湖南张家界市永定区地质灾害发育规律及易发性评价研究

张家界市复杂的地质构造背景造就了独特的地貌景观,同时存在众多地质灾害隐患。通过分析张家界市永定区2014年至2022年详细的地质灾害调查资料,对区内地质灾害发育规律及易发性进行研究。结果表明: 区内地质灾害类型以滑坡为主,地质灾害空间分布以中部断层发育区与东北部页岩地层区最多,时间分布相对集中在5、6、7月雨季; 区内地质灾害与地形地貌、岩土体类型、构造活动密切相关,并受降雨及人类工程活动影响; 在碎屑岩丘陵地貌中灾害点密度最高; 在志留系砂质页岩岩组中地质灾害最易发; 受构造影响明显,断褶构造带处灾害点密集; 灾害高发期与雨季耦合,诱发因素主要是降雨; 不合理地切坡建房、道路建设等工程活动加剧地质灾害的发生。采用易发程度指数法,基于ArcGIS信息统计分析,将全区地质灾害易发程度划分为高易发区、中易发区与低易发区。研究可为永定区国土空间规划、地质灾害防治、旅游路线及重大工程建设规划提供指导。

Research on the development law and susceptibility evaluation of geological disasters in Yongding District of Zhangjiajie City in Hunan Province

The complex geological structure in Zhangjiajie City has led to its unique landform landscape, meanwhice it has also posed numerous geological hazard risks. By analyzing detailed geological hazard investigation data of Yongding District from 2014 to 2022, the authors in this paper have studied its developmental patterns and susceptibility of geological hazards. The results indicate that landslide is the primary type of geological hazard in the area. Geological hazards are spatially most prevalent in the central fault zone and the northeastern shale formation zone, and they are temporally relatively concentrated during the rainy season in May, June and July. Geological hazards in this area are closely related to landform characteristics, lithology, and tectonic activities, and they are also influenced by rainfall and human engineering activities. The density of hazard points is highest in the debris hill landform, and the susceptibility of hazard points is highest in Silurian sandy shale formation. Besides, the geological hazards are significantly influenced by tectonics, with hazard points densely concentrated in fold and thrust structures. The high incidence period of hazards is coupled with the rainy season, and the main triggering factor is rainfall. And the unreasonable engineering activities, such as slope cutting for houses and roads construction, exacerbate the occurrence of geological hazards. By using the susceptibility index method and based on ArcGIS information statistics analysis, the authors in this paper have divided the susceptibility of geological hazards in the entire area into high, moderate, and low susceptibility zones. This study could provide guidance for land spatial planning, geological hazard prevention and control, and planning for tourism routes and major engineering construction in Yongding District.