Zobrazeno 1 - 10
of 52
pro vyhledávání: '"Don L. Stevens"'
Publikováno v:
Journal of Agricultural, Biological, and Environmental Statistics. 13:243-254
The need for aquatic resource condition surveys at scales that are too extensive to census has increased in recent years. Statistically designed sample surveys are intended to meet this need. Simple or stratified random sampling or systematic survey
Autor:
Mary E. Kentula, Susan F. Jensen, Don L. Stevens, Kristen C. Hychka, Robert P. Brooks, Denice H. Wardrop
Publikováno v:
Wetlands. 27:432-445
This paper reports on the ecological status of wetlands in the Upper Juniata watershed in Pennsylvania, USA, as determined by employing the hydrogeomorphic (HGM) approach. HGM assessment provides a measure of the potential functional performance of a
Publikováno v:
Wetlands. 27:416-431
The requirement of Section 305(b) of the Clean Water Act (CWA) that all waters of the U.S. be assessed every two years has been historically ignored for wetlands, even though they are included in the definition of “waters of the U.S.” This paper
Autor:
Don L. Stevens, Susan F. Jensen
Publikováno v:
Wetlands. 27:515-523
Probability-based sample surveys are increasingly being used to assess natural resource condition, yet many of the techniques commonly used in survey sampling are not well known to environmental scientists. Here we discuss several techniques from sur
Autor:
Don L. Stevens, Thomas E. Jordan, Amy Jacobs, Donald E. Weller, Dennis F. Whigham, Mary E. Kentula, Susan F. Jensen
Publikováno v:
Wetlands. 27:462-478
The hydrogeomorphic (HGM) approach to wetland assessment was combined with the Environmental Monitoring and Assessment Program (EMAP) survey design procedures to evaluate the condition of non-tidal riverine and flats wetlands in the Nanticoke River w
Autor:
Don L. Stevens, Anthony R. Olsen
Publikováno v:
Journal of the American Statistical Association. 99:262-278
The spatial distribution of a natural resource is an important consideration in designing an efficient survey or monitoring program for the resource. Generally, sample sites that are spatially balanced, that is, more or less evenly dispersed over the
Autor:
Don L. Stevens, Anthony R. Olsen
Publikováno v:
Environmetrics. 14:593-610
The spatial distribution of a natural resource is an important consideration in designing an efficient survey or monitoring program for the resource. We review a unified strategy for designing probability samples of discrete, finite resource populati
Autor:
Don L. Stevens Jr
Publikováno v:
Wiley StatsRef: Statistics Reference Online.
Autor:
Don L. Stevens, N. Scott Urquhart
Publikováno v:
Environmetrics. 11:13-41
In many environmental samples, the target population is distributed over space in a more or less continuous manner, e.g., the waters of a lake or the trees in a forest. Attributes of such a population can be conceptualized as a continuous function de
Autor:
Don L. Stevens
Publikováno v:
Environmetrics. 8:167-195
Many environmental resources, such as mineral resources or vegetation cover, or environmental attributes, such as chemical concentration in a stream or benthic community structure, are most appropriately sampled as continuous populations distributed