系确定的质量分形维数分别为1.74、2.29.尽管第2次所采集的污泥絮体较为密实,但其表面粗糙程度却比第1次的低.此外,研究中发现絮凝能力较高或负电荷较高的A2/O好氧污泥絮体具有高的SVI和ZSV值;分形维数较低...     

A2/O工艺中好氧污泥絮体的分形结构与理化特征分析

采用图像法和沉降柱法分别研究了A²/O工艺中好氧污泥絮体的形貌、粒度分布、低维分形维数和沉降速率、有效密度、空隙率以及质量分形维数,并尝试探讨了上述相关性质与这些污泥宏观操作性质(沉降、压缩、脱水和稳定性)相关的各种理化指标以及胞外高分子物质(EPS)的含量之间的变化关系.结果表明,污泥絮体呈现不规则的形貌,表面具有空隙.其有效密度一般随着其粒径的增加而降低,而空隙率和沉降速率却呈现与有效密度相反的变化趋势,这些均表明了污泥絮体的分形结构的存在.2次所采集的污泥絮体的中位直径分别为248.81、 332.86 μm,有效密度的平均值分别为0.004 0、 0.007 2 g·cm^-3,自由沉降速率的平均值分别为2.67、 4.79　mm·s^-1,空隙率的平均值分别为0.94、 0.89,一维分形维数分别为1.03、 1.19,二维分形维数分别为1.64、 1.84,采用基于Logan经验公式的有效密度-最大直径的双对数关系确定的质量分形维数分别为1.74、 2.29.尽管第2次所采集的污泥絮体较为密实,但其表面粗糙程度却比第1次的低.此外,研究中发现絮凝能力较高或负电荷较高的A²/O好氧污泥絮体具有高的SVI和ZSV值;分形维数较低的污泥具有高的剪切敏感性和低絮体强度,相应的污泥稳定性低;EPS总量高的污泥脱水性能差,EPS中蛋白质含量高的污泥其表面电荷也较高.     

ASAR数据与ETM＋图像融合探测干旱区浅层地下水的应用

介绍了ETM＋图像与ASAR数据在探测浅层地下水方面的优缺点,并通过对内蒙古阿拉善左旗地区遥感资料的处理,研究了光谱图像与雷达数据融合后在探测浅层地下水方面的应用效果。研究表明该方法虽不能精确地探测到浅层地下水的埋深与范围,但对掌握宏观区域上浅表层地下水的分布较之单一数据源具有更快速、更直观的效果。     

利用Google Earth研究构造对喀斯特地貌的控制和对碳酸盐岩岩系风化成土的影响

通过互联网Google Earth欧洲卫星图像资料的观察,发现贵州喀斯特地区碳酸盐岩风化成土能力与地层岩性、构造和地貌等密切相关。二叠系生物礁石漠化显著,成土能力差;三叠系大冶组薄层灰岩成土能力高,很少有石漠化;地层倾角大的碳酸盐岩区,石漠化不显著;地层平缓的碳酸盐岩区,石漠化强或中等,碳酸盐岩风化成土能力中等。另外,大型节理带对碳酸盐岩风化成土具有明显的控制作用,节理带碳酸盐岩溶蚀相对强烈,常形成低洼地形,碳酸盐岩风化成土速率较高,红粘土堆积相对厚,不容易石漠化;而节理带间的区域往往地形较高,是石漠化易发育的区域。     

庐山旅游景区环境保护浅析

庐山风景秀美、人文历史丰富,伴随着庐山旅游业的迅速发展,庐山环境问题也逐渐突显出来。本文通过问卷调查、实地考察、访谈等方式了解游客关于庐山旅游景区环境的看法,利用数理统计方法分析了水、空气、固体垃圾的污染现状,提出了改善庐山旅游环境质量的举措,将为庐山旅游景区的可持续发展提供依据。     

基于旅游生态足迹模型的山东省旅游可持续发展评价

以生态足迹理论为基础,将旅游生态足迹引入区域旅游可持续发展评价,阐述了旅游生态足迹的概念,并构建旅游生态足迹模型,用于衡量旅游可持续发展能力。以山东省作为研究对象,对旅游生态足迹模型在大尺度区域旅游业可持续发展定量测度中的运用进行实证研究,计算其2000年-2004年的旅游生态足迹。结果表明：山东省近五年出现了不同程度的旅游生态赤字和生态压力,平均存在0.133 3 hm2/人的旅游生态赤字,旅游生态压力平均值为4.898 3,并呈现出明显的逐年递增趋势,其旅游业处于不可持续发展状态。     

Landscape trajectory of natural boreal forest loss as an impediment to green infrastructure

