Synoptic monitoring of water quality and water resources. A suggestion on population and sampling approaches

Article type: Research Article

Authors: Heldal, Johan¹ | Østdahl, Torbjørn²

Note: [1] Johan Heldal is a mathematical statistician working as a senior executive in the Methods Unit of the Central Bureau of Statistics of Norway where he is employed since six years. His main assignments are quality control and combined use of sample surveys, censuses and registers. For the last four years, he has also been an advisor in methodological questions concerning environmental and resource statistics.

Note: [2] Torbjøm Østdahl is a freshwater biologist employed in the Ministry of Environment of Norway. He is associated with the Division of Environmental Statistics in the Central Bureau of Statistics of Norway since April 1984, and is working with classification systems for water quality data on a regional scale, and with the use of indicators in water quality monitoring.

Abstract: When results from monitoring surveys of water quality in rivers or lakes are presented, the results are often generalized to statements of water quality in a larger river structure or to ‘waters’ within some geographical area of interest. Such generalizations are often performed informally without applications of statistical methods for data collection or estimation. The population to which the generalizations are referred is not always well-defined. Two possible definitions of populations, one in terms of water volume and the other in terms of water momentum can be suggested. A sampling and estimation procedure is possible by which sample points can be selected and averages and proportions can be estimated in the two populations.

DOI: 10.3233/SJU-1984-2406

Journal: Statistical Journal of the United Nations Economic Commission for Europe, vol. 2, no. 4, pp. 393-406, 1984