A geomorphological assessment of landslide origin at Bukavu, Democratic Republic of the Congo
A geomorphological assessment of landslide origin at Bukavu, Democratic Republic of the Congo
复制标题
刚果民主共和国布卡武山体滑坡起源的地貌评估
DOI：
10.1016/j.enggeo.2003.06.003
复制
发表时间：
2004
期刊：
影响因子：
--
通讯作者：
L. Nahimana
中科院分区：
文献类型：
--
作者：
J. Moeyersons;P. Trefois;J. Lavreau;D. Alimasi;I. Badriyo;B. Mitima;M. Mundala;D. O. Munganga;L. Nahimana
位于刚果民主共和国基伍湖南海岸的布卡武遭受着缓慢但从未结束的山体滑坡之苦。这导致该镇几个区的房屋、建筑物以及道路、自来水厂和排污基础设施不断退化和遭到破坏。有关第三系和第四系深风化熔岩的岩土和水文地质信息有限，阻碍了对物质损耗过程的研究。对于活动断层的确切位置也存在分歧，据信这些活动断层在大规模浪费中发挥了作用。此外，关于土壤移动的确切位置和速度以及地面不稳定是由构造和地震还是由静水压力增加引起的信息很少。根据航拍解译，山体滑坡覆盖了布卡武镇15%以上的地区。31个山体滑坡发生在布卡武“微隆起”之外，没有接触活动断裂。相反，它们发生在积极切割的河流盆地中，表面上是由新构造活动引起的。在“微地堑”内的六个滑坡中，有四个比其他滑坡更大、更宽，显然是由先前存在的构造引起的地貌控制的。它们毗邻活动断裂或与活动断裂相交。它们也远远低于为北美建立并在卢旺达验证的滑坡的地形阈值。因此，这个阈值，即滑坡头部的坡度和向其排放的地表的组合，似乎是一种从水文上区分构造地震引发的滑坡的有前途的工具。布卡武最近的土壤运动通常与地貌图上描绘的滑坡分布相对应。大多数布卡武土壤的移动都发生在以前的幻灯片上。因此，从工程地质的观点来看，应该避免老的滑坡，或者，如果经济上可行，应该减轻滑坡。
Bukavu, on the south coast of Lake Kivu in the Democratic Republic of the Congo, suffers from slow but never ending landsliding. This leads to the continuous degradation and destruction of houses, buildings and of the roads, waterworks and sewerage infrastructure in several districts of the town. Research of mass-wasting processes is hampered by the limited geotechnical and hydrogeological information concerning the deeply weathered Tertiary and Quaternary lavas. There is also a disagreement about the exact location of active faults, believed to play a role in the mass wasting. Additionally, there is little information about the exact location and the rate of soil movements and whether ground instability is caused by tectonics and seismics or by increase in hydrostatic pressure. Based on aerial photographic interpretation, landslides cover more than 15% of the town of Bukavu. Thirty-one landslides occur outside the Bukavu “microrift” and do not contact active faults. Rather, they occur in actively incising river basins, ostensibly caused by neotectonic activity. Four from the six landslides within the “micrograben” are bigger and wider than the others, apparently governed by pre-existing tectonically induced landforms. They are adjacent to or crossed by active faults. They also fall far below the envelope of topographic thresholds for landslides established for North America and verified in Rwanda. Therefore, this threshold, a combination of slope at the head of the slide and surface drained to it, seems a promising tool to discriminate hydrologically from tectonically seismically induced landslides. Recent soil movements in Bukavu generally correspond to landslide distribution portrayed on the geomorphologic map. Most Bukavu soil movements occur on previous slides. Therefore, from an engineering–geologic standpoint, old landslides should be avoided, or, if economically feasible, be mitigated.