• Publications
  • Influence
Nondetects and data analysis : statistics for censored environmental data
TLDR
This paper presents a meta-modelling approach to computing summary statistics that aims to provide an apples-to- apples comparison of the data presented in this paper and some of the techniques used to derive these results.
Statistics for Censored Environmental Data Using Minitab and R
  • D. Helsel
  • Environmental Science
  • 1 February 2012
TLDR
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 and serves as a valuable reference for?environmental professionals, biologists, and ecologists who focus on the water sciences, air quality, and soil science.
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 water
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 as
More than obvious: better methods for interpreting nondetect data.
  • D. Helsel
  • Environmental Science, Medicine
    Environmental science & technology
  • 15 October 2005
Assessing ground-water vulnerability to contamination: Providing scientifically defensible information for decision makers
Throughout the United States increasing demands for safe drinking water and requirements to maintain healthy ecosystems are leading policy makers to ask complex social and scientific questions about
Regional Kendall test for trend.
  • D. Helsel, L. Frans
  • Environmental Science
    Environmental science & technology
  • 6 June 2006
TLDR
The Seasonal Kendall trend test is adapted to determine whether a consistent regional trend occurs in environmental variables within a study region at more than one site.
...
...