| This article has been：Browse 2069Times Download 3759Times |
scan it! |
|
|
| DOI：doi：10.13522/j.cnki.ggps.20180546 |
|
| Evaluating the Spatiotemporal Evolution of Drought in Guizhou Province Using the SPEI Index |
|
WANG Yingying, WANG Zhiliang, ZHANG Zezhong, LI Yanling
|
|
1.School of Water Conservancy, North China University of Water Resources and Electric Power, Zhengzhou 450045, China;2. School of Mathematics and Statistics, North China University of Water Resources and Electric Power, Zhengzhou 450045, China
|
| Abstract: |
| 【Objective】Drought could alert hydrological cycle and damage water resources management. Understanding its spatiotemporal evolution is hence essential to regional development. The purpose of this paper is to analyze the spatiotemporal change in drought in Guizhou province. 【Method】Monthly precipitation and average temperature measured from 18 meteorological stations in Guizhou province were used to calculate the standardized precipitation-evapotranspiration index from 1960 to 2012. The M-K test, B-G segmentation algorithm, extreme-point symmetric mode decomposition method and the GIS were used to analyze the spatiotemporal evolution of the drought. 【Result】The monthly, seasonal and annual SPEI all showed oscillating decrease; there is no significant difference in SPEI between summer and winter. Dry-wet alternation was consistent across the province from the 1960s to 1990s, but became inconsistent after the 21st century. Using the ESMD method, we obtained three IMF components and a R trend component, which showed an increase in drought index. The IMF1-IMF3 analysis showed that the drought had three periods: 2.1 years, 7.6 years and 26.5-year period. The B-G segmentation algorithm gave three distinctive periods: 1960 to 1986, 1987 to 2003 and 2004 to 2012. From 2004 to 2012, the northwest endured more droughts in winter, while the southwest saw more drought in spring. There were more droughts in 1987—2003 than in 2004—2012. From 1960 to 2003, the drought appeared to have shifted from southeast to northwest. 【Conclusion】Across the province, there has been an increase in droughts in both frequency and severity. |
| Key words: extreme-point symmetric mode decomposition; B-G segmentation algorithm; SPEI; drought; Guizhou |
|
|
