adjoining data occasionally. Although the item changes abnormally it turns back at the next time. We believe that it declares that the pollutant is in the range of the water self-purification and it will bring little harm to the groundwater. Moreover there may be ran dom errors that cause the changes. Considering the practicability of the mathematical model, we don t think it reflects pollution only according to these data. the Alkalinity column's data of the data set must have some problem. Bccause they are the same as the Bicarbonate'column and if we get pH value according to the‘ Alkalinity’ column’ s data, it is quite different from the'pH'column's data. But in fact, they should be coordinate. So it must have some problems Example On 95-3-21 data of MW1IB, the Alkalinity is 110mg/ Then Ig 11.8 (14) Obviously, the groundwatcr appeared considerably high alka line. It is not acord with the practical circumstance In the Carbon Total Organic' column of the data set, since 96 10-9, the unit of the data is 10 times of the preceding data and it is not ug/ but mg/ Example he consistency of carbon total organic on 97-3-18 in MW1lB is mgA, but not 1. 5ug/ In the Temperaturc column of the data set some data obvious- ly bigger than ordinary data. Through analyzing, we find that the unusual data may be Fahrenheit but not centigrade degree E 237 PDF文件使用" pdffactory"试用版本创建w, fineprint,com,cnPDF 文件使用 "pdfFactory" 试用版本创建 www.fineprint.com.cn