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81.
A Lagrangian stochastic (LS) model, which is embedded into a parallelised large-eddy simulation (LES) model, is used for dispersion
and footprint evaluations. For the first time an online coupling between LES and LS models is applied. The new model reproduces
concentration patterns, which were obtained in prior studies, provided that subgrid-scale turbulence is included in the LS
model. Comparisons with prior studies show that the model evaluates footprints successfully. Streamwise dispersion leads to
footprint maxima that are situated less far upstream than previously reported. Negative flux footprints are detected in the
convective boundary layer (CBL). The wide range of applicability of the model is shown by applying it under neutral and stable
stratification. It is pointed out that the turning of the wind direction with height leads to a considerable dependency of
source areas on height. First results of an application to a heterogeneously heated CBL are presented, which emphasize that
footprints are severely affected by the inhomogeneity. 相似文献
82.
在对涡动相关仪和大孔径闪烁仪足迹模型进行敏感性分析的基础上,利用北京密云站2006年8月至2007年12月期间的观测资料,应用足迹模型对观测通量的空间代表性做了初步的分析.结果表明:涡动相关仪和大孔径闪烁仪的源区对风向、Monin-Obukhov长度,空气动力学粗糙度和观测高度/有效高度等因子比较敏感.密云站涡动相关仪的源区白天主要分布在仪器的西南与南面,而夜间则在东北与北面.大孔径闪烁仪的源区为西南一东北向分布.涡动相关仪各月源区形状不同,但大致分布在南北长1000 m、东两宽850 m的范嗣内,而LAS各月源区为西南一东北向分布,长约2060 m,最宽处约为620 m.对涡动相关仪通量有贡献的下垫面主要为园地(67%)和耕地(19%).其中园地的通量贡献比例在夏、秋季比较大,冬、春季稍小,而耕地则相反.大孔径闪烁仪的主要通量贡献源区为园地、耕地和居民地,通量贡献比例分别为49%,28%和11%.其中园地和耕地通量贡献率的变化趋势与涡动相关仪的观测结果一致,但没有涡动相关仪的变化明显. 相似文献
83.
84.
Monitoring and minimizing tourist’s water consumption is essential for the sustainable development of mountain destinations in the world. However, available data and a generally accepted protocol on such measurement are still limited. This study uses water footprint accounting to quantify tourist’s water demand in the Liming valley, a World Heritage site and a rapidly growing tourism destination in Northwest Yunnan, China. Both the water for direct and indirect use is taken into account based on the consump... 相似文献
85.
Liaqat Ali Abdur Rashid Seema Anjum Khattak Xubo Gao Shah Jehan Asif Javed 《国际泥沙研究》2021,36(5):656-667
The objective of the current study was to assess the contamination of potentially toxic metals (PTMs) in weathered surface sediment, along stream tributaries, and surrounding area of the river Chitral, Shyok suture zone district Chitral, Pakistan. To understand the geochemical features of 113 sediment, samples were collected from the Mirkhani and Drosh area. Then, different statistical tools including the geo-accumulation index (Igeo), cluster analysis (CA), principal component analysis (PCA), and ecological risk assessment (ERA) were used to unravel the origin, intensity, and exposure level of PTMs to control risk and restore the ecosystem within the study area. The results for the PTMs namely nickle (Ni), chromium (Cr), copper (Cu), cadmium (Cd), lead (Pb), zinc (Zn), and cobalt (Co) in Mirkhani and Drosh were in the following ranges: 10–150, 15–210, 15–250, 0.08–1.00, 10–70, 76–240 and 14–51; and 13–240, 17–210, 15–150, 0.08–0.60, 7–140, 47–150 and 13–36 mg/kg, respectively. In consequence, the potential ecological risk caused by Pb, Ni, Cu, Co, Cr, and Zn is reflected by the percentages of samples with an ecological risk index (ERI) greater than one which were 100%, 91%, 100%, 100%, 92%, and 100%, respectively. However, the overall mean decreasing order of ecological risk of PTMs in the district Chitral was Pb > Ni > Cu > Co > Cr > Zn > Cd. Moreover, the PCA yielded 78% variability which indicated that mineral prospects play an important role in the contamination of sediment. Furthermore, the mineral phases of Pb and Zn suggested supersaturation, while that for Cd revealed unsaturation. The results of Igeo, ERI, and CA indicated contamination of PTMs in the study area. The ERI value of Pb, Ni, Cu, Co, Cr, and Zn was higher than 1 suggesting an ecological risk in the study area. Moreover, the current study showed the dominance of geogenic contamination with major contributions from ultramafic rock and known mineral prospects. Therefore, contaminated sediment of the Shyok suture zone is extremely detrimental to the aquatic ecosystem of the study area. 相似文献
86.
