【作者】 王毅；

【导师】 唐川； 铁永波；

【作者基本信息】 成都理工大学 ， 地质工程， 2017， 硕士

【摘要】 我国是地质灾害多发的国家,尤其是西南地区,因其地质条件和地理环境复杂多变等原因,使得地质灾害频繁发生。特别在最近时期,城镇化进程的加快,人类活动日益强烈,一旦遭遇强降雨,诱发的地质灾害就会严重威胁人民的财产和生命安全。越来越多人们意识到减轻和预防地质灾害的对城镇发展的重要性,迫切需要对地质灾害进行风险评价,从而可以对风险高的地区进行有效的控制和管理,减少人民财产的损失。因此,如何对该地区内的地质灾害开展风险评价是在城市发展及防灾减灾规划中必须要面对的重大课题。贵州省是我国泥石流灾害较为严重的地区之一,由于贵州省的泥石流多为水力类泥石流,具有潜在的危险性,如不及时采取预警报措施,在遭遇极端天气情况(如强降雨)下,有泥石流危险的地方就可能暴发泥石流,造成灾害。正是在这样的背景下,本文以贵州省威宁县二塘河流域为例,依托于贵州省国土资源厅重大专项项目-“贵州省重点地质灾害风险评价与管控示范”,充分收集已有基础数据资料,结合高分辨率遥感影像对二塘河流域猴场镇段内的崩滑体及泥石流灾害进行高精度遥感解译,并对其进行实地调查验证,确定该流域内最终灾害体。采用GIS技术与数学模型相结合的方法对流域内的泥石流进行风险性评价方法研究。本文研究目的是为了给与当地国土部门进行规划建设与防灾减灾提供合理化的建议,主要结论有以下几点:1、统计分析了流域内崩滑体、泥石流及承灾体的分布特征利用流域内高分辨率遥感影像以及1:10000基础数据构建了流域的真实三维场景,对二塘河流域猴场镇段内的崩滑体、泥石流灾害和房屋,道路,土地类型等承灾体进行高精度遥感解译并实地调查验证,建立了该研究区的地质灾害及承灾体空间数据库。并对承灾体的类型及特性进行了统计归纳。这些基础数据为后续的风险评价提供了重要的支持。2、完成了小流域泥石流灾害危险性评价小流域泥石流危险性评价根据该研究区内的泥石流发育特征,选取影响泥石流物源发生发展的状态因子(土壤侵蚀模数、泥石流最大冲出量)及地形地貌因子(流域高差、沟壑密度、形成区平均坡度、主沟纵坡降、流域面积)作为泥石流敏感性评价因子,首先利用GIS技术求出流域内土壤侵蚀模数,再根据侵蚀模数求得最大物源量,最后利用GIS技术与模糊数学相结合的方法求出研究区内的泥石流敏感性,并与降雨数据相结合,利用危险性评价模型,求出每条泥石流危险度,生成研究区的泥石流危险性评价图,为后面风险评价奠定基础。3、开展了小流域泥石流灾害易损性评价首先根据研究区的自然环境状况及实地调查情况,并结合前人对易损性的研究,本文从4个方面对研究区的易损性进行评价,即物质易损性、社会易损性、环境易损性、经济易损性。并引入承灾体折损系数和危险区的威胁系数两个指标,对威胁区范围内的承灾体构建易损性评价模型,计算出每条泥石流的易损度,从而对二塘河流域猴场镇段的泥石流进行定量易损性评价。泥石流灾害易损性评价要根据其危害的特征,首先,结合喀斯特地区的地形地貌,选取合适的评价模型,来对泥石流的最大威胁范围进行评价,本文选用ASC模型计算每条沟的最大冲出距离,并根据流域下游地区地形坡度和距离主沟的水平距离这两个主要参数,运用GIS技术进行坡度和缓冲区分析,确定泥石流的最大威胁范围。以此为依据,结合上文所求的易损性评价结果,统计泥石流所威胁范围内的易损度值,最终生成二塘河猴场镇流域泥石流易损性评价图。4、完成了小流域泥石流风险评价及制图小流域泥石流风险评价是对流域内的泥石流灾害发生的概率及所造成的损失各要素进行综合分析的结果。基于研究区泥石流危险度评价结果和易损度评价结果,构建风险评价模型,并利用GIS技术进行空间叠置运算得出泥石流风险评价结果图,它代表了该区域发生泥石流的风险程度,因此,值越高,其风险越大。并根据泥石流危险性和易损性分级标准,将风险度分为4个等级:0~0.16为低度风险、0.16~0.36为中度风险、0.36~0.64为高度风险、0.64~l为极高风险,以完成小流域泥石流风险评价及区划。从对研究区内泥石流风险评价结果的统计和泥石流区域风险区划图可知:极高风险的泥石流共有1条,为平洞村沟,其流域内分布大量房屋,人口密集,土壤侵蚀极具强烈,地形地貌条件非常有利于泥石流的爆发;高风险的泥石流有5条,为穿洞村沟、发纠村沟、吴家包沟、倮秣沙上村沟及长冲村1#沟;中风险的泥石流有6条,主要分布于长冲村流域内(#2、#3、#6、#7、#8沟)及倮秣沙沟,其余为低风险的泥石流,共5条,为明洞村沟、穿洞村三组沟、倮秣沙下村沟长冲村(#4、#5)沟。更多还原

