Bed sediment-associated trace metals in an urban stream, Oahu, Hawaii

 Of the 117 stream and lake systems sampled nationwide, fish from Manoa Stream on Oahu, Hawaii, have consistently shown the highest Pb concentrations. Therefore a detailed study was conducted to examine total metal contents in bed sediments from a 5.8-km stretch of Manoa Stream. A total of 123 samples (<63 μm) were examined for 18 elements and 14 samples for 21 elements. Selected samples were also examined using different leach solutions to examine metal phase associations. All trace metal data, computations of enrichment ratios and the modified index of geoaccumulation point to mineralogical control for Cr and Ni; minor anthropogenic contamination for Ba, Cd, Cu, Hg and Zn; and a very strong contamination signal for Pb. Maximum Pb contents (up to 1080 mg kg⁻¹) were associated with anthropogenic material dumping in minor tributaries, storm sewer sediments and sediments in the “lower” section of the basin. Proportionally Pb had the highest non-residual component of elements examined; dominantly in the reducible phase associated with Mn and amorphous Fe oxyhydroxides. The contamination signal was typically lowest in the “undisturbed” headwater reach of the basin (above 5.1 km) with significant increases throughout the “residential” and “commercial-institutional” zones of the mid-basin. The spatial pattern of bed sediment contamination and evidence from storm sewer-outlet sediments strongly indicates that Pb, and to a lesser degree some other metals, is still being transported to the stream and the primary agent is soil erosion and transport of metals sorbed to sediments. The primary source of sediment-associated metals is considered to be the automobile, though other minor sources can not be ruled out. Received: 3 November 1998 · Accepted: 26 January 1999     

Xenoliths in the Honolulu Volcanic Series, Hawaii

The Pleistocene to Holocene Honolulu Volcanic Series was eruptedfrom about 37 vents scattered over the older Koolau tholeiiteshield. The rocks of this series are compositionally zoned withrespect to the shield; near the Koolau caldera the predominantrocks are melilitenepheline basalts, but these give way outwardto nepheline basalts, and ultimately, at the apron of the shield,to alkalic olivine basalts. The xenoliths in these are likewisezoned: most of those in the caldera area consist of dunite,most of those at intermediate distances of lherzolite, and someof those in the apron of the shield consist of garnet pyroxeniteand peridotite. The zoning of the xenoliths, however, does notcoincide with that of the enclosing rocks. We believe that copiouseruption of Koolau tholeiite produced a lateral and verticalheterogeneity in the mantle beneath Oahu, and that the zoningin both Honolulu lavas and their xenoliths is caused by thatheterogeneity. The textures of the xenoliths indicate that thebasalts were mainly produced by fractional melting rather thanfractional crystallization. There is some evidence that thedunite xenoliths are mantle residua produced during the generationof the tholeiite, and that the Honolulu magmas were generatedat greater depths than the Koolau magmas, probably as a resultof elastic unloading.     

Spatial and temporal geochemical variability in basin-related volcanism, northern Israel

Middle Miocene (17-9 Ma) volcanism in northeast Israel migrated from eastern Lower Galilee (Poria, west of the Sea of Galilee) to the southwest (Yizre'el Valley) in association with the development of an extensional basin in that area. The Yizre'el Valley magmas are highly undersaturated in silica (basanites and nephelinites), while those of Poria are alkali-basaltic. Scarce Middle Miocene basalts from the Golan, further to the east, are also alkali-basaltic. Magmas from Kaukab (southeastern Lower Galilee) show a range of compositions from alkali-basalts to basanites. The patterns defined by ratios versus concentrations of incompatible elements in Kaukab basalts (e.g. versus La), as well as the scatter observed in Sr isotope ratios, are interpreted in terms of binary mixing. It is suggested that the Kaukab magmas were derived from veined lithospheric peridotites, melts of the veins and of the peridotites being the two end-members. Accordingly, alkali-basaltic- and basanite-dominated areas are underlain by vein-poor and vein-rich lithosphere, respectively. It is also suggested that melting during the Middle Miocene mainly occurred in response to extension, and that it followed the propagation of the Yizre'el-Galilee Basin from northeast to southwest.     

