인공강수가 지표수의 유기물과 부유물질 농도변화에 미치는 영향평가

초록

This study evaluates the long-term water quality responses to wintertime cloud seeding experiments conducted near the Odaecheon-1 stream site in Pyeongchang, Korea, from 1997 to 2023. The site, located approximately 17 km downstream of the Cloud Physics Observation Center (CPOS), was selected due to its minimal anthropogenic pollution and close proximity to the seeding activities. Ground-based cloud seeding using AgI and CaCl₂ has been carried out annually at CPOS during the winter season since 2006, with aircraft-based operations introduced around 2018. Water quality parameters—including water temperature, dissolved oxygen (DO), biochemical oxygen demand (BOD), chemical oxygen demand (COD), total organic carbon (TOC), and suspended solids (SS)—were analyzed for March (the post-seeding thaw period) and October (a non-seeding reference period). Statistical analyses included time series trends, Welch’s t-tests, and Pearson correlation analysis. Results revealed significant seasonal differences in water temperature and DO (p < 0.05), with March showing lower temperatures and higher DO levels, likely due to meltwater input and winter mixing conditions. Organic matter indicators (BOD, COD, TOC) showed no statistically significant seasonal variation; however, elevated outliers in March—particularly in 2018 and 2021—suggest episodic inputs potentially linked to seeding-induced snowfall and subsequent runoff. Strong correlations among TOC, COD, and SS in March indicate a predominance of particulate organic matter, while weaker correlations in October reflect more heterogeneous and possibly dissolved sources. These findings suggest that while cloud seeding may not significantly alter the mean concentrations of organic pollutants, it can indirectly influence water quality dynamics by enhancing particulate transport during melt periods.

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