HR: 0800h
AN: H11C-0650    [Abstracts]
TI: The seasonal variation for the discharge and water quality of a stream in volcanic island, Korea
AU: * Ha, K
EM: hasife@kigam.re.kr
AF: Korea Institute of Geoscience and Mineral Resources, 30 Gajeong-dong Yuseong-gu, Daejeon, 305-350, Korea, Republic of
AU: Moon, D
EM: waterfeel@naver.com
AF: Water Resources Headquarter, Jeju Provincial Government, 2778-30 Daeheul-ri Jocheon- eup, Jeju, 690-962, Korea, Republic of
AU: Park, K
EM: khpark@kigam.re.kr
AF: Korea Institute of Geoscience and Mineral Resources, 30 Gajeong-dong Yuseong-gu, Daejeon, 305-350, Korea, Republic of
AB: Assessment of the groundwater resources in a volcanic island is so difficult, because permeable and impermeable layers were formed from lava flows in different times and various lithologies. Jeju island is the largest volcanic island in Korea, and is composed of plateau and shield forming basaltic to trachytic lava flows, numerous tuff rings/cones, scoria cones during its long volcanic history (about 1.8 Ma). Most of streams in Jeju island are dry in normal times. Owing to high permeable geologic features such as clinkers, stream run-off occurs when precipitation is over 40 mm/day. To understand runoff phenomena in Jeju island, some streams are monitored automatically about stream stage, and water quality. Oedocheon (cheon means stream) is monitored during the normal and runoff period. Oedocheon is a permanent stream in Jeju island, and its water quantity and quality is originated by a spring water from lava flow boundaries. The surface limit and watershed parameters for the Oedocheon watershed were created and calculated by WMS software. Stream stages respond very quick during the runoff time, but the duration of the runoff is so short about a few hours. Parameters such as landuse, soil condition, preconditioned rainfall, and vegetables influence runoff phenomena. Periodic stream discharge measurements and chemical analyses of the water were preformed in order to analyze the seasonal variation of the stream water quantity and quality in normal times. Considering water intake quantities, ordinary stream discharge is 2,569~50,415 m3/day, average 21,215m3/day. Water qualities are dependent on each measurement season. Electrical conductivity is 101.7-202.0 ¥ìS/cm, pH is 7.38-8.38, and water temperature is 10.8-23.3¡É. Major ion concentrations also varies seasonally. Mg is 2.39-7.45 mg/l, Ca is 4.11-11.54 mg/l, Na is 4.80-13.24 mg/l, K is 1.64-3.47 mg/l, SO4 is 2.78-8.25 mg/l, HCO3 is 17.78-36.61 mg/l, and Cl is 6.43-22.77 mg/l. The stream discharge and water quality are so correlated with rainfall. The analyses of the responses to the rainfall in each season can be used to estimate the size of the underground groundwater watershed.
DE: 1804 Catchment
DE: 1829 Groundwater hydrology
DE: 1831 Groundwater quality
DE: 1836 Hydrological cycles and budgets (1218, 1655)
DE: 1860 Streamflow
SC: Hydrology [H]
MN: 2007 Fall Meeting