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1.
We applied stable carbon isotopes, ultraviolet-visible absorption(UV-Vis), fluorescence excitation-emission matrices spectroscopy(EEMs), and Fourier transform ion cyclotron resonance mass spectrometry(FT-ICR-MS) to investigate the chemical composition and sources of the dissolved organic matter(DOM) in both the water column and pore water in Xiangshan Bay, a representative semi-enclosed and eutrophic bay in Zhejiang Province, China. One protein-like fluorescent component(C1) and two humic-like fluorescent components(C2 and C3) were identified by PARAFAC modeling. The concentration of dissolved organic carbon(DOC), the relative intensities of C2, C3, and black carbon-like compounds are all negatively correlated with salinity, indicating that there is a dilution effect of terrestrial signals by seawater in Xiangshan Bay. The differences in light penetration ability of Xiangshan Bay cause different degrees of photo-degradation, which may play an important role in the transformation of organic matter in Xiangshan Bay. The weak correlation between the C1 fluorescent component and salinity indicates that autochthonous sources cannot dominate the protein-like FDOM in the Xiangshan Bay drainage area. Multiple sources(such as anthropogenic inputs and release of pore water) also affect the distribution of the protein-like fluorescent component under eutrophication conditions. The relative proportion of the protein-like fluorescent component in Xiangshan Bay is on a medium level in China and anthropogenic inputs may be a significant source of DOM in coastal bays.  相似文献   

2.
Large fluvial lakes, as part of river corridors, are recognized as spatially heterogeneous ecosystems. Due to their shallowness, the littoral zone of these lakes occupies a large proportion of their surface and is extensively covered by macrophytes that are known to affect their physical, chemical and biological environments in various ways. This study documents the small-scale (5 km) bio-optical variations associated with the longitudinal passage of a water mass through macrophyte beds during their maximal growth season. The utilization of a 2D hydrodynamic model allowed us to establish hydrological connectivity between stations within the beds, and thus to identify longitudinal heterogeneity along the macrophyte beds. Significant changes in the inherent properties of the water were observed along the upstream-downstream gradient. Due to their effects on hydrodynamics, macrophytes were responsible for a decrease in particles and dissolved organic carbon (DOC) resulting in an increasing penetration depth of ultraviolet (UV) and photosynthetically active radiation (PAR). Along the transect, chromophoric dissolved organic matter (CDOM) decreased more rapidly than DOC resulting in a decrease of the CDOM to DOC ratio. The observed changes in the DOC pool may be explained by the constant input of non-chromophoric DOC from macrophyte leachates and exudation within the bed and/or the photochemical and microbial degradation of CDOM. The implication of such small-scale heterogeneity on Lake Saint-Pierre productivity is discussed.  相似文献   

3.
The spatial and diurnal tidal variability of dissolved organic carbon (DOC) concentrations and the composition of dissolved organic matter (DOM), as evaluated by high-temperature catalytic oxidation and excitation–emission matrix combined with parallel factor analysis (EEM–PARAFAC), respectively, were determined in Liverpool Bay. EEM–PARAFAC modeling resulted in six fluorescent components characterized as terrestrial humic-like (two), microbial humic-like (two), and protein-like (two). The spatial distributions of DOC and the four humic-like components were negatively correlated with salinity in the high-salinity waters observed in this study (30.41–33.75), suggesting that terrestrial DOM was conservatively distributed. The spatial patterns of protein-like components were largely different from those of DOC, humic-like components, and chlorophyll a, suggesting that these distributions were the combined result of production and degradation in the bay in addition to river inputs. These findings suggest that the DOM dynamics in Liverpool Bay are strongly controlled by river-dominated allochthonous DOM inputs with some less significant contributions of autochthonous DOM within the bay. In addition, the temporal variations of DOM associated with the diurnal tidal cycles were determined at one inshore (31.34–32.24 salinity) and one offshore (33.64–33.75 salinity) station in the bay. Negative linear relationships between salinity and DOM characteristics, i.e., DOC, humic-like, and protein-like components, were observed at the inshore station. In contrast, no relationship was observed at the offshore station, suggesting that the export of DOM through rivers and possibly tidal flats have a noticeable influence on DOM concentration and composition up to a relatively elevated salinity of around 33 in Liverpool Bay.  相似文献   

