【作者】 朱建林；

【导师】 曾光明；

【作者基本信息】 湖南大学 ， 环境工程， 2010， 博士

【摘要】 本文将大气酸沉降现象理解为开放、耗散的大气巨系统在人为污染胁迫下的复杂行为,以理论分析、实际监测数据分析和计算机模拟相结合,研究了大气酸沉降复杂性的表现形式及其数值特征与大气污染的关系；探讨了复杂性数值特征与现行常规统计参数的联系,从而建立了复杂性特征与统计特征之间的定量关系；并基于自组织临界性理论研究了大气酸沉降复杂性产生的机理,建立了具有简明物理意义并能反映酸沉降复杂性特征的元胞自动机模型。其主要结果如下：(1)降水中自由H+、NO3-与SO42-离子沉降序列的复杂度均处于白噪声信号与混沌信号复杂度之间,且更接近于混沌信号,说明酸沉降序列中同时存在确定性与随机性；与NO3-与SO42-离子相比,H+离子沉降序列的确定性较高；H+沉降序列的复杂度随年均H+沉降量增加而增加,二者呈对数线性关系；酸沉降量越大的地区,其酸沉降序列的复杂度越大,越接近于随机行为；酸沉降量越小的地区,其酸沉降序列的复杂度越小,越接近于混沌行为。(2)H+、NO3-及SO42-离子浓度或沉降量的概率分布呈“双幂律”分布,具有标度不变性；现行环境统计中按降水量加权平均计算降水pH值的方法,掩盖了这一事实并低估了降水酸度,认为用临界pH值来描述区域降水酸度特性更为合理；此外,酸雨或非酸雨持续时间、H+沉降量的标准差σ与平均值Xm、连续的降水事件之间酸沉降的变化率、降水量对降水酸度及沉降量的影响均呈幂律关系；建立的数学模型均反映了以上幂律关系。(3)H+沉降量序列波动类似于1/fβ噪声的自仿射分形过程,具有自相似性和长程相关性,且标度行为在1个月—5年的时间区间内均成立；NO3-和SO42-沉降量的变化趋势基本与H+一致,表明导致酸沉降的相关因子可能遵从相同的演化规则；酸沉降的长程相关性可能与长期气象过程及大气自组织临界性有关。(4)酸沉降量序列具有多重分形特征,由不同局域条件或由涨落引起的参量波动导致酸沉降标度行为的变化,其非匀称性和各向异性需要采用多重分形描述；酸沉降多重分形特性是由酸沉降演变过程中的长程相关性和幂律分布共同作用的结果；其多重分形谱f(α)-α曲线跨度具有随平均pH值的增加而增加、随平均沉降量增大而减小的趋势；年均pH值越小的地区,其酸沉降序列的f(α)-α曲线跨度越小,越接近于随机行为。(5)大气酸沉降系统具有混沌系统的基本特征,多种方法均证实并相互印证了大气酸沉降的混沌现象；酸沉降时间序列的变化同时具有确定性和随机性,且自由H+沉降量的确定性远大于NO3-和SO42-沉降量的确定性；随自由H+沉降量年均值的增加,其沉降量序列的关联维数随镶入维数的变化曲线越来越接近于随机白噪声,即饱和关联维数随沉降量年均值的增加而增加,或随pH年均值的降低而增加,其随机性增加,而确定性减小；并且饱和关联维数与沉降量年均值呈对数线性关系,与pH年均值呈线性关系。(6)认为自组织临界性是酸沉降形成与演化内在机制之一,其幂律分布、长程相关性、分形与多重分形以及混沌等特性,都是自组织临界性的具体外在表现形式；标度指数α、β、γ及临界尺度Xc、nc刻划了酸沉降自组织过程的宏观数值特征,并反映了大气环境特征对酸沉降复杂性特征的影响。(7)以酸沉降形成的主要物理、化学机制作为局部相互作用规则,建立了具有简明物理意义并能反映其复杂性特征的大气酸沉降元胞自动机模型(ACA)；该模型基本重现了大气酸沉降复杂性的主要特征,特别是从机理上解释并重现了大气污染对大气酸沉降复杂性的影响；此外,ACA模型的基本思路与方法可能对于构建多组分、多变量复杂系统的元胞自动机具有一定参考意义。更多还原

【Abstract】 Considered as the result of the complex behavior of the open and dissipative atmosphere systems under pollution pressure, the complexity of atmospheric acid deposition was researched in the present dissertation, with combined methods of theoretic analysis, actual data analysis and computational simulation. The research content involved the complex behaviors and the relationship between their numerical complexity characteristics and air pollution, the evolution mechanism and the cellular automata model simulating the complexity. The main results are shown as follows:(1) The complexity degrees of H+, NO3- and SO42- deposition series are ranged between that of white noise and chaotic signal, and is more close to that of chaotic signal, indicating that there exist concurrently certainty and randomness in the acid deposition time series. H+series exhibits more deterministic than NO3- and SO42- series, with their complexity degrees increasing linearly as the logarithms of annual mean acid depositions increasing. The higher the acid deposition is, the higher the complexity degree of the series is, with its evolution behavior more similar to random process. And the lower the acid deposition is, the lower the complexity degree of the series is, with its evolution behavior more similar to chaotic process.(2) The probability density of concentration and deposition of H+、NO3- and SO42- exhibits double power-law with scale invariance property, which was ignored by the current method for pH calculation in environmental statistics by weighting the pH values with rainfall. It’s thus believed more reasonable to take the crossover pH, which represents the mostly occurred pH in rain, as the representative pH value for a given district. It’s also found that the probabilities of duration of acid/nonacid rain, the standard deviation and mean value of H+ deposition, the variation rate of successive acid deposition, and the influence of rainfall on rain acidity, obey power-law, and a mathematic model was built up to simulate these power-law properties.(3) H+ deposition series is similar to 1/fβnoise of self-affine fractal with self-similarity and long-range dependence, and the scaling behavior of long-range dependence stands in 1 month to 5 years. NO3- and SO42- deposition display similar behavior as that of H+ deposition, indicating that the relevant factors involving in acid deposition might obey the same evolution rules as that of H+ deposition. The long-range dependence of acid deposition might be related to the long-range climatic process and self-organized criticality of atmosphere.(4) Acid deposition time series behave to be multifractal, which is the result of combined effect of both long-range persistence and power-law involved in the series, and the width of singular spectrum f(α)-αincrease as mean pH value increasing. The higher the acid deposition, the wider the singular spectrum f(α)-αcurve, with its evolution behavior closer to random process.(5) Acid deposition system was proved to have the basic properties of chaotic system by employing multiple methods. The correlation dimension of acid deposition series increases linearly as mean pH value increasing, and the H+ deposition exhibits much more deterministic than NO3- and SO42- deposition.(6) Self-organized criticality was believed as one of the main mechanisms inducing acid deposition and its evolution, and the power-law, long-rang persistence and the fractal/multifractal properties are the extrinsic manifests of self-organized criticality of atmosphere system. The scaling exponentsα、β、γand critical scale Xc、nc depict the macro numerical properties of self-organized critical behavior of acid deposition, and reflect the impact of atmospheric environmental characteristics on the complex properties of acid deposition.(7) With the main physical and chemical processes taken as the local reciprocity rules, a cellular automata model (ACA) was built up to simulate the complex behaviors of acid deposition, and the main complex properties of acid deposition were recurred by the model. The basic method setting up the ACA model might be of general value to build up cellular automata model for complex system with multiple components and variables.更多还原