남강 상류 유역 시설하우스 유출수의 하천 오염기여도 평가

Abstract

This study was done to address the effect of greenhouse cultivation effluents on river waters in the Upper Nam River Basin. We measured flow rate and six water quality parameters at the final outlet of the greenhouse cultivation during eight rainfall events randomly occurred between October 2019 and April 2021 which were provided as input to a popular watershed modeling tool SWAT. The years 2012-2014, 2015-2016, and 2017-2018 were set as the warm-up, calibration and validation periods, respectively. Our findings showed that a good model performance was achieved for discharge prediction reaching minimum R2 values of 0.65, which was followed by sediments, NO3, ORGP, and BOD. Annual pollutant loads estimated from the monitoring data were slightly lower than the land-based (unit) pollutant loads. Accordingly, the pollutant load contributions to receiving waters were underestimated by 6.35% (for BOD), 1.86% (for T-N), and 3.09% (for T-P). In addition, pollutant movement, described as the delivery ratio of pollutant loads, varied largely across 18 river segments for BOD and but to only a small extent for T-N and T-P. This calls for more sophisticated monitoring and modeling efforts to develop customized water management strategies along the river segments.