【作者】 徐明星；

【导师】 赵其国； 周生路；

【作者基本信息】 南京大学 ， 自然地理学， 2011， 博士

【摘要】 土壤性质的演化关系到土壤可持续利用和区域可持续发展,理解其演化速率、机制和效应及其与环境条件变化的相互关系是土壤资源可持续管理的基础。沿海滩涂位于海陆交互过渡带,能量交换、物质迁移转化频繁,对人类活动响应剧烈,其土壤在自然和人为综合作用下演化相对快速,特别是其处于动态环境中的时间序列,能够追踪到土壤性质的演化过程和相关中间产物,是研究土壤性质演化的理想类型。江苏沿海滩涂面积不断淤涨,随着沿海发展上升为国家战略,其土壤性质的演化过程势必要受到更多的人为影响。土壤高光谱反射率作为土壤性质的综合反映,具有指示土壤性质演化的作用,特别是生态高值农业的发展需要在高新农业技术方面进行创新,其中就包括全球卫星定位支持的精准农业技术。基于以上背景,本研究以Ti/Zr比值判定剖面土壤具有成土母质连续性后,通过建立江苏沿海滩涂地区土壤时间序列,并与沿海、内陆考古遗址盐碱土进行对比,分析土壤性质的时空变化规律；讨论成土母质和人类活动对土壤性质变化的影响,定量分离不同成土母质来源的贡献；结合反射高光谱快速、无损的检测优势,对时间序列滩涂土壤、及其与考古遗址土壤性质演化的差异进行表征,应用偏PLSR法,研究原始光谱(REF)、一阶微分光谱(FDR)、光谱倒数之对数(1g(1/R))和波段深度(BD)4类光谱指标对时间序列土壤性质的反演能力,应用相关分析和多元变量统计方法,构建考古遗址土壤性质的高光谱反演模型。通过研究得到以下结论：(1)江苏沿海滩涂土壤属性在水平和垂直方向上具有多种变化特征水平方向上,以粉砂为主的时间序列土壤粒度组成与成陆时间之间、土壤微量元素(除Cd)、常量元素(除Mg)与成陆时间之间均具有线性回归或先增(减)后减(增)的Shah指数函数关系；随成陆时间增加,土壤肥力不断提高；土壤基本理化性质与成陆时间之间存在一阶对数函数和线性回归的关系。垂直方向上,土壤粒度组成在时间序列剖面中呈线性变化；土壤肥力在沿海东台(DT)和掠港(JG)剖面随深度呈一阶指数函数变化,在安丰(AF)剖面呈Shah指数变化,而在考古遗址剖面总体.上表现为现代耕层高于古文化层；基本理化性质在DT剖面中呈Shah指数函数变化,在考古遗址剖面表层出现不同程度的酸化特征。十壤微量元素含量在时间序列和梁王城(LWC)考古遗址剖面呈线性回归和Shah指数变化。JG剖面Zn元素外源组份含量自1910年以来以0.39mg(kg.a)-’的速率减小,相对变化率达0.6%a-1；DT剖面和LWC考古遗址剖面土壤微量元素外源组份含量随时间分别呈指数递减和递增变化；藤花落(THL)遗址L-1剖面As元素外源组份含量从底部至表层似乎逐渐减小,而Pb和Zn则似乎不断增加,而L-2剖面微量元素外源组份含量在各层位相对稳定。(2)成土母质奠定了江苏沿海滩涂土壤属性的总体状况,人类活动对其产生深刻影响1910年以来,JG剖面长江入海携带泥沙成土母质贡献率从剖面底部的3%上升至表层的21%,黄河入海携带泥沙成土母质贡献率从97%降至79%；AF剖面底部具有较高的海相堆积成土母质,至剖面上部,河流搬运泥沙母质占主导；DT剖面河流沉积母质变化于23%至46%之间,湖泊沉积母质的贡献率介于54%至77%之间；THL遗址的生活区(L-1)剖而土壤残积母质从表层的94%下降至底层的32%,坡积母质则呈相反变化；生产区(L-2)剖面土壤残积和坡积母质的含量相对稳定；LWC遗址剖而表层土壤坡积母质占97%,河流沉积母质仅占3%,以下下各层位坡积母质变化于44%至76%之间,剖面局部层位可能存在下蜀黄土成土母质。时间序列土壤Cr、Cu、Ni和Pb含量主要受成土母质控制,而zn含量主要受人类活动影响,Cd元素受上述两类因素综合作用。河流沉积母质对Cd、Cr和Ni的贡献率分别为47%、29%和48%,海洋沉积物的贡献率分别为53%、58%和40%,下蜀黄土贡献了另外13%的Cr和Ni含量。Zn元素含量自然来源占35%,低于人为强干扰组份65%的比重,说明人类活动已成为研究区Zn元素的主要来源。THL遗址剖面土壤微量元素具有2个来源,残积母质分别贡献了Cd、Cr、Cu和Zn含量的67%、58%和72%和33%,坡积母质则分别贡献了33%、42%、28%和66%；对Pb元素而言,自然组份和人为组份均贡献了50%。(3)高光谱反射率能够有效表征江苏沿海滩涂地区土壤性质演化的差异时间序列剖面土壤光谱反射率要低于考古遗址剖而土壤,且在可见光波段随着波长的增加,光谱反射率增长较快,曲线斜率较大。时间序列剖面上壤在Fe2+和Fe3+特征吸收波段的吸收深度要明显深于考古遗址剖面土壤,而在1400、1900和2200nm附近的光谱特征吸收波段的吸收深度则小浅十考古遗址剖面土壤。时间序列土壤性质的PLSR预测方程的收敛速度和反演精度具有成陆白年样本>成陆千年样本>总体样本的特征,所选主成分的个数则相反,模型R2分别大于0.9876、0.9805和0.71。光谱微分变换有助于提取考古土壤属性信息,基于多元线性逐步回归的反演模型要优于比率模型和弓曲差模型,R2均大于0.71,最大值为0.97,RMSE均小于6.18,最小值仅为0.004,表明模型较高的稳定性和预测性。更多还原

【Abstract】 The evolution of soil properties is relevant to the sustainable soil resources utilization and region development. Understanding the rate, mechanism and effect of soil properties evolution and its relationship with changing environment is the basis for sustainable management of soil resources. Coastal tidal region located at the interaction zone of ocean and continent, has the characteristics of frequent energy exchange and material migration, and thus, its response to human activities is violent. Soil in coastal tidal region is the ideal type of study the evolution of soil property due to its relatively fast evolution rate to the combined natural and artificial effect, and its chronosequence has beening in a dynamic environment, and thus has the opportunity for us to trace the process and intermediate during the evolution process. With the development of Jiangsu coastal ascend