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301.
The spring waters of Tuzla–Icmeler are on the Marmara Sea coast in Tuzla town of Istanbul city. The springs discharge a natural sodium chloride mineral water that consumed for ages for therapeutic purposes attributed to their chemical properties. Development of springs commenced during the Ottoman times and a surface collection structure was built at the discharge point of the main spring. Two deep wells were drilled to tap mineral water within the past decades. The bottled water of these springs is also sold for a couple of years and its consumption as a beverage is increasing. The geochemical properties of these springs were investigated by several researchers in the past. This study comprises geochemical and geophysical measurements performed between July 2001 and July 2002 in order to construct a conceptual hydrogeological model for environmental and land use planning purposes. The seasonal evaluation of Tuzla–Icmeler (mineral spring) shows that the chemical properties fluctuate from the beginning of summer until the beginning of winter. This indicates that the overdraft of water during the summer season causes the movement and mix of normal groundwater with the mineralized groundwater. As a result, mixing of less mineralized groundwater decreases the salinity of mineralized groundwater. Using the site-specific hydrogeological, geochemical and geophysical data, zones of protection areas were delineated in order to prevent a possible pollution access to the springs and surroundings from nearby dockyards, dwellings and vehicle traffic. For this purpose, a new land use plan was proposed using the existing settlement sustainability plans.  相似文献   
302.
Lake Sapanca is exposed to heavy urbanization and industrialization because of its natural beauty and its proximity to the metropolitan İstanbul, Turkey. In this study, it was aimed to investigate seasonal changes of some heavy metals (Pb, Cr, Cu, Mn, Ni, Zn and Cd) concentration of surface sediment. Nine different stations were chosen as sampling points. Samples were taken every three months and the seasonal and annual average concentration of the elements were determined. Seasonal highest values of heavy metals were observed as follows; Cr, Cu, Mn, Ni and Zn in Summer, Cd in Autumn. There was no seasonal difference for Pb, Cr and Cd. It seems that Lake Sapanca has not been polluted yet. However, it was found that Cu and Ni concentrations in surface sediment exceed lowest effect level.  相似文献   
303.
鞍山市空气颗粒物中酞酸酯的季节变化与功能区差异   总被引:2,自引:0,他引:2  
采用气相色谱-质谱仪(GC-MS)对辽宁省鞍山市空气颗粒物中15种酞酸酯夏季和冬季的浓度进行了分析测定,研究了酞酸酯污染水平的季节变化,不同功能区酞酸酯浓度的差异,以及DBP和DEHP在夏冬两季中的污染特点,将鞍山市夏冬两季酞酸酯的浓度与国内外部分城市进行了比较,分析了产生上述结果的原因,基本说明了鞍山市空气颗粒物中酞酸酯的污染状况。  相似文献   
304.
● 38 PhACs and 2 pesticides were detected in the three rivers of the Pearl River basin. ● Anti-inflammatory/analgesics drugs were the predominant PhACs. ● The concentrations of PhACs showed seasonal and spatial variation. ● Diazepam and ibuprofen were the two PhACs with a moderate environmental risk. The occurrence, fate, and environmental risk of 40 pharmaceutically active compounds (PhACs) from surface waters and sediments were comprehensively investigated in the Beijiang River, Xijiang River, and Maozhou River of the Pearl River basin, South China. Salicylic acid and diclofenac (anti-inflammatory drugs), gemfibrozil (a lipid regulator), carbamazepine (an antiepileptic drug), diazepam (a psychoactive drug), and 2-methyl-4-chloro-phenoxyacetic acid (MCPA, a pesticide) were the most ubiquitous compounds in the studied region. The average concentrations of detected PhACs in surface waters and sediments ranged from 0.17 to 19.1 ng/L and 0.10 to 10.4 ng/g, respectively. Meanwhile, PhACs concentration in surface waters and sediments varied greatly among and within the Beijiang River, Xijiang River, and Maozhou River. The largest annual flux of PhACs of the Xijiang River and Beijiang River was more than 11 000 kg per annum, whereas only 25.7 kg/a in the Maozhou River. In addition, the estimated emissions of PhACs in the Beijiang River, Xijiang River, and Maozhou River ranged respectively from 0.28 to 4.22 kg/a, 0.12 to 6.72 kg/a, and 6.66 to 91.0 kg/a, and the back-estimated usage varied with a range from 12.0 to 293 kg/a, 6.79 to 944 kg/a, 368 to 17 459 kg/a. Moreover, the emissions of PhACs showed a close relationship with the gross domestic product (GDP) of each city along the Pearl River. The environmental risk assessment suggested that diazepam and ibuprofen had a moderate risk in this region.  相似文献   
305.
