本文選題：Okeechobee湖流域 + 土壤重金屬��； 參考：《上海師范大學》2015年碩士論文

【摘要】：土壤是環(huán)境的重要組成部分,它是水、空氣和巖石之間進行生態(tài)循環(huán)的媒介。隨著經(jīng)濟的飛速發(fā)展、工農(nóng)業(yè)現(xiàn)代化水平的提高,很多地區(qū)土壤受到重金屬污染。對土壤重金屬的空間分布及污染狀況的研究,對于土壤環(huán)境保護與治理具有十分重要的意義。本文運用地統(tǒng)計學與GIS相結(jié)合的方法對美國Okeechobee湖流域土壤Cu、Zn、Pb、Cr、Cd、Co、Ni、Mn、Fe9種重金屬的空間分布特征及污染狀況進行分析,得到以下結(jié)論：1、研究區(qū)土壤重金屬數(shù)據(jù)統(tǒng)計特征分析結(jié)果表明：土壤表層Cu、Zn、Pb,亞表層Cu、Zn、Pb、Fe,均屬于強變異性,表層Fe、Cd、Co、Cr、Mn、Ni,亞表層Cd、Co、Cr、Mn、Ni的均屬于中等變異,表層Cu、Zn、Pb、Cd、Co,亞表層Cu、Zn、Pb、Fe、Cd、Co、Cr都不符合正態(tài)分布,而表層Fe、Cr、Mn、Ni,亞表層Mn、Ni均符合正態(tài)分布。2、半方差函數(shù)擬合結(jié)果表明：在各項同性條件下,土壤表層Cu、亞表層Cu分別符合球狀模型和指數(shù)模型,表層Zn和亞表層Zn均符合指數(shù)模型,表層Pb和亞表層Pb分別符合指數(shù)模型和球狀模型,表層Fe亞表層Fe符合球狀模型,表層Mn和亞表層Mn分別符合指數(shù)模型和高斯模型,表層Cd和亞表層Cd符合線性模型,表層Co、亞表層Co分別符合線性模型和高斯模型,表層Cr、亞表層Cr符合高斯模型,表層Fe、亞表層Fe符合球狀模型,表層Ni、亞表層Ni符合高斯模型。3、在各項異性條件下,各重金屬在不同方向上的變異函數(shù)差異較為明顯,除土壤表層Co、Fe,亞表層Co、Fe、Mn表現(xiàn)出較為明顯的各項同性特征外,其余均表現(xiàn)出明顯的方向性特點。土壤表層、亞表層Cd和表層、亞表層Cr在各個方向上變異程度均較大。表層Cu在2km范圍以外變化趨勢逐漸拉大,亞表層Cu在8km范圍之外,變化趨勢較為明顯。表層Mn在南北方向和西北-東南方向空間變化趨勢較大,表層、亞表層Ni在各個方向上變異程度均較大。表層Pb在7km之外變化趨勢較大,亞表層Pb在8km之外變化趨勢較大。表層Zn在各個方向上雖有變化,但是趨勢較為緩和。亞表層Zn在10km之外,西北-東南方向變化較大。4、交叉驗證結(jié)果顯示,表層土壤Cu以普通克里格插值效果最好,表層土壤Cu呈島狀與條帶狀分布相結(jié)合的特征,亞表層Cu采用泛克里格法插值效果最好,亞表層Cu的分布狀況與表層基本一致。表層Zn以普通克里格插值效果最好,表層土壤Zn呈島狀分布,亞表層Zn采用簡單克里格法插值誤差最小,呈島狀與塊狀結(jié)合分布。表層Pb以普通克里格插值效果最好,呈島狀分布,亞表層Pb以簡單克里格插值效果最好,亞表層Pb分布情況和表層類似,但含量明顯低于表層。表層Cd最適合析取克里格插值方法,呈塊狀分布,亞表層Cd采用普通克里格和泛克里格法插值精度最高,分布情況與表層類似。表層Co采用普通克里格和泛克里格插值誤差最小,呈塊狀分布,亞表層Co最適宜簡單克里格法,呈島狀和面狀分布相結(jié)合。表層Mn采用簡單克里格插值誤差最小,主要呈島狀分布,亞表層Mn采用簡單克里格法插值誤差最小,分布狀況與表層類似。表層Cr最適合的是析取克里格法,呈島狀與帶狀分布,亞表層Cr采用簡單克里格法插值誤差最小,分布狀況與表層相似。表層Fe也最適合普通克里格插值,呈現(xiàn)明顯的島狀與塊狀分布,亞表層Fe采用簡單克里格法插值,分布與表層相類似。表層Ni用簡單克里格法插值,亞表層Ni采用簡單克里格法,插值誤差較小,呈島狀分布。5、采用地累積指數(shù)法對重金屬污染狀況進行評價,結(jié)果顯示,研究區(qū)域土壤表層Cd污染比較嚴重,約70%的研究區(qū)域受Cd污染,污染區(qū)主要集中在研究區(qū)西北部和Okeechobee湖以南地區(qū)。近半數(shù)采樣點土壤Cu污染也較為嚴重,Cu污染較嚴重區(qū)域主要是在Okeechobee湖西北部和東南部,其分布受人為干擾的影響較大。根據(jù)潛在生態(tài)風險指數(shù)法評價結(jié)果,七種重金屬的生態(tài)風險由大到小分別為Cd、Cu、Pb、Ni、Zn、Mn、Cr,潛在生態(tài)危害指數(shù)RI=166.55,表明研究區(qū)域土壤表層重金屬污染存在中等生態(tài)危害。
[Abstract]:Soil is an important part of the environment. It is the medium of ecological circulation between water, air and rock. With the rapid development of the economy and the improvement of the modernization level of industry and agriculture, the soil is polluted by heavy metals in many areas. The study on the spatial distribution and pollution of heavy metals in the soil has ten. In this paper, the spatial distribution characteristics and pollution status of soil Cu, Zn, Pb, Cr, Cd, Co, Ni, Mn and Fe9 heavy metals in the soil of the Okeechobee Lake Basin in the United States were analyzed by using the method of geostatistics and GIS, and the following conclusions were obtained: 1, the statistical analysis of the data of the soil heavy gold in the study area showed that the soil surface layer Cu Surface Cu, Zn, Pb, Fe, all belong to strong variability, surface Fe, Cd, Co, Cr, Mn, Ni, subsurface Cd are medium variation. Under the condition, the soil surface Cu and subsurface Cu conforms to the spherical model and the exponential model respectively. The surface Zn and subsurface Zn conforms to the exponential model. The surface Pb and subsurface Pb conforms to the exponential model and the spherical model respectively. The subsurface Fe of the surface is conformed to the spherical model, and the surface Mn and the subsurface Mn conforms to the exponential model and the Gauss model respectively, and the surface Cd and subsurface are subsurface. Layer Cd conforms to linear model, surface Co, subsurface Co conforms to linear model and Gauss model respectively, surface Cr, subsurface Cr conforms to Gauss model, surface Fe, subsurface Fe conforms to spherical model, surface Ni, subsurface Ni conforms to Gauss model.3, under the various heterosexual conditions, the variation function of each heavy metal in different directions is more obvious, except soil The surface layer Co, Fe, subsurface Co, Fe, Mn showed obvious homosexual