Optical Properties and Estuarine Behavior of Chromophoric Particulate Organic Matter in the Jiulong Estuary

河口是连接陆地和海洋两大有机碳储库的重要纽带。颗粒有机物（POM）在河口环境的生物地球化学循环和生态学过程中扮演着重要角色。与有色溶解有机物（CDOM）一样，有色颗粒有机物（CPOM）也是河口有机碳储库的重要组分，对河口碳循环、河口光化学和光生物学等过程同样具有显著影响。目前对河口CDOM已有大量研究报道，但以CPOM的光谱特征来示踪河口POM的组成、来源、迁移和转化等过程的研究却并不常见。本论文以亚热带中小河口的代表-九龙江口为研究对象，以吸收光谱和荧光光谱作为表征手段，首先比较了不同提取方法（水溶法、碱溶法）对CPOM光谱特征的影响，进而探讨了碱溶性CPOM在九龙江口的时空变化、河口行为及...Estuaries are the major link between land and ocean organic carbon pool. Particulate organic matter (POM) plays important roles in the biogeochemical cycles and ecological processes in estuarine environments. Similar to Chromophoric dissolved organic matter (CDOM), chromophoric POM (CPOM) is a vital component of estuarine organic carbon pool and has significant influences on the fields of carbon c...学位：理学硕士院系专业：海洋与地球学院_海洋化学学号：2232013115138

Impacts of storm event on DOM composition and flux in two Jiulong Tributaries with different watershed features

通过调查2014年7月"麦德姆"台风影响期间福建九龙江北溪(流域以林地为主)和西溪(农业流域和城市背景)下游定点站DOM的时间序列,测定样品的DOC含量及其吸收光谱和三维荧光光谱,以评估不同流域背景对河流DOM动力学降雨响应的差异性,并为流域-河口系统的一体化管理提供重要参考。降雨期间,两条河流DOC浓度、吸收系数aCDOM(350)以及总荧光强度均随径流量升高而增大,并在水位下降期持续增加,且西溪增加量明显高于北溪,说明受人类活动扰动大的流域河流有机质对暴雨事件的响应更为灵敏;北溪和西溪的SUVA254分别显示出增大和减小的相反变化趋势,表明林地背景的流域主要冲刷芳香度高的DOM到河流,农业和城市背景则相反;降雨期西溪对九龙江DOM入海通量的贡献率高于北溪,与基流期北溪贡献率占主导恰巧相反,这种碳通量的逆转表明暴雨事件会放大人类活动对下游河口生态环境的影响。Watershed features have great impacts on river DOM composition and flux. In this study, temporal variations in DOM of the North(dominated by forestland)and West(dominated by farmland and urban area)Jiulong River were investigated during the typhoon"Matmo"in July, 2014. The DOM was characterized by DOC, absorption spectroscopy, and fluorescence excitation emission matrix spectroscopy(EEMs)analysis. The DOC concentration, absorption coefficient aCDO(350)and total DOM fluorescence intensity of both rivers increased significantly in both rising and falling hydrograph during the storm event. However, DOM abundance in the West River showed a much greater increase than that in the North River, suggesting more sensitivity of river DOM to rainstorm events in the watershed with greater anthropogenic perturbation. The specific absorption coefficient(SUVA254)of CDOM showed different variation tends between the North and West River,indicating that river DOM in forest-dominant watershed had high aromaticity and average molecular weight. The West River showed higher fluxes of DOM than the North River during storm event, which was opposite to that under the base flow condition. This reversion in DOM export flux suggested that storm event could amplify the influence of human activities in the watershed on the receiving estuarine ecosystems.The present findings are of great significance for the integrated management of coupled river-estuary system.国家自然科学基金项目(41276064,U1305231

Characterization of Dissolved Organic Matter in Groundwater from the Coastal Dagu River Watershed,China Using Fluorescence Excitation-Emission Matrix Spectroscopy