Stream chloride concentrations as a function of land use: a comparison of an agricultural watershed to an urban agricultural watershed

The concentration of chloride (Cl^?) in streams in northern regions has increased as a result of applications of deicers. This study focused on quantifying the relationship between land use and stream Cl^? concentrations. The study area comprises two adjacent watersheds in central Illinois, with similar geology and climate but different land uses (agricultural and urban). GIS analysis delineated watershed land use and calculated road surface areas. Stream water samples were collected and analyzed for anionic composition. During the winter months, streams dominated with urban land use experienced a 20-fold increase in Cl^? concentrations (range between 36 and 1350 mg L^?1); Cl^? concentrations in agricultural dominated streams also increased, but the increase was smaller (3X) and concentrations remained low (between 11 and 58 mg L^?1). As road salts are not the sole source of Cl^? in a stream, Cl^? and bromide (Br^?) mass ratios (Cl/Br) and Cl^? and sodium (Na) molar ratios ([Cl]/[Na]) were used to identify potential sources of Cl^?. The ratios indicate urbanized watersheds were impacted by road salts; agricultural watersheds ratios indicate other anthropogenic sources. A nonlinear relationship between urban land use and stream Cl^? concentrations indicates urban land use as low as 23% results in elevated Cl^? concentrations (greater than 150 mg L^?1) in stream waters.     

Spatial variability of topsoil contamination with trace elements in preschools in Vilnius,Lithuania

An investigation of the spatial variability of topsoil contamination level was performed in 49 preschool playgrounds located in Vilnius city and correlated with urban (height and age of the preschools and height of surrounding buildings) and natural (altitude) factors. Composite samples, consisting of 20–30 sub-samples, were collected from 10 cm topsoil layer with a 3–5 m distance from each other. Sieved fraction (< 0.63 mm) was ashed at 400 °C, ground to < 1.0 μm and analysed for the real total concentrations of 22 trace elements (Ag, B, Ba, Co, Cr, Cu, Ga, Li, Mn, Mo, Nb, Ni, Pb, Sc, Sn, Sr, Ti, V, Y, Yb, Zn and Zr) using optical atomic emission spectrophotometry. Information on construction year and height (number of building stories) of preschool and surrounding buildings was acquired from the Centre of Registers of Lithuania. Out of 22 analysed elements, 13 to a greater extent exceeded the background values in several areas and were used to calculate the total contamination index (Z_s13). Out of 49 analysed areas, 21 had moderately hazardous to hazardous levels of contamination as indicated by Z_s13. The main contaminating elements, exceeding the permissible concentrations were Ag, Cu, Mo, Pb, Sn and Zn, the origins of which coincide with city industry and traffic. Topsoil around the newer preschool buildings, despite their location, contained lower concentrations of contaminants, while areas at higher altitudes were more contaminated than those located at lower altitudes. The latter causality is biased, as the city industry, and hence the highest contamination, is in districts located higher above sea level than the remaining studied sites.     

Evaluating natural and anthropogenic trace element inputs along an alpine to urban gradient in the Provo River,Utah, USA

