Resources Science ›› 2019, Vol. 41 ›› Issue (11): 2144-2153.doi: 10.18402/resci.2019.11.16

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Relationship between drought/flood and ENSO events in Southwest China

LIU Lin1,2, XU Zongxue2,3(), YANG Xiaojing2,3   

  1. 1. College of Civil and Architectural Engineering, North China University of Science and Technology, Tangshan 063210, China
    2. College of Water Sciences, Beijing Normal University, Beijing 100875, China
    3. Beijing Key Laboratory of Urban Hydrological Cycle and Sponge City Technology, Beijing 100875, China
  • Received:2017-10-08 Revised:2019-08-09 Online:2019-11-25 Published:2019-12-03
  • Contact: XU Zongxue E-mail:zxxu@bnu.edu.cn

Abstract:

Under the background of climate change, drought and flood occur frequently in Southwest China, and El Nino and Southern Oscillation (ENSO) is an important indicator of climate change. Based on the data of sea surface temperature anomaly (SSTA), Southern Oscillation Index (SOI), precipitation, and temperature during 1960-2016 in Southwest China, the correlation between ENSO events and precipitation, temperature, and drought/flood index was analyzed by using wavelet analysis and mathematical statistics. The results show that: (1) The ENSO events have quasi-periodic changes of about 9 a, 24 a, and 3~4 a. (2) There is a significant correlation between precipitation and ENSO event intensity, and temperature is also obviously correlated with ENSO event intensity, both with a certain lag of time. In the EI Nino event years, the precipitation and temperature in Southwest China are negatively correlated with SSTA with a lag of 2~4 months. In the La Nina event years, the precipitation and temperature in Southwest China are significantly positively correlated with SSTA with a lag of 2~4 months. The correlation between temperature and ENSO events is more obvious. (3) There was a negative correlation between the ENSO intensity and drought/flood grade. When the EI Nino event intensity increased, the number of drought events in the southwest region increased, and when the intensity of La Nina events increased, the number of flood events in the southwest region increased. The drought/flood index of Standardized Precipitation Index (SPI) and SOI also showed a very significant negative correlation, and the impact of ENSO on drought and flood had a lag of 1~4 months, with the greatest impact at 3 months lag. Therefore, drought and flood disasters are likely to occur in strong ENSO event years or the following year in the southwest region. This study may provide some reference for enhancing the vigilance against droughts/floods and strengthen flood control and drought relief work in Southwest China.

Key words: ENSO events, period, correlation, precipitation, temperature, drought/flood, Southwest China