Radium （Ra） isotopes are useful for tracing water mass transport and examining estuarine hydrological dynamics. In this study, several hydrological parameters, nutrients, ehlorophyll-a （ehl-a）, suspended particula...Radium （Ra） isotopes are useful for tracing water mass transport and examining estuarine hydrological dynamics. In this study, several hydrological parameters, nutrients, ehlorophyll-a （ehl-a）, suspended particulate matter （SPM） and Ra isotopes （223Ra, 224Ra and 226Ra） of surface waters of the Zhujiang （Pearl） River estuary （ZRE） were measured. This was done for both winter （December） and summer （July） seasons, to quantitatively understand the seasonal characteristics of river plume flow rate and trajectories, as well as the ecological response. The results show that Ra concentrations in summer were higher than in winter, especially Z24Ra （about 2-5 times higher）. The spatial distribution of three Ra isotopes and relative Ra water ages indicated that river water mainly flushed out of ZRE through the western side in winter, where the water transport was about 5 days faster than in the eastern zone. In summer, diluted river water expended to the east side, resulting in fairly similar water ages for both sides of the river mouth. Although nutrients were higher during the summer season, lower chl-a concentrations indicated that reduced primary production might be caused by high SPM （low light penetration）. The results obtained from this study will provide knowledge needed for effectively developing and managing the ZRE.展开更多
基金Supported by the National Natural Science Foundation of China(Nos.41576075,41106072,41376085)the Natural Science Foundation of Shangdong Province(No.ZR2012DQ002)the Ministry of Land and Resources Program(Nos.GZH201200505,201411072)
文摘Radium （Ra） isotopes are useful for tracing water mass transport and examining estuarine hydrological dynamics. In this study, several hydrological parameters, nutrients, ehlorophyll-a （ehl-a）, suspended particulate matter （SPM） and Ra isotopes （223Ra, 224Ra and 226Ra） of surface waters of the Zhujiang （Pearl） River estuary （ZRE） were measured. This was done for both winter （December） and summer （July） seasons, to quantitatively understand the seasonal characteristics of river plume flow rate and trajectories, as well as the ecological response. The results show that Ra concentrations in summer were higher than in winter, especially Z24Ra （about 2-5 times higher）. The spatial distribution of three Ra isotopes and relative Ra water ages indicated that river water mainly flushed out of ZRE through the western side in winter, where the water transport was about 5 days faster than in the eastern zone. In summer, diluted river water expended to the east side, resulting in fairly similar water ages for both sides of the river mouth. Although nutrients were higher during the summer season, lower chl-a concentrations indicated that reduced primary production might be caused by high SPM （low light penetration）. The results obtained from this study will provide knowledge needed for effectively developing and managing the ZRE.