山东昌邑国家级海洋生态特别保护区是目前国内唯一以柽柳林生态系统为主要管理和保护对象的国家级海洋保护区。为系统、全面地了解保护区内生态环境和保护物种的变化趋势,文章对山东昌邑国家级海洋生态特别保护区生态环境现状进行了监测与评价,并根据评价结果,分析了保护区保护与管理中存在的问题。研究表明,该保护区生态环境一直处于亚健康状态,为促进保护及管护,提出了加强保护区生态建设,改变保护区开发利用模式;加强能力建设,实现保护区动态监控;协调发展与保护的关系,实现资源可持续利用;大力开展柽柳生态修复,恢复柽柳的资源状况的对策建议。 相似文献
87.
海洋生态红线制度是我国"五位一体"文明建设的具体要求。为进一步在自然科学与人文科学的联结点上探求深入开展生态红线工作的可能性,文章对比了实施多年的海洋功能区划与历史新阶段提出的海洋生态保护红线的概念和内涵,剖析了两者之间的区别与联系,指出海洋功能区划与海洋生态红线区划在法律地位和管控制度等方面具有一致性,在划分目标、空间管理及划分方法上具有差异性,海洋功能区划以"使用"为主,海洋生态红线以"保护"引领。在此基础上,建议未来海洋生态红线工作的开展可从海洋功能区划借鉴经验,建立完善的管控评估制度,确立生态保护红线的优先地位,处理好海洋功能区划与海洋生态红线区划的关系。同时,海洋生态红线区划应以维持海洋生态系统结构稳定和提高海洋生态系统服务功能为目标,将区域资源环境承载力评估作为一项参考指标,限制低承载区的开发利用,保证海洋生态环境健康可持续发展。 相似文献
88.
89.
This study examines whether an ecological worldview—operationalized by the New Ecological Paradigm (NEP) Scale--serves as the source of coherence of Environmental Concern (EC). Using data on four samples from the 1992 Gallup “Health of the Planet” Survey and the 2003 and 2010 Chinese General Social Surveys, we found that in all samples not only is the NEP the most powerful predictor of EC, but it also mediates the effects of socio-demographic variables on EC as hypothesized. The results confirm that the NEP is the source of coherence of EC, making it a meaningful construct. 相似文献
90.
文章通过对黄茅海底质沉积样品中的介形类生态类型进行研究,探讨其空间分布特征。研究结果显示:研究区内出现的介形类可划分为4种生态类型,总体表现为以近岸广盐型分子占主导地位,优势度极高;浅海多盐 真盐型分子次之;而广海真盐型和淡水 微盐型分子丰度很低。根据黄茅海河口湾的水体条件,可大致将研究区划分为5种亚环境区,各区内的介形类生态类型组成也存在较大差别,表现出不同的空间分布特征。介形类分布受海水盐度控制最大,其次为水动力条件。在水体盐度小、水动力条件强的河流入海口及其影响区域,介形类丰度小,且生态类型单一;而在黄茅海河口湾南部海域,由于海水底层盐度全年在15‰以上,水动力条件适宜,介形类丰度总体较高,生态类型增多。 相似文献