1997 Volume 117 Issue 10-11 Pages 836-849
General aspects of the deterioration and typical examples in some hot springs (Atami, Shirahama, Isawa·Kasugai, and Syuzenji Hot Springs) are outlined in this report in connection with the change of chemical constituents. (1) Deterioration of thermal spring resources generally occurs accompanied with the following phenomena : a) drawdown of the water level in thermal water wells. b) lowering of temperature of thermal springs. c) change of the water quality (salt water encroachment in the coastal region and decrease in concentration of chemical components resulting from the intrusion of underground water in the inland area).(2) Typical examples of the deterioration are summarized as follows ; [Table] (3) It has been revealed from the analyses of the statistical data of Environment Agency that the deterioration of hot spring resources in Japan is gradually progressimg.