【Abstract】 China is a geological disaster-prone countries,especially in the southwestern region,because of its geological conditions and geographical environment complex and so on,making geological disasters occur frequently.Especially in the recent period,the acceleration of the urbanization process,human activity is increasingly strong,once encountered heavy rainfall,induced geological disasters will be a serious threat to the people’s property and life safety.More and more people are aware of the importance of mitigating and preventing the development of geological disasters,and it is urgent to carry out risk assessment of geological hazards so that the areas with high risk can be effectively controlled and managed to reduce the loss of people’s property.Therefore,how to carry out risk assessment of geological disasters in the region is a major issue that must be faced in urban development and disaster prevention and mitigation planning.Guizhou Province is one of the most serious areas of debris flow disaster in China.As the debris flow in Guizhou Province is mostly dangerous for hydraulic debris flow,it is potentially dangerous.If it is not timely to take precautionary measures,in the case of extreme weather conditions(such as heavy rainfall)There is a risk of debris flow where the outbreak may be debris flow,causing disasters.It is in this context,this paper to Weili County,Guizhou Province,two Tong River Basin,for example,relying on the Guizhou Provincial Department of Land and Resources major projects-"Guizhou key geological hazard risk assessment and control demonstration" to fully collect the existing basis Data,combined with high-resolution remote sensing images,the high-resolution remote sensing interpretation of the landslide and debris flow in the monkey town of the Ertang River Basin,and the field investigation and verification to determine the final disaster.The method of quantitative risk assessment of debris flow in watershed is studied by using GIS technology and mathematical model.The purpose of this paper is to give the local land sector planning and construction and disaster prevention and mitigation to provide rationalization of the proposal,the main conclusions are the following:1、The distribution characteristics of landslide,debris flow and disaster-bearing body in the basin were analyzed statistically:Based on the high-resolution remote sensing image and 1: 10000 base data,the real three-dimensional scene of the basin is constructed.The landslide,debris flow and the land,road and land type in the monkey town of Ertang River Basin High-precision remote sensing interpretation and field investigation and verification,the establishment of the study area of geological disasters and disaster-bearing body space database.And the types and characteristics of the disaster-bearing bodies were summarized.These underlying data provide important support for subsequent risk assessment.2、The risk assessment of debris flow disaster in small watershed was completedEvaluation of Debris Flow Hazard in Small Watershed According to the characteristics of debris flow development in this study area,the state factors influencing the occurrence and development of debris flow source are selected(Soil erosion modulus,debris flow out of the largest).And topography and geomorphic factors(watershed height difference,gully density,formation area average slope,main channel longitudinal slope,basin area),As a debris flow sensitivity evaluation factor,First,the soil erosion modulus of the basin is obtained by using GIS technology,and the maximum source is obtained according to the erosion modulus.Finally,the sensitivity of debris flow in the study area is obtained by combining GIS technology with fuzzy mathematics.Combined with the risk assessment model,calculate the risk of each debris flow,the formation of the study area of debris flow risk assessment map,lay the foundation for the subsequent quantitative risk assessment.3、Carried out a small watershed debris flow disaster vulnerability assessmentFirst of all,according to the natural environment of the study area and the field investigation,combined with the previous study of vulnerability,this paper evaluates the vulnerability of the study area from four aspects: material vulnerability,social vulnerability,Environmental vulnerability,economic vulnerability.And the damage coefficient of the disaster-bearing body and the threat coefficient of the danger zone are introduced.The vulnerability assessment model is built on the disaster-bearing area within the threat area,and the vulnerability of each debris flow is calculated,Evaluation of Quantitative Vulnerability of Debris Flow in Monkey Town.In order to evaluate the maximum threat range of debris flow,this paper chooses ASC model to calculate the maximum outflow of each ditch,according to the characteristics of the hazard.First,combining the topography and geomorphology of karst area and selecting the appropriate evaluation model And the slope and buffer analysis were carried out by using GIS technology to determine the maximum threat range of debris flow according to the two main parameters of the horizontal gradient and the horizontal distance from the main channel in the lower reaches of the basin.Based on the results of the vulnerability assessment,the vulnerability value of the debris flow threat is calculated,and the volcanic erosive vulnerability evaluation map of the Ertang Monkey Field is established.4、The quantitative risk assessment and mapping of debris flow in small watershed were completedThe quantitative risk assessment of debris flow in small watershed is the result of comprehensive analysis of the occurrence of debris flow disaster in the basin and the loss caused by the factors.Based on the results of the evaluation of debris flow risk and the evaluation of vulnerability,the quantitative risk assessment model is constructed and the risk of soil debris flow is calculated by using GIS technology.It represents the degree of risk of debris flow in this area.The higher the value,the greater the risk.According to the debris flow risk and vulnerability classification criteria,the risk is divided into four grades: 0 ~ 0.16 for the low risk,0.16 ~ 0.36 for the moderate risk,0.36 ~ 0.64 for the high risk,0.64 ~ l is extremely high Risk,to complete the small watershed debris flow quantitative risk assessment and zoning.From the statistics on the quantitative risk assessment of the debris flow in the study area and the regional risk zoning of the debris flow,it is found that there are 1 high-risk debris flow,which is the Pingdong Village,which has a large number of houses,densely populated and soil erosion,Terrain and geomorphological conditions are very conducive to the outbreak of debris flow;high-risk debris flow has five,for the hole through the village ditch,hair village,Wu Jiapao ditch,sand on the village and the village of Changgong Village 1 #(# 2,# 6,# 7,# 8 ditch)and the sand ditch,the rest of the low risk of debris flow,a total of 5,for the Ming Dongcun ditch,through the village of three groups of ditch,luo Mo Sha Village under the village of long red village(# 4,# 5)ditch.更多还原