本文選題：長江中下游 + 徐六涇��； 參考：《華東師范大學(xué)》2017年碩士論文

【摘要】：通過對長江流域中下游大面站與河口觀測相結(jié)合,對懸浮顆粒物中元素含量、元素賦存形態(tài)的時空分布規(guī)律進行分析,探討流域大規(guī)模泥沙攔截以及人類活動重金屬污染輸入不斷增加的大背景下,中下游干流物質(zhì)來源的調(diào)整及季節(jié)調(diào)配的改變,取得了以下初步認識:長江中下游干、支流懸浮顆粒物中元素組成差異明顯。相對于長江干流,清江顆粒態(tài)Al、Fe、Cr、Ni、Cu、Zn、Pb、Cd元素含量遠低于干流,差異在30%以上,Mn元素含量遠高于干流,約為干流的7倍。漢江Al、Fe、Mn、Cr、Ni、Cu、Zn、Cd、Pb等元素含量遠低于干流,差異在50%以上。相對于清江、漢江,洞庭湖因其分泄長江水沙,其顆粒物組成與干流差異相對較小,Al、Fe、Mn、Cr、Ni、Zn元素與干流差異在10%以內(nèi),Cu、Cd、Pb元素與干流差異相對較大,在20%以上。盡管洪季懸浮顆粒物濃度沿程不斷降低,但其懸浮顆粒物中金屬元素含量自宜昌向下游組成非常穩(wěn)定,Al、Fe、Mn、Cr、Ni、Zn、Cd、Pb.元素含量的變異系數(shù)均在 10%以內(nèi),平均值分別為 8.3%、5.2%、0.12%、108μg/g、56μg/g、191μg/g、1.06μg/g、79μg/g。與流域大規(guī)模人類活動影響之前的文獻數(shù)據(jù)相比,元素組成并沒有發(fā)生顯著改變,基本仍代表典型的流域自然風化輸入。洪季在上游大量顆粒物輸入的作用下,中游河床侵蝕及支流輸入對干流的貢獻有限,此外,人類活動重金屬污染輸入的影響也并不顯著。枯季顆粒物元素組成及其沿中下游干流濃度變化明顯,Al、Mn、Cu、Zn、Cd、Pb等元素的變異系數(shù)較大均在20%以上,其中Mn、Cd、Pb等元素變異系數(shù)達30%以上,同時平均值遠大于80年代的數(shù)據(jù),這表明枯季流域的物源組成發(fā)生了重大調(diào)整,支流貢獻與中游河床侵蝕粗化對元素組成的影響顯著增加。漢江的匯入使得黃石站Cu、Zn、Cd、Pb元素相對于洪湖站有30%以上幅度的降低,鄱陽湖的匯入使得彭澤站Cu、Zn、Cd、Pb元素含量有20%以上幅度的降低。洪、枯季稀土元素的沿程分布的穩(wěn)定程度也體現(xiàn)了其物源上的差異。洪季各稀土元素變異系數(shù)較小,多在10%以內(nèi),沿程分布極為穩(wěn)定,而枯季稀土元素變異系數(shù)較大,多在30%以上。這是由洪、枯季顆粒物來源不同所致。從配分模式來看,長江顆粒物來源于大陸上地殼風化輸入,其相對于球粒隕石發(fā)生一定程度的分異。經(jīng)北美頁巖標準化后,洪、枯季各稀土元素的相對值在1左右,顆粒物稀土組成與北美頁巖相似度較高。Zn、Pb、Cd元素在枯季干流懸浮顆粒物中的含量顯著高于洪季,且經(jīng)A1歸一化后在中游洪湖、黃石站仍高于洪季組成,表明這些元素受人類活動污染輸入的影響較為顯著。通過干流的洪、枯季對比發(fā)現(xiàn),人類活動污染輸入影響主要出現(xiàn)在洪湖、黃石站。自鄱陽湖向下游,由于鄱陽湖采砂擾動帶來低重金屬污染的老沉積物輸入的稀釋作用,彭澤站Cu、Zn、Pb、Cd元素含量顯著下降,這種變化在元素可提取態(tài)含量中極為顯著,Cu、Zn、Cd、Pb元素的可提取態(tài)含量分別有15%、60%、68%、41%幅度的降低,這對Zn、Cd元素E1態(tài)、Cu、Zn、Cd、Pb元素E2態(tài)、Cu、Zn元素E3態(tài)有一定的稀釋作用。徐六涇定點站金屬元素含量和賦存形態(tài)與流域有著相似的季節(jié)變化規(guī)律,但這種季節(jié)差異不如流域更為顯著。枯季(10月-次年4月)Cu、Zn、Cd、Pb等大部分金屬元素含量的平均值略高于洪季(5-9月),枯季Cr、Ni、Zn、Cd、Pb元素的可提取態(tài)含量不同程度的高于洪季,表明人類活動輸入對金屬元素含量的影響在枯季更明顯,但經(jīng)過中游河床侵蝕、支流匯入的稀釋作用,這種洪、枯季差異有所減小。
[Abstract]:Through the combination of the large surface station and the estuarine observation in the middle and lower reaches of the Yangtze River Basin, the temporal and spatial distribution of elements and elements in the suspended particles is analyzed. The adjustment of the source of the main stream in the middle and lower reaches and the seasonal adjustment are discussed under the background of the large-scale sediment interception and the increasing input of heavy metal pollution in human activities. In the middle and lower reaches of the Yangtze River, the difference of element composition in the suspended particles in the middle and lower reaches of the Yangtze River is obvious. Relative to the main stream of the Yangtze River, the content of Al, Fe, Cr, Ni, Cu, Zn, Pb, Cd is far below the main stream, and the difference is more than 30%, the content of the Mn element is far higher than that of the main stream, which is about 7 times that of the main stream. The content of the equal elements is much lower than that of the main flow, and the difference is more than 50%. Compared with Qingjiang, the Qingjiang, the Han River, the difference in the particle composition and the main flow of the Yangtze River is relatively small because it divides the water and sediment of the Yangtze River. The difference of Al, Fe, Mn, Cr, Ni, Zn elements is within 10%, Cu, Cd, and the difference of Pb elements and the main flow is more than 20%. Although the concentration of suspended particles in the flood season along the range However, the content of metal elements in the suspended particulate matter is very stable from Yichang to the lower reaches. The variation coefficients of Al, Fe, Mn, Cr, Ni, Zn, Cd, Pb. elements are all within 10%, the average value is 8.3%, 5.2%, 0.12%, 108 micron, 56 mu, 191, g/g, 1.06 mu g/g, and 79 micron before the large-scale human activities in the