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561.
Grouping Lakes for Water Quality Assessment and Monitoring: The Roles of Regionalization and Spatial Scale 总被引:1,自引:0,他引:1
Cheruvelil KS Soranno PA Bremigan MT Wagner T Martin SL 《Environmental management》2008,41(3):425-440
Regionalization frameworks cluster geographic data to create contiguous regions of similar climate, geology and hydrology
by delineating land into discrete regions, such as ecoregions or watersheds, often at several spatial scales. Although most
regionalization schemes were not originally designed for aquatic ecosystem classification or management, they are often used
for such purposes, with surprisingly few explicit tests of the relative ability of different regionalization frameworks to
group lakes for water quality monitoring and assessment. We examined which of 11 different lake grouping schemes at two spatial
scales best captures the maximum amount of variation in water quality among regions for total nutrients, water clarity, chlorophyll,
overall trophic state, and alkalinity in 479 lakes in Michigan (USA). We conducted analyses on two data sets: one that included
all lakes and one that included only minimally disturbed lakes. Using hierarchical linear models that partitioned total variance
into within-region and among-region components, we found that ecological drainage units and 8-digit hydrologic units most
consistently captured among-region heterogeneity at their respective spatial scales using all lakes (variation among lake
groups = 3% to 50% and 12% to 52%, respectively). However, regionalization schemes capture less among-region variance for
minimally disturbed lakes. Diagnostics of spatial autocorrelation provided insight into the relative performance of regionalization
frameworks but also demonstrated that region size is only partly responsible for capturing variation among lakes. These results
suggest that regionalization schemes can provide useful frameworks for lake water quality assessment and monitoring but that
we must identify the appropriate spatial scale for the questions being asked, the type of management applied, and the metrics
being assessed. 相似文献
562.
Regulating BFRs--from science to policy 总被引:1,自引:0,他引:1
Hansson SO 《Chemosphere》2008,73(2):144-147
An adequate distribution of responsibilities between scientists and policy-makers requires that a distinction be made between theoretical rationality (what to believe) and practical rationality (what to do). In chemical risk management, it is often necessary to base decisions on indications of risk that do not amount to full scientific proof. Guidelines are offered for how this can be done without infringing upon the integrity of science. Furthermore, it is shown that the application of standard decision theory to chemical risks yields conclusions very much in agreement with the precautionary principle. 相似文献
563.
二沉池出水的电化学消毒试验研究 总被引:3,自引:1,他引:2
对德国威斯巴登城市污水处理厂和上海石化股份公司水质净化厂二沉池出水分别进行了电化学消毒试验。试验结果表明,用电化学方法对威斯巴登城市污水处理厂和上海石化股份公司水质净化厂二沉池出水进行消毒是可行的,消毒效果好,耗电少,杀菌率随电流、处理时间的增加而提高。 相似文献
564.
Majaron Vinícius F. da Silva Marisa Gomes Bortoletto-Santos Ricardo Klaic Rodrigo Ribeiro Sidney J. L. Polito Wagner L. Bevilaqua Denise Farinas Cristiane S. Ribeiro Caue 《Journal of Polymers and the Environment》2022,30(6):2602-2613
Journal of Polymers and the Environment - Fertilization is essential to provide suitable conditions for plant development and crop productivity, but the environmental cost of fertilizers is a... 相似文献