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煤矿塌陷区复垦土壤环境质量评价 总被引：1，自引：0，他引：1
通过对煤矿塌陷区复垦土壤采样测试,研究土壤中重金属铜、锌、镉、汞、砷、铅、铬的含量对土壤环境的影响。研究结果表明:按单因子污染指数法和内梅罗综合污染指数法,结合国家土壤环境质量标准对复垦土壤的质量进行评价:研究区内土壤环境质量良好,基本上可以达到国家土壤环境质量二级标准,安全清洁级别;参照《无公害食品蔬菜产地环境条件标准》、《绿色食品产地环境质量标准》和《有机农业生产基地环境质量标准》,对复垦土壤的农用环境进行评价:研究区内土壤全部达到绿色食品产地环境质量标准,如果选择合理的修复方法,对部分有轻微污染的土壤进行,则可以达到有机农业生产基地环境质量标准;以潜在生态危害指数RI分析,复垦区内土壤重金属潜在生态危害指数相对较低,复垦区农业生产具有良好的发展前景。 相似文献
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Diverse conservation efforts have been expanding around the globe,even under the stress of increasing agricultural production.A striking example is the supply-chain agreements put upon the Amazon forest which had reduced deforestation by 80% from the early 2000 s(27,772 km2) to 2015(6207 km2).However,evaluation of these conservation efforts usually focused on the impacts within the Amazon biome only,while the effects that spill over to other areas(e.g.,displacement of environmental pressure from one area to another) were rarely considered.Ignoring spillover effects may lead to biased or even wrong conclusions about the effectiveness of these conservation efforts because the hidden cost outside the target area of conservation may offset the achievement within it.It is thus important to assess the spillover effects of these supply-chain agreements.In this study,we used the two supply-chain agreements(i.e.,Soy Moratorium and zero-deforestation beef agreement) implemented in the Amazon biome as examples and evaluated their spillover effects to the Cerrado.To achieve a holistic evaluation of the spillover effects,we adopted the telecoupling framework in our analysis.The application of the telecoupling framework includes the interactions between distant systems and extends the analytical boundaries beyond the signatory areas,which fill the gap of previous studies.Our results indicate that the supply-chain agreements have significantly reduced deforestation by half compared to projections within the sending system(i.e.,Pará State in the Amazon,which exports soybeans and other agricultural products),but at the cost of increasing deforestation in the spillover system(i.e.,a 6.6 time increase in Tocantins State of the Cerrado,where deforestation was affected by interactions between the Amazon and other places).Our study emphasizes that spillover effects should be considered in the evaluation and planning of conservation efforts,for which the telecoupling framework works as a useful tool to do that systematically. 相似文献
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通过数值模拟来研究热带气旋中的β偶极涡环流，结果可见，在中层的偏差流场上，有清晰的β偶极涡环流，即涡旋中心以西为气旋性环流，以东为反气旋性涡旋，理论分析表明，该β偶极涡环流是由地转涡度平流造成的。 相似文献
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1INTRODUCTIONEversincethe1940抯,thetropicalcyclone(TC)hasbeenviewedasapointvortexorrigidvortex.Thepredictionissummedupasoneforairflowintheambientfield.Themethodusuallysucceeds.Thesteeringtheoryfortheairflowbecomesitstheoreticalfoundation.Thoughwithsomesuccess,theactualtrackofTCmovementcanbemuchdeviatedfromthesteeringcurrent,asseeninroutineforecastpractice.Withoutmuchchangesintheambientsteeringcurrent,theTCcanhaveunexpectedchangesinthedirection,speedofmotionorintensity.Atypicalexamplewo… 相似文献
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