工程地质学报2012，Vol.20Issue(2)：195-203,9.
震后都汶公路沿线泥石流沟堵江危险性评估
ASSESSMENT OF RIVER BLOCK PROBABILITY BY DEBRIS FLOW ALONG DUJIANGYAN-WENCHUAN HIGHWAY AFTER WENCHUAN EARTHQUAKE
摘要
Abstract
The total amount of the loose masses due to collapses and landslides by Wenchuan Earthquake reached about 28 ×108m3. The loose masses can provide abundant materials for debris flows for long term. The critical rainfall has decreased significantly. The debris flow events have occurred at high frequency and in group. Their discharges have increased. Blocking of main rivers by debris flows have occurred more frequently post the earthquake and led serious secondary disasters in the quake-hit areas. In order to evaluate the probability of blocking river by debris flow, the basic data of debris flow gullies are obtained on the basis of field investigation and scale in different precipitation frequency according to a hydrological model. Then based on the above data and the differentiation formula of debris flow blocking river,this paper assesses the degree of debris flow blocking main river of the study area. It then defines the threshold value of the differentiation formula combined with debris flows that have occurred in the study area and blocked rivers. As a result.it can be used to determine the probability of debris blocking river more accurately. Seven debris flow gullies of the study area are evaluated at different precipitation frequencies. The results show that the debris flow of Niumian gully and Guanshan gully can block the Minjing river under the 50 years return period precipitation. The debris flow of Shaofang gully ,Hongchun Gully and Mozi gully can block the Minjing river under the 10 years return period precipitation. The debris flow of Er gully and Taiping gully can block the Minjing river under the 5 years return period precipitation. The assessment result agrees with the phenomena of field investigation and can provide scientific supports for the prevention, elusion and mitigation of debris flow hazards and reconstruction project in the earthquake area.关键词
泥石流堵江/临界值/泥石流/危险性评估/都汶公路Key words
Block river/Critical value/Debris flow/Hazard assessment/Minjiang/Dujiangyan-Wenchuan highway分类
天文与地球科学引用本文复制引用
庄建琦,葛永刚,陈兴长..震后都汶公路沿线泥石流沟堵江危险性评估[J].工程地质学报,2012,20(2):195-203,9.基金项目
国家重点基础研究(973)项目(2011CB409902),国家自然科学重点基金(41030742). （973）
