USING UNCENSORED TRACE-LEVEL MEASUREMENTS TO DETECT TRENDS IN GROUND WATER CONTAMINATION

Autor:	P. Steven Porter, S. Trivikrama Rao, Maxine E. Dakins, Michele West
Rok vydání:	1996
Předmět:	Trend analysis Observational error Ecology Warning system Environmental remediation Censoring (clinical trials) Statistics Nonparametric statistics Environmental science Water quality Contamination Earth-Surface Processes Water Science and Technology
Zdroj:	Journal of the American Water Resources Association. 32:799-805
ISSN:	1752-1688 1093-474X
Popis:	Environmental decision making involving trace-levels of contaminants can be complicated by censoring, the practice of reporting concentrations either as less than the limit of detection (LOD) or as not detected (ND) when a test result is less than the LOD. Censoring can result in data series that are difficult to meaningfully summarize, graph, and analyze through traditional statistical methods. In spite of the relatively large measurement errors associated with test results below the LOD, simple and meaningful analyses can be carried out that provide valuable information not available if data are censored. For example, an indication of increasing levels of contamination at the fringe of a plume can act as an early warning signal to trigger further study, an increased sampling frequency, or a higher level of remediation at the source. This paper involves the application of nonparametric trend analyses to uncensored trace-level groundwater monitoring data collected between March 1991 and August 1994 on dissolved arsenic and chromium for seven wells at an industrial site in New York.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::669d2b9450152b135b6b1c3e24319e2b https://doi.org/10.1111/j.1752-1688.1996.tb03477.x Zobrazit plný text záznamu