With the global warming, Ningxia Hui Autonomous Region is threatened by the drought for a long time. Therefore, the analysis on the climatic background of the drought is the premise and foundation of the countermeasures and risk management.
Based on the annual drought elements from 1978 to 2010, the monthly mean air temperature and monthly precipitation of 23 meteorological stations from 1971 to 2011 in Ningxia, the climatic background of the persistent drought was analyzed according to the spatial and temporal variation characteristics of drought and climate which were analyzed in detail by Mann-Kendall test.
The drought displayed a persistent aggravation tendency in Ningxia from 1978 to 2010. The number of victims, the disaster areas of crops and the direct economic loss increased by 28.78×104person/10a, 3.16×104hm2/10a and 8504.04×104RMB/10a, respectively.
The drought aggravation speed showed a decreasing trend from the central area to the south and the north area. The climate change in Ningxia was becoming warmer and drier. In recent 41 years, the annual mean air temperature, annual mean maximum air temperature and annual mean minimum air temperature showed a significant increasing trend, with a rate of temperature rise by 0.42℃/10a, 0.37℃/10a and 0.50℃/10a,respectively.
The climate warming was characterized by temperature rise all year, and a significant warming mutation of the annual mean air temperature and annual mean maximum air temperature occurred in the early 1990s. Precipitation in Ningxia showed a non-significant decreasing trend from 1971 to 2011. The persistent drought in Ningxia was attributed to the synthetic action of the sustained and rapid rise in air temperature and the decrease in precipitation. The significant temperature rise was the main climatic factor of the aggravated drought in Ningxia.
This research is supported by the Major Science and Research Program (2012CB955404), this paper has been published in theJournal of Desert Research, Vol. 34, No. 2.