The changing pattern of droughts in the Lancang River Basin during 1960–2005

• Published in: Theoretical and applied climatology 2013-02, Vol.111 (3-4), p.401-415
• Main Authors: Li, Bin, Su, Hongbo, Chen, Fang, Li, Shenggong, Tian, Jing, Qin, Yuchu, Zhang, Renhua, Chen, Shaohui, Yang, Yongming, Rong, Yuan
• Format: Article
• Language: English
• Subjects: Analysis; Aquatic Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; Atmospheric Sciences; Climate science; Climatology; Drought; Drought index; Droughts; Earth and Environmental Science; Earth Sciences; Earth, ocean, space; Engineering and environment geology. Geothermics; Exact sciences and technology; External geophysics; Freshwater; Meteorology; Natural disasters; Natural hazards: prediction, damages, etc; Original Paper; Principal components analysis; Rain and rainfall; River basins; Rivers; Standardized precipitation index; Waste Water Technology; Water in the atmosphere (humidity, clouds, evaporation, precipitation); Water Management; Water Pollution Control; Wavelet transforms
• ISSN: 0177-798X; 1434-4483
• DOI: 10.1007/s00704-012-0658-2

Drought is one of the most costly natural disasters in the world. Understanding the drought characteristics in space and time will help deepen our apprehension of the drought formation and evolution mechanisms. It can also contribute to design monitoring system for drought warning and mitigation. In this study, we analyzed meteorological droughts, using the Standardized Precipitation Index, for Lancang River Basin, Southwest China. The 46-year (1960–2005) daily precipitation observations from 35 meteorological stations in the basin were used to derive the drought index. Spatial patterns and temporal patterns of the drought characteristics at multiple scales were investigated. The results utilizing the Principal Component Analysis and K -means clustering methods suggest that the study area can be divided into four sub-regions geographically with each sub-region having its own distinctive temporal evolution patterns of droughts. The temporal variability of droughts was investigated using the Empirical Mode Decomposition (EMD) analysis and the wavelet method. The EMD analysis showed that more than 60 % of the variance of the drought is associated with intra-decadal fluctuations in precipitation, except for one sub region, represented by the Changdu station. The wavelet transform showed an evolution of the main cycle near 3–7 years for most parts of the study area.