Relationships between Acid Ions and Carbonaceous Fly-Ash Particles in Deposition at European Mountain Lakes

The concentrations of major ions and spheroidal carbonaceous fly-ash particles (SCPs) in bulk deposition were determined in weekly samples from six European mountain lakes during 1997/98. SCPs are produced only from high temperature combustion of fossil-fuels and therefore provide an unambiguous indicator of atmospheric deposition from this source. Positive correlations were observed between SCPs and SO₄ ^2?, NO₃ ^? and NH₄ ⁺ at all sites except for some determinands at Jorisee (Switzerland) and Starolesnienske (Slovakia). Correlations between SCPs and SO₄ ^2? + NO₃ ^? were always more positive than for SCPs with 'total acid ions' (SO₄ ^2? + NO₃ ^? + NH₄ ⁺). This is in agreement with the expectation that the contribution to NH₄ ⁺ deposition made by fossil-fuels is negligible. Good positive correlations between SCPs and all acid anions were observed at Estany Redo (Pyrenees); lower but still positive correlations were observed for all acid ions with SCPs at Gossenköllesee (Austria), Lochnagar and Kårvatn (central Norway), whilst little trend in correlation was observed for Jorisee and Starolesnienske. It is suggested that this gradient reflects the influence of fossil-fuels on acid deposition in these areas. A high positive correlation was observed between SCP and Cl^? at Gossenkollesee possibly as a result of HCl from coal combustion.     

Size Distributions and Concentrations of Spheroidal Carbonaceous Fly-Ash Particles (SCPs) in Lake Sediments as an Aid to Detecting Locally Deposited Atmospheric Pollution

Size distributions and concentrations of spheroidal carbonaceous fly-ash particles (SCPs) > 5 μm have been counted in surface sediments from 20 lakes along a 62 km west-east transect in the Bergen area, Norway. Increased concentrations of SCPs are found in lakes immediately downwind, closest to the city. These lakes also have a dominance of larger particles (> 10 μm) than further downwind where smaller particles (5–10 μm) dominate. The pattern of SCPs > 5 μm is compared with a previous study of anthropogenic Pb and SCPs > 3 μm in the same sediments. Along the transect there is a difference in pattern between the concentrations of SCPs > 5 μm and the patterns of anthropogenic Pb and SCPs > 3 μm. The result indicates that increased altitude and rainfall probably explain the increased concentrations of anthropogenic Pb and SCPs > 3μm in the eastern part of the transect. Metals are in the size range for which atmospheric residence times are greatest, whereas particles > 5 μm in diameter are of the size thought to be effectively removed from the atmosphere by sedimentation. This may explain, at least partially, why there is a difference between the pattern of SCPs > 5 μm concentrations and anthropogenic Pb and SCPs > 3 μm concentrations. This study shows that SCPs > 5 μm in lake sediments can potentially provide a better signal of locally-deposited atmospheric pollution than trace elements from the same source. A SCP distribution dominated by large particles (> 10 μm) is found up to 20 km downwind of the city. Within this area, temporal SCP size distribution patterns can help detect local-deposited atmospheric pollution.     

The Use of Size Distributions of Spheroidal Carbonaceous Particles in Swimming Pool Deposits for Evaluating Atmospheric Particle Behaviour

Water, Air, &; Soil Pollution - To clarify the relationship between the transport distance of spheroidal carbonaceous particles (SCPs) and particle size, we investigated the spatial distribution...     

Characteristic Differences in the Chemical Composition of Spheroidal Carbonaceous Particles in Japanese and Chinese Cities

Spheroidal carbonaceous particles (SCPs) are produced by the high-temperature combustion of fossil fuels and are emitted to the atmosphere. We examined the surface morphology and the chemical composition of SCPs in samples of surface sediment from five industrial cities each of Japan and China, using scanning electron microscopy with energy dispersive spectroscopy (EDS). There exists a relationship between surface morphology and the chemical composition of SCPs in China, but not for SCPs in Japan. The chemical compositions of SCPs differ between Japan and China: those in Japan are S-rich, whereas those in China are Ti-rich. The results suggest that EDS can be used to identify China-derived SCPs in East Asian countries such as Japan, South Korea, and Taiwan.     

