Abstract
Ground water samples were taken from 8 wells at Kitaura area of Gogoshima in Matsuyama City. The sample water was collected every month from June 1978 to January 1979 and some anions contained in them were analyzed in order to examin the characteristics of the ground water.
The concentration of anions in this Island wells were higher 2.5-13 times than that of inland wells. The average concentration of Cl- is 23 ppm, and this shows that sea water did not permiate into it. The high concentrations of SO42-, NO-3-N, and NH+4-N may be caused by chemical manure and compost which are given to the tangerine orchard. 74% of samples analyzed showed the coexistence of NO-2-N and NH+4-N. In this area, the flow direction of under groundwater may be 5→1→2, 8→7→2 based on the analysis of concentration correlation matrix and -columner section.