Numerous natural and anthropogenic processes in a watershed produce the geochemical composition of a river, which can be altered over time by snowmelt and rainfall events and by built infrastructure (i.e., dams and diversions). Trace element concentrations coupled with isotopic ratios offer valuable insights to disentangle the effects of these processes on water quality. In this study, we measured a suite of 40+ trace and major elements (including As, Cd, Ce, Cr, Cs, Fe, La, Li, Mo, Pb, Rb, Sb, Se, Sr, Ti, Tl, U, and Zn), Sr isotopes (⁸⁷Sr/⁸⁶Sr), and stable isotopes of H and O (δD and δ¹⁸O) to investigate natural and anthropogenic processes impacting the Provo River in northern Utah, USA. The river starts as a pristine mountain stream and passes through agricultural and urban areas, with two major reservoirs and several major diversions to and from the river. We sampled the entire 120 km length of the Provo River at 13 locations from the Uinta Mountains to Utah Valley, as well as two important tributaries, across the range of hydrologic conditions from low flow to snowmelt runoff during the 2013 water year. We also sampled the furthest downstream site in the Utah Valley urban area during a major flood event. Trace element concentrations indicate that a variety of factors potentially influence Provo River chemistry, including inputs from weathering of carbonate/siliciclastic rocks (Sr) and black shales (Se and U), geothermal groundwater (As, Cs, Li, and Rb), soil erosion during snowmelt runoff (Ce, Cr, Fe, La, Pb, and Ti), legacy mining operations (Mo, Sb, and Tl), and urban runoff (Cr, Pb, and Zn). Although specific elements overlap between different groups, the combination of different elements together with isotopic measurements and streamflow observations may act as diagnostic tools to identify sources. ⁸⁷Sr/⁸⁶Sr ratios indicate a strong influence of siliciclastic bedrock in the headwaters with values exceeding 0.714 and carbonate bedrock in the lower reaches of the river with values approaching 0.709. δD and δ¹⁸O changed little throughout the year in the Provo River, suggesting that the river is primarily fed by snowmelt during spring runoff and snowmelt-fed groundwater during baseflow. Based on nonmetric multidimensional scaling (NMS) water chemistry was unique across the upper, middle, and lower portions of the river, with high temporal variability above the first reservoir but minimal temporal variability below the reservoir. Thus, the results show that dams alter water chemistry by allowing for settling of particle-associated elements and also by homogenizing inflows throughout the year to minimize dilution during snowmelt runoff. Taken together, trace element concentrations and isotopic measurements can be used to evaluate the complex geochemical patterns of rivers and their variability in space and time. These measurements are critical for identifying natural and anthropogenic impacts on river systems.     

Spatial and temporal variability of Holocene temperature in the North Atlantic region

The early Holocene climate of the North Atlantic region was influenced by two boundary conditions that were fundamentally different from the present: the presence of the decaying Laurentide Ice Sheet (LIS) and higher than present summer solar insolation. In order to assess spatial and temporal patterns of Holocene climate evolution across this region, we collated quantitative paleotemperature records at sub-millennial resolution and synthesized their temporal variability using principal components analysis (PCA). The analysis reveals considerable spatial variability, most notably in the time-transgressive expression of the Holocene thermal maximum (HTM). Most of the region, but especially areas peripheral to the Labrador Sea and hence closest to the locus of LIS disintegration, experienced maximum Holocene temperatures that lagged peak summer insolation by 1000-3000 years. Many sites from the northeastern North Atlantic sector, including the Nordic Seas and Scandinavia, either warmed in phase with maximum summer insolation (11,000-9000 years ago) or were less strongly lagged than the Baffin Bay-Labrador Sea region. These spatially complex patterns of Holocene climate development, which are defined by the PCA, resulted from the interplay between final decay of the LIS and solar insolation forcing.     

Spatial and temporal variability of soil moisture based on multifractal analysis

Based on the experimental data collected from 2002 to 2010 in Jilin province, we performed multifractal analysis to investigate the spatial variability of soil moisture during 9 years from 2002 to 2010 and about 60 days from April 21 to June 21 in 2010, and analyzed the relationship between soil moisture and precipitation. The results showed that the soil moisture was multifractal. It was intermediate variability in the soil sample. From 2002 to 2010, the spatial variation of soil moisture was charactered by long distance in 2004, 2006, and 2009 and short distance in 2002, 2003, and 2008. The spatial variation of soil moisture was charactered by long distance from April 21 to May 11 and late June. It was charactered by short distance from May 11 to June 21. From April 11 to July 1, 2010, the spatial variation of soil moisture was mainly affected by the spatial variation of precipitation. From 2002 to 2010, the spatial variation of soil moisture was mainly affected by precipitation in 2006, 2009, and 2010. The spatial variation of precipitation had little effect on soil moisture during 2002 to 2005 and 2007 to 2008. This study analyzed the multifractal characteristic of soil moisture from the perspective of water resources divisions, which can provide references for soil water resources evaluation and water resources allocation.     

