湖泊水质时空变化特征识别的贝叶斯方差分析方法

发布时间：2018-02-24 13:15

本文关键词： 贝叶斯方差分析方差分解二项分布水质指标时空变化　出处：《环境科学学报》2017年11期 　论文类型：期刊论文

【摘要】：精细识别湖泊水质的时空变化特征是确定流域污染调控措施的基础.贝叶斯方差分析具有灵活的模型结构,可直接表征变量的时空动态特征.本文据此提出了基于该方法的湖泊水质时空变化特征识别的方法框架,研究了异龙湖稳态转换条件下富营养化指标的变化特征和滇池外海特征污染物达标率的时空变化2个案例,验证了该方法在总体服从正态分布和二项分布时的适用性.针对参数可交换性假设被忽视的问题,本文提出了一种基于模型选择准则的判定方法,并将其应用于滇池案例中.结果表明:(1)相对于清水稳态,异龙湖在浊水稳态时3种富营养化指标浓度更高,且年际方差所占总方差比例减小;(2)滇池外海总氮浓度超标率由2007—2013年间的40%左右降到2014—2016年间的10%左右,且波动性降低.随着监测数据的积累和监测时空精度的增加,贝叶斯方差分析在湖泊水质时空变化特征识别中具有广阔的应用前景.
[Abstract]:The detailed identification of temporal and spatial characteristics of lake water quality is the basis for determining the pollution control measures in river basins. Bayesian ANOVA has a flexible model structure. The temporal and spatial dynamic characteristics of the variables can be directly represented. Based on this method, a method framework for identifying temporal and spatial variation characteristics of lake water quality is proposed in this paper. The change characteristics of eutrophication index and spatiotemporal variation of characteristic pollutants in the offshore of Dianchi Lake were studied under the condition of stable transformation of Isolong Lake. The applicability of this method to the normal distribution and binomial distribution is verified. A decision method based on model selection criterion is proposed to solve the problem that the assumption of parameter exchangeability is ignored. It was applied to Dianchi Lake case. The results show that the concentration of three eutrophication indexes of Isolong Lake is higher than that of water steady state. The ratio of annual variance to total variance was reduced.) the rate of excess nitrogen concentration in the offshore waters of Dianchi Lake decreased from about 40% in 2007-2013 to about 10% in 2014-2016, and the volatility decreased with the accumulation of monitoring data and the increase of monitoring accuracy. Bayesian analysis of variance (ANOVA) has a broad application prospect in the identification of temporal and spatial variation characteristics of lake water quality.
【作者单位】：北京大学环境科学与工程学院水沙科学教育部重点实验室;中国环境科学研究院国家环境保护饮用水水源地保护重点实验室;云南省高原湖泊流域污染过程与管理重点实验室;
【基金】：国家水体污染控制与治理科技重大专项(No.2012ZX07503-002)~~
【分类号】：X524

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