Fast vertical movement of groundwater at the borehole in volcanic confined aquifer detected from point-dilution test with multi-level observations

HR: 0800h
AN: H41E-0834 [Abstracts]
TI: Fast vertical movement of groundwater at the borehole in volcanic confined aquifer detected from point-dilution test with multi-level observations
AU: * Kim, Y
EM: yckim@kigam.re.kr
AF: Korea institute of geoscience and mineral resources, 30 Gajeong-dong, Yuseong-gu, daejeon, - 305-350, Korea, Republic of
AU: Han, B
EM: gagi99@kis.kigam.re.kr
AF: Korea institute of geoscience and mineral resources, 30 Gajeong-dong, Yuseong-gu, daejeon, - 305-350, Korea, Republic of
AU: Kim, k
EM: kykim@kigam.re.kr
AF: Korea institute of geoscience and mineral resources, 30 Gajeong-dong, Yuseong-gu, daejeon, - 305-350, Korea, Republic of
AU: Koh, K
EM: lavakoh@hanmail.net
AF: Jeju water resource management center, 2778-30 Daeheul1-ri, jocheon-eup, jeju-si, jej 695-811, Korea, Republic of
AU: Park, K
EM: pkh@kigam.re.kr
AF: Korea institute of geoscience and mineral resources, 30 Gajeong-dong, Yuseong-gu, daejeon, - 305-350, Korea, Republic of
AB: A point-dilution tracer test was performed at a Seokwang well field, one of the pulbic water supply system for southwestern part of Jeju island, South Korea. Seokwang well field is located at the elevation of about 180 m above mean sea level with gentle tilted surface topography to southwest direction. Based on the geological columnar section of supply well no. 3, Seokwang well field area is consisted of Basalt, tuff, clinker, and soil layer. various types of basalt such as trachy basalt, feldspar augite basalt, feldspar basalt and soil layers occurred overlapping each other and clinker zone act as permeable aquifer whereas tuff act as impermeable confining layer. 20 cubic meter's tracer solution as NaCl is injected through pipe at the depth of 170 m below top of the casing using pump and the EC breakthroughs at 18 different depths in the borehole BH3 are monitored using 5 CTD Divers and 13 series of EC sensors. The injected tracer solution transported vertically upward from the injection depth with slight downward movement of about 1 meter from the mouth of the injection pipe due to the force of inertia and gravity. The estimated vertical velocity of groundwater is 1.33 x 10^-² m/s (\ 0.424 L/s )\) , which was too fast to be detected by borehole logging using heat pulse type flowmeter.
DE: 1828 Groundwater hydraulics
DE: 1829 Groundwater hydrology
DE: 1832 Groundwater transport
DE: 1835 Hydrogeophysics
DE: 1895 Instruments and techniques: monitoring
SC: Hydrology [H]
MN: 2007 Fall Meeting