4.
Exploring the chemical characterization of dissolved organic matter (DOM) is important for understanding the fate of laterally transported organic matter in watersheds. We hypothesized that differences in water-extractable organic matter (WEOM) in soils of varying land uses and rainfall events may significantly affect the quality and the quantity of stream DOM. To test our hypotheses, characteristics of rainfall-runoff DOM and WEOM of source materials (topsoil from different land uses and gullies, as well as typical vegetation) were investigated at two adjacent catchments in the Loess Plateau of China, using ultraviolet–visible absorbance and excitation emission matrix fluorescence with parallel factor analysis (PARAFAC). Results indicated that land-use types may significantly affect the chemical composition of soil WEOM, including its aromaticity, molecular weight, and degree of humification. The PARAFAC analysis demonstrated that the soils and stream water were dominated by terrestrial/allochthonous humic-like substances and microbial transformable humic-like fluorophores. Shifts in the fluorescence properties of stream DOM suggested a pronounced change in the relative proportion of allochthonous versus autochthonous material under different rainfall patterns and land uses. For example, high proportions of forestland could provide more allochthonous DOM input. This study highlights the relevance of soils and hydrological dynamics on the composition and fluxes of DOM issuing from watersheds. The composition of DOM in soils was influenced by land-use type. Precipitation patterns influenced the proportion of terrestrial versus microbial origins of DOM in surface runoff. Contributions of allochthonous, terrestrially derived DOM inputs were highest from forested landscapes.  相似文献   

5.
6.
为了揭示湖库内源性污染物的分布、来源、组成及垂向分布特征,以新建人工深水湖泊龙景湖为研究对象,采用紫外-可见光谱和三维荧光光谱技术,研究了该湖泊以成湖前用途划分的3个特征区域(原河道底部、新淹没区底部和新淹没区边坡)的沉积物上覆水和孔隙水中的溶解性有机质(DOM)的光谱特征.结果表明,孔隙水中的DOM芳香性和腐殖化程度高于上覆水;孔隙水中疏水组分含量大于上覆水,且水体中可能存在内源孔隙水释放的低分子量DOM.龙景湖上覆水和孔隙水中的DOM主要源于水体自身的微生物,自生源特征明显,且可能存在新近释放到水体的有机质.龙景湖沉积物上覆水和孔隙水中的DOM以类腐殖酸和类蛋白质为主,且随着深度增加,类腐殖酸峰强度增强,与龙景湖的建湖背景有明显联系.  相似文献   

7.
The concentration of dissolved and particulate organic matter (OM) in Lakes Kuril'skoe and Azabach'e is shown to depend on the rate of its production by phytoplankton (and by macrophytes in Lake Azabach'e) and on the amount of allochthonous OM delivered by rivers. The rate of OM transformation in the production–destruction cycle and the regeneration of phosphates were evaluated based on the activities of redox enzymes of the electron-transport system and the hydrolytic enzymes of alkaline phosphatase and protease. The intense assimilation of allochthonous OM in lake ecosystems was found to take place due to active hydrolytic disintegration of the arriving OM.  相似文献   

8.
The evolution of Lake Ladoga ecosystem under the effect of a long period of critical anthropogenic phosphorus load is analyzed. It is shown that relatioships between organic matter accumulation and mineralization with considerable predominance of destruction over autochthonous production have formed in the lake by the moment when the input of P of anthropogenic origin dropped to the estimated admissible level. Studying the transformation of aquatic organic matter of tributaries in the water of Lake Ladoga suggest that a considerable portion of it, primarily, the conservative humic fraction, is now involved in turnover and serves as an additional source of C and P both for producer and destructor organisms. The processes taking place in Lake Ladoga suggest the allochthonous variant of ecosystem evolution.  相似文献   

