上海市霾与非霾期间长江口环境因子特征分析

发布时间：2018-05-08 08:50

本文选题：霾 + 非霾　；参考：《上海海洋大学》2015年硕士论文

【摘要】：上海毗邻长江口海域,其日益推进的工业化、城市化进程为经济带来增长的同时,也对生态环境施加了重大压力,且长江三角洲区域是霾污染的高发区,上海市年霾污染天数更是高达192天,严重的影响了长江口海域的可持续发展。霾天气下细颗粒物会在大气环流的作用下进入海洋,部分沉降,部分远距离输入远海寡营养海区,为其增添新的生产力。为了探讨霾天气下,细颗粒物对海洋生态系统环境的影响,本研究通过对上海市10个环境监测站的PM2.5浓度以及长江口43个监测站点23个环境因子进行了分析,比较了霾与非霾期间,长江口环境因子的季节变化差异,并就PM2.5、霾与各环境因子进行了Pearson相关性分析,其成果可为霾天气下海洋环境的研究以及近海养殖业的发展提供必要的科学依据,结果如下:(1)上海市日均PM2.5浓度高于0.065μg/m3的33天,其中冬季有30天,春季有3天。从霾污染等级看,重度霾出现次数:冬季春季夏季秋季;中度霾出现次数:春季夏季冬季秋季;轻度霾出现次数:春季秋季夏季=冬季。气候、降水以及人为的生物质燃烧共同作用使上海霾天气呈现春高秋低,冬季严重的状态。(2)23个环境因子中,温度、溶解氧、化学耗氧量、活性磷酸盐、总有机碳5种环境因子在霾与非霾期呈现相同的季节变化趋势,且霾期间浓度均低于非霾期间,春季的温度除外;砷、活性硅酸盐、硝酸盐,霾期间均低于非霾期;盐度霾期间高于非霾期。悬浮物浓度受长江径流输入的影响较大,终年维持着高浓度,夏、秋季向外海扩散。油类无明显的变化趋势,主要受船舶污染的影响。汞、铜、铅、镉在霾与非霾期间无明显的规律可循,但在春季汞、铅、铜霾期的浓度明显高于非霾期,可能是因为颗粒物沉降是需要一定过程的,在霾发生期间积聚增长,在非霾期间沉降。冬季是重度霾的高发期,小时霾持续时间长,经常连续12小时均出现小时霾,因此,颗粒物负载这些重金属,不断的积聚,在霾消散后再沉降,从而出现春季偏高的趋势,霾期与非霾期重金属的沉降还有待研究。其他营养盐在霾与非霾期间同样无明显的规律可循,可能是因为颗粒物所携带的营养盐只是海水水质中的一个次要因素;也可能是沉降后浮游植物群落发生变化,导致营养盐的分布与浓度也发生改变,浮游植物对霾的响应还有待研究。(3)叶绿素a是海洋浮游植物生产力的重要表征。重度霾出现时,叶绿素a浓度普遍不高。而轻度霾、中度霾出现时,叶绿素a浓度则有所上升。霾周期中,霾期间叶绿素a浓度较霾前叶绿素a浓度有所增加,霾消散后叶绿素a浓度较霾前叶绿素a浓度有所减少,且霾污染然过程对叶绿素a浓度的增长有延迟效应,推测霾对叶绿素a的影响初期主要影响因子为光照,中后期为营养盐。浮游植物、浮游动物在春、夏季其密度和生物量在霾期均要高于非霾期,推测其对霾的响应与叶绿素a类似,在轻度霾出现时,促进其生长繁殖,重度霾时,抑制其生长繁殖。(4)PM2.5和水温呈现显著的负相关关系。PM2.5细颗粒中硫酸盐类气溶胶能够直接散射和吸收太阳辐射,可以使海水表面温度降低。霾时与盐度呈显著的正相关关系,与水温和化学耗氧量存在显著的负相关性。PM2.5浓度与砷存在显著的负相关性,与镉存在显著的正相关性。PM2.5浓度升高,Cd在水中的溶解性增强,从而表现为霾期间海水中浓度较高;而As在在水中的溶解性是减弱的,所以体现为霾天的浓度普遍低于非霾天。霾时与砷在0.01水平上存在显著的负相关性,与镉不存在显著的相关性,可能是因为随着霾的持续,PM2.5粒径逐渐移向粗模态,Cd在水中微量的溶解达到饱和。PM2.5的浓度与活性硅酸盐存在显著的负相关性。霾时与硅酸盐、硝酸盐氮、活性磷酸盐呈现显著的负相关关系。可以看出,在霾发生初期,浮游植物主要利用海水中的硅酸盐,霾持续过程中,浮游植物开始利用硝酸盐氮、其次为活性磷酸盐。从三者的相关性推断这3种营养盐具有相同的来源,由于PM2.5细颗粒物中尚未有硅酸根的研究,因此有可能是来自北方的气团携带沙尘气溶胶作用于采样海域。
[Abstract]:Shanghai, which is adjacent to the Yangtze Estuary, has increased its industrialization, the urbanization process has brought economic growth and also exerted great pressure on the ecological environment, and the Yangtze River Delta region is a high haze area of haze pollution. The number of haze pollution days in Shanghai is up to 192 days, which seriously affects the sustainable development of the Yangtze Estuary. Haze weather In order to explore the effects of fine particles on the marine ecosystem environment in haze weather, the PM2.5 concentration of 10 environmental monitoring stations in Shanghai and 43 of the Yangtze Estuary are discussed. 23 environmental factors were analyzed. The seasonal variation of environmental factors in the Yangtze Estuary was compared between haze and non haze. The Pearson correlation analysis was carried out on PM2.5, haze and environmental factors. The results could provide the necessary scientific basis for the study of marine environment and the development of coastal culture in haze weather. The results are as follows. (1) the daily average PM2.5 concentration in Shanghai is higher than that of 0.065 mu g/m3, of which there are 30 days in winter and 3 days in spring. From the level of haze pollution, the occurrence times of severe haze are: winter spring, summer and autumn, the occurrence times of moderate haze, spring summer winter autumn, the occurrence times of mild haze, autumn summer = winter in spring season, climate, precipitation and human biomass burning. The joint effect makes Shanghai haze weather present high autumn and low autumn low and severe winter condition. (2) among 23 environmental factors, temperature, dissolved oxygen, chemical oxygen consumption, active phosphate, and total organic carbon 5 environmental factors show the same seasonal variation trend in haze and non haze periods, and the concentration of haze is lower than non haze period, except in spring; arsenic and active silicon Salt, nitrate and haze were all lower than non haze periods, and the concentration of salt haze was higher than non haze period. The concentration of suspended matter was greatly influenced by the input of Yangtze River runoff, maintained high concentration in the last year, and