Spatial and temporal variability of mesozooplankton and tintinnid ciliates in a seasonally hypersaline estuary

The zooplankton community of Mission Bay, San Diego, California, was monitored over two years, to study spatial and temporal patterns and the response of zooplankton species composition to environmental variation. Data were collected every two weeks from six stations and included hydrographic parameters, dissolved nutrient concentrations, and phytoplankton and zooplankton species composition. Hydrography varied seasonally, along a spatial gradient from the mouth to the back of the bay, and between the two years around the influence of rainfall. Spatially, Mission Bay could be divided into three regions during this study based on hydrography and zooplankton species composition. Zooplankton species composition followed a predictable seasonal progression, with different groups of species being characteristic to particular times of the year. Variability in zooplankton species composition was also evident between years, as certain species were more common in one or the other year of the study. Spatial patterns were more consistent than temporal ones, and related to distance from the mouth of the bay during much of the year and distance from freshwater inlets during the relatively short rainy season. Multivariate analysis revealed that variation in zooplankton species composition was best related to measured abiotic factors (temperature, salinity, rainfall, and tidal velocity).     

Optimizing urban stormwater control strategies and assessing aquifer recharge through drywells in an urban watershed

Hydrogeology Journal - A coupled simulation-optimization model (SOM) is developed in this work that links the US Environmental Protection Agency’s Storm Water Management Model (SWMM) with a...     

The evolution of trace element concentrations in basic rocks from Israel and their petrogenesis

The geochemistry of tholeiitic rocks, alkali olivine basalts and basanites of The Mesozoic province of Israel has been studied. The elemental concentration in the magmas was treated in terms of batch melting followed by fractional crystallization processes. During the latter process, the crystallizing minerals from effusive and hypabyssal bodies match the conditions of maintaining surface equilibrium with the melt (Rayleigh Law). According to the incompatible characteristics of the LIL elements which were determined, they can be divided into two groups: (1) those elements (La, Ce, Ta, Th, Hf) which maintain incompatibility for rocks having D.I. <63, and (2) those elements which can be regarded as incompatible in rocks with further restrictions for U and Ba (D.I.<50); for P₂O₅ (Ni>75 ppm); for Sr (Ni>200 ppm). Assuming that the mantle has [La] _n = 1 the spectrum of the rocks studied was generated by 0.5% to 3.2% partial melting from a single garnet peridotite source rock. The source rocks appear to be quite homogeneous with only a slightly LREE-enriched pattern. For the above melting range the D _s (bulk distribution coefficient between the source rocks and the melts) values for Ta, La, Ce, Th, U, P₂O₅, Sr, Ba, and Hf were found to be 0.0012, 0.002, 0.0029, 0.0031, 0.0039, 0.0082, 0.0083, 0.01, and 0.015, respectively. If the mantle has [La] _n =2, then for the range of 1 to 6.4% melting, the D _s values would be 0.002, 0.0035, 0.0053, 0.0055, 0.007, 0.0152, 0.0153, 0.019, and 0.027, respectively.     

Response of hepatic trace element concentrations in fish exposed to elemental and organic contaminants

Multivariate analysis of contaminant data from a multi-year monitoring program demonstrates alterations in the hepatic chemistry of metals in fish exposed to organic contaminants. Metals (Ag, As, Cd, Cu, Fe, Hg, Mn, Ni, Pb, Se, Sn, Zn) and organic chemicals (PCBs, DDTs, chlordanes, dieldrins, PAHs) were measured in liver and associated sediments for winter flounder (Pleuronectes americanus) from 23 sites along the northeast Atlantic coast and for Atlantic croaker (Micropogonias undulatus) from 30 sites along the southeast Atlantic and Gulf of Mexico coasts of the United States. Concentrations of habitat contaminants varied from nil to levels signifying important anthropogenic inputs and thus provided a range in chronic exposures and related contaminant stress levels with which to investigate the response of hepatic chemistry in fish representative of viable populations. The data, analyzed by principal component, principal component regression, and biplot procedures, demonstrated an opposing relationship between micronutrient elements, principally Zn, and exposure to organic contaminants in winter flounder. This relationship was not present in Atlantic croaker that were resident in less contaminated habitats. Based on median concentrations in sediment, exposure of winter flounder to important organic contaminants (polycyclic aromatic hydrocarbons, polychlorinated biphenyls, DDTs) exceeded that for Atlantic croaker by 7 to 50 times. Coincident with depletion of hepatic Zn and Cd in winter flounder was accumulation of Hg and Ag. My results, in agreement with those of others, implicate the negative effects of hepatic detoxification of organic contaminants on metal binding in liver, which can cause depletion of essential elements while contaminant and potentially toxic elements accumulate.     

