陕南秦巴山区地质灾害与影响因素的相关性分析

陕南秦巴山区受气象水文、地形地貌、地质构造、地层岩性及人类工程活动等因素的影响,地质灾害频繁发生。对陕南28个县(区)的县域地质灾害区划资料进行统计分析,深入探讨陕南秦巴山区地质灾害分布规律及其与各因素的相关性,得出结论:地质灾害沿主要河流、断裂、交通干道两侧一定范围内呈"带状"分布;地质灾害集中发育于年平均降雨量小于1 000mm的区域,灾害点密度随年平均降雨量的增大而减小,年平均降雨量小于800mm的区域灾害点密度最大;多数滑坡主要发生倾角范围在为20°~40°范围内;崩塌主要发生在多数崩塌倾角范围为40°~60°范围内;地质灾害集中发育于中低山区;地质灾害集中分布在泥盆系和元古宇地层岩性区;断裂的规模越大,对其两侧地质灾害发育的影响也越大,深大断裂凤镇-山阳断裂带灾害点密度最大;宝成铁路两侧1km范围内灾害点密度最大。分析结论为陕南移民搬迁提供可靠的地质灾害防治依据。

Correlation analysis between geological hazards and impact factors in Qinling2Daba mountains of south Shaanxi Province

Due t o the impact factor s such as climate, hydrolog y, geomorpholog y, geolog ical str ucture, lit ho lo gy , and human activ i2 ties, g eolog ical hazards occur often in Qinling2Daba mo untain a rea. St atistical analysis was per formed o n the geo lo gical hazar d reg ionalization in 28 co unties o r distr icts of south Shaanx i Pro vince, and the distr ibut ion r egular ities of g eolog ical hazards and the relationship betw een geo log ical haza rds and impact factor s w ere inv est igated. T he results show ed that( 1) the g eolo gical haz2 ar ds show banding distributio n along bo th sides of main r iver s, fractures, and ro ads; ( 2) the g eolog ical hazards occur mostly in the ar ea with an aver age annual rainfall less than 1000 mm. The hazar d density decr eases w ith the incr easing of aver age annual rainfall, and the hazard densit y is the g reatest in the a rea w ith an averag e annual rainfall less than 800 mm; ( 3) mo st of the land2 slides o ccur in the slo pes wit h an angle betw een 20 to 40b; ( 4) most of the collapse occur in the slopes w ith an angle between 40 to 60b; ( 5) the g eolo gica l hazards ar e mainly located in the middle and low er mo untain area, and in the litholog ic units o f Devo ni2 an and Proter ozoic eonot hem; ( 6) the effects of fr act ur e on t he g eolo gica l hazar ds on its sides enhance with t he increasing scale of fracture; and( 7) t he haza rd density is t he g reatest in the Feng zhen2Shanyang deep f racture and the area within 1 km to the Baoji2Cheng du r ailw ay. The research results can pro vide scientif ic and r eliable basis fo r the g eolog ical disaster pr evention in mi2 g rat ion relocatio n.