Prolonged duration and increased severity of agricultural droughts during 1978 to 2016 detected by ESA CCI SM in the humid Yunnan Province, Southwest China

Abstract

Droughts in humid regions may have more severe consequences owing to a lack of drought-resistant measures and awareness. The Yunnan Province, in the humid southwestern part of China, experienced an extreme drought from 2009 to 2010. However, few studies have systematically explored agricultural droughts in this region. Based on revised global multi-source microwave-based SM products, the European Space Agency's Climate Change Initiative Soil Moisture (ESA CCI SM) data, the 10-day-scale soil moisture (SM) series was constructed and applied to detect droughts and analyze changes in drought characteristics, including duration, area, frequency, intensity, and severity. The results suggest that the intensity of agricultural drought in the Yunnan Province decreased, while the drought frequency increased. Drought duration increased by 20 days, collectively leading to a significant increase in drought severity in the last decade. Qujing in the east was most sensitive to agricultural drought, followed by Kunming and Chuxiong in the central area. The southwest region was prone to long drought and maintained an upward trend in terms of drought area. Regional SM with complicated temporal-spatial change patterns cannot be attributed to a single trend of “dry to dryer, wet to wetter”. This study may provide insights into drought analysis in other humid regions.