1-A comparison of statistical methods for deriving freshwater quality criteria for the.pdfVIP

下载本文档

4
0
约3.71万字
约 9页
2017-04-11 发布于江苏
举报
版权申诉

1-A comparison of statistical methods for deriving freshwater quality criteria for the.pdf

1、有哪些信誉好的足球投注网站（book118）网站文档一经付费（服务费），不意味着购买了该文档的版权，仅供个人/单位学习、研究之用，不得用于商业用途，未经授权，严禁复制、发行、汇编、翻译或者网络传播等，侵权必究。。
2、本站所有内容均由合作方或网友上传，本站不对文档的完整性、权威性及其观点立场正确性做任何保证或承诺！文档内容仅供研究参考，付费前请自行鉴别。如您付费，意味着您自己接受本站规则且自行承担风险，本站不退款、不进行额外附加服务；查看《如何避免下载的几个坑》。如果您已付费下载过本站文档，您可以点击这里二次下载。
3、如文档侵犯商业秘密、侵犯著作权、侵犯人身权等，请点击“版权申诉”（推荐），也可以打举报电话：400-050-0827(电话支持时间：9:00-18:30)。
4、该文档为VIP文档，如果想要下载，成为VIP会员后，下载免费。
5、成为VIP后，下载本文档将扣除1次下载权益。下载后，不支持退款、换文档。如有疑问请联系我们。
6、成为VIP后，您将拥有八大权益，权益包括：VIP文档下载权益、阅读免打扰、文档格式转换、高级专利检索、专属身份标志、高级客服、多端互通、版权登记。
7、VIP文档为合作方或网友上传，每下载1次，网站将根据用户上传文档的质量评分、类型等，对文档贡献者给予高额补贴、流量扶持。如果你也想贡献VIP文档。上传文档

1-A comparison of statistical methods for deriving freshwater quality criteria for the

ENVIRONMENTAL QUALITY BENCHMARKS FOR PROTECTING AQUATIC ECOSYSTEMS A comparison of statistical methods for deriving freshwater quality criteria for the protection of aquatic organisms Liqun Xing Hongling Liu Xiaowei Zhang Markus Hecker John P. Giesy Hongxia Yu Received: 6 August 2012 /Accepted: 2 January 2013 /Published online: 15 January 2013 # Springer-Verlag Berlin Heidelberg 2013 Abstract Species sensitivity distributions (SSDs) are in- creasingly used in both ecological risk assessment and deriva- tion of water quality criteria. However, there has been debate about the choice of an appropriate approach for derivation of water quality criteria based on SSDs because the various methods can generate different values. The objective of this study was to compare the differences among various methods. Data sets of acute toxicities of 12 substances to aquatic organ- isms, representing a range of classes with different modes of action, were studied. Nine typical statistical approaches, in- cluding parametric and nonparametric methods, were used to construct SSDs for 12 chemicals. Water quality criteria, expressed as hazardous concentration for 5 % of species (HC5), were derived by use of several approaches. All approaches produced comparable results, and the data gener- ated by the different approaches were significantly correlated. Variability among estimates of HC5 of all inclusive species decreased with increasing sample size, and variability was similar among the statistical methods applied. Of the statistical methods selected, the bootstrap method represented the best- fitting model for all chemicals, while log-triangle and Weibull were the best models among the parametric methods evaluated. The bootstrap method was the primary choice to derive water quality criteria when data points are sufficient (more than 20). If the available data are few, all other methods should be constructed, and that which best describes the distribution of the data was selected. Key