HYDROGRAPHIC STRUCTURES OF YATSUSHIRO-KAI, KYUSHU, JAPAN OBSERVED BY TEN-YEAR SURVEYS CONDUCTED BY “KAIKI” AND “KAIKOU” OF MLIT

Abstract

 Hydrographic features of Yatsushiro-Kai, a semi-enclosed embayment in Kyushu, Japan, observed by a 10-year environmental monitoring between 2004 and 2013 by the Ministry of Land, Infrastructure, Transport and Tourism (MLIT), were closely examined. Stratification was stronger in the inner-most area than the middle where Kuma-River supplies a large amount of fresh water. Spatial characteristics of environment of Yatsushiro-Kai could be classified into nine categories, applying cluster analyses to bottom sediment and benthic community. One of the results of these analyses was shown that distribution of the benthic communities and the bottom sediment qualities was complex, especially in the inner-most area.