论文部分内容阅读
The middle reaches of the Yangtze River are the worst flood area of the whole basin. To study the variation regulation of the fl oods in this area over a long historical period assure improvement in prediction s of floods in the region. The trend of flood occurred frequency has close relat ionship with human activities near the river. By using statistics analysis, the fluctuations for the time series of floods since 1525 are studied. The results show that the main cycle of flood variation can be identified obviously the per iod of 2, 8 and 40 years with exceeding the level of confidence 0.03.
To study the variation regulation of the fl oods in this area over a long historical period assure improvement in prediction s of floods in the region. The trend of _9 By using statistics analysis, the fluctuations for the time series of floods since 1525 are studied. The results show that the main cycle of flood variation can be identified obviously the per iod of 2, 8 and 40 years with exceeding the level of confidence 0.03.