Loss of natural forests by forest clearcutting has been identified as a critical conservation challenge worldwide. This study addressed forest fragmentation and loss in the context of the establishment of a functional green infrastructure as a spatiotemporally connected landscape-scale network of habitats enhancing biodiversity, favorable conservation status, and ecosystem services. Through retrospective analysis of satellite images, we assessed a 50- to 60-year spatiotemporal clearcutting impact trajectory on natural and near-natural boreal forests across a sizable and representative region from the Gulf of Bothnia to the Scandinavian Mountain Range in northern Fennoscandia. This period broadly covers the whole forest clearcutting period; thus, our approach and results can be applied to comprehensive impact assessment of industrial forest management. The entire study region covers close to 46,000 km² of forest-dominated landscape in a late phase of transition from a natural or near-natural to a land-use modified state. We found a substantial loss of intact forest, in particular of large, contiguous areas, a spatial polarization of remaining forest on regional scale where the inland has been more severely affected than the mountain and coastal zones, and a pronounced impact on interior forest core areas. Salient results were a decrease in area of the largest intact forest patch from 225,853 to 68,714 ha in the mountain zone and from 257,715 to 38,668 ha in the foothills zone, a decrease from 75% to 38% intact forest in the inland zones, a decrease in largest patch core area (assessed by considering 100-m patch edge disturbance) from 6114 to 351 ha in the coastal zone, and a geographic imbalance in protected forest with an evident predominance in the mountain zone. These results demonstrate profound disturbance of configuration of the natural forest landscape and disrupted connectivity, which challenges the establishment of functional green infrastructure. Our approach supports the identification of forests for expanded protection and conservation-oriented forest landscape restoration.     

Environmental perceptions of second home tourism impacts in Finland

Experiencing nature and enjoying natural amenities have long been identified as key motives for rural second home tourism. However, the more people travel and spend time in the natural environment, the more it is disturbed by their actions and activities. In this paper, we examine how people perceive the environmental impacts of rural second home tourism and how they justify their views. The study focuses on Finland where rural second homes are widespread. Analysis is based on a questionnaire survey conducted among Finns in 2012 (n?=?1189). Responses from different groups of respondents (second home owners, regular users of second homes and non-users) are quantitatively and qualitatively analysed. The results indicate that the Finnish respondents generally think that second home tourism poses some degree of harmful environmental impacts. However, it is the second home owners who are least worried about these environmental impacts. They generally justify their opinions using a “place-related” perspective, that is, by referring to their own experiences and actions at the cottage site. In contrast, the non-users see environmental impacts more often from a broader perspective by referring to the wider environmental interconnections with second home tourism. In our discussion, we introduce the notions of place-based (relative) and phenomenon-based (relational) environmental perceptions as a potential framework for future research on this topic. In mitigating the increasing environmental impacts of second home tourism, understanding the environmental perceptions and awareness of second home owners and users is crucial to be successful in mobilising sustainable options and environmental governance.     

中国旅游业CO_2排放区域差异的空间分析

在旅游业节能减排形势严峻的背景下,深入研究中国旅游业CO_2排放问题,制定科学的区域节能减排政策已刻不容缓。本文首先运用"自下而上"法,估算了1993-2012年中国整体旅游业、旅游业各分部门、大陆各省区(不含西藏)旅游业CO_2排放量。在此基础上,对全国及三大地带旅游业CO_2排放的总体特征进行分析;利用Theil指数法分析了中国旅游业CO_2排放强度的区域差异、区域内差异和区域间差异;运用AreView软件对中国旅游业CO_2排放强度的省际差异进行直观图示。分析结果显示:1993-2012年,中国旅游业CO_2排放量从1 480.868×10~4t升至6 274.129×10~4t;全国及三大地带旅游业CO_2排放强度整体上呈现出先显著下降、再缓慢梯度下降的趋势;中国旅游业CO_2排放强度空间分布不均匀,东部地区旅游业CO_2排放强度低于中部和西部地区;中国旅游业CO_2排放强度的区域总体差异、区域间差异和区域内差异整体呈逐渐缩小的趋势,区域间差异对总体差异的贡献率为94%-98%,区域间差异占主导地位;中国旅游业CO_2排放强度省际差异明显,属于旅游业CO_2排放强度弱显著区的省区基本位于东部沿海地区,河北、湖南、河南、广西、甘肃和新疆等省区频繁出现在旅游业CO_2排放强度强显著区之列,因此上述省区应是中国旅游业CO_2未来节能减排的区域重点。据此提出差别化的CO_2减排对策:东部地区应通过技术改进和调整产业结构、能源消费结构来降低CO_2排放强度,并以此带动中部和西部地区旅游业节能减排;中部和西部地区应加强与东部地区合作,将提高能源使用率、降低CO_2排放强度作为旅游业减排工作的重点。