白水江流域滑坡地质灾害危险性评价研究

发布时间：2018-10-30 12:40

【摘要】：白水江流域地处松潘-甘孜褶皱系、秦岭褶皱系及上扬子地台的结合部位,流域内地形地貌复杂,构造活动强烈,不良物理地质现象普遍发育。流域内共发育129处大-巨型滑坡灾害,这些灾害时刻威胁着场镇居民的人身和财产安全。因此,开展白水江流域滑坡危险性评价可以给予流域内滑坡灾害防治决策一定的参考价值,对有效减少因滑坡所造成的人员伤亡与财产损失具有极其重要的现实意义。本文依托“川西北地区大型堆积体发育及其环境效应研究”项目,在野外实际调查的基础上,结合前人的研究成果,对白水江流域滑坡的工程地质条件、分布规律、发育特征、影响因素及形成机制进行了分析研究,并基于ARCGIS软件采用AHP-CF法对白水江流域滑坡地质灾害进行危险性评价。本文主要取得以下成果:(1)白水江流域位于川甘两省交界处,地势自北西向南东逐渐降低,流域内峰峦叠嶂,沟谷纵横。流域内断层、褶皱等地质构造发育,新构造运动剧烈,地震频发。流域内岩性以板岩、千枚岩、灰岩、变质砂岩为主,岩体多以软硬互层的结构存在。(2)白水江流域共发育129处大-巨型滑坡,主要沿白水江干流中游、黑河中-下游、白河中游、马连河以及中路河上游水系成带状分布,在马连河堡子坝乡一带、白水江石鸡坝乡一带以及白水江双河乡一带滑坡集群分布,并且部分滑坡对河流岸别有一定的选择性。流域内滑坡主要分布在1000-2500m的深切河谷区。流域内发育古滑坡46处,老滑坡47处,新滑坡36处。(3)在白水江流域滑坡地质灾害中,平面形态为长条形的24处,舌形43处,半圆形22处,不规则形40处;土质滑坡24处,均为黄土滑坡,岩质滑坡105处,部分滑坡堆积体上覆厚层黄土或堆积体中还含有未解体的基岩;中层滑坡41处,深层滑坡79处,超深层滑坡9处;大型滑坡75处,特大型滑坡52处,巨型滑坡2处。不同水系的滑坡发育特征不尽相同。(4)白水江流域滑坡地质灾害受地形地貌、工程地质岩组、岸坡结构、地质构造、河流水系、降雨条件、人类工程活动及地震这8个内在因素与外在因素影响,通过统计分析可知:(1)滑坡多发育在坡度为20~40°、坡高为200~600m及软硬岩相间的斜坡内,对坡向为正西和南西方向,岸坡结构为顺向坡和逆向坡的斜坡较为敏感;(2)地质构造与河流水系对滑坡的发育起到一定的控制作用;(3)流域内滑坡均发生在年均降雨量为400~600mm的范围内;(4)人类工程活动与滑坡的分布有着密切的联系。流域内滑坡的形成机制主要有3种,分别为弯曲-拉裂型、滑移-拉裂型及拉裂-溃滑型。(5)根据对白水江流域滑坡地质灾害分布规律、发育特征和影响因素的分析,选择坡度、坡向、坡高、工程地质岩组、岸坡结构、地质构造、河流水系、降雨条件、人类工程活动9个评价因子和300×300m的评价单元建立滑坡地质灾害危险性评价指标体系,并结合AHP-CF评价模型得到白水江流域滑坡地质灾害危险性评价结果,并通过数学统计法和ROC曲线分析法验证了结果的合理性。评价结果将白水江流域危险性程度划分为四个等级:(1)高危险区,面积为1557.22km2,共发育滑坡74处;(2)中危险区,面积为3327.18km2,共发育滑坡39处;(3)低危险区,面积为2584.64km2,共发育滑坡15处;(4)极低危险区,面积为788.11km2,共发育滑坡1处。
[Abstract]:The Baishuijiang River Basin is located in Songpan-Ganzi fold system, the Qinling fold system and the uplift of the upper Yangtze platform. The topography of the river basin is complicated, the tectonic activity is strong, and the adverse physical geological phenomena are generally developed. There are 129 large-mega-landslide disasters in the basin, which threaten the safety of the people and property of the residents in the field. Therefore, the risk assessment of landslide in Baishuijiang River Basin can provide some reference value for the decision-making of landslide hazard in river basin, and it is of great practical significance to effectively reduce the casualties and property loss caused by landslide. This paper relies on Study on the Development and Environmental Effects of Large-scale Accumulation in the Northwest of Sichuan On the basis of field investigation, the engineering geological conditions, distribution laws, development characteristics, influencing factors and forming mechanism of landslide in Baishuijiang River Basin are analyzed and studied in combination with previous research results. Based on the AHP-CF method, the risk assessment of landslide geological disasters in Baishui River basin was carried out. The main results are as follows: (1) The Baishuijiang River basin is located at the intersection of the two provinces of Sichuan and Gansu, and the terrain gradually decreases from the north to the east, and the peaks and valleys in the river basin are stacked and the valleys are horizontal and horizontal. The faults, folds and other geological structures in the basin are developed, the neotectonic movement is severe and the earthquake is frequent. The lithology of the river basin is mainly composed of slate, thousand marble, limestone and metamorphic sandstone, and the rock mass is present in the structure of soft and hard mutual layer. (2) There are 129 large-giant landslides in the Baishui River basin, mainly in the middle