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大(暴)雨可能引发的泥石流等地质灾害,是宝天高速公路西段安全运行的最大威胁.根据宝天高速公路西段1965-2008年麦积国家基本气象站、街子气象哨降水资料及1980-2008年天水农业气象试验站历年土壤水分含量观测资料,分析了宝天高速公路沿线降水、大(暴)雨及土壤含水量分布规律,建立了大(暴)雨引发泥石流可能发生的危险性的评价模式.结果表明:天宝高速公路西段是地质灾害高危险区,也是天水市地区的大(暴)雨中心.自20世纪60年代以来,宝天高速公路段的年降水呈20 a周期变化,大(暴)雨出现次数与年降水量距平百分率呈正相关.大(暴)雨的出现具有明显的季节性,在大(暴)雨出现的4-10月,100 cm土层土壤最大水分容纳量为86~172 mm,40 cm土层为41~69 mm.大(暴)雨引发泥石流的危险性7月最高,4月最低.7-10月泥石流发生的危险程度高于4-6月,主汛期是该线路段泥石流等地质灾害的重点防御时段.
According to Baotian Expressway west section of Maotong National Meteorological Station 1965-2008, street sub-meteorological whistle precipitation data And the observation data of soil moisture content of Tianshui Agricultural Meteorological Experimental Station from 1980 to 2008 in the past years, the distribution of precipitation, heavy rain and soil moisture along BaoTian Expressway were analyzed, and the possible causes of debris flow induced by heavy rainstorm Risk assessment model.The results show that the western section of Tianbao Expressway is a high risk area of geological disasters and also a large (storm) rain center in Tianshui area.The annual precipitation of Baotian Expressway has been around 20% since the 1960s a period change, the occurrence of heavy rain was positively correlated with the percentage of annual precipitation anomaly.The occurrence of heavy rain was obviously seasonal, and in the period from April to October when the heavy rain appeared, 100 cm soil The maximum soil water holding capacity was 86-172 mm, while the soil depth in 40 cm ranged from 41-69 mm. The risk of debris flow induced by large (storm) rainfall was highest in July and lowest in April. The risk of debris flow from July to October was high From April to June, the main flood season is such geological formations as debris flow Injury time focused on defense.