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461.
Yang Shun Mkingule Idefonce Liu Long Chen Wenqi Yuan Xiangyu Ma Zixuan Liang Liang Qian Shichao Huang Mengmeng Fei Hui 《中国海洋湖沼学报》2023,41(1):392-400
Journal of Oceanology and Limnology - Aeromonas hydrophila is a Gram-negative pathogen that can infect various fish, including largemouth bass (Micropterus salmoides), which have caused huge... 相似文献
462.
太湖北部沉积物重金属污染及其潜在生态危害评价 总被引:5,自引:0,他引:5
对太湖底北部表层20cm深沉积物样进行了重金属元素含量(Hg、Cd、Pb、Cu、Ni、Cr)分析,采用Hakanson潜在生态危害指数对其生态危害进行了评价:结果表明,沉积物表层5cm深以来Hg、Cd、Ph元素含量增加比较显著,生态危害指数比较高,构成了沉积物中等危害,其原因可能与太湖北部梅梁湾周围大量工业和生活废水未经处理直接排放相关。 相似文献
463.
464.
Chan Faith Ka Shun Gu Xinbing Qi Yunfei Thadani Dimple Chen Yongqin David Lu Xiaohui Li Lei Griffiths James Zhu Fangfang Li Jianfeng Chen Wendy Y. 《Natural Hazards》2022,110(3):2397-2404
Natural Hazards - Frequent typhoons significantly affect many coastal cities via intensive rainstorms, tidal surges and strong wind. Natural factors induced by human disturbance such as climate... 相似文献
465.
厦门岛海滩剖面对9914号台风大浪波动力的快速响应 总被引:17,自引:1,他引:17
根据 9914号台风发生前后对厦门岛滨岸海滩剖面地形的重复测量结果及有关台风要素和潮位的实测资料 ,探讨了台风袭击厦门岛期间海滩的变形特征和侵蚀状态。分析得出 ,海滩地形受台风暴浪冲击普遍发生急剧变化。横向冲淤变形以东岸海滩为最剧烈 :滩肩蚀退可达 2 5m ;滩面呈上冲下淤 ,上段和滩肩的单宽冲蚀量达 30m3 /m ;下段单宽淤积量达 17m3 /m ;剖面类型由滩肩式断面向沙坝式断面转变。这种变形特点是在台风大浪波动力和潮位暴涨的双重作用下造成的。台风期间 ,沿岸输沙能力以北岸最高 ,南岸次之 ,东岸较低 ;且自南岸到东岸 ,随着沿岸输沙量减少 ,横向变形相应有增大的趋势。这是9914号台风以偏东方向袭击厦门的结果。表明不同方向海岸岸滩地形对同一台风大浪波动力作用具有不同响应特征。 相似文献
466.
467.
In the meizoseismal areas hit by the China Wenchuan earthquake on May 12, 2008, the disasterprone environment has changed dramatically, making the susceptibility assessment of debris flow more complex and uncertain. After the earthquake, debris flow hazards occurred frequently and effective susceptibility assessment of debris flow has become extremely important. Shenxi gully in Du Jiangyan city, located in the meizoseismal areas, was selected as the study area. Based on the research of disaster-prone environment and the main factors controlling debris flow, the susceptibility zonations of debris flow were mapped using factor weight method(FW), certainty coefficient method(CF) and geomorphic information entropy method(GI). Through comparative analysis, the study showed that these three methods underestimated susceptible degree of debris flow when used in the meizoseismal areas of Wenchuan earthquake. In order to solve this problem, this paper developed a modified certainty coefficient method(M-CF) to reflect the impact of rich loose materials on the susceptible degree of debris flow. In the modified method, the distribution and area of loose materials were obtained by field investigations and postearthquake remote sensing image, and four data sets, namely, lithology, elevation, slop and aspect, wereused to calculate the CF values. The result of M-CF method is in agreement with field investigations and the accuracy of the method is satisfied. The method has a wide application to the susceptibility assessment of debris flow in the earthquake stricken areas. 相似文献
468.
天山乌鲁木齐河源区大西沟表土花粉散布特征 总被引:13,自引:5,他引:13
在天山乌鲁木齐河源区大西沟垂直植被带表土孢粉分析及植被调查的基础上,对大西沟垂直带的植被与表土孢粉的关系进行了探讨。从表土孢粉百分比含量可划分出4个孢粉带,其对应的植被带分别为高山垫状植被、高山草甸、亚高山草甸和云杉(Picea)林带。孢粉百分含量基本上反映了大西沟地区垂直植被带分布的特征。云杉、麻黄(Ephedra)、藜科(Chenopodiaceae)和蒿属(Artemisia)等植物花粉明显表现为超代表性。山谷上升气流在天山山地垂直植被带的表土孢粉散布中起着重要的作用。 相似文献
469.
阴山山地地貌类型复杂,自然条件与土地利用区域差异显著,自然带的垂直带谱比较明显。多年来开发利用没有遵循自然规律,造成生态系统失调,水土流失和沙漠化。农业生态环境建设的途径是:调整农牧林的布局,加强滩地与旱地农田的基本建设,提高森林的覆盖率,种草养畜发展牧业。 相似文献
470.
The individual or combined ef fect of water temperature and silicate on seasonal shift of dominant diatom species in a drinking water reservoir in China was studied in this paper. These ef fects were analyzed based on the field investigation of temporal dynamics in species composition and abundance of phytoplankton and environmental factors from September 2015 to August 2016. We firstly found that six dominant diatom species( Fragilaria nanana, Achnanthidium catenatum, Aulacoseira ambigua, Ulnaria ulna, Cyclotella meneghiniana and Asterionella formosa(Class Bacillariophyceae)), which accounted for98.7% of the total abundance of diatoms and 46.8% of the total abundance of phytoplankton, showed an obvious seasonal succession. Then significant driving factors for seasonal shift of the dominant diatom species were selected by Redundancy Analysis. The result showed that water temperature and silicate were the main environmental factors af fecting the growth of diatoms on temporal scales. Next, the regressions of water temperature and silicate and dominant diatom abundance were fitted in Generalized Additive Model separately, and the smoothers of water temperature and diatom species suggested that the dominant diatom species adapted to dif ferent optimum temperature ranges, which corresponded with the growth of seasonal changes. A positive linear correlation between silicate and diatom abundance was generated by Generalized Additive Model. Finally, the ordinal controls of water temperature and silicate on the growth of diatoms were analyzed on temporal scales specifically. We suggested that water temperature and silicate controlling the growth of diatoms in order. Diatoms grow well only when the two controlling factors simultaneously satisfy the growth conditions; as limiting factors, the two factors played their respective limiting roles in turn on temporal scales. 相似文献