The Spatial Distribution of Characterised Fly-Ash Particles and Trace Metals in Lake Sediments and Catchment Mosses: Ireland

Spheroidal carbonaceous particles (SCPs) from the sediments of 48 Irish lakes were enumerated and characterised according to fuel type. The concentration of metals was determined in the surface sediments and in selected mosses from the catchments of these lakes. Generally the metal concentrations in both the surface sediments and mosses were consistent with background levels found in the remote parts of Europe. Where higher metal concentrations occurred these could often be accounted for by local geochemical sources. SCP levels in the sediments of the selected lakes along the east coast were of sufficient magnitude to suggest a transboundary influence notwithstanding local sources. SCP characterisation also suggests the influence of emissions in Northern Ireland on deposition, particularly in the north-west of Ireland. There was reasonable correlation between the concentration of oil particles in the surface sediments and vanadium, but not with nickel, in mosses. SCP concentrations were not correlated with measured physical characteristics of the lakes. The level of deposition indicated is not likely to have a significant impact on human health over and above the damaging effects of urban dwelling but the adverse impact of this deposition on acid-sensitive surface waters in Ireland has been recorded.     

The Spatial Distribution of Characterised Fly-Ash Particles and Trace Metals in Lake Sediments and Catchment Mosses in the United Kingdom

Spheroidal carbonaceous particles (SCP) and trace metals (Cd, Cu, Pb, Ni, V and Zn) were analysed from 75 lake surface sediments across the UK. Trace metals were additionally analysed from catchment mosses (Hylocomium splendens and Pleurozium schreberi) from 43 of the sites but were absent from the remainder. Spatial distribution of SCP concentration and trace metal concentrations in sediments and mosses showed good agreement with each other and with known emission sources. Particles were allocated to their fuel-type and spatial trends in these data showed good agreement with potential sources. High areas of oil particle deposition were identified in the south-east of England, Merseyside, Galloway / Northern Ireland, the Firth of Forth and eastern Scotland. Oil SCP concentrations showed good agreement with Ni and V concentrations in mosses suggesting an atmospheric source for these metals from the combustion of this fuel. Characterised SCP trends also showed good agreement with predictions from models such as HARM and EMEP. Most high deposition areas of metals and particles were found to coincide with population centres suggesting a possible impact on human health.     

The Spatial Distribution of Characterised Fly-Ash Particles and Trace Metals in Lake Sediments and Catchment Mosses: Estonia

The concentrations of fly-ash particles were studied in the surface sediments of 42 lakes in Estonia. Concentrations of both spheroidal carbonaceous particles (SCPs) and inorganic ash spheres (IASs) were determined and the particles chemically characterised to different fuel types. This was accompanied by trace metal analyses from lake surface sediments and catchment mosses in order to determine the distribution of atmospheric pollutants. The obtained spatial distribution data for fly-ash particles varied to a great extent, partly due to differences in sedimentation rates but mainly due to higher deposition in industrial areas. The distribution patterns of the different particle types in lake sediments, as well as the trace metals in mosses, show that the deposition of airborne particulates is of local origin around pollution sources and that the share of long-range transported atmospheric impurities is high along the main cyclonic routes in Estonia.     

The Spatial Distribution of Characterized Fly-Ash Particles and Trace Metals in Lake Sediments and Catchment Mosses: Czech Republic

As a part of the FLAME research project funded by the EU COPERNICUS programme (1994-1996) samples of surface sediments were taken from 31 man-made lakes and one natural lake in the Czech Republic. The sites differ considerably in their altitude, area, catchment, depth, retention time, trophic status, and in parameters of local air pollution. The samples were analysed for concentration of spheroidal carbonaceous particles (SCP, numbers per gram dry mass of sediment), a characteristic component of industrial fly-ash. The extracted carbonaceous particles were allocated according to the fuel-types combusted throughout Europe (coal, oil, brown coal, peat, oil shale) using particle chemistries derived by energy dispersive spectroscopy (EDS). Trace metals were also analysed in the surface sediments as were mosses sampled at the study sites. The main objectives of the study were (i) to look for factors determining SCP concentrations in surface sediments of lakes, with special emphasis on the distribution of large fossil-fuel combustion sources (ii) to compare fuel-type allocation of carbonaceous particles with combustion of these fuels within the country, (iii) to look for trends in spatial distribution of trace metals and (iv) to characterize the impact of airborne particles from these sources on environmental and human health. The SCP concentrations show little or no relation to air-pollution parameters on a small scale, although some large-scale effects are evident. A good relationship was, however, found to site characteristics such as altitude and lake area : catchment area. The reason, why this relationship is more apparent from our dataset than from any other study published so far, is likely to be based on the high variation in the physical parameters (altitude, lake and catchment area) of the sites under study. The distribution of particles attributed to brown coal combustion are in good agreement with the distribution of major air pollution sources across the country but the fraction of particles attributed to coal seems to be overestimated by the present technique. The distribution of trace metals in surface sediments are also in agreement with expected sources. The usefulness of SCP concentrations as indicators of stress to human and environmental health is briefly discussed.     

