Author(s): Ryuichi Hirakawa; Momoka Yamada; Kojiro Nakamoto
Linked Author(s): Ryuichi Hirakawa
Keywords: Stagnant water body; Water quality; Field survey; Thermal stratification; Hypoxic water
Abstract: Lake Tataranuma in Kanto region of Japan. has been suffering from a deteriorating environment for aquatic plants and animals due to the development of the area and the increase in polluted wastewater since around the period of rapid economic growth. In many cases, water pollution in lakes is caused by a variety of factors, and it is necessary to make sure of the relationship between the phenomena and the factors. In this study, we investigated the spatiotemporal characteristics of water quality in Lake Tataranuma based on field surveys conducted four times a year. The results showed that thermal stratification in the central part of Lake Tataranuma, which has a large water depth, during the summer season. The vertical profiles of Dissolved Oxygen, pH and chlorophyll fluorescence in summer were related to thermal stratification. From 2020 to 2022, every summer, the bottom layers of the depressions experienced low oxygen conditions. The vertical temperature differences during the summer may have interfered with oxygen supply from the surface to the bottom of the lake.
Year: 2024