報告書番号

E484002

タイトル（和文）

OVERVIEW OF RIVER/LAKE WATER QUALITY AND LIMNOLOGICAL STUDIES ON VOLCANIC INORGANIC ACID LAKES IN JAPAN -IN RELATION TO THE EFFECTS OF ACID DEPOSITION-

タイトル（英文）

OVERVIEW OF RIVER/LAKE WATER QUALITY AND LIMNOLOGICAL STUDIES ON VOLCANIC INORGANIC ACID LAKES IN JAPAN -IN RELATION TO THE EFFECTS OF ACID DEPOSITION-

概要 （図表や脚注は「報告書全文」に掲載しております）

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概要 （英文）

IN THIS PAPER THE PRESENT CONDITIONS OF WATER QUALITY PARAMETERS,SUCH AS PH,ALKALINITY,OF SOME MAJOR RIVERS AND LAKES IN JAPAN,AND A REVIEW OF LIMNOLOGICAL STUDIES ON VOLCANIC INORGANIC ACID LAKES ARE DESCRIBED.THESE INFORMATIONS WILL BE EMPLOYED AS BASIC DATA WHEN WE CONSIDER THE FUTURE POSSIBILITY OF FRESHWATER ACIDIFICATIONDUE TO ACID DEPOSITION AND ITS EFFECTS IN JAPAN.THE TENTATIVE CONCLUSIONS ARE: 1)VALUES OF PH LESS THAN 5.6 HAVE NOT BEEN OBSERVED SO FAR IN MAJOR RIVERS AND LAKES IN JAPAN,EXCEPT FOR THOSE AFFECTED BY VOLCANIC ACTIVITIES. 2)TENDENCIES OF PH VALUE DECREASE OVER LONG TERM IN MAJOR RIVERS AND LAKES IN JAPAN ALSO HAVE NOT BEEN OBSERVED SO FAR,EXCEPT FOR THOSE AFFECTED BY VOLCANIC ACTIVITIES.SOME RIVERS AND LAKES IN POPULATEDAREAS SEEM TO HAVE TENDENCIES OF ALKALIZATION,REFLECTING THE INCREASE OF ALGAL PHOTOSYNTHETIC ACTIVITIES. 3)FEW DATA ARE AVAILABLE TO EVALUATE THE ACIDIFICATION IN SMALLER RIVERS/LAKES OR THAT DURING VERY SHORT TERM. 4)ALSO FEW DATA ARE AVAILABLE TO PREDICT THE FUTURE POSSIBILITY OFSURFACE WATER ACIDIFICATION OCCURENCE IN JAPAN.THEREFORE,STUDIES WITH THE FIRST PRIORTY ON THE AQUATIC ENVIRONMENT AND ACID DEPOSITION SHOULDBE ON COLLECTION OF DATA AND DEVELOPMENT OF TECHNOLOGY AVAILABLE TO ESTIMATE THE FUTURE POSSIBILITY OF ACIDIFICATION OCCURENCE IN JAPAN. 5)THERE ARE SEVERAL INORGANIC ACID RIVERS AND LAKES DUE TO VOLCANIC ACTIVITIES IN JAPAN.THEY SHOULD BE DISTINGUISHED AND THEIR DISTRIBUTION SHOULDBE DEFINED WHEN ACIDIFICATION DUE TO ACID DEPOSITION IS SURVEYED.

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