Elevated stream trace and minor element concentrations in the foreland of receding tropical glaciers

Globally, the ongoing retreat of mountain glaciers will ultimately diminish fresh water supplies. This has already begun in watersheds with greatly reduced glacial coverage. Still unknown are the affects of glacial retreat on downstream water quality, including the threats to human and ecosystem health. In the Cordillera Blanca, retreating glaciers have exposed sulfide-rich rock outcrops, negatively affecting the quality of the glacial meltwater. This study has evaluated glacial melt stream hydrogeochemistry in the sulfide-bearing Rio Quilcay watershed (∼9°27′S, ∼77°22′W) during the 2008 dry season. Surface water samples were collected from the upper 12 km of the watershed during the 2008 dry season. Dissolved (0.4 μm) and unfiltered acidified (pH < 2) Al, Co, Cu, Fe, Ni, Mn, Pb, Zn and dissolved major ions and organic C (DOC) concentrations were quantified and pH and temperature were measured in the field. Twenty of 22 stream samples had pH values below 4, generating significantly (p < 0.01, α = 0.05) greater cation denudation normalized to discharge than other worldwide glacier-fed streams. Additionally, dissolved trace and minor element concentrations were comparable to acid mine drainage. Non-conservative dissolved element behaviors resulted from adsorption/desorption reactions in tributary mixing zones. At low pH values, hydrous Fe oxides acted as the dominant sorption surfaces. The poor water quality observed in Cordillera Blanca headwaters coupled with the likely exposure of additional sulfide-rich outcrops from ongoing glacial retreat may pose water quality challenges.     

晚第四纪印度洋-太平洋交汇区降水时空演化

印度洋-太平洋交汇区(印太交汇区)作为全球的水汽和热量中心,在多种时间尺度的气候变化中都扮演着重要的角色。然而,迄今该区域晚第四纪古降水时空演化仍不清楚,主要体现在不同区域或不同指标的降水重建结果出现明显不一致、甚至相反的现象。本研究基于印太交汇区已有重建记录,总结了该区域轨道和千年时间尺度上古降水演化特征及机制。在轨道时间尺度上,尽管该区域大多数降水记录都主要受到岁差主控的日射量变化影响,但其响应的相位关系却截然不同,推测是多种气候因子共同作用的结果。在千年时间尺度上,降水变化主要受控于北大西洋千年时间尺度气候突变事件导致的热带辐合带(ITCZ)迁移;其次,厄尔尼诺与南方涛动(ENSO)以及印度洋偶极子(IOD)的活动也对该地区局部降水有所贡献。另外,苏拉威西等印太交汇区中部区域的降水受到海平面变化的显著影响。总体来看,印太交汇区古降水记录仍存在重建指标单一、部分区域缺乏高分辨率记录等问题,降水空间分布及其变化机制也尚不明朗,需更多的高分辨率古降水重建以及模拟工作的开展去全方面阐明印太交汇区降水的时空演化特征及机制。

     

Spatial and temporal variability in maximum,minimum and mean air temperatures at Madhya Pradesh in central India

In the present study, an investigation has been made to study the spatial and temporal variability in the maximum, the minimum and the mean air temperatures at Madhya Pradesh (MP), in central India on monthly, annual and seasonal time scale from 1901 to 2002. Further, impact of urbanization and cloud cover on air temperature has been studied. The annual mean, maximum and minimum temperatures are increased by 0.60, 0.60 and 0.62 °C over the past 102 years, respectively. Seasonally, the warming is more pronounced during winter than summer. The temperature decreased during the less urbanized period (from 1901 to 1951) and increased during the more urbanized period (1961 to 2001). It is also found that the minimum temperature increased at higher rate (0.42 °C) followed by the mean (0.36 °C) and the maximum (0.32 °C) temperature during the more urbanized period. Furthermore, cloud cover is significantly negatively related with air temperature in monsoon season and as a whole of the year.     