9.
长三角地区大部分湖泊为非通江湖泊,地势低平,港汊及闸坝众多,水流宣泄不畅,水力滞留时间较长,加之周边地区城镇人口稠密.因此与水滞留时间短的通江湖泊相比,非通江湖泊的有色可溶性有机物(CDOM)来源和组成具有差异性.本文选取了3个重要的中型非通江供水湖泊——滆湖、淀山湖和阳澄湖,对枯水期、平水期、丰水期3种水文情景下CDOM组成结构变化特征进行分析,从而进一步揭示该类湖泊CDOM来源和对水文情景响应的内在机理.结果表明:滆湖、淀山湖和阳澄湖通过平行因子分析法得到2种类腐殖质(C1和C4)和2种类蛋白质(C2和C3),湖泊CDOM结构受到降雨事件和人类活动的双重影响.三个湖泊类蛋白质的高值在空间上主要集中在人类活动频繁的湖区,并且类蛋白质平均荧光强度与叶绿素a浓度相关性较差,说明湖泊类蛋白质组分受到内源藻类降解、外源人类生产生活排放双重作用的影响.三个湖泊类蛋白质的平均荧光强度和总氮浓度均在枯水期显著高于丰水期,说明降雨量的增加可以稀释湖泊有机质浓度;同时,陆源类腐殖质C1与溶解性有机碳、总氮、总磷、叶绿素a浓度呈显著正相关,并且随着降雨量增加,类蛋白质的占比逐渐降低,滆湖从86.84%降低至62.49%,淀山湖从96.53%降低至90.56%,阳澄湖从98.40%降低至96.26%,说明降雨事件也可以增强径流的冲刷作用,携带更多腐殖化程度高的陆源有机质进入湖泊.本研究发现降雨过程和人类活动共同作用于滆湖、淀山湖和阳澄湖CDOM库,研究结果可以为进一步保障太湖流域人类用水安全提供参考依据.  相似文献   

10.
Chromophoric dissolved organic matter (CDOM) optical properties were measured in surface and pore waters as a function of depth and distance from an oil well in a southern California salt marsh. Higher fluorescence and absorbances in pore vs. surface waters suggest soil pore water is a reservoir of CDOM in the marsh. Protein-like fluorophores in pore waters at distinct depths corresponded to variations in sulfate depletion and Fe(II) concentrations from anaerobic microbial activity. These variations were supported by fluorescence indexes and are consistent with differences in optical molecular weight and aromaticity indicators. Fluorescence indices were consistent with autochthonous material of aquatic origin in surface waters, with more terrestrial, humified allochthonous material in deeper pore waters. CDOM optical properties were consistent with significantly enhanced microbial activity in regions closest to the oil well, along with a three-dimensional excitation/emission matrix fluorescence spectrum peak attributable to oil, suggesting anaerobic microbial degradation of oil.  相似文献   

11.
张怡晅  庞锐  任源鑫  程丹东 《湖泊科学》2022,34(5):1550-1561
城市非点源污染向水生生态系统中输入大量的溶解有机物(DOM),对生态系统健康产生重要影响.有色可溶性有机物(CDOM)是广泛分布于自然水体中的一类成分和结构复杂、含有多种高活性化学官能团的大分子聚合物,是DOM的重要组分,对水生生态系统健康、能量流动及生物地球化学循环有重要影响.光化学反应和微生物代谢过程被认为是控制水体CDOM转化、降解和循环的主要影响因素.然而,对城市化如何影响CDOM组成以及光化学和微生物如何相互作用影响城市水体CDOM动态的理解是不足的.因此,为评估光化学过程和微生物代谢对不同城市水体CDOM降解与转化的贡献,解析不同城市水体CDOM光化学/微生物降解作用机理,本研究在英国伯明翰选择3类具有典型DOM来源的水体样本,通过实验室9 d受控培养实验,对比分析光化学以及微生物影响下CDOM来源和组成的变化.结果表明:(1)城市河流由于接受上游污水排放及较短的水力滞留时间,含有丰富的芳香性碳,其CDOM光化学活性明显高于湖泊,光化学降解率为16.60%;(2)城市湖泊CDOM受人类活动影响,自生源类荧光成分富集,生物活性高,在微生物培养过程中CDOM增加了62.16%,...  相似文献   

12.
基于2017年1-12月在抚仙湖开展的逐月观测,利用紫外-可见吸收光谱和三维荧光光谱技术探讨该湖有色可溶性有机物(CDOM)的来源组成及时空变化特征.12个月CDOM吸收值a(254)的均值为3.47±0.57 m-1,范围为1.82~5.22 m-1,说明CDOM丰度较低.平行因子分析结果给出了2种类酪氨酸荧光组分(C1和C3)、1种类色氨酸荧光组分(C2)、1种类腐殖质荧光组分(C4),12个月内源组分(C1+C3)对总荧光强度的平均贡献为65.81%±15.38%,外源组分(C2+C4)的平均贡献为34.19%±15.38%;荧光指数FI的均值为1.73±0.14,腐殖化指数HIX的均值为1.02±0.37,生源化指数BIX的均值为1.23±0.27,说明CDOM主要为微生物内源产生.时空变化方面,春(3-5月)、夏(6-8月)、秋(9-11月)和冬(1、2、12月)季的a(254)分别为3.20±0.47、3.76±0.64、3.67±0.50和3.23±0.38 m-1,夏季和秋季均显著高于冬季和春季;CDOM丰度及内外源组分的空间分布具有季节异质性,可能与流域土地利用、河流输入、降雨、温度、光辐射等因素有关.  相似文献   

