Study on the variation characteristics of rainstorm and flood in Puyang River Basin

Based on the measured rainfall and runoff data of 6 hydrological stations in the Puyang River Basin for many years, the trend of rainfall and runoff series are analyzed by using the methods of the regression analysis and the Mann-Kendall test in Puyang River Basin. The main conclusions are as follows: The trend analysis results show that the annual maximum 1-hour, 3-hour and 24-hour rainfall series in the Puyang River Basin is basically on the rise, but the flood and runoff series show a downward trend. It reflects that the main reason for the decrease of runoff in the Puyang River Basin is not the climate change. It is likely to be related to the impact of human activities. In summary, under the influence of climate change and human activities, human activities are the main reason for the decrease of runoff in the Puyang River Basin.