characteristics, and the rest showed obvious directional characteristics. The soil surface, subsurface layer Cd and surface layer, subsurface Cr in each direction have greater variation degree. The surface Cu is gradually widening from the 2km range, and the subsurface Cu is outside the 8km range. It is obvious that the surface Mn changes in the north and south direction and northwest to Southeast, and the surface layer and subsurface Ni have greater variation in each direction. The surface Pb changes outside the 7km, and the subsurface Pb has a larger trend outside the 8km. The surface Zn is changed in all directions, but the trend is relatively mild. Subsurface Zn Outside the 10km, the Northwest - southeast direction has a larger change of.4. The cross validation results show that the surface soil Cu is best with the common Kriging interpolation, the surface soil Cu is characterized by the combination of island and strip distribution, and the subsurface Cu is best interpolated by Pan Kriging, and the distribution of subsurface layer Cu is basically the same as the surface layer. The surface Zn is universal. The surface soil Zn has the best effect, the surface soil is distributed in the form of island, and the subsurface Zn adopts the simple Kriging method to interpolate the smallest error. The surface Pb is the best with the common Kriging interpolation. The subsurface Pb is best with simple Kriging interpolation, and the subsurface Pb distribution is similar to the surface layer, but the surface layer is similar to the surface layer, but the surface layer is similar to the surface layer. The content of the surface Cd is better than the surface layer. The surface Cd is the most suitable for the disjunctive method. The subsurface Cd has the highest interpolation accuracy with the ordinary Craig and the pan Craig method, and the distribution is similar to the surface layer. The surface Co uses the ordinary Craig and the pan Craig interpolation error to be the smallest, and the subsurface Co is the most suitable for the simple Craig. The surface Mn uses simple Kriging interpolation to minimize the error of simple Kriging interpolation. The subsurface Mn uses simple Kriging interpolation to minimize the error, and the distribution is similar to the surface layer. The surface Cr is most suitable for the precipitation Kriging method, the island and the banded distribution, the subsurface Cr is interpolated by simple Kriging method The error is the smallest and the distribution is similar to the surface layer. The surface Fe is also most suitable for ordinary Craig interpolation, showing obvious island and massive distribution. Subsurface Fe is interpolated by simple Craig method, and the distribution is similar to the surface layer. The surface Ni is interpolated by simple Craig method, and the subsurface Ni is simple monkrige method, the interpolation error is smaller,.5 distribution in the island shape is obtained. The method of land accumulation index is used to evaluate the pollution of heavy metals. The results show that the soil surface Cd pollution in the study area is more serious, about 70% of the research area is polluted by Cd. The polluted areas are mainly concentrated in the northwest of the research area and the south of the Okeechobee Lake. The soil Cu pollution is more serious in nearly half of the sampling points, and the most serious area of Cu pollution is the main area. According to the potential ecological risk index method, the ecological risk of seven kinds of heavy metals is Cd, Cu, Pb, Ni, Zn, Mn, Cr, and the potential ecological hazard index RI=166.55, according to the evaluation result of the potential ecological risk index method, which indicates that the soil surface heavy metal pollution in the study area has medium ecological danger. Harm.

【學位授予單位】：上海師范大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：X53;X825

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本文編號：1837313