【摘要】：5.12特大地震,汶川縣作為震源中心區(qū)域,其境內(nèi)不僅誘發(fā)了大量的地震滑坡災(zāi)害,地表與生態(tài)環(huán)境更是遭受近乎毀滅性的破壞,大量的松散巖土體堆積在溝谷之內(nèi)。在震后數(shù)年時間,地表環(huán)境恢復(fù)緩慢,特別在高陡的山區(qū),植被恢復(fù)尤顯困難。加之在余震,強降雨及人類工程活動等影響之下,很多潛在不穩(wěn)定斜坡進而失穩(wěn)形成滑坡,原有滑坡的地方也誘發(fā)再次滑坡,溝谷中大量松散物質(zhì)隨水流沖刷而下形成泥石流災(zāi)害。特別近年汛期內(nèi),汶川縣多次爆發(fā)群發(fā)性泥石流災(zāi)害,堵斷河流,沖毀房屋、橋梁,淤埋道路,給當?shù)鼐用裨斐闪穗y以想象的損害�？偨Y(jié)而言,在震后很長一段時間內(nèi),汶川縣將處于滑坡、泥石流災(zāi)害頻發(fā)多發(fā)期。基于此,本文以汶川縣為例,依托于中國地質(zhì)調(diào)查局地質(zhì)調(diào)查工作項目—“西南地區(qū)重大地質(zhì)災(zāi)害調(diào)查評價與早期預(yù)警綜合研究”,在對全縣滑坡、泥石流災(zāi)害進行遙感解譯的基礎(chǔ)上,采用GIS與數(shù)學(xué)模型結(jié)合、GIS與數(shù)值模擬結(jié)合兩大類技術(shù)方法分別完成汶川全縣滑坡危險性評價、汶川全縣泥石流危險性評價、映秀地區(qū)滑坡危險性評價以及汶川縣城泥石流危險性評價四個不同區(qū)域、不同空間尺度的地質(zhì)災(zāi)害危險性評價研究。本文研究以給予當?shù)卣m當?shù)囊?guī)劃建設(shè)與防災(zāi)減災(zāi)參考為現(xiàn)實目的,其主要收獲有以下幾點:1、統(tǒng)計分析研究區(qū)滑坡災(zāi)害分布現(xiàn)狀基于全縣近年遙感影像與航拍照片,在野外調(diào)查的協(xié)助下,本文對全縣滑坡災(zāi)害進行了點狀解譯,對映秀地區(qū)滑坡進行面狀解譯。本文以解譯災(zāi)害點為統(tǒng)計樣本,分別對滑坡在地層巖性、地震烈度帶、距離水系距離、坡度、高程等因子上的分布進行統(tǒng)計歸納。這些滑坡的分布情況不僅僅為此次滑坡危險性評價分區(qū)提供基礎(chǔ)的信息參考,同時也為未來震后滑坡發(fā)育特征研究提供了良好的依據(jù)。2、論述了多種評價單元在區(qū)域性的評價分析中,最為基礎(chǔ)性的工作便是選擇一個合理的評價單元。本文在綜合考慮了空間尺度、災(zāi)害性質(zhì)等因素,選取了柵格單元、斜坡單元與集水單元三類單元作為基礎(chǔ)評價單元,在論述其各自特征的基礎(chǔ)上,采用它們分別完成了汶川全縣滑坡、泥石流災(zāi)害的危險性評價與制圖。由此為以后區(qū)域地質(zhì)災(zāi)害危險性評價單元的選取問題提供了有益的參考。3、嘗試多種危險性評價手段本文將危險性定義為易發(fā)性與時間頻率的乘積綜合,即危險性=易發(fā)性×時間頻率。這便從定義上突破了國內(nèi)部分學(xué)者將易發(fā)性與危險性等同的概念定義,將危險性視作一種可隨時間動態(tài)變化的一種屬性。對于滑坡災(zāi)害,本文在滑坡易發(fā)性的基礎(chǔ)上引入滑坡點核密度與降雨分布兩類因素間接描述滑坡的時間頻率,其中滑坡點核密度是滑坡活動強度的量化表述,其基礎(chǔ)理論是在滑坡頻發(fā)多發(fā)區(qū)域,其環(huán)境破壞應(yīng)越加嚴重,在越短的時間段內(nèi)該區(qū)域發(fā)生滑坡的可能性也理應(yīng)高于其它區(qū)域。最后綜合易發(fā)與頻率兩大因素計算區(qū)域滑坡危險性。至于全縣泥石流災(zāi)害,本文則探索性地從先天條件(地形地貌),后天儲備(物源狀態(tài))與活動頻率(觸發(fā)頻率)三個宏觀層面綜合評判泥石流危險性。最后以集水流域為包容單元,分析歸納全縣各區(qū)域面臨的泥石流災(zāi)害危險性。至于汶川縣城兩條泥石流溝(南溝、羊嶺溝),本文則采用數(shù)值模擬的方式完成泥石流危險性評價與區(qū)域劃分工作。4、危險性分區(qū)本文以汶川全縣、映秀地區(qū)與汶川縣城區(qū)域三個區(qū)域作為研究區(qū),從不同的空間尺度上完成了三個區(qū)域滑坡、泥石流災(zāi)害的危險性等級區(qū)劃工作,其中包括全縣滑坡危險性分區(qū)、全縣泥石流危險性分區(qū)、映秀地區(qū)滑坡危險性分區(qū)以及汶川縣城泥石流堆積區(qū)危險性分區(qū)。此類區(qū)劃工作為汶川縣政府實施防災(zāi)減災(zāi)與工程建設(shè)工作提供有益的參考建議。
[Abstract]:5.12 great earthquake, Wenchuan County as the center of the center of the earthquake, its territory not only induced a large number of earthquake landslides, the surface and the ecological environment are almost devastating, a large number of loose rock mass accumulated in the valley. In the years after the earthquake, the surface environment is slow, especially in the high and steep mountains, the vegetation recovery is especially obvious. In addition to the influence of aftershocks, heavy rainfall and human engineering activities, many potential unstable slopes then destabilized to form landslides, and the landslides caused landslides again. A large number of loose materials in the valley were washed down with the flow of debris and formed debris flow. In recent years, in the flood season, Wenchuan County broke out of mass debris flow many times. Damage, plugging and breaking rivers, destroying houses, bridges, and buried roads have caused unimaginable damage to the local residents. In summary, Wenchuan county will be in a long period of time after the earthquake, and the debris flow disasters frequently occur. Based on this, this article takes Wenchuan County as an example, according to the geological survey work project of the China Geological Survey - "southwest" On the basis of remote sensing interpretation of the county landslides and debris flow disasters, GIS and mathematical models are combined with two major technical methods, GIS and numerical simulation are combined to complete the landslide hazard assessment in Wenchuan County, and the risk assessment of debris flow in Wenchuan County, Yingxiu, on the basis of remote sensing interpretation of the county landslides and debris flow disasters. The risk assessment of regional landslides and the risk assessment of debris flow hazard in Wenchuan County four different regions and different spatial scales of hazard assessment of geological hazards. This study aims to give local government appropriate