13.
Most terrestrial allochthonous organic matter enters river networks through headwater streams during high flow events. In headwaters, allochthonous inputs are substantial and variable, but become less important in streams and rivers with larger watersheds. As allochthonous dissolved organic matter (DOM) moves downstream, the proportion of less aromatic organic matter with autochthonous characteristics increases. How environmental factors converge to control this transformation of DOM at a continental scale is less certain. We hypothesized that the amount of time water has spent travelling through surface waters of inland systems (streams, rivers, lakes, and reservoirs) is correlated to DOM composition. To test this hypothesis, we used established river network scaling relationships to predict relative river network flow-weighted travel time (FWTT) of water for 60 stream and river sites across the contiguous United States (3090 discrete samples over 10 water years). We estimated lentic contribution to travel times with upstream in-network lake and reservoir volume. DOM composition was quantified using ultraviolet and visible absorption and fluorescence spectroscopy. A combination of FWTT and lake and reservoir volume was the best overall predictor of DOM composition among models that also incorporated discharge, specific discharge, watershed area, and upstream channel length. DOM spectral slope ratio (R2 = 0.77) and Freshness Index (R2 = 0.78) increased and specific ultraviolet absorbance at 254 nm (R2 = 0.68) and Humification Index (R2 = 0.44) decreased across sites as a function of FWTT and upstream lake volume. This indicates autochthonous-like DOM becomes continually more dominant in waters with greater FWTT. We assert that river FWTT can be used as a metric of the continuum of DOM composition from headwaters to rivers. The nature of the changes to DOM composition detected suggest this continuum is driven by a combination of photo-oxidation, biological processes, hydrologically varying terrestrial subsidies, and aged groundwater inputs.  相似文献   

14.
Dissolved organic carbon (DOC) is one of the most abundant fractions of organic matter in aquatic systems and plays an important role in the dynamics of aquatic environments, controlling both the penetration and the underwater light radiation climate. DOC can be photodegraded by light, thus facilitating biodegradation, especially in regions where the incidence of solar radiation is high, such as higher altitudes and lower latitudes. This study quantified the photodegradation of dissolved organic material in a natural tropical lake surrounded by native forests (Brazilian Atlantic Forest) through two experiments: i) the first experiment exposed concentrated autochthonous, allochthonous, and lake water to in situ solar radiation; ii) this experiment also exposed the same organic material to artificial UV radiation in an incubator under controlled conditions. The quality and quantity of dissolved organic carbon were measured using indices based on carbon absorbance and fluorescence spectrum. In the in situ experiment, it was observed that the DOC degradation profile of the concentrated allochthonous and autochthonous organic material were distinct from each other in the absorbance indices, and the lake water mostly resembled the latter one. On the other hand, we did not see evidence of any significant difference among treatments in the laboratory experiment. An increase in the SR index and a concomitant decrease in the fluorescence of humic compounds and SUVA254 over time were observed. In both experiments, the amount of degraded organic material over time was low and some possible explanations are discussed.  相似文献   