利用三维荧光光谱研究了大沽河流域地下水中溶解有机物(dOM)的荧光组分类型及其空间分布与变化,并与地表河水进行了比较。基于平行因子分析模型在大沽河流域识别出2个类腐殖质组分及1个类蛋白质组分。研究区域上、下游地下水中各荧光组分的强度低,但中游区域呈现高值区,与人为污染的下渗输入以及为阻止海水入侵而修建的截渗墙对地下水循环模式的改变有关。地下水dOM以类腐殖质组分为主,类蛋白质组分平均只占15%,不及地表河水的一半,其新鲜度指数(β/α)也低于河水但荧光指数(fI)、腐殖化指数(HIX)高于河水,表明地下水dOM的腐殖化程度更高,与地下水停留时间长、微生物降解作用的贡献更为显著有关。本研究揭示,三维荧光指纹技术可区分天然背景及人为活动对地下水中dOM含量及性质的影响,是研究地下水环境中的碳循环过程及其影响因素的有用工具。The fluorescent properties of dissolved organic matter(DOM) from groundwater in the coastal Dagu River watershed,North China were determined using excitation-emission matrix spectroscopy(EEMs) analysis.Surface water DOM samples were also investigated for comparison.Two humic-like components(C1 : 250,355/472nm;C2 : <240,325 / 400nm) and one protein-like component(C3: <240,280/340nm) were identified using parallel factor analysis.Low intensities for all components were observed in groundwater DOM from the upper and lower reaches of the study area.However,higher abundances of these components occurred in the middle reaches,reflecting the combined effect of seepage of surface water with strong anthropogenic pollution and the alteration of groundwater circulation due to cutoff as a result of the construction of a cutoff wall since the late 1990s.The humic-like components were dominant in groundwater DOM,with the average percentage of the protein-like component being only 15%,which was less than half of the corresponding percentage in surface water DOM.The freshness index in groundwater DOM was lower than the surface water samples,while the fluorescence index and humification index were higher than in the latter.These indices demonstrated the much higher degree of humification for groundwater DOM,which may be related to the longer residence time of groundwater and greater contribution of microbial degradation in the aquifer environment.This study demonstrated that EEMs could distinguish between the effects of natural background and human activities on the quantity and characteristics of the groundwater DOM,and thus could be a useful tool for studing the carbon dynamics and the controlling factors in groundwater systems.TheNationalNaturalScienceFoundationofChina(41072174;41276064and40776041

Based on Optical Properties of Chromophoric Dissolved Organic Matter in the Monitoring of Coastal Eutrophication

富营养化是河口港湾一个重要的生态环境问题。传统的富营养化监测与评价需要依靠费时费力的人工采样、实验室分析测定,周期较长,难以实现现场实时快速监测; 与评价。本文依据2009年2月、5月、8月和10~11月在厦门湾海域的有色溶解有机物(CDOM)与主要环境要素的调查资料,探讨了利用CDOM的光; 学性质反演COD,TN,TP等富营养化参数的可行性。结果表明:(1)厦门湾表层水体CDOM存在明显的空间和季节性变化,九龙江河口区的丰度最高;(; 2)陆源输入及浮游植物的现场生产是水体中CDOM的主要来源,因此可建立利用盐度和叶绿素a浓度估算厦门湾CDOM丰度的经验算法,该经验算法的相关系; 数达0.96,经验算法估算值与实测CDOM之间的相对误差为11.1%0.71%,精度较高;(3)厦门湾各个季节COD,TN,TP与CDOM吸收系; 数、荧光组分之间有很好的相关性,总体表现春夏较高、秋季次之、冬季最差;(4)结合上述研究成果,利用厦门湾已建立的水质自动监测系统实时获取的盐度、; 叶绿素a以及经验公式推导出的CDOM荧光资料,有望克服COD,TN和TP等富营养化指标只能通过人工采样和实验室分析获取的缺点;实现对海域富营养化; 程度的快速监测与评价。Eutrophication is an important ecological environment problem in estuary and coastal area. The traditional monitoring technology for eutrophication is laborious and time-consuming, so it is difficult to realize the real-time and on-site monitoring and then rapid evaluate the eutrophication degree. Based on the investigation of chromophoric dissolved organic matter(CDOM) and other environmental parameters in Xiamen Bay in February, May, August and from October to November 2009, the feasibility of using CDOM optical properties to retrieve eutrophication parameters (COD, TN and TP) in coastal environment was evaluated. CDOM showed large spatial and seasonal changes in Xiamen Bay, with the highest CDOM abundance occurring in the Jiulong River Estuary. The terrestrial input and phytoplankton production were the main sources of CDOM in Xiamen Bay. The empirical formula to estimate the CDOM abundance in seawater was then established by using the salinity and chlorophyll-a data. The correlation coefficient of this empirical formula was 0.96 and the relative errors between fitted values and measured values for CDOM of different survey stations were (11. 1% 0.71%. There were high correlations between CDOM absorption coefficient and fluorescence components with chemical oxygen demand(COD), total nitrogen(TN), total phosphorus (TP) in all seasons, with the highest correlations in spring and summer, and the lowest in winter. Combined with the above results, instead of the data including COD, TN and TP got only through manual samplings and laboratory analysis, the data of salinity and chlorophyll a could be provided by water quality automatic monitoring system and CDOM data got by above empirical formula, so it is possible to realize the rapid monitoring and evaluation for the degree of coastal eutrophication by using in situ buoy system with CDOM sensor.国家自然科学基金项目（41276064,U1305231）; 国家海洋局西太平洋海洋环境监测预警体系建设专项项目（SOA201303）资

擦肩而過 MISS

[[abstract]]愛熱鬧卻總是一個人的LALA一直在尋找伴侶，牠穿梭在這個這個城市之中熱情的迎接每一個人,但始終遇不到對的人.直到DODO的出現,才發現一切都是最好的安