spread to the sea in the summer and autumn. There was no obvious change trend of oil. However, the concentration of mercury, lead and copper haze in the spring is obviously higher than that in the non haze period, which may be due to the need for a certain process, the accumulation of particles in the haze period, the settlement during the haze period, the high haze period of the heavy haze, the long haze duration, and the haze for 12 hours. Therefore, the particles load these heavy loads. Metal, continuous accumulation, after the haze dissipates and then subsidence, then the trend of the high in spring, the deposition of heavy metals in haze and non haze period remains to be studied. Other nutrients are also not evidently regular during haze and haze, maybe because the nutrients carried by the particles are only a minor factor in the water quality of the sea; The phytoplankton community changes and the distribution and concentration of nutrients are also changed, and the response of phytoplankton to haze remains to be studied. (3) chlorophyll a is an important characterization of the productivity of marine phytoplankton. When severe haze appears, chlorophyll a concentration is generally not high. While mild haze and moderate haze appear, the concentration of chlorophyll a In the haze period, chlorophyll a concentration in haze period is more than before haze, chlorophyll a concentration increases, chlorophyll a concentration is less than the chlorophyll a concentration before haze extinction, and the haze pollution process has delayed effect on chlorophyll a concentration growth. It is speculated that the main influence factor of haze to chlorophyll a is light in the early stage, and in the middle and later period it is nutrition. The density and biomass of zooplankton in spring and summer were higher than non haze periods in the haze period, and the response to haze was similar to chlorophyll a. When the mild haze appeared, it promoted its growth and reproduction, and inhibited its growth and reproduction when the haze was heavy. (4) PM2.5 and water temperature showed a significant negative correlation between.PM2.5 fine particles and sulphate gas. The sols can directly scatter and absorb the solar radiation, which can reduce the temperature of the surface of the sea water. There is a significant positive correlation between the salinity and the salinity. There is a significant negative correlation with the water temperature and chemical oxygen consumption, and there is a significant negative correlation between the.PM2.5 concentration and the arsenic. There is a significant positive correlation with the cadmium concentration of.PM2.5, and the solubility of Cd in the water. In the haze, the concentration of the sea water is higher, and the solubility of the As in the water is weakened, so the concentration of haze is generally lower than that of the non haze days. There is a significant negative correlation between the haze and the arsenic at the 0.01 level, and there is no significant correlation with the cadmium. It is probably because the particle size of the PM2.5 gradually moves towards the coarse with the haze. There is a significant negative correlation between the concentration of Cd in water and the concentration of saturated.PM2.5 to the active silicate in the water. The haze has a significant negative correlation with the silicate, nitrate nitrogen and active phosphate. It can be seen that phytoplankton mainly use the silicate in the sea water at the early stage of haze, and the phytoplankton begins in the haze process. Using nitrate nitrogen and followed by active phosphate, it is inferred from the correlation of the three that the 3 kinds of nutrients have the same source. Since there is no silicic acid in the PM2.5 fine particles, it is possible that the dust aerosols from the air masses from the north will act on the sampling area.

【学位授予单位】：上海海洋大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X513

【参考文献】