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Statistical methods in water resources
Presenta un estudio de los diversos metodos estadisticos usados para analisis en hidrologia
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Nondetects and data analysis : statistics for censored environmental data
Preface. Acknowledgments. Introduction: An Accident Waiting To Happen. 1. In Focus. 2. The Three Approaches. 3. Reporting Limits. 4. Storing Data in Databases. 5. Plotting Data With Nondetects. 6.Expand
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Statistics for Censored Environmental Data Using Minitab and R
Statistics for Censored Environmental Data Using Minitab and R, Second Edition is an excellent book for courses on environmental statistics at the upper-undergraduate and graduate levels. Expand
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Arsenic in Ground Water of the United States: Occurrence and Geochemistry
Concentrations of naturally occurring arsenic in ground water vary regionally due to a combination of climate and geology. Although slightly less than half of 30,000 arsenic analyses of ground waterExpand
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Less than obvious - statistical treatment of data below the detection limit
  • D. Helsel
  • Environmental Science
  • 1 December 1990
As researchers increasingly investigate grace substances in the world's soil, air, and water, they frequently find concentrations that are lower than limits deemed reliable enough to report asExpand
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More than obvious: better methods for interpreting nondetect data.
  • D. Helsel
  • Environmental Science, Medicine
  • Environmental science & technology
  • 15 October 2005
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Statistical analysis of hydrologic data.
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Regional Kendall test for trend.
  • D. Helsel, L. Frans
  • Environmental Science, Medicine
  • Environmental science & technology
  • 6 June 2006
Trends in environmental variables are often investigated within a study region at more than one site. At each site, a trend analysis determines whether a trend has occurred. Yet often also ofExpand
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Estimation of descriptive statistics for multiply censored water quality data
This paper extends the work of Gilliom and Helsel (1986) on procedures for estimating descriptive statistics of water quality data that contain “less than” observations. Previously, procedures wereExpand
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