【作者】 张国宏；

【导师】 郑有飞； 谈建国；

【作者基本信息】 南京信息工程大学 ， 气象学， 2006， 硕士

【摘要】 由上海市(1993～2003年)月降尘量资料和同期气象资料,运用相关分析、回归分析、聚类分析、小波分析、图表分析等方法,较为系统地研究了上海吴淞工业区月降尘量的时间变化特征、降尘量与主要气象因子之间的关系、降尘的天气背景类型和降尘的气象可预测性。主要结论如下: 揭示了上海市月降尘量的月、季、年变化特征。月降尘量年际变化总体为下降趋势。就季节变化来说,降尘的高峰主要出现在春季和夏季;冬春季降尘量的年际变化下降趋势较为明显。月际变化呈双峰双谷型分布,双峰分别出现在4月和7月,双谷出现在6月和10月。降尘量存在3个月、1年、准2年和准18年的显著周期振荡。降尘量时间序列表现出明显的阶段性。 研究降尘量和气象因子间的关系表明:风向、风速频率和雨日数是影响降尘量的主要气象因子,而温度、湿度对降尘量影响不明显。在分析的基础上,探讨了气象条件影响降尘量的可能机制,从气象角度解释了降尘量的年、月际变化。风向的作用是将空气中的尘粒吹向下风方向,风速的作用主要是吹起地面的扬尘,而降水兼有冲刷和湿润地面的作用。 建立了月降尘量回归预测模型。所建立的回归模型不仅具有显著的统计学意义,而且经用未参与回归建摸资料的检验,模型有较好的预测能力。表明了由气象因子预测降尘量是可行的。 聚类分析将天气背景分为了五个类型。依据出现时段、气象特征和降尘情况,可分别称为:夏春南风降尘型(A型)、夏季多雨少尘型(B型)、秋季少尘型(C型)、冬季少尘型(D型)和冬春降水降尘型(E型)。不同的天气对降尘量的影响不同。(A型)最有利于降尘。 分析降尘量和风向频率之间相关关系的时间变化规律表明:同降尘量相关性最大的风向是在变化的;风向和降尘量的相关型具有阶段性持续特征;降尘量和风向的正相关方位随着时间的变化出现一定程度的向东偏移;风向和降尘量的相关性有减弱的趋势。更多还原

【Abstract】 This paper investigated systematiclly variation characteristics of monthly dustfall and the relationships between dustfall change and meterological factors in industrial district of Wusong , Shanghai by the combination of statistical method, graphic illustration on the basis of monthly dustfall and corresponding meteorological factors from 1993 to 2003, main conclusions as follows:The distribution characteristics of monthly dustfall were disclosed in the scale of month ,season and year respectively, it is showed that interannual variation had an obvious falling trend ,which was further divided into three stages of rising ,falling and even period, that dustfall was higher in the seasons of spring and summer while lower in winter and autumn,with a monthly distribution of two high in April and July, and two low in June and October, due to meteorological reason. Analysis of wavelet found that the cycle of three months,one year, quasi-two years and quasi-18 years is obvious. Discontinuity characteristic of dustfall was found by means of analysis of self-correlation ,probabally is a reflection of effective environmental management and change of dust source.More important,the relationships between dustfall and meteorological factors were explored, it was found that the frequency of southern wind direction and high wind velocity, rainfall or rain days play a significant role in the quantity of monthly dust fall, and that the role of relative humidity and temperature might be negligible. Meanwhile, the meterological contribution mechanic and interpretation of monthly dustfall variation were gived in brevity. The role of wind direction is blowing dust particles downward,wind velocity blowing dust particles into sky,and rainfall washing dust particles from sky or weting ground.Quantitative relationship between dustfall and meterological factors was established by means of stepwise regression.the equation is not only significant in statistics,but also has a estimating capability ,which was testified by new data.This implied that it is feasible to forecast dustfall on the basis of meterological factors.Synoptic background patterns of dust deposition were classified into A,B,C,D and E,which is different in dustfall ,by method of clustering.Pattern A has the highest amount of dustfall.The sliding correlation patterns were explored . It was found that the quantity of monthly dustfall was significantly correlated with frequency of southern wind direction, which was varied with time going, that the correlation mode was characterised by piecewise continuity,that the ditnbution of positive coefficient showed a shift from south towards east, and that probabaly there is a weakening relationships between wind direction and dustfall in Shanghai, which probabaly was a reflection of environmental management.更多还原