Responses of Drought with Different Time Scalese to the ENSO Events in the Yellow River Basin
Received date: 2014-03-24
Revised date: 2014-06-23
Online published: 2015-05-20
Drought disaster, one of the main natural disasters in China, impacts the people's lives and social production to different extends. Taking the Yellow River Basin as study area, standardized precipitation evapotranspiration index (SPEI) at different time scales were calculated using monthly temperature and precipitation data during 1963-2012. Temporal-spatial correlations between SPEI and the Nino 3.4 sea surface temperature anomaly (SSTA) of the different time scales reveal the response of drought (SPEI) to the ENSO at different time scales and the impacts of ENSO to regional precipitation and temperature in the Yellow River Basin. (1) Droughts of 1, 3, 6 months' time scales in the Yellow River Basin occurred in each time segment. Droughts of 12, 24 months' time scales mainly occurred in late twentieth century and early twenty-first century in recent 20years. There is a negative correlation between SPEI at different time scales and SSTA in the upper and middle reaches of the Yellow River Basin, while positive correlation in lower reaches. (2) Correlations between SPEI at different time scales and SSTA show large spatial heterogeneity in the Yellow River Basin. Positive correlation mainly is distributed in the upper reaches of the Yellow River Basin, Ningxia, Inner Mongolia, Shaanxi and Northern Shanxi, and the lower reaches of the Yellow River Basin, and the rest are negative correlation. The significant (at significant level of 0.05) proportions of the whole basin at 1, 3, 6, 12 months and 24 months' time scales were 14%, 43%, 61%, 75% and 44% respectively. (3) The weak correlation of ENSO event intensity and precipitation occurred in the upper reaches of the Yellow River, and there was a remarkable negative correlation in the middle and lower reaches. It indicated that the enhanced ENSO would reduce the precipitation and vice versa. Temperature showed a significant positive correlation with ENSO, and the enhanced ENSO would raise the temperature. The El Ni o would raise the temperature, and the La Ni a would reduce the temperature.
Key words: Yellow River Basin; multi-time scale; drought; ENSO; correlation analysis
Zhou Dan , Zhang Bo , An Meiling , Zhang Yaozong , Luo Jing . Responses of Drought with Different Time Scalese to the ENSO Events in the Yellow River Basin[J]. Journal of Desert Research, 2015 , 35(3) : 753 -762 . DOI: 10.7522/j.issn.1000-694X.2014.00068
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