충청북도 초강 유역의 관측자료를 바탕으로 한 유출특성분석 = Analysis of Runoff Characteristics with Measured Hydrological Data at Chogang, Chungbuk

다국어 초록 (Multilingual Abstract)

There is increasing risks in water-resources management in South Korea due to large-scale floods and droughts in recent years. A detailed analysis of water budget in catchment scale is required.
Hydrological data including precipitation, stream flow, and evapotranpiration, are highly valuable and crucial for water resource studies. Chogang catchment in Chungbuk is important because evapotranspiration data have been measured at the Yuelli site in the catchment since 2019. This study analyzed the water balance and flow duration curve with measured hydrological data in the period of 2019-2021. The water balance analysis shows the potential of period analysis in the flood season (June-September) and non-flood season (October-May). The runoff ratio (runoff/rainfall) was 0.53, 0.56, and 0.43 in a year, in the flood season, and in the non-flood season, respectively. A runoff ratio of 0.42 should be applied for water resource management in the Chogang. This is smaller than South Korea's general runoff ratio of 0.6. The ratio of the observed empirical emission (AET) to potential evapotranspiration (PET) differed between the non-flood period (0.63, 0.75, 0.79, and 0.72) and the flood season (1.25, 1.29, 1.49, and 0.72), indicating that AET is greater than PET in summer due to sufficient water supply and active plant growth. The coefficients for actual and potential evapotranspiration were 1.2 and 0.7 for the flood period and non-flood period, respectively. In the future, reliable runoff characteristics of mountainous basins in Chungcheongbuk-do will be suggested based on the accumulation of hydrological observation data within the basin.