Author(s): A. H. M. Faisal Anwar; M. Fazlul Bari
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Keywords: Groundwater quality; Statistical distribution; Seasonal variation; Autocorrelation
Abstract: The increasing problem of groundwater contamination has resulted a need for the information that can be obtained from the properly designed groundwater monitoring programs. The utilization of groundwater quality data and its subsequent benefits depend upon an understanding of the statistical characteristics of groundwater quality variables. The primary objective of groundwater sampling is to provide early warning of pollution events. This involves statistical analyses of the data to detect changes in quality over time or space. In order to characterize the groundwater quality variables, it is necessary to test whether the data of concern are normally distributed, show seasonal variations or serially dependent. Groundwater quality data from about 40 wells located in northwest Bangladesh were used in this study. Nine parameters such as, chloride, nitrate, TDS, pH, SAR, sodium, iron, calcium and magnesium were selected as the groundwater quality variables for analyses. Results of statistical analyses revealed that most of the groundwater quality variables were not normally distributed, but have skewed right distribution. As such, most of the variables appeared to be lognormally distributed. Different statistical test for seasonal variation was performed and chloride, nitrate, TDS, SAR and magnesium were found to be showing seasonal patterns. The parameters like, pH, SAR, sodium, calcium and magnesium were found to be showing serial correlation. Spatial variability of these parameters was also investigated and some of the parameters like, NO3, Ca and Mg showed significant spatial variation.
Year: 2001