基于多重分形理论的近海污染物空间分布特性研究

针对我国近海污染物空间分布特征难于辩析的问题,通过对多重分形理论的研究,提出了一种新的近海污染物空间分布特征的分析方法。以天津市近岸海域20个水环境监测点为例,随机选择两个不同水期的COD监测数据进行分析,采用多重分形矩方法计算COD空间分布的多重分形维数谱函数f(α)。计算结果显示其α(q)-f(α)曲线均为连续不对称的上凸曲线,表明近海污染物在空间上的分布并不是简单的正态或对数正态分布,而是连续多重分形分布,近海污染物高浓度部分的奇异性较低浓度部分大,平水期的奇异性较丰水期大。应用表明,该分析结果与天津市近岸海域实际情况相一致,这些成果的取得为辩析近海污染物的空间分布特征,并进一步采用基于多重分形理论的算法模型计算近海水环境容量提供了理论依据。

Study on spatial characteristics of coastal pollutant by multi-fractal theory

Against the complicated pollution characteristics in Chinese coast,a new method of analysis of the spatial characteristics of coastal pollution was developed based on multi-fractal theory.The Tianjin coast as an example,a typical multi-fractal method,which called the method of moments,was applied to compute the multi-fractal dimension spectrum function f(α) of the 20 monitoring points.From the results,it could be found the curve of α(q)-f(α) was a continuous curve.The results showed that the spatial distribution mode of coastal pollution was not a normal distribution or logarithm normal distribution,but a continuous multi-fractal distribution.The level period's singularity of coastal pollution was larger than the rainy period.Through application,the results were match with the actual situation of Tianjin's coast.It could provide the theory basis for the environmental capacity in the coastal water based on multi-fractal theory.