HSPF 유역모델을 이용한 낙동강유역 실시간 수온 예측

Abstract

A watershed model was constructed using Hydrological Simulation Program Fortran to predict the water temperature at major tributaries of Nakdong River basin, Korea. Water temperature is one of the most fundamental indices used to determine the nature of an aquatic environment. Most processes of an aquatic environment such as saturation level of dissolved oxygen, the decay rate of organic matter, the growth rate of phytoplankton and zooplankton are affected by temperature. The heat flux to major reservoirs and tributaries was analyzed to simulate water temperature accurately using HSPF model. The annual mean heat flux of solar radiation was estimated to <TEX>$150{\sim}165W/m^2$</TEX>, longwave radiation to <TEX>$-48{\sim}-113W/m^2$</TEX>, evaporative heat loss to <TEX>$-39{\sim}-115W/m^2$</TEX>, sensible heat flux to <TEX>$-13{\sim}-22W/m^2$</TEX>, precipitation heat flux to <TEX>$2{\sim}4W/m^2$</TEX>, bed heat flux to <TEX>$-24{\sim}22W/m^2$</TEX> respectively. The model was calibrated at major reservoir and tributaries for a three-year period (2008 to 2010). The deviation values (Dv) of water temperature ranged from -6.0 to 3.7%, Nash-Sutcliffe efficiency(NSE) of 0.88 to 0.95, root mean square error(RMSE) of <TEX>$1.7{\sim}2.8^{\circ}C$</TEX>. The operational water temperature forecasting results presented in this study were in good agreement with measured data and had a similar accuracy with model calibration results.