15.
Lake sediments are valuable natural archives to reconstruct paleoclimate and paleoenvironmental changes which consist of inorganic and organic sediment compounds of allochthonous origin from the catchment and of autochthonous production in the lake. However, for robust paleo-reconstructions it is important to develop a better understanding about sedimentation processes, the origin of inorganic and organic sediment compounds and their distribution within the lake. In this context, modern process studies provide important insights, although environmental and anthropological changes can affect the spatial distribution of sediment compounds through time. Therefore, in this study the spatial distribution of grain size and geochemical proxies in 52 surface sediment samples from Lake Khar Nuur, a small high-altitude lake in the Mongolian Altai with a small and anthropogenically used hydrological catchment, is investigated. The results show a distinct sediment focussing in the two deep basins of the lake, which therefore act as accumulation zones. In those accumulation zones, total organic carbon (TOC), total nitrogen (N) and their isotopic composition (δ13CTOC, δ15N) as well as n-alkanes indicate that organic sediment compounds are a mixture of both allochthonous and autochthonous origin. While the recent catchment vegetation consists of grasses/herbs and the shrub Betula nana (L.) with distinct differences in their n-alkane homologue patterns, those differences are not reflected in the sediment surface samples which rather indicates that grass-derived n-alkanes become preferentially incorporated in the lake. Extensive anthropogenic activity such as grazing and housing in the southern part of the catchment causes soil erosion which is well reflected by high TOC, N and sulphur (S) contents and 15N depleted δ15N values at the central southern shore, i.e. increased allochthonous sediment input by anthropogenically-induced soil erosion. Overall, the surface sediments of Lake Khar Nuur origin from allochthonous and autochthonous sources and are focussed in the accumulation zones of the lake, while their distribution is both environmentally and anthropogenically driven.  相似文献   

16.
章奇  居琪  李健欣  曹驰程  江和龙  张晖 《湖泊科学》2020,32(4):1041-1049
为探究富营养化湖泊中自生源可溶有机质(DOM)在泥水界面的吸附行为,以马来眼子菜(Potamogeton malaianus)和铜绿微囊藻(Microcystis aeruginosa)释放的DOM为代表,考察针铁矿对草、藻源DOM中不同组分的吸附特征.三维荧光平行因子分析表明类富里酸组分C1和类胡敏酸组分C4的含量很低,而类蛋白物质(类酪氨酸组分C2和类色氨酸组分C3)分别占草、藻源DOM荧光组成的70%和93%. 2种DOM均可被针铁矿吸附,吸附过程符合伪一级动力学.通过等温线拟合发现针铁矿吸附藻源DOM的非线性更强,饱和吸附量(23.77 mg/g)高于草源DOM(19.10 mg/g).特别地,类蛋白组分呈现非线性吸附,而类腐殖物质的吸附近似线性,且针铁矿对于DOM各荧光组分的吸附量顺序为:C3C2 C4 C1,此非均质吸附特征与DOM组分的初始含量、分子大小、芳香性及有效吸附位点有关.红外光谱证实氨基、羧基和羟基是吸附过程中的重要官能团.因此,草、藻源DOM显著改变了针铁矿表面的有机物质组成,影响湖泊沉积物的生物地球化学行为.  相似文献   

17.
滇池沉水植物的分布格局及其水环境影响因子识别   总被引:2,自引:2,他引:0  
研究滇池沉水植物的分布及其与水环境因子的关系,对于滇池沉水植物的恢复具有重要的指导意义.2016年4-11月对滇池24个典型点位沉水植物群落特征进行调查,共发现16个调查区存在9种沉水植物,以篦齿眼子菜(Potamogeton pectinatus)、微齿眼子菜(P.maackianus)、穗花狐尾藻(Myriophyllum spicatum)、轮叶黑藻(Hydrilla verticillata)、马来眼子菜(P.wrightii)等为主,沉水植物主要分布在近岸3 m以内水域,盖度在10%左右.主成分分析结果表明,总氮、总磷、悬浮物、化学需氧量和叶绿素a浓度是影响沉水植物种类和生物量的主要因素,透明度是影响沉水植物盖度的主要因素;典范对应分析结果显示,滇池沉水植物的分布主要受水体中营养盐含量和化学需氧量的影响,穗花狐尾藻和轮叶黑藻对有机物和藻类的耐受能力较强,马来眼子菜和篦齿眼子菜适于生长在高营养盐的环境.滇池沉水植物恢复初级阶段的关键是降低水体中化学需氧量、抑制藻类的生长,其次是控制水体营养盐浓度.按照"一区一策"的原则,草海东风坝内和外海南部适于进行沉水植物恢复,外海北部实行控藻治理,外海东部需改善水体有机物浓度和营养盐条件,外海西部以沉水植物自然保育为主.  相似文献   

