Statiscal Analysis on Stream Pollution : I. Factor Analysis on Stream Pollution of the Yodo River

Abstract

In order to obtain the composite pollution index which may be available as the evaluation of the degree of gross stream pollution, factor analysis was carried out using monthly water examination data from 1923 to 1958 at Kunijima intake crib. Ten items i.e. turbibity, pottasium permanganate consumed, color, general bacteria count, residue by evaporation, total nitrogen, chlor ion concentration, hardness, stream flow rate and stream water temperature were adopted as variables in factor analysis. From the results of factor analysis, three definite factors i.e. pollution factor, rainfall factor and air temerature factor were identified, and correlations between these three factors and ten variables were elucidated. Computing the β weights for pollution factor, the composite pollution index was obtained.