Analysis on the change law of drought and flood disaster in Jinghe basin from 1470 to 1979

Based on 50 years data,the dynamic change law of drought and flood disaster and it's driving factors were studied in west of Jilin Province.

Based on the data of drought and flood disasters in Northeast China during 1751 to 2000,the characteristics of drought and flood disasters are analyzed.

Based on the historical records in Guangdong during the history period,the series of the drought and flood disasters,the moist index and the cold index are set up in this paper and these series are analyzed by the correlative analysis,the wavelet analysis and the power spectrum analysis.

Both drought and flood are resulted from imbalance of water in the atmosphere.

In this paper, recent water environmental problems in China, water pollution, short of water resources and drought and flood,are analyzed and generalized by quoting detailed data.

This paper analyzes the drought and flood disasters from 1950 to 2001, some importment conclusions about the features and causes of the disasters as good as follows: the circle of the disasters occurs shorter and shorter, the effect of time and space isn`t balance.

The people-made facters of drought and waterlogging and the countermeasures of lightening the effect of the disaster;

The regularity of the formation of drought and waterlogging in Hengyang has been obtained according to the statistics and analyses of the climate date from 1960 to 1994.