basin. There is no significant change in the element composition, and it still represents a typical natural weathering input in the basin. In the flood season, the contribution of the river bed erosion and the tributary input to the main stream is limited under the action of a large number of particles in the upper reaches of the upper reaches. In addition, the influence of the input of heavy metal pollution in human activities is not significant. The variation of the concentration of the main stream along the middle and lower reaches is obvious. The variation coefficients of the elements such as Al, Mn, Cu, Zn, Cd, Pb are all larger than 20%, of which the coefficient of variation of elements such as Mn, Cd and Pb is above 30%, and the average value is far greater than that of the 80s data. This indicates that the source composition of the dry season basin has been greatly adjusted, the tributary contribution and the erosion of the middle reaches of the river bed have been coarsened to the element group. The remittance of the Han River makes the Cu, Zn, Cd, Pb elements of the HuangShi Railway Station lower than 30% of the Honghu station, and the remittance of Poyang Lake makes the content of Cu, Zn, Cd, Pb elements in the Pengze station lower than 20%. The stability of the distribution of rare earth elements along the flood season also reflects the difference in its source. The coefficient of variation of rare earth elements is smaller, more than 10%, and the distribution of rare earth elements is very stable, while the variation coefficient of rare earth elements in the dry season is larger than 30%. This is the result of the different sources of the grain in the flood season and the dry season. After the standardization of the North American shale, the relative value of the rare earth elements in the flood season and the dry season is about 1, the composition of the rare-earth particles and the North American shale is high.Zn, Pb and Cd in the dry season suspended particles in the dry season are significantly higher than those in the flood season, and in the middle reaches of Honghu after A1 normalization, the HuangShi Railway Station is still higher than the flood season, indicating that these elements are affected by people. In the dry season, the influence of human activity pollution input mainly appeared in Honghu, HuangShi Railway Station. From Poyang Lake to the lower reaches, the content of Cu, Zn, Pb, Cd elements in Pengze station decreased significantly from the dilution effect of the old sediment input to the low heavy metal pollution caused by the sand mining disturbance in Poyang Lake. The extractable state content of Cu, Zn, Cd, Pb is 15%, 60%, 68%, 41%, respectively. It has a certain dilution effect on Zn, Cd element E1 state, Cu, Zn, Cd, Pb element E2 state and Pb element. The metallic element content and occurrence form of the Xuzhou six jingpoint station are similar to the watershed. The seasonal variation is not as significant as that of the watershed. The average value of most metal elements such as Cu, Zn, Cd and Pb in the dry season (October - April) is slightly higher than that of the flood season (5-9 months), and the extractable state of Cr, Ni, Zn, Cd, and Pb in the dry season is high Yu Hongji, indicating the influence of human activity input on the content of metal elements in the dry season. The season is more obvious, but after the middle reaches of the river bed erosion, the dilution effect of the tributaries converge, this flood and dry season difference has decreased.

【學(xué)位授予單位】：華東師范大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：X522;P342

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