黑方台构造地貌条件及其灾害效应
发布时间：2018-11-21 14:58
【摘要】：黑方台为刘家峡库区移民安置点,近年来,由于提水灌溉诱发大量的滑坡、崩塌、泥流等灾害,造成重大经济损失,严重威胁着当地居民的生命财产安全,引起了广泛的关注。所以对黑方台地区灾害的研究及防治迫在眉睫,而构造地貌条件在一定程度上控制了灾害的发育。通过野外调查台地周围的构造现象(断层、褶皱、节理、岩层剖面等)、卵石层发育特征(卵石层厚度、位置、卵石产状、形态大小、岩性等)、滑坡后壁发育情况等,结合DEM数据及地质图资料,用叠加计算的方法分析了台塬边坡的演化过程；用地形廊带法分析了灾害的分布及发育过程；用分形分维的方法分析了台地周围38处滑坡的形态特征；基于卵石形态及排列特征分析了地下水的径流及古河流环境。分析结果表明：(1)台地周围主要发育有7条断层,以逆断层居多,虎狼沟断层(FH)和焦家断层(FJ)第四纪以来曾发生过小幅度错动,处于活动状态,对台地下伏粘土层有较大的影响。断层面及节理发育特征所反映的断层露头处局部地应力场与现代大地构造应力场近一致。(2)黑方台缘边主要发育有两大类滑坡,在空间分布上具有分区段发育的特征,不同区段滑坡规模各异,危害程度也不同。黄土滑坡规模较小,滑距较长,分维值平均为1.75,黄土基岩滑坡规模较大,分维值为1.82。(3)黄河Ⅳ级阶地形成时的古河道水流方向与现今黄河流向近一致,古河道对地下水的径流排泄特征产生了一定的导向性。粘土层具有弱透水性,灌溉水入渗至粘土层顶面后易汇集并沿顶面高程较低的东北方向径流。(4)台地缘边发生了明显的后退及下沉现象,前缘部位则在不断堆积上升,最大下沉幅度达35 m,堆积最厚处到37 m；黑台台面自1977年到2010年的33年间,地面平均沉降幅度达1.5 m左右,台缘边坡高陡斜坡(滑坡后壁)数量有所减少,尤其大于55。边坡数量明显减少。
[Abstract]:Heifangtai is a resettlement site in the Liujiaxia reservoir area. In recent years, a large number of landslides, collapses, mudflows and other disasters caused by carrying water irrigation have caused great economic losses, seriously threatened the safety of local residents' lives and property, and caused widespread concern. Therefore, it is urgent to study and prevent the disasters in Heifangtai area, and the tectonic geomorphological conditions control the development of disasters to a certain extent. Through field investigation of the structural phenomena (faults, folds, joints, rock sections, etc.) around the platform, the developmental characteristics of the pebbles (thickness, location, occurrence, size, lithology, etc.) of the pebble layer, the development of the back wall of the landslide, etc. Combined with DEM data and geological map data, the evolution process of tableland slope is analyzed by superposition calculation method. The distribution and development process of disasters are analyzed by using the topographic corridor method, the morphological characteristics of 38 landslides around the platform are analyzed by fractal dimension method, and the runoff of groundwater and the environment of ancient rivers are analyzed based on the morphology and arrangement of pebbles. The results show that: (1) there are mainly 7 faults around the platform, most of which are reverse faults. The fault (FH) and (FJ) of the Hulanggou fault and Jiaojia fault have been staggered by a small margin since the Quaternary, and they are in active state. It has great influence on the underground clay bed. The local geostress field at outcrop of faults reflected by fault plane and joint development is nearly identical with that of modern geotectonic stress field. (2) there are two kinds of landslides in the margin of the Hei square platform, and the spatial distribution has the characteristics of segmental development. The scale of landslide is different and the degree of damage is different. The scale of loess landslide is smaller, the slip distance is longer, the average fractal dimension is 1.75, the scale of loess bedrock landslide is larger, and the fractal dimension is 1.82. (3) the direction of paleochannel flow is close to that of the present Yellow River when the Yellow River 鈪，
本文编号：2347312
[Abstract]:Heifangtai is a resettlement site in the Liujiaxia reservoir area. In recent years, a large number of landslides, collapses, mudflows and other disasters caused by carrying water irrigation have caused great economic losses, seriously threatened the safety of local residents' lives and property, and caused widespread concern. Therefore, it is urgent to study and prevent the disasters in Heifangtai area, and the tectonic geomorphological conditions control the development of disasters to a certain extent. Through field investigation of the structural phenomena (faults, folds, joints, rock sections, etc.) around the platform, the developmental characteristics of the pebbles (thickness, location, occurrence, size, lithology, etc.) of the pebble layer, the development of the back wall of the landslide, etc. Combined with DEM data and geological map data, the evolution process of tableland slope is analyzed by superposition calculation method. The distribution and development process of disasters are analyzed by using the topographic corridor method, the morphological characteristics of 38 landslides around the platform are analyzed by fractal dimension method, and the runoff of groundwater and the environment of ancient rivers are analyzed based on the morphology and arrangement of pebbles. The results show that: (1) there are mainly 7 faults around the platform, most of which are reverse faults. The fault (FH) and (FJ) of the Hulanggou fault and Jiaojia fault have been staggered by a small margin since the Quaternary, and they are in active state. It has great influence on the underground clay bed. The local geostress field at outcrop of faults reflected by fault plane and joint development is nearly identical with that of modern geotectonic stress field. (2) there are two kinds of landslides in the margin of the Hei square platform, and the spatial distribution has the characteristics of segmental development. The scale of landslide is different and the degree of damage is different. The scale of loess landslide is smaller, the slip distance is longer, the average fractal dimension is 1.75, the scale of loess bedrock landslide is larger, and the fractal dimension is 1.82. (3) the direction of paleochannel flow is close to that of the present Yellow River when the Yellow River 鈪，
本文编号：2347312
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