山洪暴发。

Torrents of water rushed down the mountain.

突然的暴雨会使山洪暴发。

Sudden rainstorms would bring the mountain torrents rushing down.

暴雨引发山洪暴发，在房山拒马河洪峰流量。

Heavy rains triggered flash floods in Fangshan, Juma River flood peak discharge.

有时山洪暴发，河堤决口，给人民的生命财产造成了无法估量的损失。

Sometimes, flash floods, the river breaches, to people's lives and property caused incalculable loss.