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82.
三沙湾海水中磷的分布和富营养化研究 总被引:1,自引:0,他引:1
根据2010、2011年三沙湾水质监测资料,评价了活性磷酸盐的分布及时空变化特征,根据N/P和Si/N比判断三沙湾浮游植物生长的限制因子,用营养状态指数评价该湾水体的富营养化状态.结果表明,霍童溪为三沙湾海水中磷的主要陆源输入来源,磷为三沙湾植物生长繁殖限制因子,磷含量季节周期变化特征明显,5月植物生长繁殖旺盛,由于磷的匮乏,生长受到限制,磷含量降至最低水平,8月由于植物腐败分解释放磷和海水水温较高抑制植物生长,使磷含量升高,11月至次年1月,磷含量持续升高.三沙湾内富营养化指数大于1,存在发生赤潮的风险. 相似文献
83.
湖北省主要城市环境空气质量特点及成因分析 总被引:1,自引:0,他引:1
在武汉、黄石、十堰、宜昌、襄樊、荆门、荆州七城市十八年空气环境例行监测的基础上 ,运用综合污染负荷系数法总结了七城市空气质量变化趋势和特点 ,对其形成的原因进行了分析 ,并就此提出了治理的方法和管理的对策 相似文献
84.
Arctic ecosystems have experienced and are projected to experience continued large increases in temperature and declines in
sea ice cover. It has been hypothesized that small changes in ecosystem drivers can fundamentally alter ecosystem functioning,
and that this might be particularly pronounced for Arctic ecosystems. We present a suite of simple statistical analyses to
identify changes in the statistical properties of data, emphasizing that changes in the standard error should be considered
in addition to changes in mean properties. The methods are exemplified using sea ice extent, and suggest that the loss rate
of sea ice accelerated by factor of ~5 in 1996, as reported in other studies, but increases in random fluctuations, as an
early warning signal, were observed already in 1990. We recommend to employ the proposed methods more systematically for analyzing
tipping points to document effects of climate change in the Arctic. 相似文献
85.
Studies dealing with media coverage of climate change have increased steadily over the last decade or so, alongside the media coverage of climate change itself. This article aims to contribute to this growing literature on two levels: to deepen understanding of distinctive patterns of language use across nations speaking a common language and to demonstrate the usefulness of a new approach for finding such patterns. Articles in The (London) Times and the New York Times, published between 2000 and 2009, were analyzed using methods related to computational linguistics. Results show that the US seemingly still constructs climate change as a problem, whereas the UK focuses on finding solutions for the (established) problem of climate change. This linguistic and conceptual gap may hamper mutual understanding and the crafting of global climate change mitigation policies. 相似文献
86.
介绍了哈密名城大气质量状况及特征,作了初步趋势分析.认为哈密地区大气主要污染物为降尘,然而大气环境质量近期发展不会严重恶化. 相似文献
87.
Evaluation of the European Space Agency Climate Change Initiative Soil Moisture Product over China Using Variance Reduction Factor 下载免费PDF全文
Xiaoji Shen Ru An Jonathan Arthur Quaye‐Ballard Ling Zhang Zhe Wang 《Journal of the American Water Resources Association》2016,52(6):1524-1535
In this study, we evaluated the European Space Agency Climate Change Initiative soil moisture product v02.1 (ESA CCI SM v02.1) using in situ observations collected at 547 stations in China from 1991 to 2013. A conventional validation was first conducted, and the triple collocation errors of ESA CCI SM and the European Centre for Medium Range Weather Forecasting reanalysis data were approximately 0.053 and 0.050 m3/m3, respectively. To obtain more reliable validation results, the average soil moisture of the in situ observations per ESA CCI SM pixel was also used as the validation sites. Variance reduction factor (VRF) was adopted to quantify the accuracy of the soil moisture validation sites, and the average VRF was estimated at 4.88%. The validation results were enhanced by excluding validation sites with VRF errors greater than 5% from the statistical analysis. Although the ESA CCI SM underestimated the in situ observations with a Bias of 0.05 m3/m3, a moderately high correlation coefficient of 0.44 and a relatively small unbiased root‐mean‐square difference of 0.05 m3/m3 were observed. This study provides information on the utilization of ESA CCI SM for ecological protection, climate change, and hydrological forecasting. It also suggests the adoption of VRF for future error corrections of satellite‐based products. 相似文献
88.
通过Quick Bird、ZY-3商业卫星影像遥感解译提取台雄水库周围区域2008年、2018年共2期的土地利用数据,基于叠图法、景观指数法分析了水库建设前后土地利用空间分布格局、变化特征等。主要结论如下:台雄水库采取了有效的植被恢复措施,工程建设对自然植被尤其是森林植被的影响有限,工程建设和运行基本未改变生态系统总体异质性,对区域生态体系的阻抗稳定性影响不大。 相似文献
89.
在与灾害进行斗争的长期过程中,人类逐步形成了关于灾害防治的指导思想,其中既有正确的、科学的成分.也有错误的、不合理的成分。本文依据灾害本身的性质与规律,从灾害与自然生态──社会经济系统的相互关系原理出发,分析并重新认识当代社会人类进行灾害防治工作的指导思想.以图确立正确的灾害防治指导思想.为减灾防灾工作顺利而有效的展开奠定基础。 相似文献
90.