Character And Cause Of Flash Flood In The Upper Reaches Of Min River After Wenchuan Earthquake

Based on multi-years runoff and rainfall data of 15 hydrological stations in the upper reaches of Minjiang River, the relationship among rainfall, runoff and flash flood of the basin is analyzed. Citing the cases of "8.13" and "8.18" flash floods, the development characters and key factors of the flash flood after the Wenchuan earthquake are explored. The results show that: OThe post-seismic floods develop in the earthquake rupture zone with high frequency. The post-seismic rainfall is the trigger factor of the development of devastating floods. The post-seismic flood has the character of high sediment concentration, abruptness and severe damage;)After the earthquake, critical rainfall of floods in the watershed reduces significantly, and the flood flow amount and frequency increases.