柳河流域径流、泥沙时变过程研究

柳河是东北地区泥沙问题最为严重的河流之一,具有河道泥沙淤积严重、大量沉积以及向辽河泥沙输出量高等特点。对柳河流域径流、泥沙要素从20世纪中叶到21世纪初的年内分配及年际变化进行时变过程分析,并研究径流量与泥沙输沙量的相关关联系数及关联度,结果表明,柳河流域径流量年内及年际分配都很不均匀,且有随时间的发展更不均匀的趋势。径流量与输沙量之间有着很密切的相关关系,各站的关联度由0.560～0.921不等,但总体上,关联度较大。     

柳河流域径流、泥沙时变过程研究

柳河是东北地区泥沙问题最为严重的河流之一,具有河道泥沙淤积严重、大量沉积以及向辽河泥沙输出量高等特点。对柳河流域径流、泥沙要素从20世纪中叶到21世纪初的年内分配及年际变化进行了时变过程分析,并研究了径流量与泥沙输沙量的相关关联系数及关联度,结果表明,柳河流域径流量年内及年际分配都很不均匀,且有随时间的发展更不均匀的趋势。径流量与输沙量之间有着很密切的相关关系,各站的关联度由0.560～0.921不等,但总体上,关联度较大。     

辽河河口芦苇湿地沉积物中有机质含量的时空变化

以辽河河口芦苇湿地为研究对象,对湿地土壤沉积物中有机质含量的变化规律进行研究,分别研究了湿地沉积物中有机质(SOM)在时间、空间上的变化规律。结果表明:时间变化上,近河区和远河区的芦苇湿地沉积物中SOM含量受时间影响显著,其中在9月份和10月份SOM含量较高,9月份SOM含量出现最大值。空间变化上,纵向上只有表层0—10cm深度和其他深度(10—20cm,20—30cm,30—40cm,40—50cm)以及10—20cm与40—50cm深度的SOM含量上有显著的差异,其他深度间差异并不明显。远河区湿地沉积物在4月、5月、6月、9月、10月份时,0—10cm和10—20cm深度的沉积物中SOM含量较高,最大值多数在0—10cm深度的沉积物上。在7月份和8月份时,0—10cm深度沉积物的SOM含量最低。近河区湿地沉积物中SOM含量变化与远河区相比有差异,在4月、5月、6月、7月、8月份时受地表径流影响较为明显,SOM含量的最大值并不显著,各深度间SOM含量相差不大,20—40cm深度的SOM含量略高。在9月、10月份,SOM最大值在0—10cm深度的沉积物上,其他深度SOM含量相差不大。并且纵向上各深度间的SOM含量存在着线性相关关系。横向上在S1—3与S2—3位于缓冲区与试验区的交界处,SOM含量较高;S1—6与S2—6和S2—7位于缓冲区与核心区的交界附近且SOM含量较高,这些点的SOM含量均远高于其他各点的SOM含量。通过研究SOM含量的时空变化,更加清楚地认识SOM的变化规律,为合理利用和开发芦苇湿地以及控制湿地污染,探究碳储量提供数据支持。     

滇池沉积物总氮的时空变化特征研究

采用GPS定位,对滇池海埂、斗南、罗家村、新街、昆阳等5个代表性样点沉积物总N含量进行为期1年的动态监测,分析了不同区域、不同层次、不同时期滇池沉积物总N的变化.结果表明全湖全年沉积物总N的平均含量为4.91g/kg,年变化范围是4.13～5.41 g/kg,呈现明显的季节性变化,总体趋势夏季高、冬季低,但不同区域变化高峰和趋势不同.沉积物总N层次变化差异显著,表现为表层＞中层＞底层,各层次年变化范围分别为表层3.54～9.10g/kg、中层2.72～8.04 g/kg、底层1.23～5.37g/kg.各区域沉积物总N平均含量以海埂和罗家村最高,斗南和新街较低.     

