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661.
Monitoring seasonal distribution of an endangered anadromous sturgeon in a large river using environmental DNA 总被引:1,自引:0,他引:1
Nian Xu Bin Zhu Fang Shi Ke Shao Yanfu Que Weitao Li Wei Li Wenjing Jiao Hua Tian Dongmei Xu Jianbo Chang 《Die Naturwissenschaften》2018,105(11-12):62
Monitoring dynamic distribution is crucial to conservation management of anadromous sturgeons, but traditional survey methods are less efficient for low-density populations in a large river. Natural propagation of Chinese sturgeon has been monitored annually mainly at the spawning ground using netting for eggs and hydroacoustics for broodstock. However, absence of spawning was observed sporadically in recent years, indicating further crises for the declining population. We analyzed eDNA of water samples collected from 24 sites across 1360 km of the migratory route of anadromous Chinese sturgeon in the middle and lower reaches of the Yangtze River. Chinese sturgeon was detected at 9 sites during the spawning season and 14 sites after the spawning season. We found that positive eDNA detection rates remained constant in the middle reaches but dramatically changed in the lower reaches, reflecting seasonal migration pattern of Chinese sturgeon. Invasive sturgeons were detected in the river, indicating their possible escape from aquaculture facilities. This study established a protocol for the use of eDNA to monitor distribution of Chinese sturgeon and could be valuable in making better policies for the conservation of this endangered species. 相似文献
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PHAST软件预测火炬的气体扩散和热辐射 总被引:1,自引:0,他引:1
石天雄 《安全.健康和环境》2010,10(7):35-38
简述了PHAST(Process Hazard Analysis Software Tool)软件中APIRP521计算模型计算火炬喷射火的要点,以某企业的液化天然气接收站火炬为例,详细说明了计算步骤,给出了计算结果,并作出简要分析。 相似文献
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Land degradation and desertification have become severe environmental problems in arid areas due to excessive use of water resources. It is urgent to reduce agricultural water use for ecological rehabilitation, which may result in a decrease in agricultural production and farmer's welfare. This paper focused on the impacts of some main measures including extensions of watersaving irrigation, expanding solar green house and increasing off-farm employment, which are generally recognized to be important to alleviate water shortage and poverty. A bioconomic model is applied taking Minqin Oasis in Gansu Province as a case study site. Simulation results showed that the effect of expanding solar greenhouse was more positive than other ones so it drew more attention. On the view of the different effects between each irrigation zone, mixed policy patterns suitable for them are suggested. In Baqu, expanding solar greenhouse should be the most important, auxiliary with encouraging pipe irrigation. Inversely, with regard to Quanshan, the major attention should be paid to subsidy for pipe irrigation and it would be better to supply the off-farm employment opportunities to the households in Huqu, where the expanding of solar greenhouse should also be summoned. Finally, it should be noted that farmer's income would only resume to 90% of the current level in the short run by putting more effort into local policies. Thus, the ecological compensation is needed to ensure farmer's welfare. 相似文献
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黄河下游泥沙灾害初步研究 总被引:8,自引:0,他引:8
基于黄河下游对泥沙运动与泥沙灾害发生的关系问题进行了分析。认为下游泥沙灾害类型主要包括洪水、河岸侵蚀、土地沙化、水涝和土地盐碱化, 并认为改造下游泥沙灾害环境应通过改变泥沙堆积分布入手。 相似文献
669.
交通安全技术研究的范围与发展趋势 总被引:23,自引:3,他引:20
概括地分析了影响道路交通安全的因素,论述了交通安全技术研究的范围及世纪之交交通安全技术发展趋势,并指出未来交通事故的严峻性。 相似文献
670.
本文介绍了二滩水电站环境影响评价,以及世界银行评估过程中专家提出的一系列环境问题,并结合我院10多年来的环境影响评价工作简述几点启示,供参考。 相似文献