Spatial and temporal variations of suspended solid concentrations from 2000 to 2013 in Poyang Lake,China

Concentrations of suspended solids in lakes can affect the latter’s primary productivity and reflect changes in sediment deposition. Determining the temporal and spatial distribution of suspended solid concentrations has important significance in lake water environmental management; this is particularly urgent for Poyang Lake, the largest freshwater lake in China. In this study, suspended solid concentration inversion models for Poyang Lake were created using a semi-empirical method with regression analysis between continuously measured suspended solid concentration data and multi-band moderate-resolution imaging spectroradiometer images for spring, summer, autumn, and winter from 2009 to 2012. The coefficient of determination (R²) is from 0.6 to 0.9 and the average relative error for the accuracy verification was between 10 and 30%. The seasonal distributions of suspended solid concentrations in Poyang Lake from 2000 to 2013 were then obtained using optimal reversal models. The results showed that the seasonal variation in suspended solid concentrations had a “W” shape in which high spring and autumn and low summer and winter values. The suspended solid concentrations increased annually from 2000 to 2013 and were mainly distributed in the northern and central portions of the lake, with lower values along the shorelines. Further analysis indicated that the large difference in water level between the wet and dry seasons is an important factor in explaining these seasonal variations. Moreover, the suspended solid concentrations were poorly correlated with water temperature and chlorophyll-a concentration but more highly correlated with the deferred chlorophyll-a concentration.     

贵阳城区大气污染物的时空变化和复合污染特征

选取贵阳市10个空气质量监测站发布的PM2.5、PM10、SO2、NO2、CO和O3实时浓度数据，通过时间序列分析法和插值法研究贵阳市大气污染物的时空变化和复合污染特征。结果表明:（1）贵阳市2014-2018年主要污染物PM2.5和PM10的年平均浓度逐渐下降，光化学污染物O3年平均浓度有所增加，空气质量逐渐转好，环境治理取得明显效果；（2）2018-2019自然年PM2.5、PM10、NO2和O3在春季污染最严重，SO2和CO在冬季污染最严重，反映出污染源、阶段性燃料燃烧和二次离子生成等因素对不同污染物的影响不同；（3）PM2.5和PM10日变化特征为“午峰晚峰”型，峰值发生的时间因季节而异，主要由不同季节人类作息的起止时间不同所致，O3日变化为单峰型，夜间O3浓度较低，从早晨8:00点开始随着太阳辐射的增大和温度的升高，在15:00-16:00点左右达到峰值；（4）PM2.5的空间分布呈现出部分郊区和工业区较高，市中心居民区较低的特征，指示城市建设向郊区推进。O3浓度呈现出市区低、郊区高的空间分布特征，反映郊区植被覆盖好，释放的天然源VOCs促进了O3生成；（5）主要污染物O3与颗粒物PM2.5和PM10在春季造成的复合污染最为严重，在夏季O3与PM10造成一定程度的复合污染，在秋冬季O3浓度最低，O3与颗粒物不产生复合污染；一天之内同一时刻O3与颗粒物不会产生叠加从而造成复合污染。      

Spatial and temporal variations of sound in an Andean City: Cajamarca,Peru

This study provides a preliminary examination of the temporal and geographic variations of sound in Cajamarca, a provincial city in the Andes of northern Peru. Sound levels were sampled in four neighborhoods of the city each representing different land-use characteristics and hypothetically distinct environmental sound profiles. The sample sites included the central plaza, the business district, a residential neighborhood, and a small residential community on the urban periphery. Sound readings were taken each hour between 6 am and 12 pm on every day of the week. Sound profiles for each location for a weekday, a Saturday, and a Sunday are presented. Distinct decibel profiles emerge, both geographically and temporally. These changing sound patterns reflect the activities of the town's residents as they move between home, work, and social/recreational activities during the course of a week. Cajamarca's sound profiles are believed to be characteristic of other provincial cities throughout the Andean region.