【摘要】 滑塌是一种复合地质灾害,它改变地貌形态,并引起诸多环境效应。以陕北子洲县庞家沟黄土洼流域内的古滑塌体为研究对象,采用文献记载、野外调查、剖面分析等方法,对古滑塌体的形成原因、形态特征及其环境效应进行了分析。结果表明:黄土洼古滑塌体形成于1569年8月,是地震的次生灾害;古滑塌阻塞沟道,产生了侵蚀堆积地貌和堆积侵蚀地貌,塑造了平川地形,减轻了侵蚀强度;黄土洼天然坝淤地、后小滩沟和大嘴沟中,泥沙淤积后的沉积物中洪水旋回层具有"二元结构",其中"细淤泥层"对洪水具有指示作用;黄土洼天然坝淤地经过了440多年的淤积,其泥沙淤积最深厚度可达50 m,有效的阻止了水土流失,产生了积极的环境效应。研究结果为黄土洼古滑塌体的综合治理、天然坝系的保护和反演黄土高原近500年来沉积环境提供科学依据。更多还原

【Abstract】 Slump is a compound geological disaster.It can change the topography and cause multiple environmental effects.Taking the palaeo-slump of Huangtuwa watershed in Pangjiagou,Zizhou County of Shanxi Province,China as the study object,applying the methods of literature review,field survey and cross-section analysis,the causes,morphological characteristics and environmental effects of Huangtuwa palaeo-slump are analyzed in this paper.Results show that:Huangtuwa palaeo-slump occurred in August 1569,which was the secondary disaster of an earthquake;this palaeo-slump,by blocking the channel,caused erosive-accumulational and accumulational-erosive landforms,shaped plains and reduced the degree of erosion;the flood cyclothem of sediments consists of the dual structure,in which the fine-grained silt layer seam is an indicator of flood,in the natural check dammed land of Huangtuwa,Houxiaotan gully and Dazui gully;after about 440 years’ sediment accumulation in the national check dam of Huangtuwa,the deepest thickness can reach 50 m,which has effectively prevented water and soil loss and brought positive environmental effects.All these provide scientific bases for the comprehensive treatment of Huangtuwa pakaeo-slump,protection of natural check dam system and inverting sedimentary environment in recent 500 years in the Loess Plateau.更多还原