为了研究九龙江流域河流中溶解碳变化规律,分别于2017年7月与2018年1月对九龙江河水溶解无机碳(DIC)与溶解有机碳(DOC)进行了分析。丰水季河水DIC浓度为7.50~49.04 mg/L,平均值为22.12 mg/L,枯水季DIC浓度为8.84~84.91 mg/L,平均浓度41.17 mg/L,丰水季河水中的DOC浓度为0.54~2.89 mg/L,平均值为1.04 mg/L,枯水季河水中DOC浓度变化在1.34~3.56 mg/L之间,平均值为2.34 mg/L,据此计算了九龙江河水DOC、DIC的入海通量。研究结果表明九龙江河水中溶解碳具有显著的时空变化特征,通过与中国其他河流溶解碳数据对比,解释了碳酸盐岩的风化、气候变化、河流中浮游植物以及人类活动对九龙江河流溶解碳浓度的影响。  相似文献   
306.
青岛近岸海域二甲基硫排放和大气中二甲基硫浓度变化   总被引:7,自引:1,他引:6  
为研究我国受人为干扰严重的近岸海域DMS排放规律,利用固体吸附-解吸的富集采样方法和冷却预浓缩的分析方法,分别在2001年夏秋季和2002年春秋季,对青岛近岸海域海水和大气中的二甲基硫进行了采样和分析.结果表明,海水中DMS浓度和海气排放通量呈现明显的空间分布和季节变化.夏季,青岛近岸的海水DMS平均浓度最高,达1169.47 ng·L-1;春季最低,只有226.99 ng·L-1.河口区、风景旅游区和奥运赛场区在夏季有显著的从高到低的浓度梯度变化,而春秋季不明显.DMS海气排放通量主要由海水浓度决定,因此两者呈现一致的变化规律.海洋大气中的DMS也呈现夏季较高(256.44 ng·m-3),秋季较低(195.64 ng·m-3)的季节变化.文中还初步探讨了大气DMS的日变化情况.  相似文献   
307.
From November 1995 to October 1996, airborne concentrations of VOCs were measured in the Madrid area to study the organic pollution in general, and the correlation between different pollutants in relation to such parameters as location and season. Mean concentrations for up to 90 compounds were measured at four test sites, including both urban and suburban areas. At the urban sites, maximum concentrations occurred in the autumn and winter, whereas minimum concentrations were reached in summer and spring. Similar changes were obtained for the lesscontaminated site located in the SE of the city, whereas a different pattern was found at the site in the NW of the city due to meteorological aspects. Mean levels of hydrocarbons in Madrid were quite similar to those found in other European cities. Chemometrical techniques were applied to the set of data in order to assess the influence of such factors as traffic, temperature and seasonal variations on the VOC levels.  相似文献   
308.
喀斯特河流受特殊生物地球化学过程影响,其溶解性有机质(DOM)变化具有显著的区域特征.然而,当前对其DOM空间变化规律,特别是生物降解特性的研究十分有限,急需相关内容的补充.以我国典型喀斯特河流—芙蓉江为研究对象,探索了 DOM光学参数(a254、a350、E2/E3、S275~295、BIX、FI、FRI和HIX)的...  相似文献   
309.
We present the first estimates of speciated monoterpene emissions from the North European coniferous forests. Measured emission factors and emission profiles of boreal tree species (Picea abies, Pinus sylvestris, Betula pendula, Salix phylicifolia, Populus tremula, and Alnus incana) were used together with detailed satellite land cover information and meteorological data in an emission model based on the Guenther emission algorithms. The variation of the coniferous biomass within the boreal region (60°N to 70°N) was obtained from forest inventory data, and the seasonal variability of the deciduous biomass was taken into account through simple boreal climatology parameterisation. The annual biogenic emissions in the boreal zone are dominated by coniferous species, but in the summer months, the deciduous contribution to the monoterpene and isoprene emissions is considerable. Norway spruce (Picea abies) is the most important isoprene emitter in the north European boreal forests. The biogenic emission fluxes in the South boreal zone are approximately twice as high as fluxes in the North boreal zone. α- and β-pinene, carene, and cineole are the most abundant emitted terpenes, with a strong contribution of isoprene and linalool during the summer months.  相似文献   
310.
Linked Hydrologic and Climate Variations in British Columbia and Yukon   总被引:1,自引:0,他引:1  
Climatic and hydrologic variations between the decades 1976–1985 and 1986–1995 are examined at 34 climate stations and 275 hydrology stations. The variations in climate are distributedacross a broad spatial area. Temperatures were generally warmerin the most recent decade, with many stations showing significantincreases during the spring and fall. No significant decreases intemperature were found. Significant increases in temperature weremore frequent in the south than in the northern portions of theregion. Significant changes in precipitation were also more prevalent in the south. In coastal areas, there were significantdecreases in precipitation during the dry season, and significantincreases during the wet season. In the BC interior, significantprecipitation decreases occurred during the fall, with significant increases during the winter and spring. In the norththere were few changes in precipitation. The hydrologic responsesto these variations in climate follow six distinctive patterns.The spatial distribution of these patterns suggests that indifferent ecozones, small variations in climate, particularlytemperature, elicit different hydrologic responses.  相似文献   
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