FORMATION AND BEHAVIORS OF ANOXIC SALINE WATER IN COASTAL LAGOONS

对北海道春取湖和武尻湖两个沿海泻湖的死水（缺氧咸水）形成机制和行为进行了研究。两个潟湖海水入侵的物理条件不同；在春取湖，入侵只发生在大潮高潮时，而在Abashiri湖，入侵发生在每日涨潮时。然而，这两个湖一直都有较低的缺氧咸水。因此，与湖泊水量相比，海水入侵量可能是有限的。春取湖内部积水现象不明显。这可能是因为在开阔的浅海区域，由于风浪的能量耗散，下风的设置不够。在Abashiri湖，观察到内部的积水，尽管每天的海水入侵经常使其模糊不清。

The mechanism on formation and behaviors of dead water (anoxic saline water) was examined in two coastal lagoons, Lake Harutori and Lake Abashiri, Hokkaido. Physical conditions of sea water intrusion are different between the two lagoons ; in Lake Harutori, the intrusion occurs only during the high spring tide, while in Lake Abashiri, it was generated during the daily high tides. Both of the lakes, however, consistently have the lower anoxic saline water. Hence the amount of sea water intrusion is probably limited compared with the lake water volume. The internal seiche was not obviously observed in Lake Harutori. This is probably because the leeward setup is not enough due to the energy dissipation by wind waves in the open shallow region. In Lake Abashiri, the internal seiche was observed, although the daily sea water intrusion frequently makes it ambiguous.