Author(s): Changkun Park; Jaehyeon Park; Yongsun Choi; Jeong-Seok Yang; Kyochul Jeong
Keywords: Groundwater dam; SPI; GOI; Operating scenario
Abstract: In Korea, the multi-regional water supply systems have supplied and distributed the water resources sufficiently in the national capital region or the metropolitan areas even under severe drought, but the provincial small cities such as Sockcho, Donghae, Taebaek, Samchuk etc. have been suffered from drought every 2-3 years. Those cities take emergency actions such as the excavation of riverbed, the restriction on water supply, etc. to overcome the drought. The medium- or small-scale developments of water resources, which covers 10-40 thousand m3/day, are more feasible than the large-scale developments to solve the shortage of local water resources. Groundwater dam is one of the alternatives to develop more water resources in relatively small watershed and Ssangchun groundwater dam is a good example of the medium-scale water resources development. Groundwater dam, which detains baseflow of watershed and prevent seawater intrusion, is an environmentally good alternative. In this study, we suggested an optimized groundwater dam operating scenarios through G. O. I. (Groundwater Dam Operating Index), which is a precipitation based index. We collected the basic hydrologic data in the Ssangchun watershed and the groundwater dam operation data, and we compared and analyzed the relationship between precipitation and groundwater levels in termed of both SPI by monthly precipitation and moving average index by daily precipitation. We could find that the 90 days moving average index is most correlated with the groundwater levels, and we call it G. O. I., which means the groundwater 4728 September 11~16, 2005, Seoul, Korea dam operating index. G. O. I. estimated the drought period well. We concluded G. O. I. could be useful for the determination of the operating scenarios of Ssangchun groundwater dam.