Distinct Propagation to Agricultural Drought Between Two Severe Meteorological Droughts in the Korean Peninsula

Abstract

Distinct responses in the soil moisture (SM) between the two most severe meteorological droughts in Korea are examined. Although total accumulated precipitation deficit during 1994–1996 drought was slightly less than in the 2013–2017 drought, 1994–1996 drought showed a record-breaking negative SM anomalies, while the accumulated negative SM anomalies during 2013–2017 were less than half of those in 1994–1996. In 1994–1996 case, robust precipitation deficits occurred early in the event, leading to subsequent precipitation shortages under dry conditions. In addition, precipitation deficit was observed not only during wet seasons but also throughout dry seasons. This amplifies the SM response, as the runoff volume remains relatively constant despite reduced precipitation in arid soil conditions, which eventually reduces soil water retention led by the precipitation deficit. Conversely, in 2013–2017 case, precipitation deficit occurred during later period of the event and wet seasons, which leads a moderate SM drying signals.