摘要
本文以我国高频率泥石流沟为研究对象,首先与中、低频泥石流进行形成条件对比,再对三大阶梯的高频泥石流以及汶川灾区部分高频泥石流激发雨量进行了分析。结果表明:高频泥石流沟与物源量和软弱岩土体密切相关;植被覆盖度只是高频泥石流的必要条件。三大地形阶梯中,泥石流暴发时雨量随整体地势降低逐渐增加,高频泥石流受"气温+前期雨强"逐渐过渡到"前期降雨+实时降雨"以及高阈值条件。绝大部分高频率泥石流沟的10 min雨量都低于7 mm/10 min,汶川灾区的高频率泥石流雨量阈值与小江、白龙江典型高频率泥石流沟10 min雨量阈值相差不大,但前期降雨历时长,雨量也高。通过我国高、中、低不同频率泥石流的"前期雨量+10 min雨量"散点图得出我国高频率泥石流发生雨量区间。
This paper firstly analyzed the formation conditions of debris flows referring to high,medium and low frequency, then the rainfall thresholds were also compared among the debris flows in eastern,southwestern,Tibet Plateau in China,as well as the Wenchuan earthquake region. The analysis revealed that active debris flows were related closely to amount and weak properties of loose materials other than necessary vegetation cover. Totally,the real-time rainfall exhibits an increasing tendency as the height decrease from eastern Tibet plateau,to eastern parts of China. These active debris flows were triggered by＂warm climate ＋ antecedent rainfall＂in Tibet plateau,＂antecedent precipitation ＋ rainfall intensity＂and high rainfall separately. Most of the active debris flows were trigged by 10 mintuts rainfall less than 7 mm.The 10 minutes rainfall of active debris flows in Wenchuan earthquake region is similar with that in Xiaojiang and Bailongjiang Rive,while the antecedent rainfall appears to be longer and higher. Finally,we developed the rainfall threshold interval by comparing the relationship of ＂antecedent rainfall ＋ rainfall intensity＂of debris flows with varying frequency.
出处
《中国地质灾害与防治学报》
CSCD
2015年第2期43-50,共8页
The Chinese Journal of Geological Hazard and Control
基金
国家科技支撑项目(2012BAK10B04)
北京林业大学新教师科研启动项目(20141054)
关键词
高频率泥石流
小江
汶川灾区
雨量
预警方法
active debris flow
Xiaojiang river
Wenchuan region
rainfall threshold
forecasting method