as national strategy, the coastal tidal of Jiangsu province, has accreting gradually, is bound to face a higher strength of the human role in the evolution of soil properties. Soil hyperspectral reflectance as a comprehensive reflection of soil properties, has the function of label the difference of soil properties evolution, especially the development of eco-high-value agriculture need the innovation in high-tech agricultural technology, which including GPS supportted precisive agriculture technology.Based on the above background, the spatial and temporal variation of soil properties was analysised through constructing soil chronosequence in the tidal region of Jiangsu province and compared to archaeological sites soil, the influence of parent material and human activities on the evolution of soil properties was diccussed, and contribution of different parent materials was partitioed quantitively, the difference in spectral reflectance between chronosequential soil profiles and archeological profiles was presented through take advantage of rapid and non-destructive testing of hyperspectral reflectance. Apply PLSR method to study the capability of REF, FDR, 1g (1/R) and BD in predicting the soil properties evolution and correlation analysis and multivariate statistical methods to construct hyperspectral models for retrieving archaeological soil properties. The results summried as follows:(1) Soil properties in the coastal tidal region of Jiangsu province have multiple variation lendnecyIn horizontal direction, chronosequential soil size composition, which dominated by silt, and trace elements (except Cd) and major elements (except Mg) has linear regression or Shah Exponential function (SEF) relationship with pedogenic time. The longer of pedogenic time, the higher of soil fertility, and vice verse. The basic physical and chemical properties of chronosequentrial soil varied in accordance with First Order Logarithm function (FOLF) and Linear Regression equation (LRE).In vertical direction, grain size parameters of chronosequential soil show linear variation. Soil fertility indexes vary with First Order Exponential function (FOEF) in profile of Dongtai (DT) and Jianggang (JG), and with SEF in profile of Anfeng (AF), and surface soil of archaeological profile of Tenghualuo (THL) has higher fertility. The basic physical and chemical properties of in profile (DT) varied in accordance with SEF. Trace elements content in chronosequential soil and LWC relic varying followed LRE and SEF in vertical direction.The anthropogenic component of Zn content decreased at rate of 0.39mg (kg.a)-1 since 1910, and at the relative variaitoin rate of 0.6%a-1. The anthropogenic component of trace elements in profile of DT and LWC present variation of confirm to expotential law. The anthropogenic component of As in profile of L-1 dereased gradually from bottom to surface layer, and increased for Pb and Zn.