tailieunhanh - Báo cáo " Quantitative distribution of groundwater chemical components in the Red River Delta based on frequency analysis "

Quantitative distribution of main ions and other chemical components of groundwater are characterized by theirs statistical parameters. They depend closely on probability distribution of the data. In this paper, by processing 760 analysis results of groundwater samples issued by Department of Geology and Minerals of Vietnam, and by using frequency analysis techniques, the authors show that the distribution of bicarbonate and calcium ions in Pleistocene and Holocene aquifer in the Red River Delta (RRD) are in accordance with normal distribution, while other ions . | VNU Journal of Science Earth Sciences 23 2007 194-201 Quantitative distribution of groundwater chemical components in the Red River Delta based on frequency analysis Dang Mai Nguyen Thanh Lan College of Science VNU Received 02 July 2007 Abstract. Quantitative distribution of main ions and other chemical components of groundwater are characterized by theirs statistical parameters. They depend closely on probability distribution of the data. In this paper by processing 760 analysis results of groundwater samples issued by Department of Geology and Minerals of Vietnam and by using frequency analysis techniques the authors show that the distribution of bicarbonate and calcium ions in Pleistocene and Holocene aquifer in the Red River Delta RRD are in accordance with normal distribution while other ions are in accordance with skew distribution. In the first case the value of mean equals the value of median but in the second case these two values should be determined at the percentile of 50 and 80 respectively. This research also indicated that Pleistocene and Holocene aquifers belong to bicarbonate - calcium type with total mineralization in Pleistocene aquifer significant less than that in Holocene one. Keywords Red River Delta Groundwater Frequency analysis Normal distribution. 1. Introduction Quantitative distribution laws of groundwater chemical compositions reveal not only geochemical kinds but also origin of groundwater. Quantitative distribution of main ions and other chemical components in groundwater are characterized by theirs statistical parameters with the most important index being the expected values and the standard deviations. The estimators of these two parameters depend on the probability distribution of content of groundwater chemical Corresponding author. Tel. 84-912646638. E-mail dangmai_diachat@ components. Statistically only in case of normal distribution the expected value equals the mean and is calculated as X 1 ịxi 1 n 1 while the .