1960-2011年西南地区干旱时空格局分析

基于西南地区130个气象站1960-2011年气象资料,计算了各站不同时间尺度的标准化降水指数(SPI),并采用Mann-Kendall趋势分析法和反距离加权插值等方法,分析了该区近52a以来干旱发生的时空变化特征。结果表明:(1)各区域干旱存在明显的年际变化波动且线性变化趋势较为显著,近12a来干旱次数明显增多。大部分区域干旱指数在春夏秋季均呈减少趋势,秋季最为明显,冬季反之。(2)空间分布方面,横断山地、广西丘陵、四川盆地东部和贵州高原南部春旱频率较高。夏旱主要发生在横断山地北部,若尔盖高原,四川盆地的西部和南部,云南高原中部和广西丘陵。云南高原南部,横断山地西南部,贵州高原和广西丘陵的秋旱频率较高。冬季干旱频率高值区主要集中在若尔盖高原、四川盆地西南部一带。     

贵州省最大日降雨量时空分布及重现期估算

利用1961—2012年贵州省81个气象观测站的逐日降雨资料,采用概率分布、线性趋势和空间分析等方法,分析了贵州省近52年来最大日降雨量的时空分布特征。结果表明:近52年来,贵州最大日降雨量呈递增趋势,递增速率为2.3mm/10a,全省最大日降雨量为336.7mm,平均最大日降雨量为205.1mm,年际变化趋势表明,2000年以后最大日降雨量呈递减趋势;最大日降雨量季节差异明显,春季、秋季最大日降雨量呈递减趋势,夏季、冬季最大日降雨量均为递增趋势,最大日降雨量空间分布不均,由北向南呈递增趋势;最大日降雨量100年和200年重现期估算值的空间分布形态具有一致性,高值区主要在贵州南部一带,100年和200年一遇的最大日降雨量分别为350.9mm和375.8mm。     

基于EOF的陕西省降水变化时空分异研究

应用经验正交函数法（empirical orthogonal function,EOF）对陕西省23 a来96个气象站点的数据进行EOF分解,分别计算出年降水场的特征向量分布和时间系数序列。结果表明,应用EOF方法可以很好地揭示降水场的时空分布特征,且对陕西省而言前3个特征向量揭示了3种典型的分布场,其累计贡献率达81.10%。陕西省降水的空间分布有3种典型的模式,即全局型、南北型和东西型。总体上3种场的特征向量分布值表现为南大北小,且高值中心都出现在陕西省的最南端,这说明南部虽然多雨,但年际变化量较大,北方少雨,但年际变化量较小。对特征向量所对应的时间系数分析发现,陕西省的降水场主要表现为6种类型。从23 a来的统计结果可以看出它与贡献率所反映的降水场的典型程度基本一致。     

黄河河口-龙门区间降雨时空分布特征及其与流域产沙的关系

[目的]揭示黄土高原典型多沙粗沙区河口—龙门区间降雨时空分布特征及其与流域产沙的关系,为区域水土保持规划的制定提供科学依据。[方法]基于降雨和产沙模数资料,采用泰森多边形加权变差系数法、K-means聚类分析以及线性回归分析,系统研究河口—龙门区间降雨和产沙的空间变异规律。[结果] 1959—2015年期间,河龙区间汛期降雨和汛期降雨侵蚀力具有相同的空间分布特征,但是汛期降雨侵蚀力表现出更强的空间变异性,两者在年内和年际时间尺度上分别表现出相同的空间分布特征,并且具有纬度地带性(p0.01)。汛期降雨和汛期降雨侵蚀力在支流尺度上的空间变异性差异不大,具有同增同减的变化趋势。[结论] 1959—2015年期间,水土流失大规模治理以前,河口—龙门区间流域产沙主要受降雨的影响(p0.01),水土流失治理以后,流域产沙量锐减,降雨和流域产沙模数无显著相关关系。     

