HR: 0800h
AN: H31D-0414    [Abstracts]
TI: Investigation of water movement in the unsaturated zones using oxygen and hydrogen isotopes
AU: * lee, K
EM: kslee@kbsi.re.kr
AF: Korea Basic Science Institute, 52 Eoeun-dong, Yusung-gu, Daejeon, 305-333 Korea, Republic of
AU: Lee, D
AF: Korea Agricultural & Rural Infrastucture Corporation, 2127-1, Samyang-dong, Jeju-do, Jeju, 690-072 Korea, Republic of
AU: Kim, Y
AF: Korea Institute of Geoscience and Mineral resources, 30, Gajeong-dong, Yusung-gu, Daejeon, 305-350 Korea, Republic of
AU: Park, W
AF: Jeju Development Institute, 390, 2do-2dong, Jeju-do, Jeju, 690-022 Korea, Republic of
AU: Ko, K
AF: Korea Institute of Geoscience and Mineral resources, 30, Gajeong-dong, Yusung-gu, Daejeon, 305-350 Korea, Republic of
AB: In other to investigate movements of water through unsaturated soil zones of temperate climates, 17 lysimeters were installed at a test site of a volcanic island, Korea and oxygen and hydrogen isotopic compositions of soil waters were monitored for one year period. For comparison of isotopic compositions, monthly composite precipitations were also collected during the study period. No or little evaporation was observed in the soil waters. This indicates that transpiration is much more important than evaporation in hydrologic budget of the island. Oxygen and hydrogen isotopic compositions of soil waters showed a seasonal variation, indicating that the isotopic compositions of soil water directly reflected those of precipitation. A seasonal change for soil waters of 30 cm depth was faster than that for soil waters of 60-80 cm depth. Overall, dampening of variation of isotopic composition was pronounced with increasing depth. Comparing deuterium excess values of precipitations and soil waters, transit time of about 2 months was estimated for infiltration of water through the soil layer to depths of 30 cm. For the soil layer of to depths of 60-80 cm, transit time of about 4-5 months was estimated. The isotopic compositions of soil waters plotted between the local meteoric water line of dry season precipitation and that of rainy season precipitation, indicating that soil waters were recharged from the whole season precipitations in the study area. This relationship may provide a useful means of evaluation or seasonality of groundwater recharge.
DE: 1800 HYDROLOGY
DE: 1818 Evapotranspiration
DE: 1854 Precipitation (3354)
DE: 1866 Soil moisture
DE: 1875 Unsaturated zone
SC: Hydrology [H]
MN: 2004 AGU Fall Meeting