四川泥石流灾害分区及其与诱发降水关系

Zoning of Debris Flow Hazards in Sichuan Province and Their Relationship with Inducing Precipitation

基于四川省1990-2009年泥石流灾害记录资料、常规气象站降水资料和地理信息资料,统计分析了四川泥石流灾害与地形、植被、地质等环境因子关系,在此基础上,对泥石流灾害进行了分区,分析了各区泥石流灾害与诱发降水关系.结果表明,四川泥石流灾害可划分为川西高原河谷区、西南山地易发区、西南山地次易发区、盆周山地易发区、盆周山地次易发区、盆中区等6个环境背景相异区;各区泥石流灾害与诱发降水关系差异较大,川西高原河谷区较小短历时雨强就可诱发泥石流灾害,而盆周山地次易发区对前期降水作用依赖性相对偏高.

Based on the records of debris flow hazards during 1990-2009,the precipitation data recorded at conventional meteorological stations and the geographic information data in Sichuan Province,the relationship between debris flow hazards and environmental factors such as topography,vegetation and geology was analyzed.Based on the results of this analysis,debris flow hazards in the province were zoned,and the relationship between the debris flow hazards in various zones and the inducing precipitation was studied.As a result,six zones were divided with different environmental backgrounds,namely the valley zone of the western Sichuan Plateau,the southwestern mountainous debris-prone zone,the southwestern mountainous debris-prone subzone,the debris-prone zone of the mountainous areas surrounding the Sichuan Basin,the debris-prone subzone of the mountainous areas surrounding the Sichuan Basin,and the central basin zone.These zones vary substantially in the relationship between debris flow hazards and inducing precipitation.A little short-duration rain intensity is enough to induce debris flow disasters in the valley zone of the western Sichuan Plateau,and a greater impact of the antecedent precipitation is needed in the debris-prone subzone of the mountainous areas surrounding the Sichuan Basin.