本文選題：三峽大壩 + 川西地震��； 參考：《電子科技大學(xué)》2014年碩士論文

【摘要】：三峽大壩自2003年開(kāi)始蓄水至2006年正式竣工,規(guī)模巨大,舉世矚目。但三峽大壩庫(kù)容巨大,可能會(huì)誘發(fā)地震,國(guó)內(nèi)外許多學(xué)者都針對(duì)這一問(wèn)題進(jìn)行了探究,但這些研究都是針對(duì)庫(kù)區(qū)的,而且大多是從地質(zhì)學(xué)、地震學(xué)角度出發(fā)。本文利用數(shù)理方法從地震數(shù)據(jù)本身出發(fā),從統(tǒng)計(jì)學(xué)角度對(duì)三峽大壩對(duì)遠(yuǎn)距離庫(kù)區(qū)以外區(qū)域地震的影響展開(kāi)研究,以川西為例,主要工作包含以下幾個(gè)方面:1.研究、分析、歸納川西地震呈現(xiàn)的特征規(guī)律,有以下幾點(diǎn):(1)三峽水庫(kù)建造后18年較之前18年川西地區(qū)的地震頻次有大幅增長(zhǎng)。(2)三峽大壩蓄水前川西地震的分布較為分散,低水位蓄水期時(shí),地震主要分布在安寧河斷裂帶周?chē)?少量分布在鮮水河斷裂帶附近,隨著水位繼續(xù)上升,地震開(kāi)始向龍門(mén)山斷裂帶附近聚集,并呈現(xiàn)向安寧河斷裂帶靠近的趨勢(shì)。(3)隨蓄水水位上升,長(zhǎng)江流域的地震向川西地區(qū)聚集。(4)三峽大壩在每個(gè)蓄水期的震源深度均值都比蓄水前小,高水位蓄水期間變化更明顯。(5)三峽大壩高水位時(shí)地震釋放的能量高于低水位時(shí)地震釋放的能量。2.利用傅立葉變換技術(shù)從頻域角度驗(yàn)證三峽大壩水位曲線與川西地震頻次曲線變化趨勢(shì)上的相似性,又從統(tǒng)計(jì)學(xué)角度利用二者的相關(guān)系數(shù)驗(yàn)證是否存在相關(guān)性,結(jié)論表明,兩者之間確實(shí)存在某種程度上的相關(guān)性。3.從川西地區(qū)重力場(chǎng)變化角度對(duì)此相關(guān)性及上面發(fā)現(xiàn)的地震規(guī)律做出相應(yīng)驗(yàn)證。伴隨三峽水庫(kù)蓄水和放水活動(dòng),川西地區(qū)重力場(chǎng)呈現(xiàn)正變化和負(fù)變化;水位上升初期,重力場(chǎng)變化不明顯,隨時(shí)間延長(zhǎng),重力場(chǎng)變化逐漸增大。所以水庫(kù)水位變化影響川西地區(qū)重力場(chǎng),而重力場(chǎng)動(dòng)態(tài)變化能夠反映地球內(nèi)部物質(zhì)變化和變形過(guò)程,并與地震有緊密聯(lián)系。所以三峽大壩會(huì)通過(guò)影響川西重力場(chǎng)變化間接影響川西地震活動(dòng)。4.最后結(jié)合三峽大壩自身,分析三峽大壩對(duì)川西地震活動(dòng)產(chǎn)生影響的原因,得出結(jié)論——三峽大壩的建造在一定程度上對(duì)川西地震活動(dòng)產(chǎn)生影響。
[Abstract]:The three Gorges Dam has been impounded since 2003 until its completion in 2006. But the reservoir capacity of the three Gorges Dam is huge, which may induce earthquakes. Many scholars at home and abroad have explored this problem, but these researches are aimed at the reservoir area, and most of them are from the point of view of geology and seismology. In this paper, the effect of the three Gorges Dam on earthquakes outside the remote reservoir area is studied from the point of view of statistics from the seismic data itself by mathematical method. Taking West Sichuan as an example, the main work includes the following several aspects: 1. Study, analysis and summary of the characteristics of the earthquake in western Sichuan, there are the following points: 1) after the three Gorges Reservoir was built, the earthquake frequency in the west of Sichuan increased significantly after 18 years compared with the previous 18 years. 2) the distribution of the earthquakes in the west of Sichuan before the three Gorges Dam impounding is relatively scattered. During the period of low water level storage, the earthquakes mainly distributed around the Anning River fault zone, and a few distributed near the Xianshuihe fault zone. As the water level continued to rise, the earthquake began to gather near the Longmenshan fault zone. There is a tendency of approaching to the Anning River fault zone. (3) with the water level rising, the earthquakes in the Yangtze River basin gather to the west of Sichuan. 4) the mean of the focal depth of the three Gorges Dam in each storage period is smaller than that before the water storage. The energy released by the three Gorges Dam at high water level is higher than that at low water level. The Fourier transform technique is used to verify the similarity between the water level curve of the three Gorges Dam and the seismic frequency curve in the west of Sichuan Province from the angle of frequency domain, and the correlation coefficient of the two curves is used to verify the correlation from the statistical point of view. There is a certain degree of correlation between the two. From the angle of variation of gravity field in western Sichuan, the correlation and the seismic law found above are verified. Along with the water storage and discharge activities of the three Gorges Reservoir, the gravity field in western Sichuan presents positive and negative changes, but at the initial stage of water level rise, the change of gravity field is not obvious, and the variation of gravity field increases with time. Therefore, the variation of reservoir water level affects the gravity field in western Sichuan, and the dynamic variation of gravity field can reflect the material change and deformation process in the earth's interior, and is closely related to earthquakes. Therefore, the three Gorges Dam will indirectly affect seismic activity. 4. 4 by influencing the variation of gravity field in western Sichuan. Finally, combined with the three Gorges Dam itself, the causes of the influence of the three Gorges Dam on the seismic activity in western Sichuan are analyzed, and the conclusion is drawn that the construction of the three Gorges Dam has an effect on the seismic activity in the west of Sichuan to a certain extent.
【學(xué)位授予單位】：電子科技大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2014
【分類號(hào)】：TV697.24
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本文編號(hào)：1803711