reaches of the main stream of Baishuijiang River, in the middle-downstream of the Baishuijiang River, the middle reaches of the Baihe River, the Ma Lianhe River and the upper reaches of the Middle Road. The distribution of landslide cluster in the area of Shijiaba Township of Baishui River and the Shuanghe Township of Baishuijiang River are distributed, and some landslide has certain selectivity to the river bank. The landslide is mainly distributed in the deep valley area of 1000-2500m. There are 46 landslides in the basin, 47 in the old landslide and 36 at the new landslide. (3) In the geological disasters of the Baishui River valley, the plane shape is 24 at the strip shape, the tongue shape is 43, the semicircular shape is 22, the irregular shape is 40, and the soil landslide 24 is a loess landslide and a rock mass landslide 105. Part of the landslide pile is covered with thick layer of loess or pile with undecomposed bed rock, middle layer landslide 41, deep landslide 79, super deep landslide 9, large landslide 75, super-large landslide 52, giant landslide 2. The development characteristics of landslides in different water systems are different. (4) The geological hazards in Baishui River basin are affected by topography, engineering geological rock group, bank slope structure, geological structure, river water system, rainfall condition, human engineering activities and earthquake. (1) The slope of the landslide is 20 ~ 40 掳, the slope height is 200 ~ 600m, and the slope of the soft and hard rock phases is in the slope, which is more sensitive to the slope towards the south west and the south west, and the bank slope structure is the slope of the forward slope and the reverse slope; (2) the geological structure and the river water system play a certain role in controlling the development of the landslide; (3) The landslide in the basin is within the range of 400 ~ 600mm annually; (4) The human engineering activities are closely related to the distribution of landslide. There are three main mechanisms of landslide formation in the basin, which are curved-pull-crack type, slip-type crack type and fracture-collapse type. (5) According to the analysis of the distribution rule, development characteristics and influencing factors of landslide hazards in Baishui River basin, the slope, slope direction, slope height, engineering geological rock group, bank slope structure, geological structure, river water system and rainfall condition are selected. The risk assessment index system of landslide hazard is established by nine evaluation factors of human engineering activities and the evaluation unit of 300x300m, and the risk assessment results of landslide hazard in Baishui River basin are obtained in combination with the AHP-CF evaluation model. The rationality of the results is verified by mathematical calculation method and ROC curve analysis method. The assessment result divides the danger degree of Baishuijiang river basin into four levels: (1) high hazard zone with an area of 1557. 22km2, developed landslide 74; (2) middle danger zone, area 3327. 18km2, co-developed landslide 39; (3) low hazard zone with area of 2584. 64km2, co-developed landslide 15; (4) Very low risk area, with an area of 788. 11km2, with a total development landslide 1.
【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P642.22

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