The paper analyzes the variations of Tongguan elevation in peach flood season related with the operational water level of Sanmenxia Reservoir,peach flood regime and antecedent channel condition based on the observed data since 1974 and points out that the conditions for reducing about 0.

Influence of spring flood on Tongguan Elevation;

The variation of flood peak discharge and maximum 10 days flood discharge of spring flood before and after the operation of Wanjiazhai reservoir is analyzed.

Optimizing process of spring flood in 2008 was discussed.

Using fuzzy set analysis method to make a division for Diaoyutai Reservoir s flood season;

The research on the flood peak flow forecast of Jiaokou head work in flood season;

Operation manner researches of water storage of Baibengzhu Reservoir during flood season concerned flood forecast and flood pre discharge;

Analysis and forecast of water regime trend in 2007 flood period of Liaoning province;

Study on utilization of water resources during flood period in Taizihe river basin;

Analysis of water regime during flood period of 2001 year in Songliao rivers basin;

Based on the daily precipitation data of 52 stations in the Lower Reaches of the Yangtze River in 1960～2003,the statistical characteristic of precipitation due to rainstorm during the rainy season of the region were studied.

Based on Grey system theory integrated with Markov state analysis,the model for forecasting rainfallduring rainy season in Northern Zhejiang was developed.

Semi-objective analysis method designed by Samel et al,Mann-Kendall test method and moving t-test technique are used based on the understanding of rainy season in order to investigate the beginning and end dates of rainy season over North China.