【作者】 孟庆华；

【导师】 殷跃平； 吴树仁；

【作者基本信息】 中国地质科学院 ， 地质工程， 2011， 博士

【摘要】 秦岭山区是我国崩滑流地质灾害高发区域,每逢雨季的强降雨会诱发大量地质灾害,造成人员伤亡及大量的财产损失。为了探索适应于秦岭山区的地质灾害风险评估技术方法,本文以陕西省凤县为例,依托陕西省宝鸡市地质灾害详细调查项目,在分析地质灾害风险评估技术方法的基础上,比较各评价方法的优缺点,按照“地质灾害易发性—危险性—风险”的研究层次关系,探索了适用于秦岭山区的地质灾害风险评估技术方法,并对凤县县内地质灾害的发育分布规律进行了研究,开展了降雨条件下区域崩滑及泥石流灾害风险评估与管理研究,并取得了下列主要进展和成果：1、初步揭示了凤县地质灾害发育特征与分布规律。区内地质灾害类型主要包括崩塌、滑坡和泥石流灾害,集中分布在人类工程活动强烈、河流沿岸及植被覆盖程度低的地区：其中滑坡灾害分布最为广泛且危害最为严重；金属矿山开采形成的尾矿堆弃体在降雨条件下形成的潜在泥石流灾害威胁最为严重；控制区域地质灾害发育的地质环境因素主要包括地形地貌、地层岩性、河流侵蚀、植被覆盖程度及断裂等；地质灾害诱发因素主要为降雨和工程切坡。2、根据秦岭山区地质灾害特点,提出了传统的基于统计的地质灾害易发性评价方法的改进方法。在研究区内利用基于统计和改进的统计评价方法进行了区域崩滑灾害易发性评价,并利用AUC曲线对两种评价结果的有效性进行了检验,结果显示：在相同评估区域内,利用改进的统计分析方法进行地质灾害易发性评价,其评价结果的准确性更高。3、结合秦岭山区地质灾害特点,提出了将地质灾害分灾种进行危险性评价的技术方法,并且提出了对区域崩滑灾害和对泥石流灾害危险性评估的技术方法。以陕西省凤县为例利用基于统计分析和基于物理力学的无限斜坡体模型的评价方法进行危险性区划研究,通过比较两种评价结果的AUC特征曲线表明：基于统计分析的区域崩滑危险性评价结果的准确性明显较高；而利用物理力学模型方法进行区域滑坡危险性评价的结果准确性,很大程度上取决于地层岩性及地下水条件的数据精度和质量,因此该模型方法更适用于地层岩性单一(如黄土地区)或滑体与滑床物理力学性质差异较小的地区。利用层次分析和模糊综合评判方法对泥石流灾害进行了危险性评估,并将其危险性划分为四个等级。4、结合山区地质灾害特点,提出了在区域上对地质灾害分灾种进行风险评估的技术方法,并且提出了可容许风险评判标准的确定方法。以陕西省凤县为例,在承灾体价值统计及其易损性评价的基础上,对研究区内崩滑和泥石流灾害分别进行了人员和财产社会风险的估算；制定研究区内可容许风险的评判标准,并对区内地质灾害综合风险等级进行了划分,针对不同风险等级提出了风险减缓措施。并且以胡家山单体大型滑坡为例,通过考虑天然状态、十年一遇降雨和五十年一遇降雨三种工况条件下斜坡的稳定性,并分别考虑三种工况条件下承灾体的易损性情况,对胡家山滑坡进行风险评价并提出风险减缓措施。更多还原

【Abstract】 The Qinling Mountain is an area where geo-hazards are most developed. In the rainy season, a lot of geo-hazards will occur due to the heavy rain, with great casualties and losses. In order to get the methods on early warning and disaster reduction for geo-hazards in the towns of Qinling Mountain, Feng County in Shaanxi province is taken as an example. Based on the analysis of disaster regularity and supported by Geological Survey Project of Baoji City in Shaanxi Province, and in accordance with the sequence of "susceptibility-hazard-risk", the risk assessment and management on landslides, rock falls and debris flows suffering rainfall were discussed with the help of statistical analysis method and mechanical model. Some results are obtained:1. The developmental character and distribution regularity was revealed. The geo-hazards include rock falls, landslides and debris flows, mainly distributed in the areas with great human activities, rivers and little vegetation. The metal mining tailings was prone to form potential debris flow when suffering rainfall and was very serious. The geo-environmental factors include landform, formation lithology, river erosion, vegetation cover and fault, etc. The main reason for geo-hazards is rainfall and cutting slope.2. The geo-hazard susceptibility was analyzed based on the comprehensive statistics method on the amount of information in the regional area and local area. The AUC curve indicated that in the same assessment region, the results based on the local statistics analysis was more accurate; and as for the same method, the accuracy increased with the geological logging preciseness.3. The geo-hazard risk assessment was discussed using the statistics method and the stability analysis on mechanical model of slope. The AUC curve indicated that the results based on statistics method are more accurate; the accuracy of stability analysis mainly depended on the data of formation lithology and underground water, and it was fit for the slope with single stratum or strata with little difference. The risk assessment on debris flow was analyzed with analytic hierarchy process and fuzzy comprehensive evaluation. And the debris flow risk was classified into four grades.4. Combined with the geo-hazard characteristics in mountain area, the risk assessment method on geo-hazard in regional area and the evaluation standard of tolerable risk were put forward. Based on the disaster-bearing body value statistics and its vulnerability assessment, the estimation on social risk of personnel and property caused by geo-hazards in Feng County was performed. The risk grade was classified according to experience of tolerable risk, and the related control measures were proposed. As a更多还原