The researchers wanted to see how snowmelt affects long-term river flows in a mountainous area in Korea. They used a snowmelt model along with a rainfall-runoff model on a specific river basin. The model accurately predicted the area covered by snow and matched actual snowfall data. They found that including the snowmelt model caused differences in soil water levels and river flows compared to when it was not considered. This suggests that considering snowmelt is crucial for accurately predicting river flows over several decades in this area.