【作者】 邢钊；

【导师】 马金辉；

【作者基本信息】 兰州大学 ， 地图学与地理信息系统， 2012， 硕士

【摘要】 白龙江流域是我国泥石流最为严重的地区之一,其泥石流灾害类型多,具有多发性和继承性的特点。受“5·12”汶川大地震影响,该区山体和岩土结构破坏加剧,诱发了包括舟曲“8·8”特大泥石流灾害在内的一系列新泥石流等地质灾害,严重威胁着当地人民的生命财产、重要基础设施甚至长江上游的生态安全。因此,针对白龙江流域进行泥石流灾害危险性评价与防治技术研究具有重要的现实意义。本文在对白龙江流域的内外动力环境因子进行分析研究,建立研究区泥石流灾害评价指标体系的基础上,分别基于信息熵和AHP模型对研究区的泥石流危险性进行评价,并对评价模型结果进行对比分析,获取了以下主要成果：1.根据野外实际考察和相关文献资料搜集所得数据,基于Geodatabase建立研究区的泥石流灾害及其相关要素空间数据库,主要包括基础资料库、地质环境空间数据库和泥石流空间数据库,为泥石流危险性评价奠定基础。2.泥石流灾害空间分布特征：空间分布特征主要表现为分布密度大、空间异质性明显、同级流域泥石流分布高度既集中又分散、泥石流大多沿断裂带和较软弱岩性区分布等特征；3.泥石流灾害时间分布特征主要包括年际时间分布规律、年内时间分布规律和日时段分布规律。年际时间分布规律表现为泥石流多发生在丰水年份和趋于丰水年份,而在低降水年份和趋于低降水年份泥石流不发育；年内时间分布规律表现泥石流发生时间也主要分布在6-9月,并集中在7-8月；日时段分布规律发布规律表现为泥石流多发生在午后(14时至20时)和夜间(24时至次日8时)。4.根据泥石流的发育背景、形成条件、分布特征等因素,对各影响因子进行逐因子分析、共线性诊断和关联度计算,分别建立基于栅格单元和基于流域单元的泥石流危险性评价指标,其中基于流域单元的影响该区域泥石流危险性指标依次为：地层岩性>主沟长度>10min平均降雨量>流域相对高差>流域面积>NDVI>主沟比降>流域切割密度。5.论文首先采用AHP模型进行泥石流危险性评价,但由于AHP方法本身的限制,评价结果有很强的主观性。为了最大程度上克服主观因素对泥石流评价结果的影响,又采用信息熵模型分别基于栅格单元和流域单元进行泥石流危险性评价,分别生产了基于栅格单元与基于流域的白龙江流域泥石流危险性评价空间分布图。结果表明两种评价单元的泥石流危险性评价结果整体相似,仅在局部存在差异,但基于流域单元的泥石流危险性评价结果与实际情况更吻合,说明流域水文地形状况对泥石流的发生具有更强的作用,在泥石流危险性评价时需采用更多水文地形指标,以使评价结果更为准确合理。6.基于栅格单元的信息熵模型和AHP模型泥石流危险性评价结果呈现出总体趋势相似,局部略微差异的特点。两种评价结果对比分析显示：断层对研究区泥石流的危险性空间分布起到主导作用。更多还原

【Abstract】 Bailong basin was one of the serious areas of debris flow in china, and having the characteristic of great frequency and hereditability. The structure of mountains, rock and soil are severely damaged under Wenchuan "5·12" earthquake influence, induced a serious of geological disasters included Zhouqu "8·8" Catastrophic debris flow. The serious geological disasters threatern the the life and property of the people, significant infrastructure and even to the Ecological Security in the Upper Reaches of the Yangzi River, controlling techniques and Risk assessment of debris flow in the Bailong basin were of important realistic significance.Based on the analysis of the environmental factors of the internal and external force, establishing the symbol system, the Information Entropy and AHP model were applied to assess the risk of debris flow in study area and have a Comparative Analysis of the result of assess model. The results showed:1. based on Geodatabas, built the space database of debris flow and its relating factors which included the underlying database, spatial database of geological environment and debris flow to develop a base for risk assessment of ebris flow in accordance with the practical investigation in the field and Related documents.2. The results showed that the spatial distribution characteristics of debris flow of the great density distribution, conspicuous spatial heterogeneity, the notable disparity of altitude distribution of debris flow in different areas of the same catchment, debris distributed along the Fault zone and the areas of the soft and weak rock mostly.3. The distribution feature of debris flow time mainly includeed the annual time distribution, years time distribution rule and day time distribution rule. The distribution for the annual time performanced that debris flow occurs in a wet year and tended to be in a wet year, and not yet developed in low rainfall and tended to be low rainfall of the year; The distribution rule for the years time of debris flow performance that the time debris occurred mainly distributed in June to September, and concentrated in July-August. The distribution rule for day time performance for the debris flow occurs in the afternoon (14to20) and the night (24to8at the next day). 4. According to the development background, the forming condition, the distribution and other factors of debris flow, do factor analysis, collinearity diagnostics and correlation calculation with every factor, established the assessment indicator for debris flow hazard degree separately based on grid unit and valley unit. And the impact factors of debris flow hazard degree based on valley unit are listed in turn here:formation lithology> main ditch length>10minutes average rainfall> valley relative relief> valley area> NDVI> main ditch gradient> valley cutting density.5. In the paper, it firstly adopted AHP model to conduct the risk assessment of debris flow, but due to the limitation of the AHP method, the evaluation result has the very strong subjectivity. In order to overcome subjective factors to affect the results of evaluation of debris flow in the largest extent, and based on grid unit and watershed unit to conduct the risk assessment of debris flow using the information entropy model, which respectively produced based on grid unit and space distribution of debris flow risk assessment in Bailong Basin. The result showed that the debris risk assessment outcomes by the two methods are alike, with difference only in local regions, however, the one based on basin unit is accordant with the actual situation, indicating that hydrologic terrain condition has a strong role the occurrence of debris flow, and more hydrological terrain index must be adopted in debris flow risk assessment, in order to make the assessment more exact and reasonable.6. Based on grid unit’s information entropy model and the AHP model of debris flow risk assessment, the two results presented a general trend similar, and the characteristics of the local slightly differences. A comparative analysis of the two kinds of evaluation results showed:a fault in the study area of space debris flow risk distribution plays a leading role.更多还原