18.
A relationship between indirect chemical indices of organic matter content of surface waters and light absorption in the visible and ultraviolet ranges is discussed. The allochthonous and autochthonous types of organic matter are found to essentially differ in the rate of light absorption. Techniques are proposed for the calculation of the concentrations of allochthonous and autochthonous organic matter by the integral rate of light consumption in the visible region and the bichromate oxidability of water, as well as by three indirect indices: chemical oxygen demand, permanganate oxidability, and water color index. The mean concentrations of allochthonous and autochthonous organic matter in large lakes (Ladoga, Onega, and Baikal) and in rivers and smaller water bodies in Karelia (>300 water objects) are analyzed. Allochthonous organic matter was found to predominate in most surface waters of Karelia (>80%), while allochthonous organic matter predominates only in lakes with a small specific catchment area (supposedly, <5) and in highly eutrophic lakes.  相似文献   

19.
内陆水域二氧化碳(CO2)排放是全球碳平衡的重要组成部分,全球CO2排放通量估算通常有很大不确定性,一方面源于CO2排放数据观测的时空离散性,另一方面也是缺少水文情景与CO2排放通量关联性的研究.本文观测了2018年洪泽湖不同水文情景表层水体CO2排放通量特征,并探讨其影响因素.结果表明,洪泽湖CO2排放通量为丰水期((106.9±73.4) mmol/(m2·d))>枯水期((18.7±13.6) mmol/(m2·d))>平水期((5.2±15.5) mmol/(m2·d)),且碳通量由丰(310.2~32.0 mmol/(m2·d))、枯(50.8~2.2 mmol/(m2·d))、平(-17.3~39.8 mmol/(m2·d))3种水文情景的交替表现出湖泊碳源到弱碳汇的转变,空间上CO2排放通量总体呈现北部成子湖区低、南部过水湖区高的分布趋势.洪泽湖CO2排放对水文情景响应敏感,特别是上游淮河流域来水量的改变,是主导该湖CO2排放时空分异的重要因子.丰水期湖泊接纳了淮河更多有机和无机碳的输入,外源碳基质的降解和矿化显著促进了水体CO2的生产与排放,同时氮、磷等营养物质的大量输入,加剧了水体营养化程度,进一步提高CO2排放量,间接反映出人类活动对洪泽湖CO2变化的深刻影响.平、枯水期随着上游淮河来水量的减少,驱动水体CO2排放的因素逐渐由外源输入转变为水体有机质的呼吸降解.此外,上游河口区DOM中陆源类腐殖质的累积与矿化能够促进CO2的排放,而内源有机质组分似乎并没有直接参与CO2的排放过程.研究结果揭示了水文情景交替对湖库CO2排放的重要影响,同时有必要进行高频观测以进一步明晰湖泊的碳通量变化及其控制因素.  相似文献   

20.
化学需氧量(COD)、五日生化需氧量(BOD_5)及溶解性有机碳(DOC)是指示湖泊水质的重要指标,然而上述指标测定通常耗费大量时间、试剂及人力物力且排放大量有害废液.有色可溶性有机物(CDOM)是溶解性有机物(DOM)中可以强烈吸收光谱中的紫外光和可见光的部分,数据测定耗时短、方便快捷,且样品处理过程环境友好,能在很大程度上反映湖泊水质.本研究基于2016年2、5和8月在太湖均匀布设的32个采样点进行样品采集,运用光谱吸收与三维荧光-平行因子分析(EEMs-PARAFAC)探究太湖CDOM的光谱吸收和荧光组分,探讨CDOM光谱指标对湖泊BOD_5、COD及DOC浓度等湖泊环境质量指标的可替代性.结果表明:(1)运用EEMs-PARAFAC方法解析出3种荧光组分:类腐殖酸C1、类酪氨酸C2和类色氨酸C3.(2) COD和BOD_5和DOC在空间上呈现出相似的分布趋势,不同水期的最高值均出现在竺山湾和梅梁湾,由西北湖区至中部敞水区、东南湖湾递减.(3)在不同水期,COD、BOD_5、DOC浓度和C1组分均表现为丰水期极显著大于枯水期和平水期,a_(254)在丰、平、枯水期间无显著性差异,最大值出现在丰水期;C2与C3组分均在枯水期和平水期极显著大于丰水期.(4)在不同水文时期,COD、BOD_5和DOC浓度均与a_(254)、类腐殖酸C1呈显著正相关,丰水期太湖COD、BOD_5和DOC浓度与CDOM光谱指标的线性相关性要优于枯水期和平水期.(5) CDOM光谱指标在不同水文时期均能很好地替代COD、BOD_5和DOC等作为反映太湖水体中有机物污染程度及湖泊水质的指标.  相似文献   

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