降雨因子对湖北省山地灾害影响的分析

Analysis of influence of rainfall factors on mountain floods and geological disasters in Hubei Province

根据湖北省1950～2003年726个山洪地质灾害样本,分析了其时空分布特征。滑动t-检验显示,逐年灾害数在1974年、1988年前后出现两次显著性突变增多(其中山洪、滑坡增多最明显),逐年降雨量也相应有两次增加,二者相关系数可达0.3。表明我省年降雨量趋势性增加是灾害增多的主要诱因。进一步分析表明,暴雨以上强降雨是山洪、滑坡、泥石流、塌陷的主要诱因,连阴雨是崩塌的主要诱因,同时对滑坡、泥石流、塌陷有重要影响,对山洪灾害影响则较小。

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 modntain floods.