岔巴沟流域泥沙输移比时空分异特征及影响因素

本文以团山沟单元小流域作为流域系统产沙的源地，将其它中小流域输沙模数与单元小流域侵蚀模数之比定义为泥沙输移比，系统的研究了岔巴沟流域次暴雨泥沙输移比的时空变化特征及降水水文影响因子和地貌形态因子的综合影响。研究发现，从长远来看，流域系统的侵蚀与产沙可达到平衡，但就次降雨或年度而言，流域系统经常处于泥沙滞留和滞留的泥沙重新侵蚀搬运的状态。降雨量、径流系数、降雨时间、水流平均含沙量能很好的表达岔巴沟各流域次暴雨泥沙输移比，在考虑地貌形态因子的影响后，得到了岔巴沟流域次暴雨泥沙输移比的降水水文因子与地貌形态因子关系的综合表达式。     

雨强对华北土石山区坡面侵蚀及其颗粒富集过程的影响

为研究雨强对华北土石山区坡面侵蚀过程和泥沙颗粒分布规律的影响,采用室内人工模拟降雨试验,以华北土石山区2种典型土壤为研究对象,在4种雨强(30,60,90,120mm/h)条件下,分析了径流的变化过程和侵蚀泥沙的颗粒组成及其颗粒富集率的变化规律。结果表明:(1)随着雨强从30mm/h增大至120mm/h,黄土性褐土和石灰性褐土的产流时间均逐渐减小,分别缩短了79%和85%;(2)在60,90,120mm/h雨强条件下,黄土性褐土的径流强度和泥沙浓度均随降雨时间先减小后增大,而后趋于稳定状态,石灰性褐土仅在120mm/h雨强条件下出现相似规律;(3)当雨强从30mm/h增大至120mm/h,黄土性褐土泥沙流失朝粗颗粒化发展,侵蚀泥沙的砂粒和粗粉粒含量分别增加了86%和21%,而石灰性褐土的变化不明显;(4)在降雨初始阶段,粒径较小的黏粒和细粉粒明显富集,而粒径较大的粗粉粒和砂粒不易流失,但随着降雨历时的延长,不同粒径泥沙颗粒的富集率趋于1,这种现象在大雨强下表现得尤为明显。     

湖北低山丘陵区侵蚀泥沙颗粒特征及其与地形因子的关系

坡面地形变化是影响侵蚀泥沙颗粒特征的重要因素,深入理解地形因子与侵蚀泥沙颗粒粒径组成及分选特征的关系是研究坡面土壤侵蚀动力学的基础.采用野外降雨试验和粒径分析试验,结合ArcGIS系统识别和提取得到地形因子数据,研究低山丘陵地区侵蚀泥沙颗粒特征及其与地形因子的关系.结果表明:(1)在试验条件下,侵蚀泥沙中黏粒和粉粒总含...     

贡嘎山东坡亚高山土壤生物有效磷的时空分异

采用湿化学浸提法测定了贡嘎山东坡亚高山带不同海拔(2 628 m、2 781 m、3 044 m和3210m)峨眉冷杉林的土壤生物有效磷(Bio-PL)含量,并利用原位树脂袋包埋法测定了土壤生物有效磷(Bio-PS)供给量,以阐明土壤生物有效磷的垂直分异和季节变化特征及其主要影响因素。研究发现:(1)土壤Bio-PL库及Bio-PS均随海拔升高呈增大趋势,低海拔地区生物有效磷因淋溶大量流失是形成这种梯度变化的主要原因。(2)随土层深度增加,Bio-PL库及Bio-PS显著降低,有机质层(O层)Bio-PL库约占土壤剖面的75%且该层的Bio-PS全年均为正值。O层中较高的有机磷含量和较强的磷酸酶活性是O层生物有效磷富集的重要原因。(3)2 781 m样点O层Bio-PS在9月最高,而3 044 m和3 210 m样点的Bio-PS在6月和9月出现两个高值。各样点矿质土层的Bio-PS全年多低于0,在8月时最低。Bio-PS的季节变化主要受生物吸收及径流流失控制。