(2) Parent material laid the general situation of soil properties in the coastal tidal region of Jiangsu province and human activities have a significant influence on its evolution.Since 1910, the parent material of sediments carried by Changjiang River increased from 3% to 21% from bottom to top of JG profile, by contrast, the sediments carried by Huanghe River decreased from 97% to 79%. Marine and fluvial deposits occupy higher ratio in lower and higher part of AF profile respectively. The parent material of fluvial sediments account for 23% to 46% in DT profile and the contribution of lake sediments ranged from 54% to 77%. The component of residual parent material accounted for 94% in surface layer and descends to 32% in bottom layer of profilre L-1 of THL relic, in contrast, the component of slope sediments shows an opposite trend. The contribution of residual parent material and slope sediments plays a same role in L-2 profile of THL relic. Slope sediments account for 97% parent material in arable layer of LWC relic, ranged from 44% to 76% in other layers, and Xiashu loess parent material may exist in part layers.As far as chronosequential soil concerned, the content of Cr, Cu, Ni and Pb under the control of parent material, the content of Zn mainly derived from anthropogenic activities, however, the content of Cd is influced by the two factors of above-mentioned. Fluvial sediment accounted for 47%,29% and 48% in the content of Cd, Cr and Ni respectively, the contribution of marine sediment is 53%,58% and 40% respectively, Xiashu loess cobtributed another 13% content Cr and Ni. Natural componen accounted for 35% in the content of Zn, lower than the contribution of 65% of the strong huma(?) disturbance component, which indicate the signifivant effect of human activities on the content of Zn i(?) the study area directly. Frequency distribution function fitting indicate that residual parent materia accounted for 67%,58%,72% and 33% in the content of Cd, Cr, Cu and Zn and slope sedimei contributed 33%,42%,28% and 66% respectively in THL relic. Natural and anthropogenic compone have same contribution in the content of Pb.(3) Hyperspectral reflectance is a powerful tool for represent difference of soil proper evolution effectivelySoil hyperspectral reflectance in the chronosequential profiles is lower than soil in archaeological profile. With the increase of wavelength in visible light, the soil hyperspectral reflectance and the slope of reflectance curve ascends rapidly. Absorption depth of chronosequential soil in the characteristic asorption band of Fe2+and Fe3+is deeper than the archaeological soil, in the contrast, in the 1400,1900,2200nm is shallower than the archaeological soil.Convergence rate and predicigting accuracy of partial least square regression (PLSR) equation for predicting chronosequential soil properties has the characteristics of samples in centural scale> samples in millennium scale> overall samples, The R2 is 0.9876,0.9805 and 0.71 respectively. More information of archeological soil was extracted after the original spectra derivate transformed. The stepwise linear regression model is superior to the ratio model and bow-curvature model, with a minimum R2 of 0.71 and maximum rmse of 6.18, which reflect its higher stability and more accurate predictability.更多还原