摘要
汶川地震对千佛山风景区造成严重的影响,直接诱发滑坡10处,崩塌数十处,形成大小堵塞坝4座,由此形成的松散物质总量大于1 700×104m3。2008年雨季有5条支沟暴发泥石流。在泥石流成因分析的基础上,选择流域形状、流域发育程度、沟床纵比降、山坡平均坡降、地层岩性和距发震断层距离6个指标,利用潜在泥石流判识模型,对流域内其余9条支沟进行了判断。结果显示,大部分沟道都具备形成泥石流的潜在条件。2009年雨季研究区全面暴发的大规模泥石流,验证判识的可靠性,表明该模型可以用于灾区潜在泥石流的判识。
Qianfoshan scenic spot, located in northwest of Anxian County, Sichuan Province, was heavily hit by the Wenchuan Earthquake. Taking the scenic spot as study area, researches on characteristics and discrimination of debris flows following the Earthquake were conducted. Based on remote sensing interpretation and field survey, it was found out that 10 landslides and dozens of rock avalanches and 4 barrier dams were induced by the earthquake, which could provide abundant loose materials for the subsequent debris flows and totaled up to 17 million m3 in the study area. There were 14 branches in this area and most of them were still in its infancy, which favored the formation of flow concentration and surface runoff. Additionally, rainfall is abundant in the a^- ca, and therefore 5 debris flows had been occurred during the rainy season of 2008. To study the properties of the other 9 branches, on the basis of cause analysis of debris flows in this area, the watershed integrity coeffi- cient, relative cutting degree, mean channel gradient, mean mountain slope, stratum lithology and the distance of geometrical center to the fault were selected as discrimination parameters. Using these parameters, the 9 branches were discriminated by the Fisher Discrimination Model. Results showed that most branches were potential debris flow gullies. In August 2009, all branches burst out large-size debris flows in the study area, which verified effectiveness and feasibility of the model. However, this model had still room for much improvement.
出处
《地理科学》
CSCD
北大核心
2011年第12期1500-1505,共6页
Scientia Geographica Sinica
基金
中国科学院知识创新项目群(KZCX2-YW-Q03-5-2)
国家科技支撑计划课题(2009BAK56B05)
西南科技大学博士研究基金项目(10zx7129)资助
关键词
汶川地震
潜在泥石流
成因分析
判识模型
千佛山风景区
The Wenchuan Earthquake
potential debris flow
cause analysis
discrimination model
Qianfoshan scenic spot
