Changing Patterns of Water Quality Associated with Hyporheic Flow of a Gravel Bar in the Kamo River

dissolved oxygen

京都大学防災研究所年報

Synopsis: Aquatic environmental conditions of the hyporheic zone in a gravel bar were investigated under normal low-flow conditions in the Kamo River, in Kyoto city, Japan. Horizontal distribution and chronological changes in DO concentration, water temperature and electric conductivity in the hyporheic zone were examined in relation to the hyporheic flow as a factor for the changes in water quality. Distribution patterns of the water quality parameters showed that the reduction in DO concentration was strongly related to the hyporheic water temperature, indicating that it was influenced by decomposition process of organic matters as well as the liquidity of the hyporheic flow. Hyporheic water temperature at the area without vegetation cover tended to rise following the increase in the ground surface temperature in the daytime.