大巴山区暴雨特征及其对坡地灾害地貌的影响

大巴山区坡地灾害地貌十分严重,引起坡地灾害地貌的原因主要是暴雨和连日降雨.降雨特征是:(1)暴雨出现频率高,强度大;(2)连续降雨时间长,次降雨过程的雨量大;(3)受地形影响,降雨分布的地区差异大.降雨对坡地灾害地貌的影响分三种类型:(1)突然暴雨主要引起崩塌和坡面泥石流;(2)连日降雨主要引起滑坡和特殊地段的坡面泥石流;(3)久雨后的暴雨主要引起沟谷泥石流和滑坡.

THE RAINSTORM FEATURE IN THE AREA OF DABA MOUNTAIN AND ITS EFFECT TO THE DISASTROUS LANDFORMS OF HILLSLOPE

The disastrous landform on hillslope is quite serious in the area of Daba Mountain. The principal account which it is caused is rainstorm and consecutive rainfall. The featurs of rainfall are:1. The number of times which the rainstorm falls is very high and the rainfall is very heavy!2. The period which it rains consecutively is rather long) and each rainfall is plentiful; and3. The difference of rainfall in regions is very notable because it is affected by topography.It can be divided into three types that rainfall caues effect to tlie disastrous landforms of hillslope:1. The rainstorm comes suddenly that often causes collapse from hills and debris flow from the surface of the hillslope;2. Consecutive rainfall often causes landslip and debris flow on the specific topography; and3. The debris flow in stream valley and landslip are mainly coused by the rainstorm after it has rained for a long time.