Based on 726 cases of mountain floods and geological disasters from 1950 to 2003 in Hubei Province

their temporal and spatial distribution properties are analyzed first; then two abrupt increasing points(1974

1988) of the annual numbers of cases are checked out by moving t-test method (the mountain floods and slope-slip most remarkably)

and annual rainfall also suddenly increased at these two years

and their correlative coefficient is 0.3

which means rainfall is the main natural forcing factors to mountain floods and geological disasters; further analysis shows that severe rainfall above rainstorm is the main leading factors to mountain floods

slope-slip

debris flows

landslide; and lasting rain is the main leading factors to subsiding and also has important impact on slope-slip

debris flows

landslide

but the least impact to mountain floods.