【中文摘要】 地震滑坡是一種常見的地震次生災害,因其巨大的致災力而廣泛引起人們的關注。目前,單體滑坡的穩定性評價和滑坡預報研究已取得了較為深入的研究成果,但在向區域滑坡穩定性評價推廣時會遇到許多困難。隨著遙感和地理資訊技術的發展,作為一種新的調查、監測途徑和手段,在地震滑坡領域已得到廣泛運用。2008年5月12日,四川省汶川縣發生Ms 8.0強震,直接導致數萬人死亡,數十萬人受傷,同時地震誘發大量的滑坡、崩塌和泥石流等地質災害,給當地人民帶來了極大的影響。為了有效避免次生災害對災區造成進一步的危害,本文選取重災區——汶川縣作為研究區域,基於地震滑坡原理,利用遙感與地理資訊科技,綜合各種數字滑坡技術獲取滑坡資訊,全面分析了研究區內滑坡與各影響因子間的相關性特徵,運用資訊量法與邏輯迴歸模型進行災害危險性評價,並對兩種方法進行了比較分析,主要研究內容如下:(1)基於遙感資料,論述了一系列數字影象處理技術(影像融合、影像校正),研究獲取影響滑坡災害因素資訊的方法,並對研究區地震滑坡特徵進行分析。(2)按照指標體系所確定的指標因子進行資料採集,並按照統一的.數字研究環境框架的規範進入GIS資料庫,建立研究區域滑...更多坡空間資料庫,包括滑坡分佈資料庫和滑坡因子資料庫,為研究區域地質災害預警資訊系統建設提供了豐富的滑坡災害基礎資料。(3)選取高程、坡度、坡向、巖性、地震斷裂、烈度以及水系因子7個評價因子,採用資訊量法與邏輯迴歸模型進行滑坡災害危險性評價,將研究區滑坡危險性劃分為極輕度、輕度、中度、高度和極高危險五個級別,合理地反映區內滑坡災害發育的總體特徵。(4)將資訊量模型與邏輯迴歸模型進行比較分析,發現邏輯迴歸法能較好地避免滑坡危險度區劃研究中評價因子選擇及權重賦值的主觀性,具有更高的評價精度。在GIS支援下對研究區遙感影像進行解譯和資訊提取,獲取其地震滑坡特性,獲得了汶川地區一些預測和危險性分析的結果,對於該地區震後恢復重建、居民地選址、次生災害的預警與防治等工作都有一些建設性的指導意義
【英文摘要】 As a kind of secondary disaster caused by strong earthquake, the earthquake-induced landslide has drawn much attention in the world due to the severe hazard. Nowadays, researches on single landslides have been carried out more successfully comparing to the ones on regional landslides. To a certain degree, remote sensing and GIS, as new kinds of tools for investigation and monitor, have been used in many researches on landslide susceptibility and hazard Ms 8.0 Wenchuan earthquake, occurred on 12 May 2008 in Sichuan Province, made a great many houses collapsed and hundreds thousand people injured. Meanwhile, damage caused by earthquake-induced landslides, collapse and debris flow became the major part of total losses. In order to remove threat from the secondary disasters effectively, this study used information value method and logistic regression, coupled with techniques of remote sensing and GIS, to generate susceptibility maps, taking the case of Wenchuan County. Main con...更多tent and production can be summarized as follows:(1) Based on the remote sensing data, this paper introduces the significance of digital image processing technology (e.g. data fusion and ortho-rectification), illustrates the procedures and techniques of information extraction and analyses the characteristics of earthquake-induced landslides in the research area.(2) To perform the potential analysis, it was necessary to establish spatial database of landslides containing landslides’attributes and variables contributing to landslide in the study area. The database following the unified standard of digital surrounding can provide plenty of basic data for advanced process.(3) Seven factors controlling landslide occurrence have been taken account into the susceptibility assessment, including elevation, slop, aspect, lithology, seismic intensity, distance to faults and rivers. According to the probability that predicts the possibility of landslide occurrence calculated applying information value method and logistic regression separately, the study zone was ultimately categorized into five classes, specifically,“extremely low”,“low”,“moderate”,“high”and“very high”. These results have been proved to reflect closely the spatial distributions of landslides in the study area.(4) It has been found that the predictive capability of logistic regression model appears to be more accurate comparing to information value method. It is mostly because logistic regression could reduce effectively the subjectivity in selection of evaluation factors and weight sum, this paper extracts some information from remote sensing data, analyses the characteristic of earthquake-induced landslides under a GIS environment and accordingly generates the susceptibility maps in Wenchuan County, which undoubtedly contributes to recovered construction, location of habitation and prevention of secondary disasters in the study area.
【中文關鍵詞】 地理資訊系統; 地震; 滑坡; 危險性評價; 資訊提取; 遙感