planning and construction and disaster prevention and mitigation reference. The main results are as follows: 1, landslide disaster in statistical analysis and research area The present situation of the damage distribution is based on the remote sensing image and aerial photograph of the county in recent years. With the assistance of the field survey, the landslide disaster in the county is interpreted in this paper, and the landslide in Yingxiu area is interpreted face-to-face. This paper takes the interpretation of the disaster points as the statistical samples, and respectively to the stratigraphic rock, seismic intensity zone, distance water distance, slope, elevation respectively. The distribution of these factors is summed up. The distribution of these landslides not only provides information for the basis of the landslide hazard assessment division, but also provides a good basis for the study of the development characteristics of the future post earthquake landslides, and discusses the most basic work in the regional evaluation and analysis of a variety of evaluation units. In this paper, a reasonable evaluation unit is chosen. In this paper, the grid unit, the slope unit and the water collecting unit are selected as the basic evaluation units, which are taken into consideration of the spatial scale and the nature of the disaster. On the basis of their respective characteristics, the landslide hazard assessment of the Wenchuan county and the debris flow hazard is completed respectively. Price and mapping provide a useful reference for the selection of regional geological hazard risk assessment unit (.3), and a variety of risk assessment methods are tried to define the risk as the product synthesis of the susceptibility to time and frequency, that is, risk = prone x time frequency. The concept definition of the equivalent of risk and hair is considered as a kind of property that can change dynamically with time. For landslide disaster, this paper describes the time frequency of landslide indirectly by introducing two factors of landslide point nuclear density and rainfall distribution on the basis of landslide susceptibility. The core density of landslides is the quantification of landslide activity intensity. The basic theory is that the basic theory is in the frequent occurrence area of landslide, its environmental damage should be more serious, and the possibility of landslide in the region should be higher than other regions in the shorter time period. Finally, the landslide hazard is calculated by two factors that are easy to hair and frequency. As for the whole county debris flow disaster, this article explores from the innate bar. The hazard of debris flow is evaluated synthetically by the three macro levels, such as topographic and geomorphology, day after day reserve (source state) and activity frequency (triggering frequency). Finally, the hazard of debris flow disaster in all regions of the county is analyzed and summed up with water catchment basin as an inclusive unit. As for the two debris flow gully (south ditch, Yang Ling Gou) in Wenchuan County, the numerical model is used in this paper. The risk assessment and regional division work of debris flow are completed by the proposed method.4. In this paper, three regions of Wenchuan County, Yingxiu area and Wenchuan county area are taken as research areas in this paper, and three regional landslides and dangerous grade zoning of debris flow disasters are completed from different spatial scales, including the landslide hazard in the county. The zoning, the hazard zoning of the whole county debris flow, the landslide hazard zoning in Yingxiu area and the hazard zoning of the debris flow accumulation area in the Wenchuan county city provide useful reference for the government of Wenchuan county to implement the disaster prevention and disaster reduction and the construction work.
【學(xué)位授予單位】：成都理工大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：P694

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